three#LineSegments JavaScript Examples

makeObject(item) 
	{
		var object = new Object3D();
		var line = new LineSegments(this.makeLineGeometry(item),this.makeLineMaterial(this.rotating));
		var cone = this.makeCone(item);
		var sphere = this.makeSphere(item);
		object.add(line);
		object.add(cone);
		object.add(sphere);
		object.rotation.y = item.rotation.y;
		object.position.x = item.position.x;
		object.position.z = item.position.z;
		object.position.y = this.height;
		return object;
	}

constructor (game) {
    this.game = game
    this.texture = this.game.al.get('blocksAtlasSnap')
    this.texture.magFilter = NearestFilter
    this.cursor = new Mesh(
      new BoxBufferGeometry(1.001, 1.001, 1.001),
      new MeshBasicMaterial({
        map: this.texture,
        transparent: true
      })
    )
    this.lastPos = []
    this.cursorOut = new LineSegments(
      new EdgesGeometry(this.cursor.geometry),
      new LineBasicMaterial({
        color: 0x000000
      })
    )
    this.game.scene.add(this.cursor, this.cursorOut)
    this.uv = {}
    this.isDigging = false
    this.done = true
    this.setState(0)
  }

function FaceNormalsHelper( object, size, hex, linewidth ) {

	// FaceNormalsHelper only supports THREE.Geometry

	this.object = object;

	this.size = ( size !== undefined ) ? size : 1;

	var color = ( hex !== undefined ) ? hex : 0xffff00;

	var width = ( linewidth !== undefined ) ? linewidth : 1;

	//

	var nNormals = 0;

	var objGeometry = this.object.geometry;

	if ( objGeometry && objGeometry.isGeometry ) {

		nNormals = objGeometry.faces.length;

	} else {

		console.warn( 'THREE.FaceNormalsHelper: only THREE.Geometry is supported. Use THREE.VertexNormalsHelper, instead.' );

	}

	//

	var geometry = new BufferGeometry();

	var positions = new Float32BufferAttribute( nNormals * 2 * 3, 3 );

	geometry.setAttribute( 'position', positions );

	LineSegments.call( this, geometry, new LineBasicMaterial( { color: color, linewidth: width } ) );

	this.type = 'FaceNormalsHelper';

	//

	this.matrixAutoUpdate = false;
	this.update();

}

FaceNormalsHelper.prototype = Object.create( LineSegments.prototype );

function VertexNormalsHelper( object, size, hex ) {

	this.object = object;

	this.size = ( size !== undefined ) ? size : 0.1;

	var color = ( hex !== undefined ) ? hex : 0xff0000;

	//

	var nNormals = 0;

	var objGeometry = this.object.geometry;

	if ( objGeometry && objGeometry.isGeometry ) {

		nNormals = objGeometry.faces.length * 3;

	} else if ( objGeometry && objGeometry.isBufferGeometry ) {

		nNormals = objGeometry.attributes.normal.count;

	}

	//

	var geometry = new BufferGeometry();

	var positions = new Float32BufferAttribute( nNormals * 2 * 3, 3 );

	geometry.setAttribute( 'position', positions );

	LineSegments.call( this, geometry, new LineBasicMaterial( { color: color, toneMapped: false } ) );

	this.type = 'VertexNormalsHelper';

	//

	this.matrixAutoUpdate = false;

	this.update();

}

VertexNormalsHelper.prototype = Object.create( LineSegments.prototype );

function VertexTangentsHelper( object, size, hex ) {

	this.object = object;

	this.size = ( size !== undefined ) ? size : 1;

	var color = ( hex !== undefined ) ? hex : 0x00ffff;

	//

	var objGeometry = this.object.geometry;

	if ( ! ( objGeometry && objGeometry.isBufferGeometry ) ) {

		console.error( 'THREE.VertexTangentsHelper: geometry not an instance of THREE.BufferGeometry.', objGeometry );
		return;

	}

	var nTangents = objGeometry.attributes.tangent.count;

	//

	var geometry = new BufferGeometry();

	var positions = new Float32BufferAttribute( nTangents * 2 * 3, 3 );

	geometry.setAttribute( 'position', positions );

	LineSegments.call( this, geometry, new LineBasicMaterial( { color: color, toneMapped: false } ) );

	this.type = 'VertexTangentsHelper';

	//

	this.matrixAutoUpdate = false;

	this.update();

}

VertexTangentsHelper.prototype = Object.create( LineSegments.prototype );

constructor(scene, world, options = {}) {
     this.scene = scene;
     this.world = world;
     this.options = options;
     this.debugDrawMode = options.debugDrawMode || AmmoDebugConstants.DrawWireframe;
     const drawOnTop = this.debugDrawMode & AmmoDebugConstants.DrawOnTop || false;
     const maxBufferSize = options.maxBufferSize || 1000000;
 
     this.geometry = new BufferGeometry()
     const vertices = new Float32Array(maxBufferSize * 3)
     const colors = new Float32Array(maxBufferSize * 3)
 
     /*
     I do not know the difference, just using the first one.
     export const StaticDrawUsage: Usage;
     export const DynamicDrawUsage: Usage;
     export const StreamDrawUsage: Usage;
     export const StaticReadUsage: Usage;
     export const DynamicReadUsage: Usage;
     export const StreamReadUsage: Usage;
     export const StaticCopyUsage: Usage;
     export const DynamicCopyUsage: Usage;
     export const StreamCopyUsage: Usage;
      */
     this.geometry.setAttribute('position', new BufferAttribute(vertices, 3).setUsage(StaticDrawUsage))
     this.geometry.setAttribute('color', new BufferAttribute(colors, 3).setUsage(StaticDrawUsage))
 
     this.index = 0
 
     const material = new LineBasicMaterial({
       vertexColors: true,
       depthTest: !drawOnTop
     });
 
     this.mesh = new LineSegments(this.geometry, material);
     if (drawOnTop) this.mesh.renderOrder = 999;
     this.mesh.frustumCulled = false;
 
     this.enabled = false;
 
     this.debugDrawer = new Ammo.DebugDrawer();
     this.debugDrawer.drawLine = this.drawLine.bind(this);
     this.debugDrawer.drawContactPoint = this.drawContactPoint.bind(this);
     this.debugDrawer.reportErrorWarning = this.reportErrorWarning.bind(this);
     this.debugDrawer.draw3dText = this.draw3dText.bind(this);
     this.debugDrawer.setDebugMode = this.setDebugMode.bind(this);
     this.debugDrawer.getDebugMode = this.getDebugMode.bind(this);
 
     this.world.setDebugDrawer(this.debugDrawer);
   }

OBJLoader = (function () {
  // o object_name | g group_name
  var object_pattern = /^[og]\s*(.+)?/;
  // mtllib file_reference
  var material_library_pattern = /^mtllib /;
  // usemtl material_name
  var material_use_pattern = /^usemtl /;
  // usemap map_name
  var map_use_pattern = /^usemap /;

  function ParserState() {
    var state = {
      objects: [],
      object: {},

      vertices: [],
      normals: [],
      colors: [],
      uvs: [],

      materialLibraries: [],

      startObject: function (name, fromDeclaration) {
        // If the current object (initial from reset) is not from a g/o declaration in the parsed
        // file. We need to use it for the first parsed g/o to keep things in sync.
        if (this.object && this.object.fromDeclaration === false) {
          this.object.name = name;
          this.object.fromDeclaration = fromDeclaration !== false;
          return;
        }

        var previousMaterial =
          this.object && typeof this.object.currentMaterial === "function"
            ? this.object.currentMaterial()
            : undefined;

        if (this.object && typeof this.object._finalize === "function") {
          this.object._finalize(true);
        }

        this.object = {
          name: name || "",
          fromDeclaration: fromDeclaration !== false,

          geometry: {
            vertices: [],
            normals: [],
            colors: [],
            uvs: [],
          },
          materials: [],
          smooth: true,

          startMaterial: function (name, libraries) {
            var previous = this._finalize(false);

            // New usemtl declaration overwrites an inherited material, except if faces were declared
            // after the material, then it must be preserved for proper MultiMaterial continuation.
            if (previous && (previous.inherited || previous.groupCount <= 0)) {
              this.materials.splice(previous.index, 1);
            }

            var material = {
              index: this.materials.length,
              name: name || "",
              mtllib:
                Array.isArray(libraries) && libraries.length > 0
                  ? libraries[libraries.length - 1]
                  : "",
              smooth: previous !== undefined ? previous.smooth : this.smooth,
              groupStart: previous !== undefined ? previous.groupEnd : 0,
              groupEnd: -1,
              groupCount: -1,
              inherited: false,

              clone: function (index) {
                var cloned = {
                  index: typeof index === "number" ? index : this.index,
                  name: this.name,
                  mtllib: this.mtllib,
                  smooth: this.smooth,
                  groupStart: 0,
                  groupEnd: -1,
                  groupCount: -1,
                  inherited: false,
                };
                cloned.clone = this.clone.bind(cloned);
                return cloned;
              },
            };

            this.materials.push(material);

            return material;
          },

          currentMaterial: function () {
            if (this.materials.length > 0) {
              return this.materials[this.materials.length - 1];
            }

            return undefined;
          },

          _finalize: function (end) {
            var lastMultiMaterial = this.currentMaterial();
            if (lastMultiMaterial && lastMultiMaterial.groupEnd === -1) {
              lastMultiMaterial.groupEnd = this.geometry.vertices.length / 3;
              lastMultiMaterial.groupCount =
                lastMultiMaterial.groupEnd - lastMultiMaterial.groupStart;
              lastMultiMaterial.inherited = false;
            }

            // Ignore objects tail materials if no face declarations followed them before a new o/g started.
            if (end && this.materials.length > 1) {
              for (var mi = this.materials.length - 1; mi >= 0; mi--) {
                if (this.materials[mi].groupCount <= 0) {
                  this.materials.splice(mi, 1);
                }
              }
            }

            // Guarantee at least one empty material, this makes the creation later more straight forward.
            if (end && this.materials.length === 0) {
              this.materials.push({
                name: "",
                smooth: this.smooth,
              });
            }

            return lastMultiMaterial;
          },
        };

        // Inherit previous objects material.
        // Spec tells us that a declared material must be set to all objects until a new material is declared.
        // If a usemtl declaration is encountered while this new object is being parsed, it will
        // overwrite the inherited material. Exception being that there was already face declarations
        // to the inherited material, then it will be preserved for proper MultiMaterial continuation.

        if (
          previousMaterial &&
          previousMaterial.name &&
          typeof previousMaterial.clone === "function"
        ) {
          var declared = previousMaterial.clone(0);
          declared.inherited = true;
          this.object.materials.push(declared);
        }

        this.objects.push(this.object);
      },

      finalize: function () {
        if (this.object && typeof this.object._finalize === "function") {
          this.object._finalize(true);
        }
      },

      parseVertexIndex: function (value, len) {
        var index = parseInt(value, 10);
        return (index >= 0 ? index - 1 : index + len / 3) * 3;
      },

      parseNormalIndex: function (value, len) {
        var index = parseInt(value, 10);
        return (index >= 0 ? index - 1 : index + len / 3) * 3;
      },

      parseUVIndex: function (value, len) {
        var index = parseInt(value, 10);
        return (index >= 0 ? index - 1 : index + len / 2) * 2;
      },

      addVertex: function (a, b, c) {
        var src = this.vertices;
        var dst = this.object.geometry.vertices;

        dst.push(src[a + 0], src[a + 1], src[a + 2]);
        dst.push(src[b + 0], src[b + 1], src[b + 2]);
        dst.push(src[c + 0], src[c + 1], src[c + 2]);
      },

      addVertexPoint: function (a) {
        var src = this.vertices;
        var dst = this.object.geometry.vertices;

        dst.push(src[a + 0], src[a + 1], src[a + 2]);
      },

      addVertexLine: function (a) {
        var src = this.vertices;
        var dst = this.object.geometry.vertices;

        dst.push(src[a + 0], src[a + 1], src[a + 2]);
      },

      addNormal: function (a, b, c) {
        var src = this.normals;
        var dst = this.object.geometry.normals;

        dst.push(src[a + 0], src[a + 1], src[a + 2]);
        dst.push(src[b + 0], src[b + 1], src[b + 2]);
        dst.push(src[c + 0], src[c + 1], src[c + 2]);
      },

      addColor: function (a, b, c) {
        var src = this.colors;
        var dst = this.object.geometry.colors;

        dst.push(src[a + 0], src[a + 1], src[a + 2]);
        dst.push(src[b + 0], src[b + 1], src[b + 2]);
        dst.push(src[c + 0], src[c + 1], src[c + 2]);
      },

      addUV: function (a, b, c) {
        var src = this.uvs;
        var dst = this.object.geometry.uvs;

        dst.push(src[a + 0], src[a + 1]);
        dst.push(src[b + 0], src[b + 1]);
        dst.push(src[c + 0], src[c + 1]);
      },

      addUVLine: function (a) {
        var src = this.uvs;
        var dst = this.object.geometry.uvs;

        dst.push(src[a + 0], src[a + 1]);
      },

      addFace: function (a, b, c, ua, ub, uc, na, nb, nc) {
        var vLen = this.vertices.length;

        var ia = this.parseVertexIndex(a, vLen);
        var ib = this.parseVertexIndex(b, vLen);
        var ic = this.parseVertexIndex(c, vLen);

        this.addVertex(ia, ib, ic);

        if (this.colors.length > 0) {
          this.addColor(ia, ib, ic);
        }

        if (ua !== undefined && ua !== "") {
          var uvLen = this.uvs.length;
          ia = this.parseUVIndex(ua, uvLen);
          ib = this.parseUVIndex(ub, uvLen);
          ic = this.parseUVIndex(uc, uvLen);
          this.addUV(ia, ib, ic);
        }

        if (na !== undefined && na !== "") {
          // Normals are many times the same. If so, skip function call and parseInt.
          var nLen = this.normals.length;
          ia = this.parseNormalIndex(na, nLen);

          ib = na === nb ? ia : this.parseNormalIndex(nb, nLen);
          ic = na === nc ? ia : this.parseNormalIndex(nc, nLen);

          this.addNormal(ia, ib, ic);
        }
      },

      addPointGeometry: function (vertices) {
        this.object.geometry.type = "Points";

        var vLen = this.vertices.length;

        for (var vi = 0, l = vertices.length; vi < l; vi++) {
          this.addVertexPoint(this.parseVertexIndex(vertices[vi], vLen));
        }
      },

      addLineGeometry: function (vertices, uvs) {
        this.object.geometry.type = "Line";

        var vLen = this.vertices.length;
        var uvLen = this.uvs.length;

        for (var vi = 0, l = vertices.length; vi < l; vi++) {
          this.addVertexLine(this.parseVertexIndex(vertices[vi], vLen));
        }

        for (var uvi = 0, l = uvs.length; uvi < l; uvi++) {
          this.addUVLine(this.parseUVIndex(uvs[uvi], uvLen));
        }
      },
    };

    state.startObject("", false);

    return state;
  }

  //

  function OBJLoader(manager) {
    Loader.call(this, manager);

    this.materials = null;
  }

  OBJLoader.prototype = Object.assign(Object.create(Loader.prototype), {
    constructor: OBJLoader,

    load: function (url, onLoad, onProgress, onError) {
      var scope = this;

      var loader = new FileLoader(scope.manager);
      loader.setPath(this.path);
      loader.load(
        url,
        function (text) {
          onLoad(scope.parse(text));
        },
        onProgress,
        onError
      );
    },

    setMaterials: function (materials) {
      this.materials = materials;

      return this;
    },

    parse: function (text) {
      console.time("OBJLoader");

      var state = new ParserState();

      if (text.indexOf("\r\n") !== -1) {
        // This is faster than String.split with regex that splits on both
        text = text.replace(/\r\n/g, "\n");
      }

      if (text.indexOf("\\\n") !== -1) {
        // join lines separated by a line continuation character (\)
        text = text.replace(/\\\n/g, "");
      }

      var lines = text.split("\n");
      var line = "",
        lineFirstChar = "";
      var lineLength = 0;
      var result = [];

      // Faster to just trim left side of the line. Use if available.
      var trimLeft = typeof "".trimLeft === "function";

      for (var i = 0, l = lines.length; i < l; i++) {
        line = lines[i];

        line = trimLeft ? line.trimLeft() : line.trim();

        lineLength = line.length;

        if (lineLength === 0) continue;

        lineFirstChar = line.charAt(0);

        // @todo invoke passed in handler if any
        if (lineFirstChar === "#") continue;

        if (lineFirstChar === "v") {
          var data = line.split(/\s+/);

          switch (data[0]) {
            case "v":
              state.vertices.push(
                parseFloat(data[1]),
                parseFloat(data[2]),
                parseFloat(data[3])
              );
              if (data.length >= 7) {
                state.colors.push(
                  parseFloat(data[4]),
                  parseFloat(data[5]),
                  parseFloat(data[6])
                );
              }
              break;
            case "vn":
              state.normals.push(
                parseFloat(data[1]),
                parseFloat(data[2]),
                parseFloat(data[3])
              );
              break;
            case "vt":
              state.uvs.push(parseFloat(data[1]), parseFloat(data[2]));
              break;
          }
        } else if (lineFirstChar === "f") {
          var lineData = line.substr(1).trim();
          var vertexData = lineData.split(/\s+/);
          var faceVertices = [];

          // Parse the face vertex data into an easy to work with format

          for (var j = 0, jl = vertexData.length; j < jl; j++) {
            var vertex = vertexData[j];

            if (vertex.length > 0) {
              var vertexParts = vertex.split("/");
              faceVertices.push(vertexParts);
            }
          }

          // Draw an edge between the first vertex and all subsequent vertices to form an n-gon

          var v1 = faceVertices[0];

          for (var j = 1, jl = faceVertices.length - 1; j < jl; j++) {
            var v2 = faceVertices[j];
            var v3 = faceVertices[j + 1];

            state.addFace(
              v1[0],
              v2[0],
              v3[0],
              v1[1],
              v2[1],
              v3[1],
              v1[2],
              v2[2],
              v3[2]
            );
          }
        } else if (lineFirstChar === "l") {
          var lineParts = line.substring(1).trim().split(" ");
          var lineVertices = [],
            lineUVs = [];

          if (line.indexOf("/") === -1) {
            lineVertices = lineParts;
          } else {
            for (var li = 0, llen = lineParts.length; li < llen; li++) {
              var parts = lineParts[li].split("/");

              if (parts[0] !== "") lineVertices.push(parts[0]);
              if (parts[1] !== "") lineUVs.push(parts[1]);
            }
          }
          state.addLineGeometry(lineVertices, lineUVs);
        } else if (lineFirstChar === "p") {
          var lineData = line.substr(1).trim();
          var pointData = lineData.split(" ");

          state.addPointGeometry(pointData);
        } else if ((result = object_pattern.exec(line)) !== null) {
          // o object_name
          // or
          // g group_name

          // WORKAROUND: https://bugs.chromium.org/p/v8/issues/detail?id=2869
          // var name = result[ 0 ].substr( 1 ).trim();
          var name = (" " + result[0].substr(1).trim()).substr(1);

          state.startObject(name);
        } else if (material_use_pattern.test(line)) {
          // material

          state.object.startMaterial(
            line.substring(7).trim(),
            state.materialLibraries
          );
        } else if (material_library_pattern.test(line)) {
          // mtl file

          state.materialLibraries.push(line.substring(7).trim());
        } else if (map_use_pattern.test(line)) {
          // the line is parsed but ignored since the loader assumes textures are defined MTL files
          // (according to https://www.okino.com/conv/imp_wave.htm, 'usemap' is the old-style Wavefront texture reference method)

          console.warn(
            'THREE.OBJLoader: Rendering identifier "usemap" not supported. Textures must be defined in MTL files.'
          );
        } else if (lineFirstChar === "s") {
          result = line.split(" ");

          // smooth shading

          // @todo Handle files that have varying smooth values for a set of faces inside one geometry,
          // but does not define a usemtl for each face set.
          // This should be detected and a dummy material created (later MultiMaterial and geometry groups).
          // This requires some care to not create extra material on each smooth value for "normal" obj files.
          // where explicit usemtl defines geometry groups.
          // Example asset: examples/models/obj/cerberus/Cerberus.obj

          /*
           * http://paulbourke.net/dataformats/obj/
           * or
           * http://www.cs.utah.edu/~boulos/cs3505/obj_spec.pdf
           *
           * From chapter "Grouping" Syntax explanation "s group_number":
           * "group_number is the smoothing group number. To turn off smoothing groups, use a value of 0 or off.
           * Polygonal elements use group numbers to put elements in different smoothing groups. For free-form
           * surfaces, smoothing groups are either turned on or off; there is no difference between values greater
           * than 0."
           */
          if (result.length > 1) {
            var value = result[1].trim().toLowerCase();
            state.object.smooth = value !== "0" && value !== "off";
          } else {
            // ZBrush can produce "s" lines #11707
            state.object.smooth = true;
          }
          var material = state.object.currentMaterial();
          if (material) material.smooth = state.object.smooth;
        } else {
          // Handle null terminated files without exception
          if (line === "\0") continue;

          throw new Error('THREE.OBJLoader: Unexpected line: "' + line + '"');
        }
      }

      state.finalize();

      var container = new Group();
      container.materialLibraries = [].concat(state.materialLibraries);

      for (var i = 0, l = state.objects.length; i < l; i++) {
        var object = state.objects[i];
        var geometry = object.geometry;
        var materials = object.materials;
        var isLine = geometry.type === "Line";
        var isPoints = geometry.type === "Points";
        var hasVertexColors = false;

        // Skip o/g line declarations that did not follow with any faces
        if (geometry.vertices.length === 0) continue;

        var buffergeometry = new BufferGeometry();

        buffergeometry.setAttribute(
          "position",
          new Float32BufferAttribute(geometry.vertices, 3)
        );

        if (geometry.normals.length > 0) {
          buffergeometry.setAttribute(
            "normal",
            new Float32BufferAttribute(geometry.normals, 3)
          );
        } else {
          buffergeometry.computeVertexNormals();
        }

        if (geometry.colors.length > 0) {
          hasVertexColors = true;
          buffergeometry.setAttribute(
            "color",
            new Float32BufferAttribute(geometry.colors, 3)
          );
        }

        if (geometry.uvs.length > 0) {
          buffergeometry.setAttribute(
            "uv",
            new Float32BufferAttribute(geometry.uvs, 2)
          );
        }

        // Create materials

        var createdMaterials = [];

        for (var mi = 0, miLen = materials.length; mi < miLen; mi++) {
          var sourceMaterial = materials[mi];
          var material = undefined;

          if (this.materials !== null) {
            material = this.materials.create(sourceMaterial.name);

            // mtl etc. loaders probably can't create line materials correctly, copy properties to a line material.
            if (
              isLine &&
              material &&
              !(material instanceof LineBasicMaterial)
            ) {
              var materialLine = new LineBasicMaterial();
              Material.prototype.copy.call(materialLine, material);
              materialLine.color.copy(material.color);
              material = materialLine;
            } else if (
              isPoints &&
              material &&
              !(material instanceof PointsMaterial)
            ) {
              var materialPoints = new PointsMaterial({
                size: 10,
                sizeAttenuation: false,
              });
              Material.prototype.copy.call(materialPoints, material);
              materialPoints.color.copy(material.color);
              materialPoints.map = material.map;
              material = materialPoints;
            }
          }

          if (!material) {
            if (isLine) {
              material = new LineBasicMaterial();
            } else if (isPoints) {
              material = new PointsMaterial({
                size: 1,
                sizeAttenuation: false,
              });
            } else {
              material = new MeshPhongMaterial();
            }

            material.name = sourceMaterial.name;
          }

          material.flatShading = sourceMaterial.smooth ? false : true;
          material.vertexColors = hasVertexColors ? VertexColors : NoColors;

          createdMaterials.push(material);
        }

        // Create mesh

        var mesh;

        if (createdMaterials.length > 1) {
          for (var mi = 0, miLen = materials.length; mi < miLen; mi++) {
            var sourceMaterial = materials[mi];
            buffergeometry.addGroup(
              sourceMaterial.groupStart,
              sourceMaterial.groupCount,
              mi
            );
          }

          if (isLine) {
            mesh = new LineSegments(buffergeometry, createdMaterials);
          } else if (isPoints) {
            mesh = new Points(buffergeometry, createdMaterials);
          } else {
            mesh = new Mesh(buffergeometry, createdMaterials);
          }
        } else {
          if (isLine) {
            mesh = new LineSegments(buffergeometry, createdMaterials[0]);
          } else if (isPoints) {
            mesh = new Points(buffergeometry, createdMaterials[0]);
          } else {
            mesh = new Mesh(buffergeometry, createdMaterials[0]);
          }
        }

        mesh.name = object.name;

        container.add(mesh);
      }

      console.timeEnd("OBJLoader");

      return container;
    },
  });

  return OBJLoader;
})()

GLTFLoader = ( function () {

	function GLTFLoader( manager ) {

		Loader.call( this, manager );

		this.dracoLoader = null;
		this.ddsLoader = null;

	}

	GLTFLoader.prototype = Object.assign( Object.create( Loader.prototype ), {

		constructor: GLTFLoader,

		load: function ( url, onLoad, onProgress, onError ) {

			var scope = this;

			var resourcePath;

			if ( this.resourcePath !== '' ) {

				resourcePath = this.resourcePath;

			} else if ( this.path !== '' ) {

				resourcePath = this.path;

			} else {

				resourcePath = LoaderUtils.extractUrlBase( url );

			}

			// Tells the LoadingManager to track an extra item, which resolves after
			// the model is fully loaded. This means the count of items loaded will
			// be incorrect, but ensures manager.onLoad() does not fire early.
			scope.manager.itemStart( url );

			var _onError = function ( e ) {

				if ( onError ) {

					onError( e );

				} else {

					console.error( e );

				}

				scope.manager.itemError( url );
				scope.manager.itemEnd( url );

			};

			var loader = new FileLoader( scope.manager );

			loader.setPath( this.path );
			loader.setResponseType( 'arraybuffer' );

			if ( scope.crossOrigin === 'use-credentials' ) {

				loader.setWithCredentials( true );

			}

			loader.load( url, function ( data ) {

				try {

					scope.parse( data, resourcePath, function ( gltf ) {

						onLoad( gltf );

						scope.manager.itemEnd( url );

					}, _onError );

				} catch ( e ) {

					_onError( e );

				}

			}, onProgress, _onError );

		},

		setDRACOLoader: function ( dracoLoader ) {

			this.dracoLoader = dracoLoader;
			return this;

		},

		setDDSLoader: function ( ddsLoader ) {

			this.ddsLoader = ddsLoader;
			return this;

		},

		parse: function ( data, path, onLoad, onError ) {

			var content;
			var extensions = {};

			if ( typeof data === 'string' ) {

				content = data;

			} else {

				var magic = LoaderUtils.decodeText( new Uint8Array( data, 0, 4 ) );

				if ( magic === BINARY_EXTENSION_HEADER_MAGIC ) {

					try {

						extensions[ EXTENSIONS.KHR_BINARY_GLTF ] = new GLTFBinaryExtension( data );

					} catch ( error ) {

						if ( onError ) onError( error );
						return;

					}

					content = extensions[ EXTENSIONS.KHR_BINARY_GLTF ].content;

				} else {

					content = LoaderUtils.decodeText( new Uint8Array( data ) );

				}

			}

			var json = JSON.parse( content );

			if ( json.asset === undefined || json.asset.version[ 0 ] < 2 ) {

				if ( onError ) onError( new Error( 'THREE.GLTFLoader: Unsupported asset. glTF versions >=2.0 are supported.' ) );
				return;

			}

			if ( json.extensionsUsed ) {

				for ( var i = 0; i < json.extensionsUsed.length; ++ i ) {

					var extensionName = json.extensionsUsed[ i ];
					var extensionsRequired = json.extensionsRequired || [];

					switch ( extensionName ) {

						case EXTENSIONS.KHR_LIGHTS_PUNCTUAL:
							extensions[ extensionName ] = new GLTFLightsExtension( json );
							break;

						case EXTENSIONS.KHR_MATERIALS_CLEARCOAT:
							extensions[ extensionName ] = new GLTFMaterialsClearcoatExtension();
							break;

						case EXTENSIONS.KHR_MATERIALS_UNLIT:
							extensions[ extensionName ] = new GLTFMaterialsUnlitExtension();
							break;

						case EXTENSIONS.KHR_MATERIALS_PBR_SPECULAR_GLOSSINESS:
							extensions[ extensionName ] = new GLTFMaterialsPbrSpecularGlossinessExtension();
							break;

						case EXTENSIONS.KHR_DRACO_MESH_COMPRESSION:
							extensions[ extensionName ] = new GLTFDracoMeshCompressionExtension( json, this.dracoLoader );
							break;

						case EXTENSIONS.MSFT_TEXTURE_DDS:
							extensions[ extensionName ] = new GLTFTextureDDSExtension( this.ddsLoader );
							break;

						case EXTENSIONS.KHR_TEXTURE_TRANSFORM:
							extensions[ extensionName ] = new GLTFTextureTransformExtension();
							break;

						case EXTENSIONS.KHR_MESH_QUANTIZATION:
							extensions[ extensionName ] = new GLTFMeshQuantizationExtension();
							break;

						default:

							if ( extensionsRequired.indexOf( extensionName ) >= 0 ) {

								console.warn( 'THREE.GLTFLoader: Unknown extension "' + extensionName + '".' );

							}

					}

				}

			}

			var parser = new GLTFParser( json, extensions, {

				path: path || this.resourcePath || '',
				crossOrigin: this.crossOrigin,
				manager: this.manager

			} );

			parser.parse( onLoad, onError );

		}

	} );

	/* GLTFREGISTRY */

	function GLTFRegistry() {

		var objects = {};

		return	{

			get: function ( key ) {

				return objects[ key ];

			},

			add: function ( key, object ) {

				objects[ key ] = object;

			},

			remove: function ( key ) {

				delete objects[ key ];

			},

			removeAll: function () {

				objects = {};

			}

		};

	}

	/*********************************/
	/********** EXTENSIONS ***********/
	/*********************************/

	var EXTENSIONS = {
		KHR_BINARY_GLTF: 'KHR_binary_glTF',
		KHR_DRACO_MESH_COMPRESSION: 'KHR_draco_mesh_compression',
		KHR_LIGHTS_PUNCTUAL: 'KHR_lights_punctual',
		KHR_MATERIALS_CLEARCOAT: 'KHR_materials_clearcoat',
		KHR_MATERIALS_PBR_SPECULAR_GLOSSINESS: 'KHR_materials_pbrSpecularGlossiness',
		KHR_MATERIALS_UNLIT: 'KHR_materials_unlit',
		KHR_TEXTURE_TRANSFORM: 'KHR_texture_transform',
		KHR_MESH_QUANTIZATION: 'KHR_mesh_quantization',
		MSFT_TEXTURE_DDS: 'MSFT_texture_dds'
	};

	/**
	 * DDS Texture Extension
	 *
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Vendor/MSFT_texture_dds
	 *
	 */
	function GLTFTextureDDSExtension( ddsLoader ) {

		if ( ! ddsLoader ) {

			throw new Error( 'THREE.GLTFLoader: Attempting to load .dds texture without importing DDSLoader' );

		}

		this.name = EXTENSIONS.MSFT_TEXTURE_DDS;
		this.ddsLoader = ddsLoader;

	}

	/**
	 * Punctual Lights Extension
	 *
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_lights_punctual
	 */
	function GLTFLightsExtension( json ) {

		this.name = EXTENSIONS.KHR_LIGHTS_PUNCTUAL;

		var extension = ( json.extensions && json.extensions[ EXTENSIONS.KHR_LIGHTS_PUNCTUAL ] ) || {};
		this.lightDefs = extension.lights || [];

	}

	GLTFLightsExtension.prototype.loadLight = function ( lightIndex ) {

		var lightDef = this.lightDefs[ lightIndex ];
		var lightNode;

		var color = new Color( 0xffffff );
		if ( lightDef.color !== undefined ) color.fromArray( lightDef.color );

		var range = lightDef.range !== undefined ? lightDef.range : 0;

		switch ( lightDef.type ) {

			case 'directional':
				lightNode = new DirectionalLight( color );
				lightNode.target.position.set( 0, 0, - 1 );
				lightNode.add( lightNode.target );
				break;

			case 'point':
				lightNode = new PointLight( color );
				lightNode.distance = range;
				break;

			case 'spot':
				lightNode = new SpotLight( color );
				lightNode.distance = range;
				// Handle spotlight properties.
				lightDef.spot = lightDef.spot || {};
				lightDef.spot.innerConeAngle = lightDef.spot.innerConeAngle !== undefined ? lightDef.spot.innerConeAngle : 0;
				lightDef.spot.outerConeAngle = lightDef.spot.outerConeAngle !== undefined ? lightDef.spot.outerConeAngle : Math.PI / 4.0;
				lightNode.angle = lightDef.spot.outerConeAngle;
				lightNode.penumbra = 1.0 - lightDef.spot.innerConeAngle / lightDef.spot.outerConeAngle;
				lightNode.target.position.set( 0, 0, - 1 );
				lightNode.add( lightNode.target );
				break;

			default:
				throw new Error( 'THREE.GLTFLoader: Unexpected light type, "' + lightDef.type + '".' );

		}

		// Some lights (e.g. spot) default to a position other than the origin. Reset the position
		// here, because node-level parsing will only override position if explicitly specified.
		lightNode.position.set( 0, 0, 0 );

		lightNode.decay = 2;

		if ( lightDef.intensity !== undefined ) lightNode.intensity = lightDef.intensity;

		lightNode.name = lightDef.name || ( 'light_' + lightIndex );

		return Promise.resolve( lightNode );

	};

	/**
	 * Unlit Materials Extension
	 *
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_materials_unlit
	 */
	function GLTFMaterialsUnlitExtension() {

		this.name = EXTENSIONS.KHR_MATERIALS_UNLIT;

	}

	GLTFMaterialsUnlitExtension.prototype.getMaterialType = function () {

		return MeshBasicMaterial;

	};

	GLTFMaterialsUnlitExtension.prototype.extendParams = function ( materialParams, materialDef, parser ) {

		var pending = [];

		materialParams.color = new Color( 1.0, 1.0, 1.0 );
		materialParams.opacity = 1.0;

		var metallicRoughness = materialDef.pbrMetallicRoughness;

		if ( metallicRoughness ) {

			if ( Array.isArray( metallicRoughness.baseColorFactor ) ) {

				var array = metallicRoughness.baseColorFactor;

				materialParams.color.fromArray( array );
				materialParams.opacity = array[ 3 ];

			}

			if ( metallicRoughness.baseColorTexture !== undefined ) {

				pending.push( parser.assignTexture( materialParams, 'map', metallicRoughness.baseColorTexture ) );

			}

		}

		return Promise.all( pending );

	};

	/**
	 * Clearcoat Materials Extension
	 *
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_materials_clearcoat
	 */
	function GLTFMaterialsClearcoatExtension() {

		this.name = EXTENSIONS.KHR_MATERIALS_CLEARCOAT;

	}

	GLTFMaterialsClearcoatExtension.prototype.getMaterialType = function () {

		return MeshPhysicalMaterial;

	};

	GLTFMaterialsClearcoatExtension.prototype.extendParams = function ( materialParams, materialDef, parser ) {

		var pending = [];

		var extension = materialDef.extensions[ this.name ];

		if ( extension.clearcoatFactor !== undefined ) {

			materialParams.clearcoat = extension.clearcoatFactor;

		}

		if ( extension.clearcoatTexture !== undefined ) {

			pending.push( parser.assignTexture( materialParams, 'clearcoatMap', extension.clearcoatTexture ) );

		}

		if ( extension.clearcoatRoughnessFactor !== undefined ) {

			materialParams.clearcoatRoughness = extension.clearcoatRoughnessFactor;

		}

		if ( extension.clearcoatRoughnessTexture !== undefined ) {

			pending.push( parser.assignTexture( materialParams, 'clearcoatRoughnessMap', extension.clearcoatRoughnessTexture ) );

		}

		if ( extension.clearcoatNormalTexture !== undefined ) {

			pending.push( parser.assignTexture( materialParams, 'clearcoatNormalMap', extension.clearcoatNormalTexture ) );

			if ( extension.clearcoatNormalTexture.scale !== undefined ) {

				var scale = extension.clearcoatNormalTexture.scale;

				materialParams.clearcoatNormalScale = new Vector2( scale, scale );

			}

		}

		return Promise.all( pending );

	};

	/* BINARY EXTENSION */
	var BINARY_EXTENSION_HEADER_MAGIC = 'glTF';
	var BINARY_EXTENSION_HEADER_LENGTH = 12;
	var BINARY_EXTENSION_CHUNK_TYPES = { JSON: 0x4E4F534A, BIN: 0x004E4942 };

	function GLTFBinaryExtension( data ) {

		this.name = EXTENSIONS.KHR_BINARY_GLTF;
		this.content = null;
		this.body = null;

		var headerView = new DataView( data, 0, BINARY_EXTENSION_HEADER_LENGTH );

		this.header = {
			magic: LoaderUtils.decodeText( new Uint8Array( data.slice( 0, 4 ) ) ),
			version: headerView.getUint32( 4, true ),
			length: headerView.getUint32( 8, true )
		};

		if ( this.header.magic !== BINARY_EXTENSION_HEADER_MAGIC ) {

			throw new Error( 'THREE.GLTFLoader: Unsupported glTF-Binary header.' );

		} else if ( this.header.version < 2.0 ) {

			throw new Error( 'THREE.GLTFLoader: Legacy binary file detected.' );

		}

		var chunkView = new DataView( data, BINARY_EXTENSION_HEADER_LENGTH );
		var chunkIndex = 0;

		while ( chunkIndex < chunkView.byteLength ) {

			var chunkLength = chunkView.getUint32( chunkIndex, true );
			chunkIndex += 4;

			var chunkType = chunkView.getUint32( chunkIndex, true );
			chunkIndex += 4;

			if ( chunkType === BINARY_EXTENSION_CHUNK_TYPES.JSON ) {

				var contentArray = new Uint8Array( data, BINARY_EXTENSION_HEADER_LENGTH + chunkIndex, chunkLength );
				this.content = LoaderUtils.decodeText( contentArray );

			} else if ( chunkType === BINARY_EXTENSION_CHUNK_TYPES.BIN ) {

				var byteOffset = BINARY_EXTENSION_HEADER_LENGTH + chunkIndex;
				this.body = data.slice( byteOffset, byteOffset + chunkLength );

			}

			// Clients must ignore chunks with unknown types.

			chunkIndex += chunkLength;

		}

		if ( this.content === null ) {

			throw new Error( 'THREE.GLTFLoader: JSON content not found.' );

		}

	}

	/**
	 * DRACO Mesh Compression Extension
	 *
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_draco_mesh_compression
	 */
	function GLTFDracoMeshCompressionExtension( json, dracoLoader ) {

		if ( ! dracoLoader ) {

			throw new Error( 'THREE.GLTFLoader: No DRACOLoader instance provided.' );

		}

		this.name = EXTENSIONS.KHR_DRACO_MESH_COMPRESSION;
		this.json = json;
		this.dracoLoader = dracoLoader;
		this.dracoLoader.preload();

	}

	GLTFDracoMeshCompressionExtension.prototype.decodePrimitive = function ( primitive, parser ) {

		var json = this.json;
		var dracoLoader = this.dracoLoader;
		var bufferViewIndex = primitive.extensions[ this.name ].bufferView;
		var gltfAttributeMap = primitive.extensions[ this.name ].attributes;
		var threeAttributeMap = {};
		var attributeNormalizedMap = {};
		var attributeTypeMap = {};

		for ( var attributeName in gltfAttributeMap ) {

			var threeAttributeName = ATTRIBUTES[ attributeName ] || attributeName.toLowerCase();

			threeAttributeMap[ threeAttributeName ] = gltfAttributeMap[ attributeName ];

		}

		for ( attributeName in primitive.attributes ) {

			var threeAttributeName = ATTRIBUTES[ attributeName ] || attributeName.toLowerCase();

			if ( gltfAttributeMap[ attributeName ] !== undefined ) {

				var accessorDef = json.accessors[ primitive.attributes[ attributeName ] ];
				var componentType = WEBGL_COMPONENT_TYPES[ accessorDef.componentType ];

				attributeTypeMap[ threeAttributeName ] = componentType;
				attributeNormalizedMap[ threeAttributeName ] = accessorDef.normalized === true;

			}

		}

		return parser.getDependency( 'bufferView', bufferViewIndex ).then( function ( bufferView ) {

			return new Promise( function ( resolve ) {

				dracoLoader.decodeDracoFile( bufferView, function ( geometry ) {

					for ( var attributeName in geometry.attributes ) {

						var attribute = geometry.attributes[ attributeName ];
						var normalized = attributeNormalizedMap[ attributeName ];

						if ( normalized !== undefined ) attribute.normalized = normalized;

					}

					resolve( geometry );

				}, threeAttributeMap, attributeTypeMap );

			} );

		} );

	};

	/**
	 * Texture Transform Extension
	 *
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_texture_transform
	 */
	function GLTFTextureTransformExtension() {

		this.name = EXTENSIONS.KHR_TEXTURE_TRANSFORM;

	}

	GLTFTextureTransformExtension.prototype.extendTexture = function ( texture, transform ) {

		texture = texture.clone();

		if ( transform.offset !== undefined ) {

			texture.offset.fromArray( transform.offset );

		}

		if ( transform.rotation !== undefined ) {

			texture.rotation = transform.rotation;

		}

		if ( transform.scale !== undefined ) {

			texture.repeat.fromArray( transform.scale );

		}

		if ( transform.texCoord !== undefined ) {

			console.warn( 'THREE.GLTFLoader: Custom UV sets in "' + this.name + '" extension not yet supported.' );

		}

		texture.needsUpdate = true;

		return texture;

	};

	/**
	 * Specular-Glossiness Extension
	 *
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_materials_pbrSpecularGlossiness
	 */

	/**
	 * A sub class of StandardMaterial with some of the functionality
	 * changed via the `onBeforeCompile` callback
	 * @pailhead
	 */

	function GLTFMeshStandardSGMaterial( params ) {

		MeshStandardMaterial.call( this );

		this.isGLTFSpecularGlossinessMaterial = true;

		//various chunks that need replacing
		var specularMapParsFragmentChunk = [
			'#ifdef USE_SPECULARMAP',
			'	uniform sampler2D specularMap;',
			'#endif'
		].join( '\n' );

		var glossinessMapParsFragmentChunk = [
			'#ifdef USE_GLOSSINESSMAP',
			'	uniform sampler2D glossinessMap;',
			'#endif'
		].join( '\n' );

		var specularMapFragmentChunk = [
			'vec3 specularFactor = specular;',
			'#ifdef USE_SPECULARMAP',
			'	vec4 texelSpecular = texture2D( specularMap, vUv );',
			'	texelSpecular = sRGBToLinear( texelSpecular );',
			'	// reads channel RGB, compatible with a glTF Specular-Glossiness (RGBA) texture',
			'	specularFactor *= texelSpecular.rgb;',
			'#endif'
		].join( '\n' );

		var glossinessMapFragmentChunk = [
			'float glossinessFactor = glossiness;',
			'#ifdef USE_GLOSSINESSMAP',
			'	vec4 texelGlossiness = texture2D( glossinessMap, vUv );',
			'	// reads channel A, compatible with a glTF Specular-Glossiness (RGBA) texture',
			'	glossinessFactor *= texelGlossiness.a;',
			'#endif'
		].join( '\n' );

		var lightPhysicalFragmentChunk = [
			'PhysicalMaterial material;',
			'material.diffuseColor = diffuseColor.rgb;',
			'vec3 dxy = max( abs( dFdx( geometryNormal ) ), abs( dFdy( geometryNormal ) ) );',
			'float geometryRoughness = max( max( dxy.x, dxy.y ), dxy.z );',
			'material.specularRoughness = max( 1.0 - glossinessFactor, 0.0525 );// 0.0525 corresponds to the base mip of a 256 cubemap.',
			'material.specularRoughness += geometryRoughness;',
			'material.specularRoughness = min( material.specularRoughness, 1.0 );',
			'material.specularColor = specularFactor.rgb;',
		].join( '\n' );

		var uniforms = {
			specular: { value: new Color().setHex( 0xffffff ) },
			glossiness: { value: 1 },
			specularMap: { value: null },
			glossinessMap: { value: null }
		};

		this._extraUniforms = uniforms;

		// please see #14031 or #13198 for an alternate approach
		this.onBeforeCompile = function ( shader ) {

			for ( var uniformName in uniforms ) {

				shader.uniforms[ uniformName ] = uniforms[ uniformName ];

			}

			shader.fragmentShader = shader.fragmentShader.replace( 'uniform float roughness;', 'uniform vec3 specular;' );
			shader.fragmentShader = shader.fragmentShader.replace( 'uniform float metalness;', 'uniform float glossiness;' );
			shader.fragmentShader = shader.fragmentShader.replace( '#include <roughnessmap_pars_fragment>', specularMapParsFragmentChunk );
			shader.fragmentShader = shader.fragmentShader.replace( '#include <metalnessmap_pars_fragment>', glossinessMapParsFragmentChunk );
			shader.fragmentShader = shader.fragmentShader.replace( '#include <roughnessmap_fragment>', specularMapFragmentChunk );
			shader.fragmentShader = shader.fragmentShader.replace( '#include <metalnessmap_fragment>', glossinessMapFragmentChunk );
			shader.fragmentShader = shader.fragmentShader.replace( '#include <lights_physical_fragment>', lightPhysicalFragmentChunk );

		};

		/*eslint-disable*/
		Object.defineProperties(
			this,
			{
				specular: {
					get: function () { return uniforms.specular.value; },
					set: function ( v ) { uniforms.specular.value = v; }
				},
				specularMap: {
					get: function () { return uniforms.specularMap.value; },
					set: function ( v ) { uniforms.specularMap.value = v; }
				},
				glossiness: {
					get: function () { return uniforms.glossiness.value; },
					set: function ( v ) { uniforms.glossiness.value = v; }
				},
				glossinessMap: {
					get: function () { return uniforms.glossinessMap.value; },
					set: function ( v ) {

						uniforms.glossinessMap.value = v;
						//how about something like this - @pailhead
						if ( v ) {

							this.defines.USE_GLOSSINESSMAP = '';
							// set USE_ROUGHNESSMAP to enable vUv
							this.defines.USE_ROUGHNESSMAP = '';

						} else {

							delete this.defines.USE_ROUGHNESSMAP;
							delete this.defines.USE_GLOSSINESSMAP;

						}

					}
				}
			}
		);

		/*eslint-enable*/
		delete this.metalness;
		delete this.roughness;
		delete this.metalnessMap;
		delete this.roughnessMap;

		this.setValues( params );

	}

	GLTFMeshStandardSGMaterial.prototype = Object.create( MeshStandardMaterial.prototype );
	GLTFMeshStandardSGMaterial.prototype.constructor = GLTFMeshStandardSGMaterial;

	GLTFMeshStandardSGMaterial.prototype.copy = function ( source ) {

		MeshStandardMaterial.prototype.copy.call( this, source );
		this.specularMap = source.specularMap;
		this.specular.copy( source.specular );
		this.glossinessMap = source.glossinessMap;
		this.glossiness = source.glossiness;
		delete this.metalness;
		delete this.roughness;
		delete this.metalnessMap;
		delete this.roughnessMap;
		return this;

	};

	function GLTFMaterialsPbrSpecularGlossinessExtension() {

		return {

			name: EXTENSIONS.KHR_MATERIALS_PBR_SPECULAR_GLOSSINESS,

			specularGlossinessParams: [
				'color',
				'map',
				'lightMap',
				'lightMapIntensity',
				'aoMap',
				'aoMapIntensity',
				'emissive',
				'emissiveIntensity',
				'emissiveMap',
				'bumpMap',
				'bumpScale',
				'normalMap',
				'normalMapType',
				'displacementMap',
				'displacementScale',
				'displacementBias',
				'specularMap',
				'specular',
				'glossinessMap',
				'glossiness',
				'alphaMap',
				'envMap',
				'envMapIntensity',
				'refractionRatio',
			],

			getMaterialType: function () {

				return GLTFMeshStandardSGMaterial;

			},

			extendParams: function ( materialParams, materialDef, parser ) {

				var pbrSpecularGlossiness = materialDef.extensions[ this.name ];

				materialParams.color = new Color( 1.0, 1.0, 1.0 );
				materialParams.opacity = 1.0;

				var pending = [];

				if ( Array.isArray( pbrSpecularGlossiness.diffuseFactor ) ) {

					var array = pbrSpecularGlossiness.diffuseFactor;

					materialParams.color.fromArray( array );
					materialParams.opacity = array[ 3 ];

				}

				if ( pbrSpecularGlossiness.diffuseTexture !== undefined ) {

					pending.push( parser.assignTexture( materialParams, 'map', pbrSpecularGlossiness.diffuseTexture ) );

				}

				materialParams.emissive = new Color( 0.0, 0.0, 0.0 );
				materialParams.glossiness = pbrSpecularGlossiness.glossinessFactor !== undefined ? pbrSpecularGlossiness.glossinessFactor : 1.0;
				materialParams.specular = new Color( 1.0, 1.0, 1.0 );

				if ( Array.isArray( pbrSpecularGlossiness.specularFactor ) ) {

					materialParams.specular.fromArray( pbrSpecularGlossiness.specularFactor );

				}

				if ( pbrSpecularGlossiness.specularGlossinessTexture !== undefined ) {

					var specGlossMapDef = pbrSpecularGlossiness.specularGlossinessTexture;
					pending.push( parser.assignTexture( materialParams, 'glossinessMap', specGlossMapDef ) );
					pending.push( parser.assignTexture( materialParams, 'specularMap', specGlossMapDef ) );

				}

				return Promise.all( pending );

			},

			createMaterial: function ( materialParams ) {

				var material = new GLTFMeshStandardSGMaterial( materialParams );
				material.fog = true;

				material.color = materialParams.color;

				material.map = materialParams.map === undefined ? null : materialParams.map;

				material.lightMap = null;
				material.lightMapIntensity = 1.0;

				material.aoMap = materialParams.aoMap === undefined ? null : materialParams.aoMap;
				material.aoMapIntensity = 1.0;

				material.emissive = materialParams.emissive;
				material.emissiveIntensity = 1.0;
				material.emissiveMap = materialParams.emissiveMap === undefined ? null : materialParams.emissiveMap;

				material.bumpMap = materialParams.bumpMap === undefined ? null : materialParams.bumpMap;
				material.bumpScale = 1;

				material.normalMap = materialParams.normalMap === undefined ? null : materialParams.normalMap;
				material.normalMapType = TangentSpaceNormalMap;

				if ( materialParams.normalScale ) material.normalScale = materialParams.normalScale;

				material.displacementMap = null;
				material.displacementScale = 1;
				material.displacementBias = 0;

				material.specularMap = materialParams.specularMap === undefined ? null : materialParams.specularMap;
				material.specular = materialParams.specular;

				material.glossinessMap = materialParams.glossinessMap === undefined ? null : materialParams.glossinessMap;
				material.glossiness = materialParams.glossiness;

				material.alphaMap = null;

				material.envMap = materialParams.envMap === undefined ? null : materialParams.envMap;
				material.envMapIntensity = 1.0;

				material.refractionRatio = 0.98;

				return material;

			},

		};

	}

	/**
	 * Mesh Quantization Extension
	 *
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_mesh_quantization
	 */
	function GLTFMeshQuantizationExtension() {

		this.name = EXTENSIONS.KHR_MESH_QUANTIZATION;

	}

	/*********************************/
	/********** INTERPOLATION ********/
	/*********************************/

	// Spline Interpolation
	// Specification: https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#appendix-c-spline-interpolation
	function GLTFCubicSplineInterpolant( parameterPositions, sampleValues, sampleSize, resultBuffer ) {

		Interpolant.call( this, parameterPositions, sampleValues, sampleSize, resultBuffer );

	}

	GLTFCubicSplineInterpolant.prototype = Object.create( Interpolant.prototype );
	GLTFCubicSplineInterpolant.prototype.constructor = GLTFCubicSplineInterpolant;

	GLTFCubicSplineInterpolant.prototype.copySampleValue_ = function ( index ) {

		// Copies a sample value to the result buffer. See description of glTF
		// CUBICSPLINE values layout in interpolate_() function below.

		var result = this.resultBuffer,
			values = this.sampleValues,
			valueSize = this.valueSize,
			offset = index * valueSize * 3 + valueSize;

		for ( var i = 0; i !== valueSize; i ++ ) {

			result[ i ] = values[ offset + i ];

		}

		return result;

	};

	GLTFCubicSplineInterpolant.prototype.beforeStart_ = GLTFCubicSplineInterpolant.prototype.copySampleValue_;

	GLTFCubicSplineInterpolant.prototype.afterEnd_ = GLTFCubicSplineInterpolant.prototype.copySampleValue_;

	GLTFCubicSplineInterpolant.prototype.interpolate_ = function ( i1, t0, t, t1 ) {

		var result = this.resultBuffer;
		var values = this.sampleValues;
		var stride = this.valueSize;

		var stride2 = stride * 2;
		var stride3 = stride * 3;

		var td = t1 - t0;

		var p = ( t - t0 ) / td;
		var pp = p * p;
		var ppp = pp * p;

		var offset1 = i1 * stride3;
		var offset0 = offset1 - stride3;

		var s2 = - 2 * ppp + 3 * pp;
		var s3 = ppp - pp;
		var s0 = 1 - s2;
		var s1 = s3 - pp + p;

		// Layout of keyframe output values for CUBICSPLINE animations:
		//   [ inTangent_1, splineVertex_1, outTangent_1, inTangent_2, splineVertex_2, ... ]
		for ( var i = 0; i !== stride; i ++ ) {

			var p0 = values[ offset0 + i + stride ]; // splineVertex_k
			var m0 = values[ offset0 + i + stride2 ] * td; // outTangent_k * (t_k+1 - t_k)
			var p1 = values[ offset1 + i + stride ]; // splineVertex_k+1
			var m1 = values[ offset1 + i ] * td; // inTangent_k+1 * (t_k+1 - t_k)

			result[ i ] = s0 * p0 + s1 * m0 + s2 * p1 + s3 * m1;

		}

		return result;

	};

	/*********************************/
	/********** INTERNALS ************/
	/*********************************/

	/* CONSTANTS */

	var WEBGL_CONSTANTS = {
		FLOAT: 5126,
		//FLOAT_MAT2: 35674,
		FLOAT_MAT3: 35675,
		FLOAT_MAT4: 35676,
		FLOAT_VEC2: 35664,
		FLOAT_VEC3: 35665,
		FLOAT_VEC4: 35666,
		LINEAR: 9729,
		REPEAT: 10497,
		SAMPLER_2D: 35678,
		POINTS: 0,
		LINES: 1,
		LINE_LOOP: 2,
		LINE_STRIP: 3,
		TRIANGLES: 4,
		TRIANGLE_STRIP: 5,
		TRIANGLE_FAN: 6,
		UNSIGNED_BYTE: 5121,
		UNSIGNED_SHORT: 5123
	};

	var WEBGL_COMPONENT_TYPES = {
		5120: Int8Array,
		5121: Uint8Array,
		5122: Int16Array,
		5123: Uint16Array,
		5125: Uint32Array,
		5126: Float32Array
	};

	var WEBGL_FILTERS = {
		9728: NearestFilter,
		9729: LinearFilter,
		9984: NearestMipmapNearestFilter,
		9985: LinearMipmapNearestFilter,
		9986: NearestMipmapLinearFilter,
		9987: LinearMipmapLinearFilter
	};

	var WEBGL_WRAPPINGS = {
		33071: ClampToEdgeWrapping,
		33648: MirroredRepeatWrapping,
		10497: RepeatWrapping
	};

	var WEBGL_TYPE_SIZES = {
		'SCALAR': 1,
		'VEC2': 2,
		'VEC3': 3,
		'VEC4': 4,
		'MAT2': 4,
		'MAT3': 9,
		'MAT4': 16
	};

	var ATTRIBUTES = {
		POSITION: 'position',
		NORMAL: 'normal',
		TANGENT: 'tangent',
		TEXCOORD_0: 'uv',
		TEXCOORD_1: 'uv2',
		COLOR_0: 'color',
		WEIGHTS_0: 'skinWeight',
		JOINTS_0: 'skinIndex',
	};

	var PATH_PROPERTIES = {
		scale: 'scale',
		translation: 'position',
		rotation: 'quaternion',
		weights: 'morphTargetInfluences'
	};

	var INTERPOLATION = {
		CUBICSPLINE: undefined, // We use a custom interpolant (GLTFCubicSplineInterpolation) for CUBICSPLINE tracks. Each
		                        // keyframe track will be initialized with a default interpolation type, then modified.
		LINEAR: InterpolateLinear,
		STEP: InterpolateDiscrete
	};

	var ALPHA_MODES = {
		OPAQUE: 'OPAQUE',
		MASK: 'MASK',
		BLEND: 'BLEND'
	};

	var MIME_TYPE_FORMATS = {
		'image/png': RGBAFormat,
		'image/jpeg': RGBFormat
	};

	/* UTILITY FUNCTIONS */

	function resolveURL( url, path ) {

		// Invalid URL
		if ( typeof url !== 'string' || url === '' ) return '';

		// Host Relative URL
		if ( /^https?:\/\//i.test( path ) && /^\//.test( url ) ) {

			path = path.replace( /(^https?:\/\/[^\/]+).*/i, '$1' );

		}

		// Absolute URL http://,https://,//
		if ( /^(https?:)?\/\//i.test( url ) ) return url;

		// Data URI
		if ( /^data:.*,.*$/i.test( url ) ) return url;

		// Blob URL
		if ( /^blob:.*$/i.test( url ) ) return url;

		// Relative URL
		return path + url;

	}

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#default-material
	 */
	function createDefaultMaterial( cache ) {

		if ( cache[ 'DefaultMaterial' ] === undefined ) {

			cache[ 'DefaultMaterial' ] = new MeshStandardMaterial( {
				color: 0xFFFFFF,
				emissive: 0x000000,
				metalness: 1,
				roughness: 1,
				transparent: false,
				depthTest: true,
				side: FrontSide
			} );

		}

		return cache[ 'DefaultMaterial' ];

	}

	function addUnknownExtensionsToUserData( knownExtensions, object, objectDef ) {

		// Add unknown glTF extensions to an object's userData.

		for ( var name in objectDef.extensions ) {

			if ( knownExtensions[ name ] === undefined ) {

				object.userData.gltfExtensions = object.userData.gltfExtensions || {};
				object.userData.gltfExtensions[ name ] = objectDef.extensions[ name ];

			}

		}

	}

	/**
	 * @param {Object3D|Material|BufferGeometry} object
	 * @param {GLTF.definition} gltfDef
	 */
	function assignExtrasToUserData( object, gltfDef ) {

		if ( gltfDef.extras !== undefined ) {

			if ( typeof gltfDef.extras === 'object' ) {

				Object.assign( object.userData, gltfDef.extras );

			} else {

				console.warn( 'THREE.GLTFLoader: Ignoring primitive type .extras, ' + gltfDef.extras );

			}

		}

	}

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#morph-targets
	 *
	 * @param {BufferGeometry} geometry
	 * @param {Array<GLTF.Target>} targets
	 * @param {GLTFParser} parser
	 * @return {Promise<BufferGeometry>}
	 */
	function addMorphTargets( geometry, targets, parser ) {

		var hasMorphPosition = false;
		var hasMorphNormal = false;

		for ( var i = 0, il = targets.length; i < il; i ++ ) {

			var target = targets[ i ];

			if ( target.POSITION !== undefined ) hasMorphPosition = true;
			if ( target.NORMAL !== undefined ) hasMorphNormal = true;

			if ( hasMorphPosition && hasMorphNormal ) break;

		}

		if ( ! hasMorphPosition && ! hasMorphNormal ) return Promise.resolve( geometry );

		var pendingPositionAccessors = [];
		var pendingNormalAccessors = [];

		for ( var i = 0, il = targets.length; i < il; i ++ ) {

			var target = targets[ i ];

			if ( hasMorphPosition ) {

				var pendingAccessor = target.POSITION !== undefined
					? parser.getDependency( 'accessor', target.POSITION )
					: geometry.attributes.position;

				pendingPositionAccessors.push( pendingAccessor );

			}

			if ( hasMorphNormal ) {

				var pendingAccessor = target.NORMAL !== undefined
					? parser.getDependency( 'accessor', target.NORMAL )
					: geometry.attributes.normal;

				pendingNormalAccessors.push( pendingAccessor );

			}

		}

		return Promise.all( [
			Promise.all( pendingPositionAccessors ),
			Promise.all( pendingNormalAccessors )
		] ).then( function ( accessors ) {

			var morphPositions = accessors[ 0 ];
			var morphNormals = accessors[ 1 ];

			if ( hasMorphPosition ) geometry.morphAttributes.position = morphPositions;
			if ( hasMorphNormal ) geometry.morphAttributes.normal = morphNormals;
			geometry.morphTargetsRelative = true;

			return geometry;

		} );

	}

	/**
	 * @param {Mesh} mesh
	 * @param {GLTF.Mesh} meshDef
	 */
	function updateMorphTargets( mesh, meshDef ) {

		mesh.updateMorphTargets();

		if ( meshDef.weights !== undefined ) {

			for ( var i = 0, il = meshDef.weights.length; i < il; i ++ ) {

				mesh.morphTargetInfluences[ i ] = meshDef.weights[ i ];

			}

		}

		// .extras has user-defined data, so check that .extras.targetNames is an array.
		if ( meshDef.extras && Array.isArray( meshDef.extras.targetNames ) ) {

			var targetNames = meshDef.extras.targetNames;

			if ( mesh.morphTargetInfluences.length === targetNames.length ) {

				mesh.morphTargetDictionary = {};

				for ( var i = 0, il = targetNames.length; i < il; i ++ ) {

					mesh.morphTargetDictionary[ targetNames[ i ] ] = i;

				}

			} else {

				console.warn( 'THREE.GLTFLoader: Invalid extras.targetNames length. Ignoring names.' );

			}

		}

	}

	function createPrimitiveKey( primitiveDef ) {

		var dracoExtension = primitiveDef.extensions && primitiveDef.extensions[ EXTENSIONS.KHR_DRACO_MESH_COMPRESSION ];
		var geometryKey;

		if ( dracoExtension ) {

			geometryKey = 'draco:' + dracoExtension.bufferView
				+ ':' + dracoExtension.indices
				+ ':' + createAttributesKey( dracoExtension.attributes );

		} else {

			geometryKey = primitiveDef.indices + ':' + createAttributesKey( primitiveDef.attributes ) + ':' + primitiveDef.mode;

		}

		return geometryKey;

	}

	function createAttributesKey( attributes ) {

		var attributesKey = '';

		var keys = Object.keys( attributes ).sort();

		for ( var i = 0, il = keys.length; i < il; i ++ ) {

			attributesKey += keys[ i ] + ':' + attributes[ keys[ i ] ] + ';';

		}

		return attributesKey;

	}

	/* GLTF PARSER */

	function GLTFParser( json, extensions, options ) {

		this.json = json || {};
		this.extensions = extensions || {};
		this.options = options || {};

		// loader object cache
		this.cache = new GLTFRegistry();

		// BufferGeometry caching
		this.primitiveCache = {};

		this.textureLoader = new TextureLoader( this.options.manager );
		this.textureLoader.setCrossOrigin( this.options.crossOrigin );

		this.fileLoader = new FileLoader( this.options.manager );
		this.fileLoader.setResponseType( 'arraybuffer' );

		if ( this.options.crossOrigin === 'use-credentials' ) {

			this.fileLoader.setWithCredentials( true );

		}

	}

	GLTFParser.prototype.parse = function ( onLoad, onError ) {

		var parser = this;
		var json = this.json;
		var extensions = this.extensions;

		// Clear the loader cache
		this.cache.removeAll();

		// Mark the special nodes/meshes in json for efficient parse
		this.markDefs();

		Promise.all( [

			this.getDependencies( 'scene' ),
			this.getDependencies( 'animation' ),
			this.getDependencies( 'camera' ),

		] ).then( function ( dependencies ) {

			var result = {
				scene: dependencies[ 0 ][ json.scene || 0 ],
				scenes: dependencies[ 0 ],
				animations: dependencies[ 1 ],
				cameras: dependencies[ 2 ],
				asset: json.asset,
				parser: parser,
				userData: {}
			};

			addUnknownExtensionsToUserData( extensions, result, json );

			assignExtrasToUserData( result, json );

			onLoad( result );

		} ).catch( onError );

	};

	/**
	 * Marks the special nodes/meshes in json for efficient parse.
	 */
	GLTFParser.prototype.markDefs = function () {

		var nodeDefs = this.json.nodes || [];
		var skinDefs = this.json.skins || [];
		var meshDefs = this.json.meshes || [];

		var meshReferences = {};
		var meshUses = {};

		// Nothing in the node definition indicates whether it is a Bone or an
		// Object3D. Use the skins' joint references to mark bones.
		for ( var skinIndex = 0, skinLength = skinDefs.length; skinIndex < skinLength; skinIndex ++ ) {

			var joints = skinDefs[ skinIndex ].joints;

			for ( var i = 0, il = joints.length; i < il; i ++ ) {

				nodeDefs[ joints[ i ] ].isBone = true;

			}

		}

		// Meshes can (and should) be reused by multiple nodes in a glTF asset. To
		// avoid having more than one Mesh with the same name, count
		// references and rename instances below.
		//
		// Example: CesiumMilkTruck sample model reuses "Wheel" meshes.
		for ( var nodeIndex = 0, nodeLength = nodeDefs.length; nodeIndex < nodeLength; nodeIndex ++ ) {

			var nodeDef = nodeDefs[ nodeIndex ];

			if ( nodeDef.mesh !== undefined ) {

				if ( meshReferences[ nodeDef.mesh ] === undefined ) {

					meshReferences[ nodeDef.mesh ] = meshUses[ nodeDef.mesh ] = 0;

				}

				meshReferences[ nodeDef.mesh ] ++;

				// Nothing in the mesh definition indicates whether it is
				// a SkinnedMesh or Mesh. Use the node's mesh reference
				// to mark SkinnedMesh if node has skin.
				if ( nodeDef.skin !== undefined ) {

					meshDefs[ nodeDef.mesh ].isSkinnedMesh = true;

				}

			}

		}

		this.json.meshReferences = meshReferences;
		this.json.meshUses = meshUses;

	};

	/**
	 * Requests the specified dependency asynchronously, with caching.
	 * @param {string} type
	 * @param {number} index
	 * @return {Promise<Object3D|Material|THREE.Texture|AnimationClip|ArrayBuffer|Object>}
	 */
	GLTFParser.prototype.getDependency = function ( type, index ) {

		var cacheKey = type + ':' + index;
		var dependency = this.cache.get( cacheKey );

		if ( ! dependency ) {

			switch ( type ) {

				case 'scene':
					dependency = this.loadScene( index );
					break;

				case 'node':
					dependency = this.loadNode( index );
					break;

				case 'mesh':
					dependency = this.loadMesh( index );
					break;

				case 'accessor':
					dependency = this.loadAccessor( index );
					break;

				case 'bufferView':
					dependency = this.loadBufferView( index );
					break;

				case 'buffer':
					dependency = this.loadBuffer( index );
					break;

				case 'material':
					dependency = this.loadMaterial( index );
					break;

				case 'texture':
					dependency = this.loadTexture( index );
					break;

				case 'skin':
					dependency = this.loadSkin( index );
					break;

				case 'animation':
					dependency = this.loadAnimation( index );
					break;

				case 'camera':
					dependency = this.loadCamera( index );
					break;

				case 'light':
					dependency = this.extensions[ EXTENSIONS.KHR_LIGHTS_PUNCTUAL ].loadLight( index );
					break;

				default:
					throw new Error( 'Unknown type: ' + type );

			}

			this.cache.add( cacheKey, dependency );

		}

		return dependency;

	};

	/**
	 * Requests all dependencies of the specified type asynchronously, with caching.
	 * @param {string} type
	 * @return {Promise<Array<Object>>}
	 */
	GLTFParser.prototype.getDependencies = function ( type ) {

		var dependencies = this.cache.get( type );

		if ( ! dependencies ) {

			var parser = this;
			var defs = this.json[ type + ( type === 'mesh' ? 'es' : 's' ) ] || [];

			dependencies = Promise.all( defs.map( function ( def, index ) {

				return parser.getDependency( type, index );

			} ) );

			this.cache.add( type, dependencies );

		}

		return dependencies;

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#buffers-and-buffer-views
	 * @param {number} bufferIndex
	 * @return {Promise<ArrayBuffer>}
	 */
	GLTFParser.prototype.loadBuffer = function ( bufferIndex ) {

		var bufferDef = this.json.buffers[ bufferIndex ];
		var loader = this.fileLoader;

		if ( bufferDef.type && bufferDef.type !== 'arraybuffer' ) {

			throw new Error( 'THREE.GLTFLoader: ' + bufferDef.type + ' buffer type is not supported.' );

		}

		// If present, GLB container is required to be the first buffer.
		if ( bufferDef.uri === undefined && bufferIndex === 0 ) {

			return Promise.resolve( this.extensions[ EXTENSIONS.KHR_BINARY_GLTF ].body );

		}

		var options = this.options;

		return new Promise( function ( resolve, reject ) {

			loader.load( resolveURL( bufferDef.uri, options.path ), resolve, undefined, function () {

				reject( new Error( 'THREE.GLTFLoader: Failed to load buffer "' + bufferDef.uri + '".' ) );

			} );

		} );

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#buffers-and-buffer-views
	 * @param {number} bufferViewIndex
	 * @return {Promise<ArrayBuffer>}
	 */
	GLTFParser.prototype.loadBufferView = function ( bufferViewIndex ) {

		var bufferViewDef = this.json.bufferViews[ bufferViewIndex ];

		return this.getDependency( 'buffer', bufferViewDef.buffer ).then( function ( buffer ) {

			var byteLength = bufferViewDef.byteLength || 0;
			var byteOffset = bufferViewDef.byteOffset || 0;
			return buffer.slice( byteOffset, byteOffset + byteLength );

		} );

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#accessors
	 * @param {number} accessorIndex
	 * @return {Promise<BufferAttribute|InterleavedBufferAttribute>}
	 */
	GLTFParser.prototype.loadAccessor = function ( accessorIndex ) {

		var parser = this;
		var json = this.json;

		var accessorDef = this.json.accessors[ accessorIndex ];

		if ( accessorDef.bufferView === undefined && accessorDef.sparse === undefined ) {

			// Ignore empty accessors, which may be used to declare runtime
			// information about attributes coming from another source (e.g. Draco
			// compression extension).
			return Promise.resolve( null );

		}

		var pendingBufferViews = [];

		if ( accessorDef.bufferView !== undefined ) {

			pendingBufferViews.push( this.getDependency( 'bufferView', accessorDef.bufferView ) );

		} else {

			pendingBufferViews.push( null );

		}

		if ( accessorDef.sparse !== undefined ) {

			pendingBufferViews.push( this.getDependency( 'bufferView', accessorDef.sparse.indices.bufferView ) );
			pendingBufferViews.push( this.getDependency( 'bufferView', accessorDef.sparse.values.bufferView ) );

		}

		return Promise.all( pendingBufferViews ).then( function ( bufferViews ) {

			var bufferView = bufferViews[ 0 ];

			var itemSize = WEBGL_TYPE_SIZES[ accessorDef.type ];
			var TypedArray = WEBGL_COMPONENT_TYPES[ accessorDef.componentType ];

			// For VEC3: itemSize is 3, elementBytes is 4, itemBytes is 12.
			var elementBytes = TypedArray.BYTES_PER_ELEMENT;
			var itemBytes = elementBytes * itemSize;
			var byteOffset = accessorDef.byteOffset || 0;
			var byteStride = accessorDef.bufferView !== undefined ? json.bufferViews[ accessorDef.bufferView ].byteStride : undefined;
			var normalized = accessorDef.normalized === true;
			var array, bufferAttribute;

			// The buffer is not interleaved if the stride is the item size in bytes.
			if ( byteStride && byteStride !== itemBytes ) {

				// Each "slice" of the buffer, as defined by 'count' elements of 'byteStride' bytes, gets its own InterleavedBuffer
				// This makes sure that IBA.count reflects accessor.count properly
				var ibSlice = Math.floor( byteOffset / byteStride );
				var ibCacheKey = 'InterleavedBuffer:' + accessorDef.bufferView + ':' + accessorDef.componentType + ':' + ibSlice + ':' + accessorDef.count;
				var ib = parser.cache.get( ibCacheKey );

				if ( ! ib ) {

					array = new TypedArray( bufferView, ibSlice * byteStride, accessorDef.count * byteStride / elementBytes );

					// Integer parameters to IB/IBA are in array elements, not bytes.
					ib = new InterleavedBuffer( array, byteStride / elementBytes );

					parser.cache.add( ibCacheKey, ib );

				}

				bufferAttribute = new InterleavedBufferAttribute( ib, itemSize, ( byteOffset % byteStride ) / elementBytes, normalized );

			} else {

				if ( bufferView === null ) {

					array = new TypedArray( accessorDef.count * itemSize );

				} else {

					array = new TypedArray( bufferView, byteOffset, accessorDef.count * itemSize );

				}

				bufferAttribute = new BufferAttribute( array, itemSize, normalized );

			}

			// https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#sparse-accessors
			if ( accessorDef.sparse !== undefined ) {

				var itemSizeIndices = WEBGL_TYPE_SIZES.SCALAR;
				var TypedArrayIndices = WEBGL_COMPONENT_TYPES[ accessorDef.sparse.indices.componentType ];

				var byteOffsetIndices = accessorDef.sparse.indices.byteOffset || 0;
				var byteOffsetValues = accessorDef.sparse.values.byteOffset || 0;

				var sparseIndices = new TypedArrayIndices( bufferViews[ 1 ], byteOffsetIndices, accessorDef.sparse.count * itemSizeIndices );
				var sparseValues = new TypedArray( bufferViews[ 2 ], byteOffsetValues, accessorDef.sparse.count * itemSize );

				if ( bufferView !== null ) {

					// Avoid modifying the original ArrayBuffer, if the bufferView wasn't initialized with zeroes.
					bufferAttribute = new BufferAttribute( bufferAttribute.array.slice(), bufferAttribute.itemSize, bufferAttribute.normalized );

				}

				for ( var i = 0, il = sparseIndices.length; i < il; i ++ ) {

					var index = sparseIndices[ i ];

					bufferAttribute.setX( index, sparseValues[ i * itemSize ] );
					if ( itemSize >= 2 ) bufferAttribute.setY( index, sparseValues[ i * itemSize + 1 ] );
					if ( itemSize >= 3 ) bufferAttribute.setZ( index, sparseValues[ i * itemSize + 2 ] );
					if ( itemSize >= 4 ) bufferAttribute.setW( index, sparseValues[ i * itemSize + 3 ] );
					if ( itemSize >= 5 ) throw new Error( 'THREE.GLTFLoader: Unsupported itemSize in sparse BufferAttribute.' );

				}

			}

			return bufferAttribute;

		} );

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#textures
	 * @param {number} textureIndex
	 * @return {Promise<THREE.Texture>}
	 */
	GLTFParser.prototype.loadTexture = function ( textureIndex ) {

		var parser = this;
		var json = this.json;
		var options = this.options;
		var textureLoader = this.textureLoader;

		var URL = self.URL || self.webkitURL;

		var textureDef = json.textures[ textureIndex ];

		var textureExtensions = textureDef.extensions || {};

		var source;

		if ( textureExtensions[ EXTENSIONS.MSFT_TEXTURE_DDS ] ) {

			source = json.images[ textureExtensions[ EXTENSIONS.MSFT_TEXTURE_DDS ].source ];

		} else {

			source = json.images[ textureDef.source ];

		}

		var sourceURI = source.uri;
		var isObjectURL = false;

		if ( source.bufferView !== undefined ) {

			// Load binary image data from bufferView, if provided.

			sourceURI = parser.getDependency( 'bufferView', source.bufferView ).then( function ( bufferView ) {

				isObjectURL = true;
				var blob = new Blob( [ bufferView ], { type: source.mimeType } );
				sourceURI = URL.createObjectURL( blob );
				return sourceURI;

			} );

		}

		return Promise.resolve( sourceURI ).then( function ( sourceURI ) {

			// Load Texture resource.

			var loader = options.manager.getHandler( sourceURI );

			if ( ! loader ) {

				loader = textureExtensions[ EXTENSIONS.MSFT_TEXTURE_DDS ]
					? parser.extensions[ EXTENSIONS.MSFT_TEXTURE_DDS ].ddsLoader
					: textureLoader;

			}

			return new Promise( function ( resolve, reject ) {

				loader.load( resolveURL( sourceURI, options.path ), resolve, undefined, reject );

			} );

		} ).then( function ( texture ) {

			// Clean up resources and configure Texture.

			if ( isObjectURL === true ) {

				URL.revokeObjectURL( sourceURI );

			}

			texture.flipY = false;

			if ( textureDef.name ) texture.name = textureDef.name;

			// Ignore unknown mime types, like DDS files.
			if ( source.mimeType in MIME_TYPE_FORMATS ) {

				texture.format = MIME_TYPE_FORMATS[ source.mimeType ];

			}

			var samplers = json.samplers || {};
			var sampler = samplers[ textureDef.sampler ] || {};

			texture.magFilter = WEBGL_FILTERS[ sampler.magFilter ] || LinearFilter;
			texture.minFilter = WEBGL_FILTERS[ sampler.minFilter ] || LinearMipmapLinearFilter;
			texture.wrapS = WEBGL_WRAPPINGS[ sampler.wrapS ] || RepeatWrapping;
			texture.wrapT = WEBGL_WRAPPINGS[ sampler.wrapT ] || RepeatWrapping;

			return texture;

		} );

	};

	/**
	 * Asynchronously assigns a texture to the given material parameters.
	 * @param {Object} materialParams
	 * @param {string} mapName
	 * @param {Object} mapDef
	 * @return {Promise}
	 */
	GLTFParser.prototype.assignTexture = function ( materialParams, mapName, mapDef ) {

		var parser = this;

		return this.getDependency( 'texture', mapDef.index ).then( function ( texture ) {

			if ( ! texture.isCompressedTexture ) {

				switch ( mapName ) {

					case 'aoMap':
					case 'emissiveMap':
					case 'metalnessMap':
					case 'normalMap':
					case 'roughnessMap':
						texture.format = RGBFormat;
						break;

				}

			}

			// Materials sample aoMap from UV set 1 and other maps from UV set 0 - this can't be configured
			// However, we will copy UV set 0 to UV set 1 on demand for aoMap
			if ( mapDef.texCoord !== undefined && mapDef.texCoord != 0 && ! ( mapName === 'aoMap' && mapDef.texCoord == 1 ) ) {

				console.warn( 'THREE.GLTFLoader: Custom UV set ' + mapDef.texCoord + ' for texture ' + mapName + ' not yet supported.' );

			}

			if ( parser.extensions[ EXTENSIONS.KHR_TEXTURE_TRANSFORM ] ) {

				var transform = mapDef.extensions !== undefined ? mapDef.extensions[ EXTENSIONS.KHR_TEXTURE_TRANSFORM ] : undefined;

				if ( transform ) {

					texture = parser.extensions[ EXTENSIONS.KHR_TEXTURE_TRANSFORM ].extendTexture( texture, transform );

				}

			}

			materialParams[ mapName ] = texture;

		} );

	};

	/**
	 * Assigns final material to a Mesh, Line, or Points instance. The instance
	 * already has a material (generated from the glTF material options alone)
	 * but reuse of the same glTF material may require multiple threejs materials
	 * to accomodate different primitive types, defines, etc. New materials will
	 * be created if necessary, and reused from a cache.
	 * @param  {Object3D} mesh Mesh, Line, or Points instance.
	 */
	GLTFParser.prototype.assignFinalMaterial = function ( mesh ) {

		var geometry = mesh.geometry;
		var material = mesh.material;

		var useVertexTangents = geometry.attributes.tangent !== undefined;
		var useVertexColors = geometry.attributes.color !== undefined;
		var useFlatShading = geometry.attributes.normal === undefined;
		var useSkinning = mesh.isSkinnedMesh === true;
		var useMorphTargets = Object.keys( geometry.morphAttributes ).length > 0;
		var useMorphNormals = useMorphTargets && geometry.morphAttributes.normal !== undefined;

		if ( mesh.isPoints ) {

			var cacheKey = 'PointsMaterial:' + material.uuid;

			var pointsMaterial = this.cache.get( cacheKey );

			if ( ! pointsMaterial ) {

				pointsMaterial = new PointsMaterial();
				Material.prototype.copy.call( pointsMaterial, material );
				pointsMaterial.color.copy( material.color );
				pointsMaterial.map = material.map;
				pointsMaterial.sizeAttenuation = false; // glTF spec says points should be 1px

				this.cache.add( cacheKey, pointsMaterial );

			}

			material = pointsMaterial;

		} else if ( mesh.isLine ) {

			var cacheKey = 'LineBasicMaterial:' + material.uuid;

			var lineMaterial = this.cache.get( cacheKey );

			if ( ! lineMaterial ) {

				lineMaterial = new LineBasicMaterial();
				Material.prototype.copy.call( lineMaterial, material );
				lineMaterial.color.copy( material.color );

				this.cache.add( cacheKey, lineMaterial );

			}

			material = lineMaterial;

		}

		// Clone the material if it will be modified
		if ( useVertexTangents || useVertexColors || useFlatShading || useSkinning || useMorphTargets ) {

			var cacheKey = 'ClonedMaterial:' + material.uuid + ':';

			if ( material.isGLTFSpecularGlossinessMaterial ) cacheKey += 'specular-glossiness:';
			if ( useSkinning ) cacheKey += 'skinning:';
			if ( useVertexTangents ) cacheKey += 'vertex-tangents:';
			if ( useVertexColors ) cacheKey += 'vertex-colors:';
			if ( useFlatShading ) cacheKey += 'flat-shading:';
			if ( useMorphTargets ) cacheKey += 'morph-targets:';
			if ( useMorphNormals ) cacheKey += 'morph-normals:';

			var cachedMaterial = this.cache.get( cacheKey );

			if ( ! cachedMaterial ) {

				cachedMaterial = material.clone();

				if ( useSkinning ) cachedMaterial.skinning = true;
				if ( useVertexTangents ) cachedMaterial.vertexTangents = true;
				if ( useVertexColors ) cachedMaterial.vertexColors = true;
				if ( useFlatShading ) cachedMaterial.flatShading = true;
				if ( useMorphTargets ) cachedMaterial.morphTargets = true;
				if ( useMorphNormals ) cachedMaterial.morphNormals = true;

				this.cache.add( cacheKey, cachedMaterial );

			}

			material = cachedMaterial;

		}

		// workarounds for mesh and geometry

		if ( material.aoMap && geometry.attributes.uv2 === undefined && geometry.attributes.uv !== undefined ) {

			geometry.setAttribute( 'uv2', geometry.attributes.uv );

		}

		// https://github.com/mrdoob/three.js/issues/11438#issuecomment-507003995
		if ( material.normalScale && ! useVertexTangents ) {

			material.normalScale.y = - material.normalScale.y;

		}

		if ( material.clearcoatNormalScale && ! useVertexTangents ) {

			material.clearcoatNormalScale.y = - material.clearcoatNormalScale.y;

		}

		mesh.material = material;

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#materials
	 * @param {number} materialIndex
	 * @return {Promise<Material>}
	 */
	GLTFParser.prototype.loadMaterial = function ( materialIndex ) {

		var parser = this;
		var json = this.json;
		var extensions = this.extensions;
		var materialDef = json.materials[ materialIndex ];

		var materialType;
		var materialParams = {};
		var materialExtensions = materialDef.extensions || {};

		var pending = [];

		if ( materialExtensions[ EXTENSIONS.KHR_MATERIALS_PBR_SPECULAR_GLOSSINESS ] ) {

			var sgExtension = extensions[ EXTENSIONS.KHR_MATERIALS_PBR_SPECULAR_GLOSSINESS ];
			materialType = sgExtension.getMaterialType();
			pending.push( sgExtension.extendParams( materialParams, materialDef, parser ) );

		} else if ( materialExtensions[ EXTENSIONS.KHR_MATERIALS_UNLIT ] ) {

			var kmuExtension = extensions[ EXTENSIONS.KHR_MATERIALS_UNLIT ];
			materialType = kmuExtension.getMaterialType();
			pending.push( kmuExtension.extendParams( materialParams, materialDef, parser ) );

		} else {

			// Specification:
			// https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#metallic-roughness-material

			materialType = MeshStandardMaterial;

			var metallicRoughness = materialDef.pbrMetallicRoughness || {};

			materialParams.color = new Color( 1.0, 1.0, 1.0 );
			materialParams.opacity = 1.0;

			if ( Array.isArray( metallicRoughness.baseColorFactor ) ) {

				var array = metallicRoughness.baseColorFactor;

				materialParams.color.fromArray( array );
				materialParams.opacity = array[ 3 ];

			}

			if ( metallicRoughness.baseColorTexture !== undefined ) {

				pending.push( parser.assignTexture( materialParams, 'map', metallicRoughness.baseColorTexture ) );

			}

			materialParams.metalness = metallicRoughness.metallicFactor !== undefined ? metallicRoughness.metallicFactor : 1.0;
			materialParams.roughness = metallicRoughness.roughnessFactor !== undefined ? metallicRoughness.roughnessFactor : 1.0;

			if ( metallicRoughness.metallicRoughnessTexture !== undefined ) {

				pending.push( parser.assignTexture( materialParams, 'metalnessMap', metallicRoughness.metallicRoughnessTexture ) );
				pending.push( parser.assignTexture( materialParams, 'roughnessMap', metallicRoughness.metallicRoughnessTexture ) );

			}

		}

		if ( materialDef.doubleSided === true ) {

			materialParams.side = DoubleSide;

		}

		var alphaMode = materialDef.alphaMode || ALPHA_MODES.OPAQUE;

		if ( alphaMode === ALPHA_MODES.BLEND ) {

			materialParams.transparent = true;

			// See: https://github.com/mrdoob/three.js/issues/17706
			materialParams.depthWrite = false;

		} else {

			materialParams.transparent = false;

			if ( alphaMode === ALPHA_MODES.MASK ) {

				materialParams.alphaTest = materialDef.alphaCutoff !== undefined ? materialDef.alphaCutoff : 0.5;

			}

		}

		if ( materialDef.normalTexture !== undefined && materialType !== MeshBasicMaterial ) {

			pending.push( parser.assignTexture( materialParams, 'normalMap', materialDef.normalTexture ) );

			materialParams.normalScale = new Vector2( 1, 1 );

			if ( materialDef.normalTexture.scale !== undefined ) {

				materialParams.normalScale.set( materialDef.normalTexture.scale, materialDef.normalTexture.scale );

			}

		}

		if ( materialDef.occlusionTexture !== undefined && materialType !== MeshBasicMaterial ) {

			pending.push( parser.assignTexture( materialParams, 'aoMap', materialDef.occlusionTexture ) );

			if ( materialDef.occlusionTexture.strength !== undefined ) {

				materialParams.aoMapIntensity = materialDef.occlusionTexture.strength;

			}

		}

		if ( materialDef.emissiveFactor !== undefined && materialType !== MeshBasicMaterial ) {

			materialParams.emissive = new Color().fromArray( materialDef.emissiveFactor );

		}

		if ( materialDef.emissiveTexture !== undefined && materialType !== MeshBasicMaterial ) {

			pending.push( parser.assignTexture( materialParams, 'emissiveMap', materialDef.emissiveTexture ) );

		}

		if ( materialExtensions[ EXTENSIONS.KHR_MATERIALS_CLEARCOAT ] ) {

			var clearcoatExtension = extensions[ EXTENSIONS.KHR_MATERIALS_CLEARCOAT ];
			materialType = clearcoatExtension.getMaterialType();
			pending.push( clearcoatExtension.extendParams( materialParams, { extensions: materialExtensions }, parser ) );

		}

		return Promise.all( pending ).then( function () {

			var material;

			if ( materialType === GLTFMeshStandardSGMaterial ) {

				material = extensions[ EXTENSIONS.KHR_MATERIALS_PBR_SPECULAR_GLOSSINESS ].createMaterial( materialParams );

			} else {

				material = new materialType( materialParams );

			}

			if ( materialDef.name ) material.name = materialDef.name;

			// baseColorTexture, emissiveTexture, and specularGlossinessTexture use sRGB encoding.
			if ( material.map ) material.map.encoding = sRGBEncoding;
			if ( material.emissiveMap ) material.emissiveMap.encoding = sRGBEncoding;

			assignExtrasToUserData( material, materialDef );

			if ( materialDef.extensions ) addUnknownExtensionsToUserData( extensions, material, materialDef );

			return material;

		} );

	};

	/**
	 * @param {BufferGeometry} geometry
	 * @param {GLTF.Primitive} primitiveDef
	 * @param {GLTFParser} parser
	 */
	function computeBounds( geometry, primitiveDef, parser ) {

		var attributes = primitiveDef.attributes;

		var box = new Box3();

		if ( attributes.POSITION !== undefined ) {

			var accessor = parser.json.accessors[ attributes.POSITION ];

			var min = accessor.min;
			var max = accessor.max;

			// glTF requires 'min' and 'max', but VRM (which extends glTF) currently ignores that requirement.

			if ( min !== undefined && max !== undefined ) {

				box.set(
					new Vector3( min[ 0 ], min[ 1 ], min[ 2 ] ),
					new Vector3( max[ 0 ], max[ 1 ], max[ 2 ] ) );

			} else {

				console.warn( 'THREE.GLTFLoader: Missing min/max properties for accessor POSITION.' );

				return;

			}

		} else {

			return;

		}

		var targets = primitiveDef.targets;

		if ( targets !== undefined ) {

			var maxDisplacement = new Vector3();
			var vector = new Vector3();

			for ( var i = 0, il = targets.length; i < il; i ++ ) {

				var target = targets[ i ];

				if ( target.POSITION !== undefined ) {

					var accessor = parser.json.accessors[ target.POSITION ];
					var min = accessor.min;
					var max = accessor.max;

					// glTF requires 'min' and 'max', but VRM (which extends glTF) currently ignores that requirement.

					if ( min !== undefined && max !== undefined ) {

						// we need to get max of absolute components because target weight is [-1,1]
						vector.setX( Math.max( Math.abs( min[ 0 ] ), Math.abs( max[ 0 ] ) ) );
						vector.setY( Math.max( Math.abs( min[ 1 ] ), Math.abs( max[ 1 ] ) ) );
						vector.setZ( Math.max( Math.abs( min[ 2 ] ), Math.abs( max[ 2 ] ) ) );

						// Note: this assumes that the sum of all weights is at most 1. This isn't quite correct - it's more conservative
						// to assume that each target can have a max weight of 1. However, for some use cases - notably, when morph targets
						// are used to implement key-frame animations and as such only two are active at a time - this results in very large
						// boxes. So for now we make a box that's sometimes a touch too small but is hopefully mostly of reasonable size.
						maxDisplacement.max( vector );

					} else {

						console.warn( 'THREE.GLTFLoader: Missing min/max properties for accessor POSITION.' );

					}

				}

			}

			// As per comment above this box isn't conservative, but has a reasonable size for a very large number of morph targets.
			box.expandByVector( maxDisplacement );

		}

		geometry.boundingBox = box;

		var sphere = new Sphere();

		box.getCenter( sphere.center );
		sphere.radius = box.min.distanceTo( box.max ) / 2;

		geometry.boundingSphere = sphere;

	}

	/**
	 * @param {BufferGeometry} geometry
	 * @param {GLTF.Primitive} primitiveDef
	 * @param {GLTFParser} parser
	 * @return {Promise<BufferGeometry>}
	 */
	function addPrimitiveAttributes( geometry, primitiveDef, parser ) {

		var attributes = primitiveDef.attributes;

		var pending = [];

		function assignAttributeAccessor( accessorIndex, attributeName ) {

			return parser.getDependency( 'accessor', accessorIndex )
				.then( function ( accessor ) {

					geometry.setAttribute( attributeName, accessor );

				} );

		}

		for ( var gltfAttributeName in attributes ) {

			var threeAttributeName = ATTRIBUTES[ gltfAttributeName ] || gltfAttributeName.toLowerCase();

			// Skip attributes already provided by e.g. Draco extension.
			if ( threeAttributeName in geometry.attributes ) continue;

			pending.push( assignAttributeAccessor( attributes[ gltfAttributeName ], threeAttributeName ) );

		}

		if ( primitiveDef.indices !== undefined && ! geometry.index ) {

			var accessor = parser.getDependency( 'accessor', primitiveDef.indices ).then( function ( accessor ) {

				geometry.setIndex( accessor );

			} );

			pending.push( accessor );

		}

		assignExtrasToUserData( geometry, primitiveDef );

		computeBounds( geometry, primitiveDef, parser );

		return Promise.all( pending ).then( function () {

			return primitiveDef.targets !== undefined
				? addMorphTargets( geometry, primitiveDef.targets, parser )
				: geometry;

		} );

	}

	/**
	 * @param {BufferGeometry} geometry
	 * @param {Number} drawMode
	 * @return {BufferGeometry}
	 */
	function toTrianglesDrawMode( geometry, drawMode ) {

		var index = geometry.getIndex();

		// generate index if not present

		if ( index === null ) {

			var indices = [];

			var position = geometry.getAttribute( 'position' );

			if ( position !== undefined ) {

				for ( var i = 0; i < position.count; i ++ ) {

					indices.push( i );

				}

				geometry.setIndex( indices );
				index = geometry.getIndex();

			} else {

				console.error( 'THREE.GLTFLoader.toTrianglesDrawMode(): Undefined position attribute. Processing not possible.' );
				return geometry;

			}

		}

		//

		var numberOfTriangles = index.count - 2;
		var newIndices = [];

		if ( drawMode === TriangleFanDrawMode ) {

			// gl.TRIANGLE_FAN

			for ( var i = 1; i <= numberOfTriangles; i ++ ) {

				newIndices.push( index.getX( 0 ) );
				newIndices.push( index.getX( i ) );
				newIndices.push( index.getX( i + 1 ) );

			}

		} else {

			// gl.TRIANGLE_STRIP

			for ( var i = 0; i < numberOfTriangles; i ++ ) {

				if ( i % 2 === 0 ) {

					newIndices.push( index.getX( i ) );
					newIndices.push( index.getX( i + 1 ) );
					newIndices.push( index.getX( i + 2 ) );


				} else {

					newIndices.push( index.getX( i + 2 ) );
					newIndices.push( index.getX( i + 1 ) );
					newIndices.push( index.getX( i ) );

				}

			}

		}

		if ( ( newIndices.length / 3 ) !== numberOfTriangles ) {

			console.error( 'THREE.GLTFLoader.toTrianglesDrawMode(): Unable to generate correct amount of triangles.' );

		}

		// build final geometry

		var newGeometry = geometry.clone();
		newGeometry.setIndex( newIndices );

		return newGeometry;

	}

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#geometry
	 *
	 * Creates BufferGeometries from primitives.
	 *
	 * @param {Array<GLTF.Primitive>} primitives
	 * @return {Promise<Array<BufferGeometry>>}
	 */
	GLTFParser.prototype.loadGeometries = function ( primitives ) {

		var parser = this;
		var extensions = this.extensions;
		var cache = this.primitiveCache;

		function createDracoPrimitive( primitive ) {

			return extensions[ EXTENSIONS.KHR_DRACO_MESH_COMPRESSION ]
				.decodePrimitive( primitive, parser )
				.then( function ( geometry ) {

					return addPrimitiveAttributes( geometry, primitive, parser );

				} );

		}

		var pending = [];

		for ( var i = 0, il = primitives.length; i < il; i ++ ) {

			var primitive = primitives[ i ];
			var cacheKey = createPrimitiveKey( primitive );

			// See if we've already created this geometry
			var cached = cache[ cacheKey ];

			if ( cached ) {

				// Use the cached geometry if it exists
				pending.push( cached.promise );

			} else {

				var geometryPromise;

				if ( primitive.extensions && primitive.extensions[ EXTENSIONS.KHR_DRACO_MESH_COMPRESSION ] ) {

					// Use DRACO geometry if available
					geometryPromise = createDracoPrimitive( primitive );

				} else {

					// Otherwise create a new geometry
					geometryPromise = addPrimitiveAttributes( new BufferGeometry(), primitive, parser );

				}

				// Cache this geometry
				cache[ cacheKey ] = { primitive: primitive, promise: geometryPromise };

				pending.push( geometryPromise );

			}

		}

		return Promise.all( pending );

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#meshes
	 * @param {number} meshIndex
	 * @return {Promise<Group|Mesh|SkinnedMesh>}
	 */
	GLTFParser.prototype.loadMesh = function ( meshIndex ) {

		var parser = this;
		var json = this.json;

		var meshDef = json.meshes[ meshIndex ];
		var primitives = meshDef.primitives;

		var pending = [];

		for ( var i = 0, il = primitives.length; i < il; i ++ ) {

			var material = primitives[ i ].material === undefined
				? createDefaultMaterial( this.cache )
				: this.getDependency( 'material', primitives[ i ].material );

			pending.push( material );

		}

		pending.push( parser.loadGeometries( primitives ) );

		return Promise.all( pending ).then( function ( results ) {

			var materials = results.slice( 0, results.length - 1 );
			var geometries = results[ results.length - 1 ];

			var meshes = [];

			for ( var i = 0, il = geometries.length; i < il; i ++ ) {

				var geometry = geometries[ i ];
				var primitive = primitives[ i ];

				// 1. create Mesh

				var mesh;

				var material = materials[ i ];

				if ( primitive.mode === WEBGL_CONSTANTS.TRIANGLES ||
					primitive.mode === WEBGL_CONSTANTS.TRIANGLE_STRIP ||
					primitive.mode === WEBGL_CONSTANTS.TRIANGLE_FAN ||
					primitive.mode === undefined ) {

					// .isSkinnedMesh isn't in glTF spec. See .markDefs()
					mesh = meshDef.isSkinnedMesh === true
						? new SkinnedMesh( geometry, material )
						: new Mesh( geometry, material );

					if ( mesh.isSkinnedMesh === true && ! mesh.geometry.attributes.skinWeight.normalized ) {

						// we normalize floating point skin weight array to fix malformed assets (see #15319)
						// it's important to skip this for non-float32 data since normalizeSkinWeights assumes non-normalized inputs
						mesh.normalizeSkinWeights();

					}

					if ( primitive.mode === WEBGL_CONSTANTS.TRIANGLE_STRIP ) {

						mesh.geometry = toTrianglesDrawMode( mesh.geometry, TriangleStripDrawMode );

					} else if ( primitive.mode === WEBGL_CONSTANTS.TRIANGLE_FAN ) {

						mesh.geometry = toTrianglesDrawMode( mesh.geometry, TriangleFanDrawMode );

					}

				} else if ( primitive.mode === WEBGL_CONSTANTS.LINES ) {

					mesh = new LineSegments( geometry, material );

				} else if ( primitive.mode === WEBGL_CONSTANTS.LINE_STRIP ) {

					mesh = new Line( geometry, material );

				} else if ( primitive.mode === WEBGL_CONSTANTS.LINE_LOOP ) {

					mesh = new LineLoop( geometry, material );

				} else if ( primitive.mode === WEBGL_CONSTANTS.POINTS ) {

					mesh = new Points( geometry, material );

				} else {

					throw new Error( 'THREE.GLTFLoader: Primitive mode unsupported: ' + primitive.mode );

				}

				if ( Object.keys( mesh.geometry.morphAttributes ).length > 0 ) {

					updateMorphTargets( mesh, meshDef );

				}

				mesh.name = meshDef.name || ( 'mesh_' + meshIndex );

				if ( geometries.length > 1 ) mesh.name += '_' + i;

				assignExtrasToUserData( mesh, meshDef );

				parser.assignFinalMaterial( mesh );

				meshes.push( mesh );

			}

			if ( meshes.length === 1 ) {

				return meshes[ 0 ];

			}

			var group = new Group();

			for ( var i = 0, il = meshes.length; i < il; i ++ ) {

				group.add( meshes[ i ] );

			}

			return group;

		} );

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#cameras
	 * @param {number} cameraIndex
	 * @return {Promise<THREE.Camera>}
	 */
	GLTFParser.prototype.loadCamera = function ( cameraIndex ) {

		var camera;
		var cameraDef = this.json.cameras[ cameraIndex ];
		var params = cameraDef[ cameraDef.type ];

		if ( ! params ) {

			console.warn( 'THREE.GLTFLoader: Missing camera parameters.' );
			return;

		}

		if ( cameraDef.type === 'perspective' ) {

			camera = new PerspectiveCamera( MathUtils.radToDeg( params.yfov ), params.aspectRatio || 1, params.znear || 1, params.zfar || 2e6 );

		} else if ( cameraDef.type === 'orthographic' ) {

			camera = new OrthographicCamera( - params.xmag, params.xmag, params.ymag, - params.ymag, params.znear, params.zfar );

		}

		if ( cameraDef.name ) camera.name = cameraDef.name;

		assignExtrasToUserData( camera, cameraDef );

		return Promise.resolve( camera );

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#skins
	 * @param {number} skinIndex
	 * @return {Promise<Object>}
	 */
	GLTFParser.prototype.loadSkin = function ( skinIndex ) {

		var skinDef = this.json.skins[ skinIndex ];

		var skinEntry = { joints: skinDef.joints };

		if ( skinDef.inverseBindMatrices === undefined ) {

			return Promise.resolve( skinEntry );

		}

		return this.getDependency( 'accessor', skinDef.inverseBindMatrices ).then( function ( accessor ) {

			skinEntry.inverseBindMatrices = accessor;

			return skinEntry;

		} );

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#animations
	 * @param {number} animationIndex
	 * @return {Promise<AnimationClip>}
	 */
	GLTFParser.prototype.loadAnimation = function ( animationIndex ) {

		var json = this.json;

		var animationDef = json.animations[ animationIndex ];

		var pendingNodes = [];
		var pendingInputAccessors = [];
		var pendingOutputAccessors = [];
		var pendingSamplers = [];
		var pendingTargets = [];

		for ( var i = 0, il = animationDef.channels.length; i < il; i ++ ) {

			var channel = animationDef.channels[ i ];
			var sampler = animationDef.samplers[ channel.sampler ];
			var target = channel.target;
			var name = target.node !== undefined ? target.node : target.id; // NOTE: target.id is deprecated.
			var input = animationDef.parameters !== undefined ? animationDef.parameters[ sampler.input ] : sampler.input;
			var output = animationDef.parameters !== undefined ? animationDef.parameters[ sampler.output ] : sampler.output;

			pendingNodes.push( this.getDependency( 'node', name ) );
			pendingInputAccessors.push( this.getDependency( 'accessor', input ) );
			pendingOutputAccessors.push( this.getDependency( 'accessor', output ) );
			pendingSamplers.push( sampler );
			pendingTargets.push( target );

		}

		return Promise.all( [

			Promise.all( pendingNodes ),
			Promise.all( pendingInputAccessors ),
			Promise.all( pendingOutputAccessors ),
			Promise.all( pendingSamplers ),
			Promise.all( pendingTargets )

		] ).then( function ( dependencies ) {

			var nodes = dependencies[ 0 ];
			var inputAccessors = dependencies[ 1 ];
			var outputAccessors = dependencies[ 2 ];
			var samplers = dependencies[ 3 ];
			var targets = dependencies[ 4 ];

			var tracks = [];

			for ( var i = 0, il = nodes.length; i < il; i ++ ) {

				var node = nodes[ i ];
				var inputAccessor = inputAccessors[ i ];
				var outputAccessor = outputAccessors[ i ];
				var sampler = samplers[ i ];
				var target = targets[ i ];

				if ( node === undefined ) continue;

				node.updateMatrix();
				node.matrixAutoUpdate = true;

				var TypedKeyframeTrack;

				switch ( PATH_PROPERTIES[ target.path ] ) {

					case PATH_PROPERTIES.weights:

						TypedKeyframeTrack = NumberKeyframeTrack;
						break;

					case PATH_PROPERTIES.rotation:

						TypedKeyframeTrack = QuaternionKeyframeTrack;
						break;

					case PATH_PROPERTIES.position:
					case PATH_PROPERTIES.scale:
					default:

						TypedKeyframeTrack = VectorKeyframeTrack;
						break;

				}

				var targetName = node.name ? node.name : node.uuid;

				var interpolation = sampler.interpolation !== undefined ? INTERPOLATION[ sampler.interpolation ] : InterpolateLinear;

				var targetNames = [];

				if ( PATH_PROPERTIES[ target.path ] === PATH_PROPERTIES.weights ) {

					// Node may be a Group (glTF mesh with several primitives) or a Mesh.
					node.traverse( function ( object ) {

						if ( object.isMesh === true && object.morphTargetInfluences ) {

							targetNames.push( object.name ? object.name : object.uuid );

						}

					} );

				} else {

					targetNames.push( targetName );

				}

				var outputArray = outputAccessor.array;

				if ( outputAccessor.normalized ) {

					var scale;

					if ( outputArray.constructor === Int8Array ) {

						scale = 1 / 127;

					} else if ( outputArray.constructor === Uint8Array ) {

						scale = 1 / 255;

					} else if ( outputArray.constructor == Int16Array ) {

						scale = 1 / 32767;

					} else if ( outputArray.constructor === Uint16Array ) {

						scale = 1 / 65535;

					} else {

						throw new Error( 'THREE.GLTFLoader: Unsupported output accessor component type.' );

					}

					var scaled = new Float32Array( outputArray.length );

					for ( var j = 0, jl = outputArray.length; j < jl; j ++ ) {

						scaled[ j ] = outputArray[ j ] * scale;

					}

					outputArray = scaled;

				}

				for ( var j = 0, jl = targetNames.length; j < jl; j ++ ) {

					var track = new TypedKeyframeTrack(
						targetNames[ j ] + '.' + PATH_PROPERTIES[ target.path ],
						inputAccessor.array,
						outputArray,
						interpolation
					);

					// Override interpolation with custom factory method.
					if ( sampler.interpolation === 'CUBICSPLINE' ) {

						track.createInterpolant = function InterpolantFactoryMethodGLTFCubicSpline( result ) {

							// A CUBICSPLINE keyframe in glTF has three output values for each input value,
							// representing inTangent, splineVertex, and outTangent. As a result, track.getValueSize()
							// must be divided by three to get the interpolant's sampleSize argument.

							return new GLTFCubicSplineInterpolant( this.times, this.values, this.getValueSize() / 3, result );

						};

						// Mark as CUBICSPLINE. `track.getInterpolation()` doesn't support custom interpolants.
						track.createInterpolant.isInterpolantFactoryMethodGLTFCubicSpline = true;

					}

					tracks.push( track );

				}

			}

			var name = animationDef.name ? animationDef.name : 'animation_' + animationIndex;

			return new AnimationClip( name, undefined, tracks );

		} );

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#nodes-and-hierarchy
	 * @param {number} nodeIndex
	 * @return {Promise<Object3D>}
	 */
	GLTFParser.prototype.loadNode = function ( nodeIndex ) {

		var json = this.json;
		var extensions = this.extensions;
		var parser = this;

		var meshReferences = json.meshReferences;
		var meshUses = json.meshUses;

		var nodeDef = json.nodes[ nodeIndex ];

		return ( function () {

			var pending = [];

			if ( nodeDef.mesh !== undefined ) {

				pending.push( parser.getDependency( 'mesh', nodeDef.mesh ).then( function ( mesh ) {

					var node;

					if ( meshReferences[ nodeDef.mesh ] > 1 ) {

						var instanceNum = meshUses[ nodeDef.mesh ] ++;

						node = mesh.clone();
						node.name += '_instance_' + instanceNum;

					} else {

						node = mesh;

					}

					// if weights are provided on the node, override weights on the mesh.
					if ( nodeDef.weights !== undefined ) {

						node.traverse( function ( o ) {

							if ( ! o.isMesh ) return;

							for ( var i = 0, il = nodeDef.weights.length; i < il; i ++ ) {

								o.morphTargetInfluences[ i ] = nodeDef.weights[ i ];

							}

						} );

					}

					return node;

				} ) );

			}

			if ( nodeDef.camera !== undefined ) {

				pending.push( parser.getDependency( 'camera', nodeDef.camera ) );

			}

			if ( nodeDef.extensions
				&& nodeDef.extensions[ EXTENSIONS.KHR_LIGHTS_PUNCTUAL ]
				&& nodeDef.extensions[ EXTENSIONS.KHR_LIGHTS_PUNCTUAL ].light !== undefined ) {

				pending.push( parser.getDependency( 'light', nodeDef.extensions[ EXTENSIONS.KHR_LIGHTS_PUNCTUAL ].light ) );

			}

			return Promise.all( pending );

		}() ).then( function ( objects ) {

			var node;

			// .isBone isn't in glTF spec. See .markDefs
			if ( nodeDef.isBone === true ) {

				node = new Bone();

			} else if ( objects.length > 1 ) {

				node = new Group();

			} else if ( objects.length === 1 ) {

				node = objects[ 0 ];

			} else {

				node = new Object3D();

			}

			if ( node !== objects[ 0 ] ) {

				for ( var i = 0, il = objects.length; i < il; i ++ ) {

					node.add( objects[ i ] );

				}

			}

			if ( nodeDef.name ) {

				node.userData.name = nodeDef.name;
				node.name = PropertyBinding.sanitizeNodeName( nodeDef.name );

			}

			assignExtrasToUserData( node, nodeDef );

			if ( nodeDef.extensions ) addUnknownExtensionsToUserData( extensions, node, nodeDef );

			if ( nodeDef.matrix !== undefined ) {

				var matrix = new Matrix4();
				matrix.fromArray( nodeDef.matrix );
				node.applyMatrix4( matrix );

			} else {

				if ( nodeDef.translation !== undefined ) {

					node.position.fromArray( nodeDef.translation );

				}

				if ( nodeDef.rotation !== undefined ) {

					node.quaternion.fromArray( nodeDef.rotation );

				}

				if ( nodeDef.scale !== undefined ) {

					node.scale.fromArray( nodeDef.scale );

				}

			}

			return node;

		} );

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#scenes
	 * @param {number} sceneIndex
	 * @return {Promise<Group>}
	 */
	GLTFParser.prototype.loadScene = function () {

		// scene node hierachy builder

		function buildNodeHierachy( nodeId, parentObject, json, parser ) {

			var nodeDef = json.nodes[ nodeId ];

			return parser.getDependency( 'node', nodeId ).then( function ( node ) {

				if ( nodeDef.skin === undefined ) return node;

				// build skeleton here as well

				var skinEntry;

				return parser.getDependency( 'skin', nodeDef.skin ).then( function ( skin ) {

					skinEntry = skin;

					var pendingJoints = [];

					for ( var i = 0, il = skinEntry.joints.length; i < il; i ++ ) {

						pendingJoints.push( parser.getDependency( 'node', skinEntry.joints[ i ] ) );

					}

					return Promise.all( pendingJoints );

				} ).then( function ( jointNodes ) {

					node.traverse( function ( mesh ) {

						if ( ! mesh.isMesh ) return;

						var bones = [];
						var boneInverses = [];

						for ( var j = 0, jl = jointNodes.length; j < jl; j ++ ) {

							var jointNode = jointNodes[ j ];

							if ( jointNode ) {

								bones.push( jointNode );

								var mat = new Matrix4();

								if ( skinEntry.inverseBindMatrices !== undefined ) {

									mat.fromArray( skinEntry.inverseBindMatrices.array, j * 16 );

								}

								boneInverses.push( mat );

							} else {

								console.warn( 'THREE.GLTFLoader: Joint "%s" could not be found.', skinEntry.joints[ j ] );

							}

						}

						mesh.bind( new Skeleton( bones, boneInverses ), mesh.matrixWorld );

					} );

					return node;

				} );

			} ).then( function ( node ) {

				// build node hierachy

				parentObject.add( node );

				var pending = [];

				if ( nodeDef.children ) {

					var children = nodeDef.children;

					for ( var i = 0, il = children.length; i < il; i ++ ) {

						var child = children[ i ];
						pending.push( buildNodeHierachy( child, node, json, parser ) );

					}

				}

				return Promise.all( pending );

			} );

		}

		return function loadScene( sceneIndex ) {

			var json = this.json;
			var extensions = this.extensions;
			var sceneDef = this.json.scenes[ sceneIndex ];
			var parser = this;

			// Loader returns Group, not Scene.
			// See: https://github.com/mrdoob/three.js/issues/18342#issuecomment-578981172
			var scene = new Group();
			if ( sceneDef.name ) scene.name = sceneDef.name;

			assignExtrasToUserData( scene, sceneDef );

			if ( sceneDef.extensions ) addUnknownExtensionsToUserData( extensions, scene, sceneDef );

			var nodeIds = sceneDef.nodes || [];

			var pending = [];

			for ( var i = 0, il = nodeIds.length; i < il; i ++ ) {

				pending.push( buildNodeHierachy( nodeIds[ i ], scene, json, parser ) );

			}

			return Promise.all( pending ).then( function () {

				return scene;

			} );

		};

	}();

	return GLTFLoader;

} )()

GLTFLoader = ( function () {

	function GLTFLoader( manager ) {

		Loader.call( this, manager );

		this.dracoLoader = null;
		this.ddsLoader = null;

	}

	GLTFLoader.prototype = Object.assign( Object.create( Loader.prototype ), {

		constructor: GLTFLoader,

		load: function ( url, onLoad, onProgress, onError ) {

			var scope = this;

			var resourcePath;

			if ( this.resourcePath !== '' ) {

				resourcePath = this.resourcePath;

			} else if ( this.path !== '' ) {

				resourcePath = this.path;

			} else {

				resourcePath = LoaderUtils.extractUrlBase( url );

			}

			// Tells the LoadingManager to track an extra item, which resolves after
			// the model is fully loaded. This means the count of items loaded will
			// be incorrect, but ensures manager.onLoad() does not fire early.
			scope.manager.itemStart( url );

			var _onError = function ( e ) {

				if ( onError ) {

					onError( e );

				} else {

					console.error( e );

				}

				scope.manager.itemError( url );
				scope.manager.itemEnd( url );

			};

			var loader = new FileLoader( scope.manager );

			loader.setPath( this.path );
			loader.setResponseType( 'arraybuffer' );

			if ( scope.crossOrigin === 'use-credentials' ) {

				loader.setWithCredentials( true );

			}

			loader.load( url, function ( data ) {

				try {

					scope.parse( data, resourcePath, function ( gltf ) {

						onLoad( gltf );

						scope.manager.itemEnd( url );

					}, _onError );

				} catch ( e ) {

					_onError( e );

				}

			}, onProgress, _onError );

		},

		setDRACOLoader: function ( dracoLoader ) {

			this.dracoLoader = dracoLoader;
			return this;

		},

		setDDSLoader: function ( ddsLoader ) {

			this.ddsLoader = ddsLoader;
			return this;

		},

		parse: function ( data, path, onLoad, onError ) {

			var content;
			var extensions = {};

			if ( typeof data === 'string' ) {

				content = data;

			} else {

				var magic = LoaderUtils.decodeText( new Uint8Array( data, 0, 4 ) );

				if ( magic === BINARY_EXTENSION_HEADER_MAGIC ) {

					try {

						extensions[ EXTENSIONS.KHR_BINARY_GLTF ] = new GLTFBinaryExtension( data );

					} catch ( error ) {

						if ( onError ) onError( error );
						return;

					}

					content = extensions[ EXTENSIONS.KHR_BINARY_GLTF ].content;

				} else {

					content = LoaderUtils.decodeText( new Uint8Array( data ) );

				}

			}

			var json = JSON.parse( content );

			if ( json.asset === undefined || json.asset.version[ 0 ] < 2 ) {

				if ( onError ) onError( new Error( 'THREE.GLTFLoader: Unsupported asset. glTF versions >=2.0 are supported.' ) );
				return;

			}

			if ( json.extensionsUsed ) {

				for ( var i = 0; i < json.extensionsUsed.length; ++ i ) {

					var extensionName = json.extensionsUsed[ i ];
					var extensionsRequired = json.extensionsRequired || [];

					switch ( extensionName ) {

						case EXTENSIONS.KHR_LIGHTS_PUNCTUAL:
							extensions[ extensionName ] = new GLTFLightsExtension( json );
							break;

						case EXTENSIONS.KHR_MATERIALS_CLEARCOAT:
							extensions[ extensionName ] = new GLTFMaterialsClearcoatExtension();
							break;

						case EXTENSIONS.KHR_MATERIALS_UNLIT:
							extensions[ extensionName ] = new GLTFMaterialsUnlitExtension();
							break;

						case EXTENSIONS.KHR_MATERIALS_PBR_SPECULAR_GLOSSINESS:
							extensions[ extensionName ] = new GLTFMaterialsPbrSpecularGlossinessExtension();
							break;

						case EXTENSIONS.KHR_DRACO_MESH_COMPRESSION:
							extensions[ extensionName ] = new GLTFDracoMeshCompressionExtension( json, this.dracoLoader );
							break;

						case EXTENSIONS.MSFT_TEXTURE_DDS:
							extensions[ extensionName ] = new GLTFTextureDDSExtension( this.ddsLoader );
							break;

						case EXTENSIONS.KHR_TEXTURE_TRANSFORM:
							extensions[ extensionName ] = new GLTFTextureTransformExtension();
							break;

						case EXTENSIONS.KHR_MESH_QUANTIZATION:
							extensions[ extensionName ] = new GLTFMeshQuantizationExtension();
							break;

						default:

							if ( extensionsRequired.indexOf( extensionName ) >= 0 ) {

								console.warn( 'THREE.GLTFLoader: Unknown extension "' + extensionName + '".' );

							}

					}

				}

			}

			var parser = new GLTFParser( json, extensions, {

				path: path || this.resourcePath || '',
				crossOrigin: this.crossOrigin,
				manager: this.manager

			} );

			parser.parse( onLoad, onError );

		}

	} );

	/* GLTFREGISTRY */

	function GLTFRegistry() {

		var objects = {};

		return	{

			get: function ( key ) {

				return objects[ key ];

			},

			add: function ( key, object ) {

				objects[ key ] = object;

			},

			remove: function ( key ) {

				delete objects[ key ];

			},

			removeAll: function () {

				objects = {};

			}

		};

	}

	/*********************************/
	/********** EXTENSIONS ***********/
	/*********************************/

	var EXTENSIONS = {
		KHR_BINARY_GLTF: 'KHR_binary_glTF',
		KHR_DRACO_MESH_COMPRESSION: 'KHR_draco_mesh_compression',
		KHR_LIGHTS_PUNCTUAL: 'KHR_lights_punctual',
		KHR_MATERIALS_CLEARCOAT: 'KHR_materials_clearcoat',
		KHR_MATERIALS_PBR_SPECULAR_GLOSSINESS: 'KHR_materials_pbrSpecularGlossiness',
		KHR_MATERIALS_UNLIT: 'KHR_materials_unlit',
		KHR_TEXTURE_TRANSFORM: 'KHR_texture_transform',
		KHR_MESH_QUANTIZATION: 'KHR_mesh_quantization',
		MSFT_TEXTURE_DDS: 'MSFT_texture_dds'
	};

	/**
	 * DDS Texture Extension
	 *
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Vendor/MSFT_texture_dds
	 *
	 */
	function GLTFTextureDDSExtension( ddsLoader ) {

		if ( ! ddsLoader ) {

			throw new Error( 'THREE.GLTFLoader: Attempting to load .dds texture without importing DDSLoader' );

		}

		this.name = EXTENSIONS.MSFT_TEXTURE_DDS;
		this.ddsLoader = ddsLoader;

	}

	/**
	 * Punctual Lights Extension
	 *
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_lights_punctual
	 */
	function GLTFLightsExtension( json ) {

		this.name = EXTENSIONS.KHR_LIGHTS_PUNCTUAL;

		var extension = ( json.extensions && json.extensions[ EXTENSIONS.KHR_LIGHTS_PUNCTUAL ] ) || {};
		this.lightDefs = extension.lights || [];

	}

	GLTFLightsExtension.prototype.loadLight = function ( lightIndex ) {

		var lightDef = this.lightDefs[ lightIndex ];
		var lightNode;

		var color = new Color( 0xffffff );
		if ( lightDef.color !== undefined ) color.fromArray( lightDef.color );

		var range = lightDef.range !== undefined ? lightDef.range : 0;

		switch ( lightDef.type ) {

			case 'directional':
				lightNode = new DirectionalLight( color );
				lightNode.target.position.set( 0, 0, - 1 );
				lightNode.add( lightNode.target );
				break;

			case 'point':
				lightNode = new PointLight( color );
				lightNode.distance = range;
				break;

			case 'spot':
				lightNode = new SpotLight( color );
				lightNode.distance = range;
				// Handle spotlight properties.
				lightDef.spot = lightDef.spot || {};
				lightDef.spot.innerConeAngle = lightDef.spot.innerConeAngle !== undefined ? lightDef.spot.innerConeAngle : 0;
				lightDef.spot.outerConeAngle = lightDef.spot.outerConeAngle !== undefined ? lightDef.spot.outerConeAngle : Math.PI / 4.0;
				lightNode.angle = lightDef.spot.outerConeAngle;
				lightNode.penumbra = 1.0 - lightDef.spot.innerConeAngle / lightDef.spot.outerConeAngle;
				lightNode.target.position.set( 0, 0, - 1 );
				lightNode.add( lightNode.target );
				break;

			default:
				throw new Error( 'THREE.GLTFLoader: Unexpected light type, "' + lightDef.type + '".' );

		}

		// Some lights (e.g. spot) default to a position other than the origin. Reset the position
		// here, because node-level parsing will only override position if explicitly specified.
		lightNode.position.set( 0, 0, 0 );

		lightNode.decay = 2;

		if ( lightDef.intensity !== undefined ) lightNode.intensity = lightDef.intensity;

		lightNode.name = lightDef.name || ( 'light_' + lightIndex );

		return Promise.resolve( lightNode );

	};

	/**
	 * Unlit Materials Extension
	 *
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_materials_unlit
	 */
	function GLTFMaterialsUnlitExtension() {

		this.name = EXTENSIONS.KHR_MATERIALS_UNLIT;

	}

	GLTFMaterialsUnlitExtension.prototype.getMaterialType = function () {

		return MeshBasicMaterial;

	};

	GLTFMaterialsUnlitExtension.prototype.extendParams = function ( materialParams, materialDef, parser ) {

		var pending = [];

		materialParams.color = new Color( 1.0, 1.0, 1.0 );
		materialParams.opacity = 1.0;

		var metallicRoughness = materialDef.pbrMetallicRoughness;

		if ( metallicRoughness ) {

			if ( Array.isArray( metallicRoughness.baseColorFactor ) ) {

				var array = metallicRoughness.baseColorFactor;

				materialParams.color.fromArray( array );
				materialParams.opacity = array[ 3 ];

			}

			if ( metallicRoughness.baseColorTexture !== undefined ) {

				pending.push( parser.assignTexture( materialParams, 'map', metallicRoughness.baseColorTexture ) );

			}

		}

		return Promise.all( pending );

	};

	/**
	 * Clearcoat Materials Extension
	 *
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_materials_clearcoat
	 */
	function GLTFMaterialsClearcoatExtension() {

		this.name = EXTENSIONS.KHR_MATERIALS_CLEARCOAT;

	}

	GLTFMaterialsClearcoatExtension.prototype.getMaterialType = function () {

		return MeshPhysicalMaterial;

	};

	GLTFMaterialsClearcoatExtension.prototype.extendParams = function ( materialParams, materialDef, parser ) {

		var pending = [];

		var extension = materialDef.extensions[ this.name ];

		if ( extension.clearcoatFactor !== undefined ) {

			materialParams.clearcoat = extension.clearcoatFactor;

		}

		if ( extension.clearcoatTexture !== undefined ) {

			pending.push( parser.assignTexture( materialParams, 'clearcoatMap', extension.clearcoatTexture ) );

		}

		if ( extension.clearcoatRoughnessFactor !== undefined ) {

			materialParams.clearcoatRoughness = extension.clearcoatRoughnessFactor;

		}

		if ( extension.clearcoatRoughnessTexture !== undefined ) {

			pending.push( parser.assignTexture( materialParams, 'clearcoatRoughnessMap', extension.clearcoatRoughnessTexture ) );

		}

		if ( extension.clearcoatNormalTexture !== undefined ) {

			pending.push( parser.assignTexture( materialParams, 'clearcoatNormalMap', extension.clearcoatNormalTexture ) );

			if ( extension.clearcoatNormalTexture.scale !== undefined ) {

				var scale = extension.clearcoatNormalTexture.scale;

				materialParams.clearcoatNormalScale = new Vector2( scale, scale );

			}

		}

		return Promise.all( pending );

	};

	/* BINARY EXTENSION */
	var BINARY_EXTENSION_HEADER_MAGIC = 'glTF';
	var BINARY_EXTENSION_HEADER_LENGTH = 12;
	var BINARY_EXTENSION_CHUNK_TYPES = { JSON: 0x4E4F534A, BIN: 0x004E4942 };

	function GLTFBinaryExtension( data ) {

		this.name = EXTENSIONS.KHR_BINARY_GLTF;
		this.content = null;
		this.body = null;

		var headerView = new DataView( data, 0, BINARY_EXTENSION_HEADER_LENGTH );

		this.header = {
			magic: LoaderUtils.decodeText( new Uint8Array( data.slice( 0, 4 ) ) ),
			version: headerView.getUint32( 4, true ),
			length: headerView.getUint32( 8, true )
		};

		if ( this.header.magic !== BINARY_EXTENSION_HEADER_MAGIC ) {

			throw new Error( 'THREE.GLTFLoader: Unsupported glTF-Binary header.' );

		} else if ( this.header.version < 2.0 ) {

			throw new Error( 'THREE.GLTFLoader: Legacy binary file detected.' );

		}

		var chunkView = new DataView( data, BINARY_EXTENSION_HEADER_LENGTH );
		var chunkIndex = 0;

		while ( chunkIndex < chunkView.byteLength ) {

			var chunkLength = chunkView.getUint32( chunkIndex, true );
			chunkIndex += 4;

			var chunkType = chunkView.getUint32( chunkIndex, true );
			chunkIndex += 4;

			if ( chunkType === BINARY_EXTENSION_CHUNK_TYPES.JSON ) {

				var contentArray = new Uint8Array( data, BINARY_EXTENSION_HEADER_LENGTH + chunkIndex, chunkLength );
				this.content = LoaderUtils.decodeText( contentArray );

			} else if ( chunkType === BINARY_EXTENSION_CHUNK_TYPES.BIN ) {

				var byteOffset = BINARY_EXTENSION_HEADER_LENGTH + chunkIndex;
				this.body = data.slice( byteOffset, byteOffset + chunkLength );

			}

			// Clients must ignore chunks with unknown types.

			chunkIndex += chunkLength;

		}

		if ( this.content === null ) {

			throw new Error( 'THREE.GLTFLoader: JSON content not found.' );

		}

	}

	/**
	 * DRACO Mesh Compression Extension
	 *
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_draco_mesh_compression
	 */
	function GLTFDracoMeshCompressionExtension( json, dracoLoader ) {

		if ( ! dracoLoader ) {

			throw new Error( 'THREE.GLTFLoader: No DRACOLoader instance provided.' );

		}

		this.name = EXTENSIONS.KHR_DRACO_MESH_COMPRESSION;
		this.json = json;
		this.dracoLoader = dracoLoader;
		this.dracoLoader.preload();

	}

	GLTFDracoMeshCompressionExtension.prototype.decodePrimitive = function ( primitive, parser ) {

		var json = this.json;
		var dracoLoader = this.dracoLoader;
		var bufferViewIndex = primitive.extensions[ this.name ].bufferView;
		var gltfAttributeMap = primitive.extensions[ this.name ].attributes;
		var threeAttributeMap = {};
		var attributeNormalizedMap = {};
		var attributeTypeMap = {};

		for ( var attributeName in gltfAttributeMap ) {

			var threeAttributeName = ATTRIBUTES[ attributeName ] || attributeName.toLowerCase();

			threeAttributeMap[ threeAttributeName ] = gltfAttributeMap[ attributeName ];

		}

		for ( attributeName in primitive.attributes ) {

			var threeAttributeName = ATTRIBUTES[ attributeName ] || attributeName.toLowerCase();

			if ( gltfAttributeMap[ attributeName ] !== undefined ) {

				var accessorDef = json.accessors[ primitive.attributes[ attributeName ] ];
				var componentType = WEBGL_COMPONENT_TYPES[ accessorDef.componentType ];

				attributeTypeMap[ threeAttributeName ] = componentType;
				attributeNormalizedMap[ threeAttributeName ] = accessorDef.normalized === true;

			}

		}

		return parser.getDependency( 'bufferView', bufferViewIndex ).then( function ( bufferView ) {

			return new Promise( function ( resolve ) {

				dracoLoader.decodeDracoFile( bufferView, function ( geometry ) {

					for ( var attributeName in geometry.attributes ) {

						var attribute = geometry.attributes[ attributeName ];
						var normalized = attributeNormalizedMap[ attributeName ];

						if ( normalized !== undefined ) attribute.normalized = normalized;

					}

					resolve( geometry );

				}, threeAttributeMap, attributeTypeMap );

			} );

		} );

	};

	/**
	 * Texture Transform Extension
	 *
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_texture_transform
	 */
	function GLTFTextureTransformExtension() {

		this.name = EXTENSIONS.KHR_TEXTURE_TRANSFORM;

	}

	GLTFTextureTransformExtension.prototype.extendTexture = function ( texture, transform ) {

		texture = texture.clone();

		if ( transform.offset !== undefined ) {

			texture.offset.fromArray( transform.offset );

		}

		if ( transform.rotation !== undefined ) {

			texture.rotation = transform.rotation;

		}

		if ( transform.scale !== undefined ) {

			texture.repeat.fromArray( transform.scale );

		}

		if ( transform.texCoord !== undefined ) {

			console.warn( 'THREE.GLTFLoader: Custom UV sets in "' + this.name + '" extension not yet supported.' );

		}

		texture.needsUpdate = true;

		return texture;

	};

	/**
	 * Specular-Glossiness Extension
	 *
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_materials_pbrSpecularGlossiness
	 */

	/**
	 * A sub class of StandardMaterial with some of the functionality
	 * changed via the `onBeforeCompile` callback
	 * @pailhead
	 */

	function GLTFMeshStandardSGMaterial( params ) {

		MeshStandardMaterial.call( this );

		this.isGLTFSpecularGlossinessMaterial = true;

		//various chunks that need replacing
		var specularMapParsFragmentChunk = [
			'#ifdef USE_SPECULARMAP',
			'	uniform sampler2D specularMap;',
			'#endif'
		].join( '\n' );

		var glossinessMapParsFragmentChunk = [
			'#ifdef USE_GLOSSINESSMAP',
			'	uniform sampler2D glossinessMap;',
			'#endif'
		].join( '\n' );

		var specularMapFragmentChunk = [
			'vec3 specularFactor = specular;',
			'#ifdef USE_SPECULARMAP',
			'	vec4 texelSpecular = texture2D( specularMap, vUv );',
			'	texelSpecular = sRGBToLinear( texelSpecular );',
			'	// reads channel RGB, compatible with a glTF Specular-Glossiness (RGBA) texture',
			'	specularFactor *= texelSpecular.rgb;',
			'#endif'
		].join( '\n' );

		var glossinessMapFragmentChunk = [
			'float glossinessFactor = glossiness;',
			'#ifdef USE_GLOSSINESSMAP',
			'	vec4 texelGlossiness = texture2D( glossinessMap, vUv );',
			'	// reads channel A, compatible with a glTF Specular-Glossiness (RGBA) texture',
			'	glossinessFactor *= texelGlossiness.a;',
			'#endif'
		].join( '\n' );

		var lightPhysicalFragmentChunk = [
			'PhysicalMaterial material;',
			'material.diffuseColor = diffuseColor.rgb;',
			'vec3 dxy = max( abs( dFdx( geometryNormal ) ), abs( dFdy( geometryNormal ) ) );',
			'float geometryRoughness = max( max( dxy.x, dxy.y ), dxy.z );',
			'material.specularRoughness = max( 1.0 - glossinessFactor, 0.0525 );// 0.0525 corresponds to the base mip of a 256 cubemap.',
			'material.specularRoughness += geometryRoughness;',
			'material.specularRoughness = min( material.specularRoughness, 1.0 );',
			'material.specularColor = specularFactor.rgb;',
		].join( '\n' );

		var uniforms = {
			specular: { value: new Color().setHex( 0xffffff ) },
			glossiness: { value: 1 },
			specularMap: { value: null },
			glossinessMap: { value: null }
		};

		this._extraUniforms = uniforms;

		// please see #14031 or #13198 for an alternate approach
		this.onBeforeCompile = function ( shader ) {

			for ( var uniformName in uniforms ) {

				shader.uniforms[ uniformName ] = uniforms[ uniformName ];

			}

			shader.fragmentShader = shader.fragmentShader.replace( 'uniform float roughness;', 'uniform vec3 specular;' );
			shader.fragmentShader = shader.fragmentShader.replace( 'uniform float metalness;', 'uniform float glossiness;' );
			shader.fragmentShader = shader.fragmentShader.replace( '#include <roughnessmap_pars_fragment>', specularMapParsFragmentChunk );
			shader.fragmentShader = shader.fragmentShader.replace( '#include <metalnessmap_pars_fragment>', glossinessMapParsFragmentChunk );
			shader.fragmentShader = shader.fragmentShader.replace( '#include <roughnessmap_fragment>', specularMapFragmentChunk );
			shader.fragmentShader = shader.fragmentShader.replace( '#include <metalnessmap_fragment>', glossinessMapFragmentChunk );
			shader.fragmentShader = shader.fragmentShader.replace( '#include <lights_physical_fragment>', lightPhysicalFragmentChunk );

		};

		/*eslint-disable*/
		Object.defineProperties(
			this,
			{
				specular: {
					get: function () { return uniforms.specular.value; },
					set: function ( v ) { uniforms.specular.value = v; }
				},
				specularMap: {
					get: function () { return uniforms.specularMap.value; },
					set: function ( v ) { uniforms.specularMap.value = v; }
				},
				glossiness: {
					get: function () { return uniforms.glossiness.value; },
					set: function ( v ) { uniforms.glossiness.value = v; }
				},
				glossinessMap: {
					get: function () { return uniforms.glossinessMap.value; },
					set: function ( v ) {

						uniforms.glossinessMap.value = v;
						//how about something like this - @pailhead
						if ( v ) {

							this.defines.USE_GLOSSINESSMAP = '';
							// set USE_ROUGHNESSMAP to enable vUv
							this.defines.USE_ROUGHNESSMAP = '';

						} else {

							delete this.defines.USE_ROUGHNESSMAP;
							delete this.defines.USE_GLOSSINESSMAP;

						}

					}
				}
			}
		);

		/*eslint-enable*/
		delete this.metalness;
		delete this.roughness;
		delete this.metalnessMap;
		delete this.roughnessMap;

		this.setValues( params );

	}

	GLTFMeshStandardSGMaterial.prototype = Object.create( MeshStandardMaterial.prototype );
	GLTFMeshStandardSGMaterial.prototype.constructor = GLTFMeshStandardSGMaterial;

	GLTFMeshStandardSGMaterial.prototype.copy = function ( source ) {

		MeshStandardMaterial.prototype.copy.call( this, source );
		this.specularMap = source.specularMap;
		this.specular.copy( source.specular );
		this.glossinessMap = source.glossinessMap;
		this.glossiness = source.glossiness;
		delete this.metalness;
		delete this.roughness;
		delete this.metalnessMap;
		delete this.roughnessMap;
		return this;

	};

	function GLTFMaterialsPbrSpecularGlossinessExtension() {

		return {

			name: EXTENSIONS.KHR_MATERIALS_PBR_SPECULAR_GLOSSINESS,

			specularGlossinessParams: [
				'color',
				'map',
				'lightMap',
				'lightMapIntensity',
				'aoMap',
				'aoMapIntensity',
				'emissive',
				'emissiveIntensity',
				'emissiveMap',
				'bumpMap',
				'bumpScale',
				'normalMap',
				'normalMapType',
				'displacementMap',
				'displacementScale',
				'displacementBias',
				'specularMap',
				'specular',
				'glossinessMap',
				'glossiness',
				'alphaMap',
				'envMap',
				'envMapIntensity',
				'refractionRatio',
			],

			getMaterialType: function () {

				return GLTFMeshStandardSGMaterial;

			},

			extendParams: function ( materialParams, materialDef, parser ) {

				var pbrSpecularGlossiness = materialDef.extensions[ this.name ];

				materialParams.color = new Color( 1.0, 1.0, 1.0 );
				materialParams.opacity = 1.0;

				var pending = [];

				if ( Array.isArray( pbrSpecularGlossiness.diffuseFactor ) ) {

					var array = pbrSpecularGlossiness.diffuseFactor;

					materialParams.color.fromArray( array );
					materialParams.opacity = array[ 3 ];

				}

				if ( pbrSpecularGlossiness.diffuseTexture !== undefined ) {

					pending.push( parser.assignTexture( materialParams, 'map', pbrSpecularGlossiness.diffuseTexture ) );

				}

				materialParams.emissive = new Color( 0.0, 0.0, 0.0 );
				materialParams.glossiness = pbrSpecularGlossiness.glossinessFactor !== undefined ? pbrSpecularGlossiness.glossinessFactor : 1.0;
				materialParams.specular = new Color( 1.0, 1.0, 1.0 );

				if ( Array.isArray( pbrSpecularGlossiness.specularFactor ) ) {

					materialParams.specular.fromArray( pbrSpecularGlossiness.specularFactor );

				}

				if ( pbrSpecularGlossiness.specularGlossinessTexture !== undefined ) {

					var specGlossMapDef = pbrSpecularGlossiness.specularGlossinessTexture;
					pending.push( parser.assignTexture( materialParams, 'glossinessMap', specGlossMapDef ) );
					pending.push( parser.assignTexture( materialParams, 'specularMap', specGlossMapDef ) );

				}

				return Promise.all( pending );

			},

			createMaterial: function ( materialParams ) {

				var material = new GLTFMeshStandardSGMaterial( materialParams );
				material.fog = true;

				material.color = materialParams.color;

				material.map = materialParams.map === undefined ? null : materialParams.map;

				material.lightMap = null;
				material.lightMapIntensity = 1.0;

				material.aoMap = materialParams.aoMap === undefined ? null : materialParams.aoMap;
				material.aoMapIntensity = 1.0;

				material.emissive = materialParams.emissive;
				material.emissiveIntensity = 1.0;
				material.emissiveMap = materialParams.emissiveMap === undefined ? null : materialParams.emissiveMap;

				material.bumpMap = materialParams.bumpMap === undefined ? null : materialParams.bumpMap;
				material.bumpScale = 1;

				material.normalMap = materialParams.normalMap === undefined ? null : materialParams.normalMap;
				material.normalMapType = TangentSpaceNormalMap;

				if ( materialParams.normalScale ) material.normalScale = materialParams.normalScale;

				material.displacementMap = null;
				material.displacementScale = 1;
				material.displacementBias = 0;

				material.specularMap = materialParams.specularMap === undefined ? null : materialParams.specularMap;
				material.specular = materialParams.specular;

				material.glossinessMap = materialParams.glossinessMap === undefined ? null : materialParams.glossinessMap;
				material.glossiness = materialParams.glossiness;

				material.alphaMap = null;

				material.envMap = materialParams.envMap === undefined ? null : materialParams.envMap;
				material.envMapIntensity = 1.0;

				material.refractionRatio = 0.98;

				return material;

			},

		};

	}

	/**
	 * Mesh Quantization Extension
	 *
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_mesh_quantization
	 */
	function GLTFMeshQuantizationExtension() {

		this.name = EXTENSIONS.KHR_MESH_QUANTIZATION;

	}

	/*********************************/
	/********** INTERPOLATION ********/
	/*********************************/

	// Spline Interpolation
	// Specification: https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#appendix-c-spline-interpolation
	function GLTFCubicSplineInterpolant( parameterPositions, sampleValues, sampleSize, resultBuffer ) {

		Interpolant.call( this, parameterPositions, sampleValues, sampleSize, resultBuffer );

	}

	GLTFCubicSplineInterpolant.prototype = Object.create( Interpolant.prototype );
	GLTFCubicSplineInterpolant.prototype.constructor = GLTFCubicSplineInterpolant;

	GLTFCubicSplineInterpolant.prototype.copySampleValue_ = function ( index ) {

		// Copies a sample value to the result buffer. See description of glTF
		// CUBICSPLINE values layout in interpolate_() function below.

		var result = this.resultBuffer,
			values = this.sampleValues,
			valueSize = this.valueSize,
			offset = index * valueSize * 3 + valueSize;

		for ( var i = 0; i !== valueSize; i ++ ) {

			result[ i ] = values[ offset + i ];

		}

		return result;

	};

	GLTFCubicSplineInterpolant.prototype.beforeStart_ = GLTFCubicSplineInterpolant.prototype.copySampleValue_;

	GLTFCubicSplineInterpolant.prototype.afterEnd_ = GLTFCubicSplineInterpolant.prototype.copySampleValue_;

	GLTFCubicSplineInterpolant.prototype.interpolate_ = function ( i1, t0, t, t1 ) {

		var result = this.resultBuffer;
		var values = this.sampleValues;
		var stride = this.valueSize;

		var stride2 = stride * 2;
		var stride3 = stride * 3;

		var td = t1 - t0;

		var p = ( t - t0 ) / td;
		var pp = p * p;
		var ppp = pp * p;

		var offset1 = i1 * stride3;
		var offset0 = offset1 - stride3;

		var s2 = - 2 * ppp + 3 * pp;
		var s3 = ppp - pp;
		var s0 = 1 - s2;
		var s1 = s3 - pp + p;

		// Layout of keyframe output values for CUBICSPLINE animations:
		//   [ inTangent_1, splineVertex_1, outTangent_1, inTangent_2, splineVertex_2, ... ]
		for ( var i = 0; i !== stride; i ++ ) {

			var p0 = values[ offset0 + i + stride ]; // splineVertex_k
			var m0 = values[ offset0 + i + stride2 ] * td; // outTangent_k * (t_k+1 - t_k)
			var p1 = values[ offset1 + i + stride ]; // splineVertex_k+1
			var m1 = values[ offset1 + i ] * td; // inTangent_k+1 * (t_k+1 - t_k)

			result[ i ] = s0 * p0 + s1 * m0 + s2 * p1 + s3 * m1;

		}

		return result;

	};

	/*********************************/
	/********** INTERNALS ************/
	/*********************************/

	/* CONSTANTS */

	var WEBGL_CONSTANTS = {
		FLOAT: 5126,
		//FLOAT_MAT2: 35674,
		FLOAT_MAT3: 35675,
		FLOAT_MAT4: 35676,
		FLOAT_VEC2: 35664,
		FLOAT_VEC3: 35665,
		FLOAT_VEC4: 35666,
		LINEAR: 9729,
		REPEAT: 10497,
		SAMPLER_2D: 35678,
		POINTS: 0,
		LINES: 1,
		LINE_LOOP: 2,
		LINE_STRIP: 3,
		TRIANGLES: 4,
		TRIANGLE_STRIP: 5,
		TRIANGLE_FAN: 6,
		UNSIGNED_BYTE: 5121,
		UNSIGNED_SHORT: 5123
	};

	var WEBGL_COMPONENT_TYPES = {
		5120: Int8Array,
		5121: Uint8Array,
		5122: Int16Array,
		5123: Uint16Array,
		5125: Uint32Array,
		5126: Float32Array
	};

	var WEBGL_FILTERS = {
		9728: NearestFilter,
		9729: LinearFilter,
		9984: NearestMipmapNearestFilter,
		9985: LinearMipmapNearestFilter,
		9986: NearestMipmapLinearFilter,
		9987: LinearMipmapLinearFilter
	};

	var WEBGL_WRAPPINGS = {
		33071: ClampToEdgeWrapping,
		33648: MirroredRepeatWrapping,
		10497: RepeatWrapping
	};

	var WEBGL_TYPE_SIZES = {
		'SCALAR': 1,
		'VEC2': 2,
		'VEC3': 3,
		'VEC4': 4,
		'MAT2': 4,
		'MAT3': 9,
		'MAT4': 16
	};

	var ATTRIBUTES = {
		POSITION: 'position',
		NORMAL: 'normal',
		TANGENT: 'tangent',
		TEXCOORD_0: 'uv',
		TEXCOORD_1: 'uv2',
		COLOR_0: 'color',
		WEIGHTS_0: 'skinWeight',
		JOINTS_0: 'skinIndex',
	};

	var PATH_PROPERTIES = {
		scale: 'scale',
		translation: 'position',
		rotation: 'quaternion',
		weights: 'morphTargetInfluences'
	};

	var INTERPOLATION = {
		CUBICSPLINE: undefined, // We use a custom interpolant (GLTFCubicSplineInterpolation) for CUBICSPLINE tracks. Each
		                        // keyframe track will be initialized with a default interpolation type, then modified.
		LINEAR: InterpolateLinear,
		STEP: InterpolateDiscrete
	};

	var ALPHA_MODES = {
		OPAQUE: 'OPAQUE',
		MASK: 'MASK',
		BLEND: 'BLEND'
	};

	var MIME_TYPE_FORMATS = {
		'image/png': RGBAFormat,
		'image/jpeg': RGBFormat
	};

	/* UTILITY FUNCTIONS */

	function resolveURL( url, path ) {

		// Invalid URL
		if ( typeof url !== 'string' || url === '' ) return '';

		// Host Relative URL
		if ( /^https?:\/\//i.test( path ) && /^\//.test( url ) ) {

			path = path.replace( /(^https?:\/\/[^\/]+).*/i, '$1' );

		}

		// Absolute URL http://,https://,//
		if ( /^(https?:)?\/\//i.test( url ) ) return url;

		// Data URI
		if ( /^data:.*,.*$/i.test( url ) ) return url;

		// Blob URL
		if ( /^blob:.*$/i.test( url ) ) return url;

		// Relative URL
		return path + url;

	}

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#default-material
	 */
	function createDefaultMaterial( cache ) {

		if ( cache[ 'DefaultMaterial' ] === undefined ) {

			cache[ 'DefaultMaterial' ] = new MeshStandardMaterial( {
				color: 0xFFFFFF,
				emissive: 0x000000,
				metalness: 1,
				roughness: 1,
				transparent: false,
				depthTest: true,
				side: FrontSide
			} );

		}

		return cache[ 'DefaultMaterial' ];

	}

	function addUnknownExtensionsToUserData( knownExtensions, object, objectDef ) {

		// Add unknown glTF extensions to an object's userData.

		for ( var name in objectDef.extensions ) {

			if ( knownExtensions[ name ] === undefined ) {

				object.userData.gltfExtensions = object.userData.gltfExtensions || {};
				object.userData.gltfExtensions[ name ] = objectDef.extensions[ name ];

			}

		}

	}

	/**
	 * @param {Object3D|Material|BufferGeometry} object
	 * @param {GLTF.definition} gltfDef
	 */
	function assignExtrasToUserData( object, gltfDef ) {

		if ( gltfDef.extras !== undefined ) {

			if ( typeof gltfDef.extras === 'object' ) {

				Object.assign( object.userData, gltfDef.extras );

			} else {

				console.warn( 'THREE.GLTFLoader: Ignoring primitive type .extras, ' + gltfDef.extras );

			}

		}

	}

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#morph-targets
	 *
	 * @param {BufferGeometry} geometry
	 * @param {Array<GLTF.Target>} targets
	 * @param {GLTFParser} parser
	 * @return {Promise<BufferGeometry>}
	 */
	function addMorphTargets( geometry, targets, parser ) {

		var hasMorphPosition = false;
		var hasMorphNormal = false;

		for ( var i = 0, il = targets.length; i < il; i ++ ) {

			var target = targets[ i ];

			if ( target.POSITION !== undefined ) hasMorphPosition = true;
			if ( target.NORMAL !== undefined ) hasMorphNormal = true;

			if ( hasMorphPosition && hasMorphNormal ) break;

		}

		if ( ! hasMorphPosition && ! hasMorphNormal ) return Promise.resolve( geometry );

		var pendingPositionAccessors = [];
		var pendingNormalAccessors = [];

		for ( var i = 0, il = targets.length; i < il; i ++ ) {

			var target = targets[ i ];

			if ( hasMorphPosition ) {

				var pendingAccessor = target.POSITION !== undefined
					? parser.getDependency( 'accessor', target.POSITION )
					: geometry.attributes.position;

				pendingPositionAccessors.push( pendingAccessor );

			}

			if ( hasMorphNormal ) {

				var pendingAccessor = target.NORMAL !== undefined
					? parser.getDependency( 'accessor', target.NORMAL )
					: geometry.attributes.normal;

				pendingNormalAccessors.push( pendingAccessor );

			}

		}

		return Promise.all( [
			Promise.all( pendingPositionAccessors ),
			Promise.all( pendingNormalAccessors )
		] ).then( function ( accessors ) {

			var morphPositions = accessors[ 0 ];
			var morphNormals = accessors[ 1 ];

			if ( hasMorphPosition ) geometry.morphAttributes.position = morphPositions;
			if ( hasMorphNormal ) geometry.morphAttributes.normal = morphNormals;
			geometry.morphTargetsRelative = true;

			return geometry;

		} );

	}

	/**
	 * @param {Mesh} mesh
	 * @param {GLTF.Mesh} meshDef
	 */
	function updateMorphTargets( mesh, meshDef ) {

		mesh.updateMorphTargets();

		if ( meshDef.weights !== undefined ) {

			for ( var i = 0, il = meshDef.weights.length; i < il; i ++ ) {

				mesh.morphTargetInfluences[ i ] = meshDef.weights[ i ];

			}

		}

		// .extras has user-defined data, so check that .extras.targetNames is an array.
		if ( meshDef.extras && Array.isArray( meshDef.extras.targetNames ) ) {

			var targetNames = meshDef.extras.targetNames;

			if ( mesh.morphTargetInfluences.length === targetNames.length ) {

				mesh.morphTargetDictionary = {};

				for ( var i = 0, il = targetNames.length; i < il; i ++ ) {

					mesh.morphTargetDictionary[ targetNames[ i ] ] = i;

				}

			} else {

				console.warn( 'THREE.GLTFLoader: Invalid extras.targetNames length. Ignoring names.' );

			}

		}

	}

	function createPrimitiveKey( primitiveDef ) {

		var dracoExtension = primitiveDef.extensions && primitiveDef.extensions[ EXTENSIONS.KHR_DRACO_MESH_COMPRESSION ];
		var geometryKey;

		if ( dracoExtension ) {

			geometryKey = 'draco:' + dracoExtension.bufferView
				+ ':' + dracoExtension.indices
				+ ':' + createAttributesKey( dracoExtension.attributes );

		} else {

			geometryKey = primitiveDef.indices + ':' + createAttributesKey( primitiveDef.attributes ) + ':' + primitiveDef.mode;

		}

		return geometryKey;

	}

	function createAttributesKey( attributes ) {

		var attributesKey = '';

		var keys = Object.keys( attributes ).sort();

		for ( var i = 0, il = keys.length; i < il; i ++ ) {

			attributesKey += keys[ i ] + ':' + attributes[ keys[ i ] ] + ';';

		}

		return attributesKey;

	}

	/* GLTF PARSER */

	function GLTFParser( json, extensions, options ) {

		this.json = json || {};
		this.extensions = extensions || {};
		this.options = options || {};

		// loader object cache
		this.cache = new GLTFRegistry();

		// BufferGeometry caching
		this.primitiveCache = {};

		this.textureLoader = new TextureLoader( this.options.manager );
		this.textureLoader.setCrossOrigin( this.options.crossOrigin );

		this.fileLoader = new FileLoader( this.options.manager );
		this.fileLoader.setResponseType( 'arraybuffer' );

		if ( this.options.crossOrigin === 'use-credentials' ) {

			this.fileLoader.setWithCredentials( true );

		}

	}

	GLTFParser.prototype.parse = function ( onLoad, onError ) {

		var parser = this;
		var json = this.json;
		var extensions = this.extensions;

		// Clear the loader cache
		this.cache.removeAll();

		// Mark the special nodes/meshes in json for efficient parse
		this.markDefs();

		Promise.all( [

			this.getDependencies( 'scene' ),
			this.getDependencies( 'animation' ),
			this.getDependencies( 'camera' ),

		] ).then( function ( dependencies ) {

			var result = {
				scene: dependencies[ 0 ][ json.scene || 0 ],
				scenes: dependencies[ 0 ],
				animations: dependencies[ 1 ],
				cameras: dependencies[ 2 ],
				asset: json.asset,
				parser: parser,
				userData: {}
			};

			addUnknownExtensionsToUserData( extensions, result, json );

			assignExtrasToUserData( result, json );

			onLoad( result );

		} ).catch( onError );

	};

	/**
	 * Marks the special nodes/meshes in json for efficient parse.
	 */
	GLTFParser.prototype.markDefs = function () {

		var nodeDefs = this.json.nodes || [];
		var skinDefs = this.json.skins || [];
		var meshDefs = this.json.meshes || [];

		var meshReferences = {};
		var meshUses = {};

		// Nothing in the node definition indicates whether it is a Bone or an
		// Object3D. Use the skins' joint references to mark bones.
		for ( var skinIndex = 0, skinLength = skinDefs.length; skinIndex < skinLength; skinIndex ++ ) {

			var joints = skinDefs[ skinIndex ].joints;

			for ( var i = 0, il = joints.length; i < il; i ++ ) {

				nodeDefs[ joints[ i ] ].isBone = true;

			}

		}

		// Meshes can (and should) be reused by multiple nodes in a glTF asset. To
		// avoid having more than one Mesh with the same name, count
		// references and rename instances below.
		//
		// Example: CesiumMilkTruck sample model reuses "Wheel" meshes.
		for ( var nodeIndex = 0, nodeLength = nodeDefs.length; nodeIndex < nodeLength; nodeIndex ++ ) {

			var nodeDef = nodeDefs[ nodeIndex ];

			if ( nodeDef.mesh !== undefined ) {

				if ( meshReferences[ nodeDef.mesh ] === undefined ) {

					meshReferences[ nodeDef.mesh ] = meshUses[ nodeDef.mesh ] = 0;

				}

				meshReferences[ nodeDef.mesh ] ++;

				// Nothing in the mesh definition indicates whether it is
				// a SkinnedMesh or Mesh. Use the node's mesh reference
				// to mark SkinnedMesh if node has skin.
				if ( nodeDef.skin !== undefined ) {

					meshDefs[ nodeDef.mesh ].isSkinnedMesh = true;

				}

			}

		}

		this.json.meshReferences = meshReferences;
		this.json.meshUses = meshUses;

	};

	/**
	 * Requests the specified dependency asynchronously, with caching.
	 * @param {string} type
	 * @param {number} index
	 * @return {Promise<Object3D|Material|THREE.Texture|AnimationClip|ArrayBuffer|Object>}
	 */
	GLTFParser.prototype.getDependency = function ( type, index ) {

		var cacheKey = type + ':' + index;
		var dependency = this.cache.get( cacheKey );

		if ( ! dependency ) {

			switch ( type ) {

				case 'scene':
					dependency = this.loadScene( index );
					break;

				case 'node':
					dependency = this.loadNode( index );
					break;

				case 'mesh':
					dependency = this.loadMesh( index );
					break;

				case 'accessor':
					dependency = this.loadAccessor( index );
					break;

				case 'bufferView':
					dependency = this.loadBufferView( index );
					break;

				case 'buffer':
					dependency = this.loadBuffer( index );
					break;

				case 'material':
					dependency = this.loadMaterial( index );
					break;

				case 'texture':
					dependency = this.loadTexture( index );
					break;

				case 'skin':
					dependency = this.loadSkin( index );
					break;

				case 'animation':
					dependency = this.loadAnimation( index );
					break;

				case 'camera':
					dependency = this.loadCamera( index );
					break;

				case 'light':
					dependency = this.extensions[ EXTENSIONS.KHR_LIGHTS_PUNCTUAL ].loadLight( index );
					break;

				default:
					throw new Error( 'Unknown type: ' + type );

			}

			this.cache.add( cacheKey, dependency );

		}

		return dependency;

	};

	/**
	 * Requests all dependencies of the specified type asynchronously, with caching.
	 * @param {string} type
	 * @return {Promise<Array<Object>>}
	 */
	GLTFParser.prototype.getDependencies = function ( type ) {

		var dependencies = this.cache.get( type );

		if ( ! dependencies ) {

			var parser = this;
			var defs = this.json[ type + ( type === 'mesh' ? 'es' : 's' ) ] || [];

			dependencies = Promise.all( defs.map( function ( def, index ) {

				return parser.getDependency( type, index );

			} ) );

			this.cache.add( type, dependencies );

		}

		return dependencies;

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#buffers-and-buffer-views
	 * @param {number} bufferIndex
	 * @return {Promise<ArrayBuffer>}
	 */
	GLTFParser.prototype.loadBuffer = function ( bufferIndex ) {

		var bufferDef = this.json.buffers[ bufferIndex ];
		var loader = this.fileLoader;

		if ( bufferDef.type && bufferDef.type !== 'arraybuffer' ) {

			throw new Error( 'THREE.GLTFLoader: ' + bufferDef.type + ' buffer type is not supported.' );

		}

		// If present, GLB container is required to be the first buffer.
		if ( bufferDef.uri === undefined && bufferIndex === 0 ) {

			return Promise.resolve( this.extensions[ EXTENSIONS.KHR_BINARY_GLTF ].body );

		}

		var options = this.options;

		return new Promise( function ( resolve, reject ) {

			loader.load( resolveURL( bufferDef.uri, options.path ), resolve, undefined, function () {

				reject( new Error( 'THREE.GLTFLoader: Failed to load buffer "' + bufferDef.uri + '".' ) );

			} );

		} );

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#buffers-and-buffer-views
	 * @param {number} bufferViewIndex
	 * @return {Promise<ArrayBuffer>}
	 */
	GLTFParser.prototype.loadBufferView = function ( bufferViewIndex ) {

		var bufferViewDef = this.json.bufferViews[ bufferViewIndex ];

		return this.getDependency( 'buffer', bufferViewDef.buffer ).then( function ( buffer ) {

			var byteLength = bufferViewDef.byteLength || 0;
			var byteOffset = bufferViewDef.byteOffset || 0;
			return buffer.slice( byteOffset, byteOffset + byteLength );

		} );

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#accessors
	 * @param {number} accessorIndex
	 * @return {Promise<BufferAttribute|InterleavedBufferAttribute>}
	 */
	GLTFParser.prototype.loadAccessor = function ( accessorIndex ) {

		var parser = this;
		var json = this.json;

		var accessorDef = this.json.accessors[ accessorIndex ];

		if ( accessorDef.bufferView === undefined && accessorDef.sparse === undefined ) {

			// Ignore empty accessors, which may be used to declare runtime
			// information about attributes coming from another source (e.g. Draco
			// compression extension).
			return Promise.resolve( null );

		}

		var pendingBufferViews = [];

		if ( accessorDef.bufferView !== undefined ) {

			pendingBufferViews.push( this.getDependency( 'bufferView', accessorDef.bufferView ) );

		} else {

			pendingBufferViews.push( null );

		}

		if ( accessorDef.sparse !== undefined ) {

			pendingBufferViews.push( this.getDependency( 'bufferView', accessorDef.sparse.indices.bufferView ) );
			pendingBufferViews.push( this.getDependency( 'bufferView', accessorDef.sparse.values.bufferView ) );

		}

		return Promise.all( pendingBufferViews ).then( function ( bufferViews ) {

			var bufferView = bufferViews[ 0 ];

			var itemSize = WEBGL_TYPE_SIZES[ accessorDef.type ];
			var TypedArray = WEBGL_COMPONENT_TYPES[ accessorDef.componentType ];

			// For VEC3: itemSize is 3, elementBytes is 4, itemBytes is 12.
			var elementBytes = TypedArray.BYTES_PER_ELEMENT;
			var itemBytes = elementBytes * itemSize;
			var byteOffset = accessorDef.byteOffset || 0;
			var byteStride = accessorDef.bufferView !== undefined ? json.bufferViews[ accessorDef.bufferView ].byteStride : undefined;
			var normalized = accessorDef.normalized === true;
			var array, bufferAttribute;

			// The buffer is not interleaved if the stride is the item size in bytes.
			if ( byteStride && byteStride !== itemBytes ) {

				// Each "slice" of the buffer, as defined by 'count' elements of 'byteStride' bytes, gets its own InterleavedBuffer
				// This makes sure that IBA.count reflects accessor.count properly
				var ibSlice = Math.floor( byteOffset / byteStride );
				var ibCacheKey = 'InterleavedBuffer:' + accessorDef.bufferView + ':' + accessorDef.componentType + ':' + ibSlice + ':' + accessorDef.count;
				var ib = parser.cache.get( ibCacheKey );

				if ( ! ib ) {

					array = new TypedArray( bufferView, ibSlice * byteStride, accessorDef.count * byteStride / elementBytes );

					// Integer parameters to IB/IBA are in array elements, not bytes.
					ib = new InterleavedBuffer( array, byteStride / elementBytes );

					parser.cache.add( ibCacheKey, ib );

				}

				bufferAttribute = new InterleavedBufferAttribute( ib, itemSize, ( byteOffset % byteStride ) / elementBytes, normalized );

			} else {

				if ( bufferView === null ) {

					array = new TypedArray( accessorDef.count * itemSize );

				} else {

					array = new TypedArray( bufferView, byteOffset, accessorDef.count * itemSize );

				}

				bufferAttribute = new BufferAttribute( array, itemSize, normalized );

			}

			// https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#sparse-accessors
			if ( accessorDef.sparse !== undefined ) {

				var itemSizeIndices = WEBGL_TYPE_SIZES.SCALAR;
				var TypedArrayIndices = WEBGL_COMPONENT_TYPES[ accessorDef.sparse.indices.componentType ];

				var byteOffsetIndices = accessorDef.sparse.indices.byteOffset || 0;
				var byteOffsetValues = accessorDef.sparse.values.byteOffset || 0;

				var sparseIndices = new TypedArrayIndices( bufferViews[ 1 ], byteOffsetIndices, accessorDef.sparse.count * itemSizeIndices );
				var sparseValues = new TypedArray( bufferViews[ 2 ], byteOffsetValues, accessorDef.sparse.count * itemSize );

				if ( bufferView !== null ) {

					// Avoid modifying the original ArrayBuffer, if the bufferView wasn't initialized with zeroes.
					bufferAttribute = new BufferAttribute( bufferAttribute.array.slice(), bufferAttribute.itemSize, bufferAttribute.normalized );

				}

				for ( var i = 0, il = sparseIndices.length; i < il; i ++ ) {

					var index = sparseIndices[ i ];

					bufferAttribute.setX( index, sparseValues[ i * itemSize ] );
					if ( itemSize >= 2 ) bufferAttribute.setY( index, sparseValues[ i * itemSize + 1 ] );
					if ( itemSize >= 3 ) bufferAttribute.setZ( index, sparseValues[ i * itemSize + 2 ] );
					if ( itemSize >= 4 ) bufferAttribute.setW( index, sparseValues[ i * itemSize + 3 ] );
					if ( itemSize >= 5 ) throw new Error( 'THREE.GLTFLoader: Unsupported itemSize in sparse BufferAttribute.' );

				}

			}

			return bufferAttribute;

		} );

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#textures
	 * @param {number} textureIndex
	 * @return {Promise<THREE.Texture>}
	 */
	GLTFParser.prototype.loadTexture = function ( textureIndex ) {

		var parser = this;
		var json = this.json;
		var options = this.options;
		var textureLoader = this.textureLoader;

		var URL = self.URL || self.webkitURL;

		var textureDef = json.textures[ textureIndex ];

		var textureExtensions = textureDef.extensions || {};

		var source;

		if ( textureExtensions[ EXTENSIONS.MSFT_TEXTURE_DDS ] ) {

			source = json.images[ textureExtensions[ EXTENSIONS.MSFT_TEXTURE_DDS ].source ];

		} else {

			source = json.images[ textureDef.source ];

		}

		var sourceURI = source.uri;
		var isObjectURL = false;

		if ( source.bufferView !== undefined ) {

			// Load binary image data from bufferView, if provided.

			sourceURI = parser.getDependency( 'bufferView', source.bufferView ).then( function ( bufferView ) {

				isObjectURL = true;
				var blob = new Blob( [ bufferView ], { type: source.mimeType } );
				sourceURI = URL.createObjectURL( blob );
				return sourceURI;

			} );

		}

		return Promise.resolve( sourceURI ).then( function ( sourceURI ) {

			// Load Texture resource.

			var loader = options.manager.getHandler( sourceURI );

			if ( ! loader ) {

				loader = textureExtensions[ EXTENSIONS.MSFT_TEXTURE_DDS ]
					? parser.extensions[ EXTENSIONS.MSFT_TEXTURE_DDS ].ddsLoader
					: textureLoader;

			}

			return new Promise( function ( resolve, reject ) {

				loader.load( resolveURL( sourceURI, options.path ), resolve, undefined, reject );

			} );

		} ).then( function ( texture ) {

			// Clean up resources and configure Texture.

			if ( isObjectURL === true ) {

				URL.revokeObjectURL( sourceURI );

			}

			texture.flipY = false;

			if ( textureDef.name ) texture.name = textureDef.name;

			// Ignore unknown mime types, like DDS files.
			if ( source.mimeType in MIME_TYPE_FORMATS ) {

				texture.format = MIME_TYPE_FORMATS[ source.mimeType ];

			}

			var samplers = json.samplers || {};
			var sampler = samplers[ textureDef.sampler ] || {};

			texture.magFilter = WEBGL_FILTERS[ sampler.magFilter ] || LinearFilter;
			texture.minFilter = WEBGL_FILTERS[ sampler.minFilter ] || LinearMipmapLinearFilter;
			texture.wrapS = WEBGL_WRAPPINGS[ sampler.wrapS ] || RepeatWrapping;
			texture.wrapT = WEBGL_WRAPPINGS[ sampler.wrapT ] || RepeatWrapping;

			return texture;

		} );

	};

	/**
	 * Asynchronously assigns a texture to the given material parameters.
	 * @param {Object} materialParams
	 * @param {string} mapName
	 * @param {Object} mapDef
	 * @return {Promise}
	 */
	GLTFParser.prototype.assignTexture = function ( materialParams, mapName, mapDef ) {

		var parser = this;

		return this.getDependency( 'texture', mapDef.index ).then( function ( texture ) {

			if ( ! texture.isCompressedTexture ) {

				switch ( mapName ) {

					case 'aoMap':
					case 'emissiveMap':
					case 'metalnessMap':
					case 'normalMap':
					case 'roughnessMap':
						texture.format = RGBFormat;
						break;

				}

			}

			// Materials sample aoMap from UV set 1 and other maps from UV set 0 - this can't be configured
			// However, we will copy UV set 0 to UV set 1 on demand for aoMap
			if ( mapDef.texCoord !== undefined && mapDef.texCoord != 0 && ! ( mapName === 'aoMap' && mapDef.texCoord == 1 ) ) {

				console.warn( 'THREE.GLTFLoader: Custom UV set ' + mapDef.texCoord + ' for texture ' + mapName + ' not yet supported.' );

			}

			if ( parser.extensions[ EXTENSIONS.KHR_TEXTURE_TRANSFORM ] ) {

				var transform = mapDef.extensions !== undefined ? mapDef.extensions[ EXTENSIONS.KHR_TEXTURE_TRANSFORM ] : undefined;

				if ( transform ) {

					texture = parser.extensions[ EXTENSIONS.KHR_TEXTURE_TRANSFORM ].extendTexture( texture, transform );

				}

			}

			materialParams[ mapName ] = texture;

		} );

	};

	/**
	 * Assigns final material to a Mesh, Line, or Points instance. The instance
	 * already has a material (generated from the glTF material options alone)
	 * but reuse of the same glTF material may require multiple threejs materials
	 * to accomodate different primitive types, defines, etc. New materials will
	 * be created if necessary, and reused from a cache.
	 * @param  {Object3D} mesh Mesh, Line, or Points instance.
	 */
	GLTFParser.prototype.assignFinalMaterial = function ( mesh ) {

		var geometry = mesh.geometry;
		var material = mesh.material;

		var useVertexTangents = geometry.attributes.tangent !== undefined;
		var useVertexColors = geometry.attributes.color !== undefined;
		var useFlatShading = geometry.attributes.normal === undefined;
		var useSkinning = mesh.isSkinnedMesh === true;
		var useMorphTargets = Object.keys( geometry.morphAttributes ).length > 0;
		var useMorphNormals = useMorphTargets && geometry.morphAttributes.normal !== undefined;

		if ( mesh.isPoints ) {

			var cacheKey = 'PointsMaterial:' + material.uuid;

			var pointsMaterial = this.cache.get( cacheKey );

			if ( ! pointsMaterial ) {

				pointsMaterial = new PointsMaterial();
				Material.prototype.copy.call( pointsMaterial, material );
				pointsMaterial.color.copy( material.color );
				pointsMaterial.map = material.map;
				pointsMaterial.sizeAttenuation = false; // glTF spec says points should be 1px

				this.cache.add( cacheKey, pointsMaterial );

			}

			material = pointsMaterial;

		} else if ( mesh.isLine ) {

			var cacheKey = 'LineBasicMaterial:' + material.uuid;

			var lineMaterial = this.cache.get( cacheKey );

			if ( ! lineMaterial ) {

				lineMaterial = new LineBasicMaterial();
				Material.prototype.copy.call( lineMaterial, material );
				lineMaterial.color.copy( material.color );

				this.cache.add( cacheKey, lineMaterial );

			}

			material = lineMaterial;

		}

		// Clone the material if it will be modified
		if ( useVertexTangents || useVertexColors || useFlatShading || useSkinning || useMorphTargets ) {

			var cacheKey = 'ClonedMaterial:' + material.uuid + ':';

			if ( material.isGLTFSpecularGlossinessMaterial ) cacheKey += 'specular-glossiness:';
			if ( useSkinning ) cacheKey += 'skinning:';
			if ( useVertexTangents ) cacheKey += 'vertex-tangents:';
			if ( useVertexColors ) cacheKey += 'vertex-colors:';
			if ( useFlatShading ) cacheKey += 'flat-shading:';
			if ( useMorphTargets ) cacheKey += 'morph-targets:';
			if ( useMorphNormals ) cacheKey += 'morph-normals:';

			var cachedMaterial = this.cache.get( cacheKey );

			if ( ! cachedMaterial ) {

				cachedMaterial = material.clone();

				if ( useSkinning ) cachedMaterial.skinning = true;
				if ( useVertexTangents ) cachedMaterial.vertexTangents = true;
				if ( useVertexColors ) cachedMaterial.vertexColors = true;
				if ( useFlatShading ) cachedMaterial.flatShading = true;
				if ( useMorphTargets ) cachedMaterial.morphTargets = true;
				if ( useMorphNormals ) cachedMaterial.morphNormals = true;

				this.cache.add( cacheKey, cachedMaterial );

			}

			material = cachedMaterial;

		}

		// workarounds for mesh and geometry

		if ( material.aoMap && geometry.attributes.uv2 === undefined && geometry.attributes.uv !== undefined ) {

			geometry.setAttribute( 'uv2', new BufferAttribute( geometry.attributes.uv.array, 2 ) );

		}

		// https://github.com/mrdoob/three.js/issues/11438#issuecomment-507003995
		if ( material.normalScale && ! useVertexTangents ) {

			material.normalScale.y = - material.normalScale.y;

		}

		if ( material.clearcoatNormalScale && ! useVertexTangents ) {

			material.clearcoatNormalScale.y = - material.clearcoatNormalScale.y;

		}

		mesh.material = material;

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#materials
	 * @param {number} materialIndex
	 * @return {Promise<Material>}
	 */
	GLTFParser.prototype.loadMaterial = function ( materialIndex ) {

		var parser = this;
		var json = this.json;
		var extensions = this.extensions;
		var materialDef = json.materials[ materialIndex ];

		var materialType;
		var materialParams = {};
		var materialExtensions = materialDef.extensions || {};

		var pending = [];

		if ( materialExtensions[ EXTENSIONS.KHR_MATERIALS_PBR_SPECULAR_GLOSSINESS ] ) {

			var sgExtension = extensions[ EXTENSIONS.KHR_MATERIALS_PBR_SPECULAR_GLOSSINESS ];
			materialType = sgExtension.getMaterialType();
			pending.push( sgExtension.extendParams( materialParams, materialDef, parser ) );

		} else if ( materialExtensions[ EXTENSIONS.KHR_MATERIALS_UNLIT ] ) {

			var kmuExtension = extensions[ EXTENSIONS.KHR_MATERIALS_UNLIT ];
			materialType = kmuExtension.getMaterialType();
			pending.push( kmuExtension.extendParams( materialParams, materialDef, parser ) );

		} else {

			// Specification:
			// https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#metallic-roughness-material

			materialType = MeshStandardMaterial;

			var metallicRoughness = materialDef.pbrMetallicRoughness || {};

			materialParams.color = new Color( 1.0, 1.0, 1.0 );
			materialParams.opacity = 1.0;

			if ( Array.isArray( metallicRoughness.baseColorFactor ) ) {

				var array = metallicRoughness.baseColorFactor;

				materialParams.color.fromArray( array );
				materialParams.opacity = array[ 3 ];

			}

			if ( metallicRoughness.baseColorTexture !== undefined ) {

				pending.push( parser.assignTexture( materialParams, 'map', metallicRoughness.baseColorTexture ) );

			}

			materialParams.metalness = metallicRoughness.metallicFactor !== undefined ? metallicRoughness.metallicFactor : 1.0;
			materialParams.roughness = metallicRoughness.roughnessFactor !== undefined ? metallicRoughness.roughnessFactor : 1.0;

			if ( metallicRoughness.metallicRoughnessTexture !== undefined ) {

				pending.push( parser.assignTexture( materialParams, 'metalnessMap', metallicRoughness.metallicRoughnessTexture ) );
				pending.push( parser.assignTexture( materialParams, 'roughnessMap', metallicRoughness.metallicRoughnessTexture ) );

			}

		}

		if ( materialDef.doubleSided === true ) {

			materialParams.side = DoubleSide;

		}

		var alphaMode = materialDef.alphaMode || ALPHA_MODES.OPAQUE;

		if ( alphaMode === ALPHA_MODES.BLEND ) {

			materialParams.transparent = true;

			// See: https://github.com/mrdoob/three.js/issues/17706
			materialParams.depthWrite = false;

		} else {

			materialParams.transparent = false;

			if ( alphaMode === ALPHA_MODES.MASK ) {

				materialParams.alphaTest = materialDef.alphaCutoff !== undefined ? materialDef.alphaCutoff : 0.5;

			}

		}

		if ( materialDef.normalTexture !== undefined && materialType !== MeshBasicMaterial ) {

			pending.push( parser.assignTexture( materialParams, 'normalMap', materialDef.normalTexture ) );

			materialParams.normalScale = new Vector2( 1, 1 );

			if ( materialDef.normalTexture.scale !== undefined ) {

				materialParams.normalScale.set( materialDef.normalTexture.scale, materialDef.normalTexture.scale );

			}

		}

		if ( materialDef.occlusionTexture !== undefined && materialType !== MeshBasicMaterial ) {

			pending.push( parser.assignTexture( materialParams, 'aoMap', materialDef.occlusionTexture ) );

			if ( materialDef.occlusionTexture.strength !== undefined ) {

				materialParams.aoMapIntensity = materialDef.occlusionTexture.strength;

			}

		}

		if ( materialDef.emissiveFactor !== undefined && materialType !== MeshBasicMaterial ) {

			materialParams.emissive = new Color().fromArray( materialDef.emissiveFactor );

		}

		if ( materialDef.emissiveTexture !== undefined && materialType !== MeshBasicMaterial ) {

			pending.push( parser.assignTexture( materialParams, 'emissiveMap', materialDef.emissiveTexture ) );

		}

		if ( materialExtensions[ EXTENSIONS.KHR_MATERIALS_CLEARCOAT ] ) {

			var clearcoatExtension = extensions[ EXTENSIONS.KHR_MATERIALS_CLEARCOAT ];
			materialType = clearcoatExtension.getMaterialType();
			pending.push( clearcoatExtension.extendParams( materialParams, { extensions: materialExtensions }, parser ) );

		}

		return Promise.all( pending ).then( function () {

			var material;

			if ( materialType === GLTFMeshStandardSGMaterial ) {

				material = extensions[ EXTENSIONS.KHR_MATERIALS_PBR_SPECULAR_GLOSSINESS ].createMaterial( materialParams );

			} else {

				material = new materialType( materialParams );

			}

			if ( materialDef.name ) material.name = materialDef.name;

			// baseColorTexture, emissiveTexture, and specularGlossinessTexture use sRGB encoding.
			if ( material.map ) material.map.encoding = sRGBEncoding;
			if ( material.emissiveMap ) material.emissiveMap.encoding = sRGBEncoding;

			assignExtrasToUserData( material, materialDef );

			if ( materialDef.extensions ) addUnknownExtensionsToUserData( extensions, material, materialDef );

			return material;

		} );

	};

	/**
	 * @param {BufferGeometry} geometry
	 * @param {GLTF.Primitive} primitiveDef
	 * @param {GLTFParser} parser
	 */
	function computeBounds( geometry, primitiveDef, parser ) {

		var attributes = primitiveDef.attributes;

		var box = new Box3();

		if ( attributes.POSITION !== undefined ) {

			var accessor = parser.json.accessors[ attributes.POSITION ];

			var min = accessor.min;
			var max = accessor.max;

			// glTF requires 'min' and 'max', but VRM (which extends glTF) currently ignores that requirement.

			if ( min !== undefined && max !== undefined ) {

				box.set(
					new Vector3( min[ 0 ], min[ 1 ], min[ 2 ] ),
					new Vector3( max[ 0 ], max[ 1 ], max[ 2 ] ) );

			} else {

				console.warn( 'THREE.GLTFLoader: Missing min/max properties for accessor POSITION.' );

				return;

			}

		} else {

			return;

		}

		var targets = primitiveDef.targets;

		if ( targets !== undefined ) {

			var maxDisplacement = new Vector3();
			var vector = new Vector3();

			for ( var i = 0, il = targets.length; i < il; i ++ ) {

				var target = targets[ i ];

				if ( target.POSITION !== undefined ) {

					var accessor = parser.json.accessors[ target.POSITION ];
					var min = accessor.min;
					var max = accessor.max;

					// glTF requires 'min' and 'max', but VRM (which extends glTF) currently ignores that requirement.

					if ( min !== undefined && max !== undefined ) {

						// we need to get max of absolute components because target weight is [-1,1]
						vector.setX( Math.max( Math.abs( min[ 0 ] ), Math.abs( max[ 0 ] ) ) );
						vector.setY( Math.max( Math.abs( min[ 1 ] ), Math.abs( max[ 1 ] ) ) );
						vector.setZ( Math.max( Math.abs( min[ 2 ] ), Math.abs( max[ 2 ] ) ) );

						// Note: this assumes that the sum of all weights is at most 1. This isn't quite correct - it's more conservative
						// to assume that each target can have a max weight of 1. However, for some use cases - notably, when morph targets
						// are used to implement key-frame animations and as such only two are active at a time - this results in very large
						// boxes. So for now we make a box that's sometimes a touch too small but is hopefully mostly of reasonable size.
						maxDisplacement.max( vector );

					} else {

						console.warn( 'THREE.GLTFLoader: Missing min/max properties for accessor POSITION.' );

					}

				}

			}

			// As per comment above this box isn't conservative, but has a reasonable size for a very large number of morph targets.
			box.expandByVector( maxDisplacement );

		}

		geometry.boundingBox = box;

		var sphere = new Sphere();

		box.getCenter( sphere.center );
		sphere.radius = box.min.distanceTo( box.max ) / 2;

		geometry.boundingSphere = sphere;

	}

	/**
	 * @param {BufferGeometry} geometry
	 * @param {GLTF.Primitive} primitiveDef
	 * @param {GLTFParser} parser
	 * @return {Promise<BufferGeometry>}
	 */
	function addPrimitiveAttributes( geometry, primitiveDef, parser ) {

		var attributes = primitiveDef.attributes;

		var pending = [];

		function assignAttributeAccessor( accessorIndex, attributeName ) {

			return parser.getDependency( 'accessor', accessorIndex )
				.then( function ( accessor ) {

					geometry.setAttribute( attributeName, accessor );

				} );

		}

		for ( var gltfAttributeName in attributes ) {

			var threeAttributeName = ATTRIBUTES[ gltfAttributeName ] || gltfAttributeName.toLowerCase();

			// Skip attributes already provided by e.g. Draco extension.
			if ( threeAttributeName in geometry.attributes ) continue;

			pending.push( assignAttributeAccessor( attributes[ gltfAttributeName ], threeAttributeName ) );

		}

		if ( primitiveDef.indices !== undefined && ! geometry.index ) {

			var accessor = parser.getDependency( 'accessor', primitiveDef.indices ).then( function ( accessor ) {

				geometry.setIndex( accessor );

			} );

			pending.push( accessor );

		}

		assignExtrasToUserData( geometry, primitiveDef );

		computeBounds( geometry, primitiveDef, parser );

		return Promise.all( pending ).then( function () {

			return primitiveDef.targets !== undefined
				? addMorphTargets( geometry, primitiveDef.targets, parser )
				: geometry;

		} );

	}

	/**
	 * @param {BufferGeometry} geometry
	 * @param {Number} drawMode
	 * @return {BufferGeometry}
	 */
	function toTrianglesDrawMode( geometry, drawMode ) {

		var index = geometry.getIndex();

		// generate index if not present

		if ( index === null ) {

			var indices = [];

			var position = geometry.getAttribute( 'position' );

			if ( position !== undefined ) {

				for ( var i = 0; i < position.count; i ++ ) {

					indices.push( i );

				}

				geometry.setIndex( indices );
				index = geometry.getIndex();

			} else {

				console.error( 'THREE.GLTFLoader.toTrianglesDrawMode(): Undefined position attribute. Processing not possible.' );
				return geometry;

			}

		}

		//

		var numberOfTriangles = index.count - 2;
		var newIndices = [];

		if ( drawMode === TriangleFanDrawMode ) {

			// gl.TRIANGLE_FAN

			for ( var i = 1; i <= numberOfTriangles; i ++ ) {

				newIndices.push( index.getX( 0 ) );
				newIndices.push( index.getX( i ) );
				newIndices.push( index.getX( i + 1 ) );

			}

		} else {

			// gl.TRIANGLE_STRIP

			for ( var i = 0; i < numberOfTriangles; i ++ ) {

				if ( i % 2 === 0 ) {

					newIndices.push( index.getX( i ) );
					newIndices.push( index.getX( i + 1 ) );
					newIndices.push( index.getX( i + 2 ) );


				} else {

					newIndices.push( index.getX( i + 2 ) );
					newIndices.push( index.getX( i + 1 ) );
					newIndices.push( index.getX( i ) );

				}

			}

		}

		if ( ( newIndices.length / 3 ) !== numberOfTriangles ) {

			console.error( 'THREE.GLTFLoader.toTrianglesDrawMode(): Unable to generate correct amount of triangles.' );

		}

		// build final geometry

		var newGeometry = geometry.clone();
		newGeometry.setIndex( newIndices );

		return newGeometry;

	}

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#geometry
	 *
	 * Creates BufferGeometries from primitives.
	 *
	 * @param {Array<GLTF.Primitive>} primitives
	 * @return {Promise<Array<BufferGeometry>>}
	 */
	GLTFParser.prototype.loadGeometries = function ( primitives ) {

		var parser = this;
		var extensions = this.extensions;
		var cache = this.primitiveCache;

		function createDracoPrimitive( primitive ) {

			return extensions[ EXTENSIONS.KHR_DRACO_MESH_COMPRESSION ]
				.decodePrimitive( primitive, parser )
				.then( function ( geometry ) {

					return addPrimitiveAttributes( geometry, primitive, parser );

				} );

		}

		var pending = [];

		for ( var i = 0, il = primitives.length; i < il; i ++ ) {

			var primitive = primitives[ i ];
			var cacheKey = createPrimitiveKey( primitive );

			// See if we've already created this geometry
			var cached = cache[ cacheKey ];

			if ( cached ) {

				// Use the cached geometry if it exists
				pending.push( cached.promise );

			} else {

				var geometryPromise;

				if ( primitive.extensions && primitive.extensions[ EXTENSIONS.KHR_DRACO_MESH_COMPRESSION ] ) {

					// Use DRACO geometry if available
					geometryPromise = createDracoPrimitive( primitive );

				} else {

					// Otherwise create a new geometry
					geometryPromise = addPrimitiveAttributes( new BufferGeometry(), primitive, parser );

				}

				// Cache this geometry
				cache[ cacheKey ] = { primitive: primitive, promise: geometryPromise };

				pending.push( geometryPromise );

			}

		}

		return Promise.all( pending );

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#meshes
	 * @param {number} meshIndex
	 * @return {Promise<Group|Mesh|SkinnedMesh>}
	 */
	GLTFParser.prototype.loadMesh = function ( meshIndex ) {

		var parser = this;
		var json = this.json;

		var meshDef = json.meshes[ meshIndex ];
		var primitives = meshDef.primitives;

		var pending = [];

		for ( var i = 0, il = primitives.length; i < il; i ++ ) {

			var material = primitives[ i ].material === undefined
				? createDefaultMaterial( this.cache )
				: this.getDependency( 'material', primitives[ i ].material );

			pending.push( material );

		}

		pending.push( parser.loadGeometries( primitives ) );

		return Promise.all( pending ).then( function ( results ) {

			var materials = results.slice( 0, results.length - 1 );
			var geometries = results[ results.length - 1 ];

			var meshes = [];

			for ( var i = 0, il = geometries.length; i < il; i ++ ) {

				var geometry = geometries[ i ];
				var primitive = primitives[ i ];

				// 1. create Mesh

				var mesh;

				var material = materials[ i ];

				if ( primitive.mode === WEBGL_CONSTANTS.TRIANGLES ||
					primitive.mode === WEBGL_CONSTANTS.TRIANGLE_STRIP ||
					primitive.mode === WEBGL_CONSTANTS.TRIANGLE_FAN ||
					primitive.mode === undefined ) {

					// .isSkinnedMesh isn't in glTF spec. See .markDefs()
					mesh = meshDef.isSkinnedMesh === true
						? new SkinnedMesh( geometry, material )
						: new Mesh( geometry, material );

					if ( mesh.isSkinnedMesh === true && ! mesh.geometry.attributes.skinWeight.normalized ) {

						// we normalize floating point skin weight array to fix malformed assets (see #15319)
						// it's important to skip this for non-float32 data since normalizeSkinWeights assumes non-normalized inputs
						mesh.normalizeSkinWeights();

					}

					if ( primitive.mode === WEBGL_CONSTANTS.TRIANGLE_STRIP ) {

						mesh.geometry = toTrianglesDrawMode( mesh.geometry, TriangleStripDrawMode );

					} else if ( primitive.mode === WEBGL_CONSTANTS.TRIANGLE_FAN ) {

						mesh.geometry = toTrianglesDrawMode( mesh.geometry, TriangleFanDrawMode );

					}

				} else if ( primitive.mode === WEBGL_CONSTANTS.LINES ) {

					mesh = new LineSegments( geometry, material );

				} else if ( primitive.mode === WEBGL_CONSTANTS.LINE_STRIP ) {

					mesh = new Line( geometry, material );

				} else if ( primitive.mode === WEBGL_CONSTANTS.LINE_LOOP ) {

					mesh = new LineLoop( geometry, material );

				} else if ( primitive.mode === WEBGL_CONSTANTS.POINTS ) {

					mesh = new Points( geometry, material );

				} else {

					throw new Error( 'THREE.GLTFLoader: Primitive mode unsupported: ' + primitive.mode );

				}

				if ( Object.keys( mesh.geometry.morphAttributes ).length > 0 ) {

					updateMorphTargets( mesh, meshDef );

				}

				mesh.name = meshDef.name || ( 'mesh_' + meshIndex );

				if ( geometries.length > 1 ) mesh.name += '_' + i;

				assignExtrasToUserData( mesh, meshDef );

				parser.assignFinalMaterial( mesh );

				meshes.push( mesh );

			}

			if ( meshes.length === 1 ) {

				return meshes[ 0 ];

			}

			var group = new Group();

			for ( var i = 0, il = meshes.length; i < il; i ++ ) {

				group.add( meshes[ i ] );

			}

			return group;

		} );

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#cameras
	 * @param {number} cameraIndex
	 * @return {Promise<THREE.Camera>}
	 */
	GLTFParser.prototype.loadCamera = function ( cameraIndex ) {

		var camera;
		var cameraDef = this.json.cameras[ cameraIndex ];
		var params = cameraDef[ cameraDef.type ];

		if ( ! params ) {

			console.warn( 'THREE.GLTFLoader: Missing camera parameters.' );
			return;

		}

		if ( cameraDef.type === 'perspective' ) {

			camera = new PerspectiveCamera( MathUtils.radToDeg( params.yfov ), params.aspectRatio || 1, params.znear || 1, params.zfar || 2e6 );

		} else if ( cameraDef.type === 'orthographic' ) {

			camera = new OrthographicCamera( params.xmag / - 2, params.xmag / 2, params.ymag / 2, params.ymag / - 2, params.znear, params.zfar );

		}

		if ( cameraDef.name ) camera.name = cameraDef.name;

		assignExtrasToUserData( camera, cameraDef );

		return Promise.resolve( camera );

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#skins
	 * @param {number} skinIndex
	 * @return {Promise<Object>}
	 */
	GLTFParser.prototype.loadSkin = function ( skinIndex ) {

		var skinDef = this.json.skins[ skinIndex ];

		var skinEntry = { joints: skinDef.joints };

		if ( skinDef.inverseBindMatrices === undefined ) {

			return Promise.resolve( skinEntry );

		}

		return this.getDependency( 'accessor', skinDef.inverseBindMatrices ).then( function ( accessor ) {

			skinEntry.inverseBindMatrices = accessor;

			return skinEntry;

		} );

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#animations
	 * @param {number} animationIndex
	 * @return {Promise<AnimationClip>}
	 */
	GLTFParser.prototype.loadAnimation = function ( animationIndex ) {

		var json = this.json;

		var animationDef = json.animations[ animationIndex ];

		var pendingNodes = [];
		var pendingInputAccessors = [];
		var pendingOutputAccessors = [];
		var pendingSamplers = [];
		var pendingTargets = [];

		for ( var i = 0, il = animationDef.channels.length; i < il; i ++ ) {

			var channel = animationDef.channels[ i ];
			var sampler = animationDef.samplers[ channel.sampler ];
			var target = channel.target;
			var name = target.node !== undefined ? target.node : target.id; // NOTE: target.id is deprecated.
			var input = animationDef.parameters !== undefined ? animationDef.parameters[ sampler.input ] : sampler.input;
			var output = animationDef.parameters !== undefined ? animationDef.parameters[ sampler.output ] : sampler.output;

			pendingNodes.push( this.getDependency( 'node', name ) );
			pendingInputAccessors.push( this.getDependency( 'accessor', input ) );
			pendingOutputAccessors.push( this.getDependency( 'accessor', output ) );
			pendingSamplers.push( sampler );
			pendingTargets.push( target );

		}

		return Promise.all( [

			Promise.all( pendingNodes ),
			Promise.all( pendingInputAccessors ),
			Promise.all( pendingOutputAccessors ),
			Promise.all( pendingSamplers ),
			Promise.all( pendingTargets )

		] ).then( function ( dependencies ) {

			var nodes = dependencies[ 0 ];
			var inputAccessors = dependencies[ 1 ];
			var outputAccessors = dependencies[ 2 ];
			var samplers = dependencies[ 3 ];
			var targets = dependencies[ 4 ];

			var tracks = [];

			for ( var i = 0, il = nodes.length; i < il; i ++ ) {

				var node = nodes[ i ];
				var inputAccessor = inputAccessors[ i ];
				var outputAccessor = outputAccessors[ i ];
				var sampler = samplers[ i ];
				var target = targets[ i ];

				if ( node === undefined ) continue;

				node.updateMatrix();
				node.matrixAutoUpdate = true;

				var TypedKeyframeTrack;

				switch ( PATH_PROPERTIES[ target.path ] ) {

					case PATH_PROPERTIES.weights:

						TypedKeyframeTrack = NumberKeyframeTrack;
						break;

					case PATH_PROPERTIES.rotation:

						TypedKeyframeTrack = QuaternionKeyframeTrack;
						break;

					case PATH_PROPERTIES.position:
					case PATH_PROPERTIES.scale:
					default:

						TypedKeyframeTrack = VectorKeyframeTrack;
						break;

				}

				var targetName = node.name ? node.name : node.uuid;

				var interpolation = sampler.interpolation !== undefined ? INTERPOLATION[ sampler.interpolation ] : InterpolateLinear;

				var targetNames = [];

				if ( PATH_PROPERTIES[ target.path ] === PATH_PROPERTIES.weights ) {

					// Node may be a Group (glTF mesh with several primitives) or a Mesh.
					node.traverse( function ( object ) {

						if ( object.isMesh === true && object.morphTargetInfluences ) {

							targetNames.push( object.name ? object.name : object.uuid );

						}

					} );

				} else {

					targetNames.push( targetName );

				}

				var outputArray = outputAccessor.array;

				if ( outputAccessor.normalized ) {

					var scale;

					if ( outputArray.constructor === Int8Array ) {

						scale = 1 / 127;

					} else if ( outputArray.constructor === Uint8Array ) {

						scale = 1 / 255;

					} else if ( outputArray.constructor == Int16Array ) {

						scale = 1 / 32767;

					} else if ( outputArray.constructor === Uint16Array ) {

						scale = 1 / 65535;

					} else {

						throw new Error( 'THREE.GLTFLoader: Unsupported output accessor component type.' );

					}

					var scaled = new Float32Array( outputArray.length );

					for ( var j = 0, jl = outputArray.length; j < jl; j ++ ) {

						scaled[ j ] = outputArray[ j ] * scale;

					}

					outputArray = scaled;

				}

				for ( var j = 0, jl = targetNames.length; j < jl; j ++ ) {

					var track = new TypedKeyframeTrack(
						targetNames[ j ] + '.' + PATH_PROPERTIES[ target.path ],
						inputAccessor.array,
						outputArray,
						interpolation
					);

					// Override interpolation with custom factory method.
					if ( sampler.interpolation === 'CUBICSPLINE' ) {

						track.createInterpolant = function InterpolantFactoryMethodGLTFCubicSpline( result ) {

							// A CUBICSPLINE keyframe in glTF has three output values for each input value,
							// representing inTangent, splineVertex, and outTangent. As a result, track.getValueSize()
							// must be divided by three to get the interpolant's sampleSize argument.

							return new GLTFCubicSplineInterpolant( this.times, this.values, this.getValueSize() / 3, result );

						};

						// Mark as CUBICSPLINE. `track.getInterpolation()` doesn't support custom interpolants.
						track.createInterpolant.isInterpolantFactoryMethodGLTFCubicSpline = true;

					}

					tracks.push( track );

				}

			}

			var name = animationDef.name ? animationDef.name : 'animation_' + animationIndex;

			return new AnimationClip( name, undefined, tracks );

		} );

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#nodes-and-hierarchy
	 * @param {number} nodeIndex
	 * @return {Promise<Object3D>}
	 */
	GLTFParser.prototype.loadNode = function ( nodeIndex ) {

		var json = this.json;
		var extensions = this.extensions;
		var parser = this;

		var meshReferences = json.meshReferences;
		var meshUses = json.meshUses;

		var nodeDef = json.nodes[ nodeIndex ];

		return ( function () {

			var pending = [];

			if ( nodeDef.mesh !== undefined ) {

				pending.push( parser.getDependency( 'mesh', nodeDef.mesh ).then( function ( mesh ) {

					var node;

					if ( meshReferences[ nodeDef.mesh ] > 1 ) {

						var instanceNum = meshUses[ nodeDef.mesh ] ++;

						node = mesh.clone();
						node.name += '_instance_' + instanceNum;

					} else {

						node = mesh;

					}

					// if weights are provided on the node, override weights on the mesh.
					if ( nodeDef.weights !== undefined ) {

						node.traverse( function ( o ) {

							if ( ! o.isMesh ) return;

							for ( var i = 0, il = nodeDef.weights.length; i < il; i ++ ) {

								o.morphTargetInfluences[ i ] = nodeDef.weights[ i ];

							}

						} );

					}

					return node;

				} ) );

			}

			if ( nodeDef.camera !== undefined ) {

				pending.push( parser.getDependency( 'camera', nodeDef.camera ) );

			}

			if ( nodeDef.extensions
				&& nodeDef.extensions[ EXTENSIONS.KHR_LIGHTS_PUNCTUAL ]
				&& nodeDef.extensions[ EXTENSIONS.KHR_LIGHTS_PUNCTUAL ].light !== undefined ) {

				pending.push( parser.getDependency( 'light', nodeDef.extensions[ EXTENSIONS.KHR_LIGHTS_PUNCTUAL ].light ) );

			}

			return Promise.all( pending );

		}() ).then( function ( objects ) {

			var node;

			// .isBone isn't in glTF spec. See .markDefs
			if ( nodeDef.isBone === true ) {

				node = new Bone();

			} else if ( objects.length > 1 ) {

				node = new Group();

			} else if ( objects.length === 1 ) {

				node = objects[ 0 ];

			} else {

				node = new Object3D();

			}

			if ( node !== objects[ 0 ] ) {

				for ( var i = 0, il = objects.length; i < il; i ++ ) {

					node.add( objects[ i ] );

				}

			}

			if ( nodeDef.name ) {

				node.userData.name = nodeDef.name;
				node.name = PropertyBinding.sanitizeNodeName( nodeDef.name );

			}

			assignExtrasToUserData( node, nodeDef );

			if ( nodeDef.extensions ) addUnknownExtensionsToUserData( extensions, node, nodeDef );

			if ( nodeDef.matrix !== undefined ) {

				var matrix = new Matrix4();
				matrix.fromArray( nodeDef.matrix );
				node.applyMatrix4( matrix );

			} else {

				if ( nodeDef.translation !== undefined ) {

					node.position.fromArray( nodeDef.translation );

				}

				if ( nodeDef.rotation !== undefined ) {

					node.quaternion.fromArray( nodeDef.rotation );

				}

				if ( nodeDef.scale !== undefined ) {

					node.scale.fromArray( nodeDef.scale );

				}

			}

			return node;

		} );

	};

	/**
	 * Specification: https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#scenes
	 * @param {number} sceneIndex
	 * @return {Promise<Group>}
	 */
	GLTFParser.prototype.loadScene = function () {

		// scene node hierachy builder

		function buildNodeHierachy( nodeId, parentObject, json, parser ) {

			var nodeDef = json.nodes[ nodeId ];

			return parser.getDependency( 'node', nodeId ).then( function ( node ) {

				if ( nodeDef.skin === undefined ) return node;

				// build skeleton here as well

				var skinEntry;

				return parser.getDependency( 'skin', nodeDef.skin ).then( function ( skin ) {

					skinEntry = skin;

					var pendingJoints = [];

					for ( var i = 0, il = skinEntry.joints.length; i < il; i ++ ) {

						pendingJoints.push( parser.getDependency( 'node', skinEntry.joints[ i ] ) );

					}

					return Promise.all( pendingJoints );

				} ).then( function ( jointNodes ) {

					node.traverse( function ( mesh ) {

						if ( ! mesh.isMesh ) return;

						var bones = [];
						var boneInverses = [];

						for ( var j = 0, jl = jointNodes.length; j < jl; j ++ ) {

							var jointNode = jointNodes[ j ];

							if ( jointNode ) {

								bones.push( jointNode );

								var mat = new Matrix4();

								if ( skinEntry.inverseBindMatrices !== undefined ) {

									mat.fromArray( skinEntry.inverseBindMatrices.array, j * 16 );

								}

								boneInverses.push( mat );

							} else {

								console.warn( 'THREE.GLTFLoader: Joint "%s" could not be found.', skinEntry.joints[ j ] );

							}

						}

						mesh.bind( new Skeleton( bones, boneInverses ), mesh.matrixWorld );

					} );

					return node;

				} );

			} ).then( function ( node ) {

				// build node hierachy

				parentObject.add( node );

				var pending = [];

				if ( nodeDef.children ) {

					var children = nodeDef.children;

					for ( var i = 0, il = children.length; i < il; i ++ ) {

						var child = children[ i ];
						pending.push( buildNodeHierachy( child, node, json, parser ) );

					}

				}

				return Promise.all( pending );

			} );

		}

		return function loadScene( sceneIndex ) {

			var json = this.json;
			var extensions = this.extensions;
			var sceneDef = this.json.scenes[ sceneIndex ];
			var parser = this;

			// Loader returns Group, not Scene.
			// See: https://github.com/mrdoob/three.js/issues/18342#issuecomment-578981172
			var scene = new Group();
			if ( sceneDef.name ) scene.name = sceneDef.name;

			assignExtrasToUserData( scene, sceneDef );

			if ( sceneDef.extensions ) addUnknownExtensionsToUserData( extensions, scene, sceneDef );

			var nodeIds = sceneDef.nodes || [];

			var pending = [];

			for ( var i = 0, il = nodeIds.length; i < il; i ++ ) {

				pending.push( buildNodeHierachy( nodeIds[ i ], scene, json, parser ) );

			}

			return Promise.all( pending ).then( function () {

				return scene;

			} );

		};

	}();

	return GLTFLoader;

} )()

parse( text, path ) {

		function getElementsByTagName( xml, name ) {

			// Non recursive xml.getElementsByTagName() ...

			const array = [];
			const childNodes = xml.childNodes;

			for ( let i = 0, l = childNodes.length; i < l; i ++ ) {

				const child = childNodes[ i ];

				if ( child.nodeName === name ) {

					array.push( child );

				}

			}

			return array;

		}

		function parseStrings( text ) {

			if ( text.length === 0 ) return [];

			const parts = text.trim().split( /\s+/ );
			const array = new Array( parts.length );

			for ( let i = 0, l = parts.length; i < l; i ++ ) {

				array[ i ] = parts[ i ];

			}

			return array;

		}

		function parseFloats( text ) {

			if ( text.length === 0 ) return [];

			const parts = text.trim().split( /\s+/ );
			const array = new Array( parts.length );

			for ( let i = 0, l = parts.length; i < l; i ++ ) {

				array[ i ] = parseFloat( parts[ i ] );

			}

			return array;

		}

		function parseInts( text ) {

			if ( text.length === 0 ) return [];

			const parts = text.trim().split( /\s+/ );
			const array = new Array( parts.length );

			for ( let i = 0, l = parts.length; i < l; i ++ ) {

				array[ i ] = parseInt( parts[ i ] );

			}

			return array;

		}

		function parseId( text ) {

			return text.substring( 1 );

		}

		function generateId() {

			return 'three_default_' + ( count ++ );

		}

		function isEmpty( object ) {

			return Object.keys( object ).length === 0;

		}

		// asset

		function parseAsset( xml ) {

			return {
				unit: parseAssetUnit( getElementsByTagName( xml, 'unit' )[ 0 ] ),
				upAxis: parseAssetUpAxis( getElementsByTagName( xml, 'up_axis' )[ 0 ] )
			};

		}

		function parseAssetUnit( xml ) {

			if ( ( xml !== undefined ) && ( xml.hasAttribute( 'meter' ) === true ) ) {

				return parseFloat( xml.getAttribute( 'meter' ) );

			} else {

				return 1; // default 1 meter

			}

		}

		function parseAssetUpAxis( xml ) {

			return xml !== undefined ? xml.textContent : 'Y_UP';

		}

		// library

		function parseLibrary( xml, libraryName, nodeName, parser ) {

			const library = getElementsByTagName( xml, libraryName )[ 0 ];

			if ( library !== undefined ) {

				const elements = getElementsByTagName( library, nodeName );

				for ( let i = 0; i < elements.length; i ++ ) {

					parser( elements[ i ] );

				}

			}

		}

		function buildLibrary( data, builder ) {

			for ( const name in data ) {

				const object = data[ name ];
				object.build = builder( data[ name ] );

			}

		}

		// get

		function getBuild( data, builder ) {

			if ( data.build !== undefined ) return data.build;

			data.build = builder( data );

			return data.build;

		}

		// animation

		function parseAnimation( xml ) {

			const data = {
				sources: {},
				samplers: {},
				channels: {}
			};

			let hasChildren = false;

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				let id;

				switch ( child.nodeName ) {

					case 'source':
						id = child.getAttribute( 'id' );
						data.sources[ id ] = parseSource( child );
						break;

					case 'sampler':
						id = child.getAttribute( 'id' );
						data.samplers[ id ] = parseAnimationSampler( child );
						break;

					case 'channel':
						id = child.getAttribute( 'target' );
						data.channels[ id ] = parseAnimationChannel( child );
						break;

					case 'animation':
						// hierarchy of related animations
						parseAnimation( child );
						hasChildren = true;
						break;

					default:
						console.log( child );

				}

			}

			if ( hasChildren === false ) {

				// since 'id' attributes can be optional, it's necessary to generate a UUID for unqiue assignment

				library.animations[ xml.getAttribute( 'id' ) || MathUtils.generateUUID() ] = data;

			}

		}

		function parseAnimationSampler( xml ) {

			const data = {
				inputs: {},
			};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'input':
						const id = parseId( child.getAttribute( 'source' ) );
						const semantic = child.getAttribute( 'semantic' );
						data.inputs[ semantic ] = id;
						break;

				}

			}

			return data;

		}

		function parseAnimationChannel( xml ) {

			const data = {};

			const target = xml.getAttribute( 'target' );

			// parsing SID Addressing Syntax

			let parts = target.split( '/' );

			const id = parts.shift();
			let sid = parts.shift();

			// check selection syntax

			const arraySyntax = ( sid.indexOf( '(' ) !== - 1 );
			const memberSyntax = ( sid.indexOf( '.' ) !== - 1 );

			if ( memberSyntax ) {

				//  member selection access

				parts = sid.split( '.' );
				sid = parts.shift();
				data.member = parts.shift();

			} else if ( arraySyntax ) {

				// array-access syntax. can be used to express fields in one-dimensional vectors or two-dimensional matrices.

				const indices = sid.split( '(' );
				sid = indices.shift();

				for ( let i = 0; i < indices.length; i ++ ) {

					indices[ i ] = parseInt( indices[ i ].replace( /\)/, '' ) );

				}

				data.indices = indices;

			}

			data.id = id;
			data.sid = sid;

			data.arraySyntax = arraySyntax;
			data.memberSyntax = memberSyntax;

			data.sampler = parseId( xml.getAttribute( 'source' ) );

			return data;

		}

		function buildAnimation( data ) {

			const tracks = [];

			const channels = data.channels;
			const samplers = data.samplers;
			const sources = data.sources;

			for ( const target in channels ) {

				if ( channels.hasOwnProperty( target ) ) {

					const channel = channels[ target ];
					const sampler = samplers[ channel.sampler ];

					const inputId = sampler.inputs.INPUT;
					const outputId = sampler.inputs.OUTPUT;

					const inputSource = sources[ inputId ];
					const outputSource = sources[ outputId ];

					const animation = buildAnimationChannel( channel, inputSource, outputSource );

					createKeyframeTracks( animation, tracks );

				}

			}

			return tracks;

		}

		function getAnimation( id ) {

			return getBuild( library.animations[ id ], buildAnimation );

		}

		function buildAnimationChannel( channel, inputSource, outputSource ) {

			const node = library.nodes[ channel.id ];
			const object3D = getNode( node.id );

			const transform = node.transforms[ channel.sid ];
			const defaultMatrix = node.matrix.clone().transpose();

			let time, stride;
			let i, il, j, jl;

			const data = {};

			// the collada spec allows the animation of data in various ways.
			// depending on the transform type (matrix, translate, rotate, scale), we execute different logic

			switch ( transform ) {

				case 'matrix':

					for ( i = 0, il = inputSource.array.length; i < il; i ++ ) {

						time = inputSource.array[ i ];
						stride = i * outputSource.stride;

						if ( data[ time ] === undefined ) data[ time ] = {};

						if ( channel.arraySyntax === true ) {

							const value = outputSource.array[ stride ];
							const index = channel.indices[ 0 ] + 4 * channel.indices[ 1 ];

							data[ time ][ index ] = value;

						} else {

							for ( j = 0, jl = outputSource.stride; j < jl; j ++ ) {

								data[ time ][ j ] = outputSource.array[ stride + j ];

							}

						}

					}

					break;

				case 'translate':
					console.warn( 'THREE.ColladaLoader: Animation transform type "%s" not yet implemented.', transform );
					break;

				case 'rotate':
					console.warn( 'THREE.ColladaLoader: Animation transform type "%s" not yet implemented.', transform );
					break;

				case 'scale':
					console.warn( 'THREE.ColladaLoader: Animation transform type "%s" not yet implemented.', transform );
					break;

			}

			const keyframes = prepareAnimationData( data, defaultMatrix );

			const animation = {
				name: object3D.uuid,
				keyframes: keyframes
			};

			return animation;

		}

		function prepareAnimationData( data, defaultMatrix ) {

			const keyframes = [];

			// transfer data into a sortable array

			for ( const time in data ) {

				keyframes.push( { time: parseFloat( time ), value: data[ time ] } );

			}

			// ensure keyframes are sorted by time

			keyframes.sort( ascending );

			// now we clean up all animation data, so we can use them for keyframe tracks

			for ( let i = 0; i < 16; i ++ ) {

				transformAnimationData( keyframes, i, defaultMatrix.elements[ i ] );

			}

			return keyframes;

			// array sort function

			function ascending( a, b ) {

				return a.time - b.time;

			}

		}

		const position = new Vector3();
		const scale = new Vector3();
		const quaternion = new Quaternion();

		function createKeyframeTracks( animation, tracks ) {

			const keyframes = animation.keyframes;
			const name = animation.name;

			const times = [];
			const positionData = [];
			const quaternionData = [];
			const scaleData = [];

			for ( let i = 0, l = keyframes.length; i < l; i ++ ) {

				const keyframe = keyframes[ i ];

				const time = keyframe.time;
				const value = keyframe.value;

				matrix.fromArray( value ).transpose();
				matrix.decompose( position, quaternion, scale );

				times.push( time );
				positionData.push( position.x, position.y, position.z );
				quaternionData.push( quaternion.x, quaternion.y, quaternion.z, quaternion.w );
				scaleData.push( scale.x, scale.y, scale.z );

			}

			if ( positionData.length > 0 ) tracks.push( new VectorKeyframeTrack( name + '.position', times, positionData ) );
			if ( quaternionData.length > 0 ) tracks.push( new QuaternionKeyframeTrack( name + '.quaternion', times, quaternionData ) );
			if ( scaleData.length > 0 ) tracks.push( new VectorKeyframeTrack( name + '.scale', times, scaleData ) );

			return tracks;

		}

		function transformAnimationData( keyframes, property, defaultValue ) {

			let keyframe;

			let empty = true;
			let i, l;

			// check, if values of a property are missing in our keyframes

			for ( i = 0, l = keyframes.length; i < l; i ++ ) {

				keyframe = keyframes[ i ];

				if ( keyframe.value[ property ] === undefined ) {

					keyframe.value[ property ] = null; // mark as missing

				} else {

					empty = false;

				}

			}

			if ( empty === true ) {

				// no values at all, so we set a default value

				for ( i = 0, l = keyframes.length; i < l; i ++ ) {

					keyframe = keyframes[ i ];

					keyframe.value[ property ] = defaultValue;

				}

			} else {

				// filling gaps

				createMissingKeyframes( keyframes, property );

			}

		}

		function createMissingKeyframes( keyframes, property ) {

			let prev, next;

			for ( let i = 0, l = keyframes.length; i < l; i ++ ) {

				const keyframe = keyframes[ i ];

				if ( keyframe.value[ property ] === null ) {

					prev = getPrev( keyframes, i, property );
					next = getNext( keyframes, i, property );

					if ( prev === null ) {

						keyframe.value[ property ] = next.value[ property ];
						continue;

					}

					if ( next === null ) {

						keyframe.value[ property ] = prev.value[ property ];
						continue;

					}

					interpolate( keyframe, prev, next, property );

				}

			}

		}

		function getPrev( keyframes, i, property ) {

			while ( i >= 0 ) {

				const keyframe = keyframes[ i ];

				if ( keyframe.value[ property ] !== null ) return keyframe;

				i --;

			}

			return null;

		}

		function getNext( keyframes, i, property ) {

			while ( i < keyframes.length ) {

				const keyframe = keyframes[ i ];

				if ( keyframe.value[ property ] !== null ) return keyframe;

				i ++;

			}

			return null;

		}

		function interpolate( key, prev, next, property ) {

			if ( ( next.time - prev.time ) === 0 ) {

				key.value[ property ] = prev.value[ property ];
				return;

			}

			key.value[ property ] = ( ( key.time - prev.time ) * ( next.value[ property ] - prev.value[ property ] ) / ( next.time - prev.time ) ) + prev.value[ property ];

		}

		// animation clips

		function parseAnimationClip( xml ) {

			const data = {
				name: xml.getAttribute( 'id' ) || 'default',
				start: parseFloat( xml.getAttribute( 'start' ) || 0 ),
				end: parseFloat( xml.getAttribute( 'end' ) || 0 ),
				animations: []
			};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'instance_animation':
						data.animations.push( parseId( child.getAttribute( 'url' ) ) );
						break;

				}

			}

			library.clips[ xml.getAttribute( 'id' ) ] = data;

		}

		function buildAnimationClip( data ) {

			const tracks = [];

			const name = data.name;
			const duration = ( data.end - data.start ) || - 1;
			const animations = data.animations;

			for ( let i = 0, il = animations.length; i < il; i ++ ) {

				const animationTracks = getAnimation( animations[ i ] );

				for ( let j = 0, jl = animationTracks.length; j < jl; j ++ ) {

					tracks.push( animationTracks[ j ] );

				}

			}

			return new AnimationClip( name, duration, tracks );

		}

		function getAnimationClip( id ) {

			return getBuild( library.clips[ id ], buildAnimationClip );

		}

		// controller

		function parseController( xml ) {

			const data = {};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'skin':
						// there is exactly one skin per controller
						data.id = parseId( child.getAttribute( 'source' ) );
						data.skin = parseSkin( child );
						break;

					case 'morph':
						data.id = parseId( child.getAttribute( 'source' ) );
						console.warn( 'THREE.ColladaLoader: Morph target animation not supported yet.' );
						break;

				}

			}

			library.controllers[ xml.getAttribute( 'id' ) ] = data;

		}

		function parseSkin( xml ) {

			const data = {
				sources: {}
			};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'bind_shape_matrix':
						data.bindShapeMatrix = parseFloats( child.textContent );
						break;

					case 'source':
						const id = child.getAttribute( 'id' );
						data.sources[ id ] = parseSource( child );
						break;

					case 'joints':
						data.joints = parseJoints( child );
						break;

					case 'vertex_weights':
						data.vertexWeights = parseVertexWeights( child );
						break;

				}

			}

			return data;

		}

		function parseJoints( xml ) {

			const data = {
				inputs: {}
			};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'input':
						const semantic = child.getAttribute( 'semantic' );
						const id = parseId( child.getAttribute( 'source' ) );
						data.inputs[ semantic ] = id;
						break;

				}

			}

			return data;

		}

		function parseVertexWeights( xml ) {

			const data = {
				inputs: {}
			};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'input':
						const semantic = child.getAttribute( 'semantic' );
						const id = parseId( child.getAttribute( 'source' ) );
						const offset = parseInt( child.getAttribute( 'offset' ) );
						data.inputs[ semantic ] = { id: id, offset: offset };
						break;

					case 'vcount':
						data.vcount = parseInts( child.textContent );
						break;

					case 'v':
						data.v = parseInts( child.textContent );
						break;

				}

			}

			return data;

		}

		function buildController( data ) {

			const build = {
				id: data.id
			};

			const geometry = library.geometries[ build.id ];

			if ( data.skin !== undefined ) {

				build.skin = buildSkin( data.skin );

				// we enhance the 'sources' property of the corresponding geometry with our skin data

				geometry.sources.skinIndices = build.skin.indices;
				geometry.sources.skinWeights = build.skin.weights;

			}

			return build;

		}

		function buildSkin( data ) {

			const BONE_LIMIT = 4;

			const build = {
				joints: [], // this must be an array to preserve the joint order
				indices: {
					array: [],
					stride: BONE_LIMIT
				},
				weights: {
					array: [],
					stride: BONE_LIMIT
				}
			};

			const sources = data.sources;
			const vertexWeights = data.vertexWeights;

			const vcount = vertexWeights.vcount;
			const v = vertexWeights.v;
			const jointOffset = vertexWeights.inputs.JOINT.offset;
			const weightOffset = vertexWeights.inputs.WEIGHT.offset;

			const jointSource = data.sources[ data.joints.inputs.JOINT ];
			const inverseSource = data.sources[ data.joints.inputs.INV_BIND_MATRIX ];

			const weights = sources[ vertexWeights.inputs.WEIGHT.id ].array;
			let stride = 0;

			let i, j, l;

			// procces skin data for each vertex

			for ( i = 0, l = vcount.length; i < l; i ++ ) {

				const jointCount = vcount[ i ]; // this is the amount of joints that affect a single vertex
				const vertexSkinData = [];

				for ( j = 0; j < jointCount; j ++ ) {

					const skinIndex = v[ stride + jointOffset ];
					const weightId = v[ stride + weightOffset ];
					const skinWeight = weights[ weightId ];

					vertexSkinData.push( { index: skinIndex, weight: skinWeight } );

					stride += 2;

				}

				// we sort the joints in descending order based on the weights.
				// this ensures, we only procced the most important joints of the vertex

				vertexSkinData.sort( descending );

				// now we provide for each vertex a set of four index and weight values.
				// the order of the skin data matches the order of vertices

				for ( j = 0; j < BONE_LIMIT; j ++ ) {

					const d = vertexSkinData[ j ];

					if ( d !== undefined ) {

						build.indices.array.push( d.index );
						build.weights.array.push( d.weight );

					} else {

						build.indices.array.push( 0 );
						build.weights.array.push( 0 );

					}

				}

			}

			// setup bind matrix

			if ( data.bindShapeMatrix ) {

				build.bindMatrix = new Matrix4().fromArray( data.bindShapeMatrix ).transpose();

			} else {

				build.bindMatrix = new Matrix4().identity();

			}

			// process bones and inverse bind matrix data

			for ( i = 0, l = jointSource.array.length; i < l; i ++ ) {

				const name = jointSource.array[ i ];
				const boneInverse = new Matrix4().fromArray( inverseSource.array, i * inverseSource.stride ).transpose();

				build.joints.push( { name: name, boneInverse: boneInverse } );

			}

			return build;

			// array sort function

			function descending( a, b ) {

				return b.weight - a.weight;

			}

		}

		function getController( id ) {

			return getBuild( library.controllers[ id ], buildController );

		}

		// image

		function parseImage( xml ) {

			const data = {
				init_from: getElementsByTagName( xml, 'init_from' )[ 0 ].textContent
			};

			library.images[ xml.getAttribute( 'id' ) ] = data;

		}

		function buildImage( data ) {

			if ( data.build !== undefined ) return data.build;

			return data.init_from;

		}

		function getImage( id ) {

			const data = library.images[ id ];

			if ( data !== undefined ) {

				return getBuild( data, buildImage );

			}

			console.warn( 'THREE.ColladaLoader: Couldn\'t find image with ID:', id );

			return null;

		}

		// effect

		function parseEffect( xml ) {

			const data = {};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'profile_COMMON':
						data.profile = parseEffectProfileCOMMON( child );
						break;

				}

			}

			library.effects[ xml.getAttribute( 'id' ) ] = data;

		}

		function parseEffectProfileCOMMON( xml ) {

			const data = {
				surfaces: {},
				samplers: {}
			};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'newparam':
						parseEffectNewparam( child, data );
						break;

					case 'technique':
						data.technique = parseEffectTechnique( child );
						break;

					case 'extra':
						data.extra = parseEffectExtra( child );
						break;

				}

			}

			return data;

		}

		function parseEffectNewparam( xml, data ) {

			const sid = xml.getAttribute( 'sid' );

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'surface':
						data.surfaces[ sid ] = parseEffectSurface( child );
						break;

					case 'sampler2D':
						data.samplers[ sid ] = parseEffectSampler( child );
						break;

				}

			}

		}

		function parseEffectSurface( xml ) {

			const data = {};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'init_from':
						data.init_from = child.textContent;
						break;

				}

			}

			return data;

		}

		function parseEffectSampler( xml ) {

			const data = {};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'source':
						data.source = child.textContent;
						break;

				}

			}

			return data;

		}

		function parseEffectTechnique( xml ) {

			const data = {};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'constant':
					case 'lambert':
					case 'blinn':
					case 'phong':
						data.type = child.nodeName;
						data.parameters = parseEffectParameters( child );
						break;

					case 'extra':
						data.extra = parseEffectExtra( child );
						break;

				}

			}

			return data;

		}

		function parseEffectParameters( xml ) {

			const data = {};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'emission':
					case 'diffuse':
					case 'specular':
					case 'bump':
					case 'ambient':
					case 'shininess':
					case 'transparency':
						data[ child.nodeName ] = parseEffectParameter( child );
						break;
					case 'transparent':
						data[ child.nodeName ] = {
							opaque: child.hasAttribute( 'opaque' ) ? child.getAttribute( 'opaque' ) : 'A_ONE',
							data: parseEffectParameter( child )
						};
						break;

				}

			}

			return data;

		}

		function parseEffectParameter( xml ) {

			const data = {};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'color':
						data[ child.nodeName ] = parseFloats( child.textContent );
						break;

					case 'float':
						data[ child.nodeName ] = parseFloat( child.textContent );
						break;

					case 'texture':
						data[ child.nodeName ] = { id: child.getAttribute( 'texture' ), extra: parseEffectParameterTexture( child ) };
						break;

				}

			}

			return data;

		}

		function parseEffectParameterTexture( xml ) {

			const data = {
				technique: {}
			};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'extra':
						parseEffectParameterTextureExtra( child, data );
						break;

				}

			}

			return data;

		}

		function parseEffectParameterTextureExtra( xml, data ) {

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'technique':
						parseEffectParameterTextureExtraTechnique( child, data );
						break;

				}

			}

		}

		function parseEffectParameterTextureExtraTechnique( xml, data ) {

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'repeatU':
					case 'repeatV':
					case 'offsetU':
					case 'offsetV':
						data.technique[ child.nodeName ] = parseFloat( child.textContent );
						break;

					case 'wrapU':
					case 'wrapV':

						// some files have values for wrapU/wrapV which become NaN via parseInt

						if ( child.textContent.toUpperCase() === 'TRUE' ) {

							data.technique[ child.nodeName ] = 1;

						} else if ( child.textContent.toUpperCase() === 'FALSE' ) {

							data.technique[ child.nodeName ] = 0;

						} else {

							data.technique[ child.nodeName ] = parseInt( child.textContent );

						}

						break;

					case 'bump':
						data[ child.nodeName ] = parseEffectExtraTechniqueBump( child );
						break;

				}

			}

		}

		function parseEffectExtra( xml ) {

			const data = {};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'technique':
						data.technique = parseEffectExtraTechnique( child );
						break;

				}

			}

			return data;

		}

		function parseEffectExtraTechnique( xml ) {

			const data = {};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'double_sided':
						data[ child.nodeName ] = parseInt( child.textContent );
						break;

					case 'bump':
						data[ child.nodeName ] = parseEffectExtraTechniqueBump( child );
						break;

				}

			}

			return data;

		}

		function parseEffectExtraTechniqueBump( xml ) {

			const data = {};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'texture':
						data[ child.nodeName ] = { id: child.getAttribute( 'texture' ), texcoord: child.getAttribute( 'texcoord' ), extra: parseEffectParameterTexture( child ) };
						break;

				}

			}

			return data;

		}

		function buildEffect( data ) {

			return data;

		}

		function getEffect( id ) {

			return getBuild( library.effects[ id ], buildEffect );

		}

		// material

		function parseMaterial( xml ) {

			const data = {
				name: xml.getAttribute( 'name' )
			};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'instance_effect':
						data.url = parseId( child.getAttribute( 'url' ) );
						break;

				}

			}

			library.materials[ xml.getAttribute( 'id' ) ] = data;

		}

		function getTextureLoader( image ) {

			let loader;

			let extension = image.slice( ( image.lastIndexOf( '.' ) - 1 >>> 0 ) + 2 ); // http://www.jstips.co/en/javascript/get-file-extension/
			extension = extension.toLowerCase();

			switch ( extension ) {

				case 'tga':
					loader = tgaLoader;
					break;

				default:
					loader = textureLoader;

			}

			return loader;

		}

		function buildMaterial( data ) {

			const effect = getEffect( data.url );
			const technique = effect.profile.technique;

			let material;

			switch ( technique.type ) {

				case 'phong':
				case 'blinn':
					material = new MeshPhongMaterial();
					break;

				case 'lambert':
					material = new MeshLambertMaterial();
					break;

				default:
					material = new MeshBasicMaterial();
					break;

			}

			material.name = data.name || '';

			function getTexture( textureObject, encoding = null ) {

				const sampler = effect.profile.samplers[ textureObject.id ];
				let image = null;

				// get image

				if ( sampler !== undefined ) {

					const surface = effect.profile.surfaces[ sampler.source ];
					image = getImage( surface.init_from );

				} else {

					console.warn( 'THREE.ColladaLoader: Undefined sampler. Access image directly (see #12530).' );
					image = getImage( textureObject.id );

				}

				// create texture if image is avaiable

				if ( image !== null ) {

					const loader = getTextureLoader( image );

					if ( loader !== undefined ) {

						const texture = loader.load( image );

						const extra = textureObject.extra;

						if ( extra !== undefined && extra.technique !== undefined && isEmpty( extra.technique ) === false ) {

							const technique = extra.technique;

							texture.wrapS = technique.wrapU ? RepeatWrapping : ClampToEdgeWrapping;
							texture.wrapT = technique.wrapV ? RepeatWrapping : ClampToEdgeWrapping;

							texture.offset.set( technique.offsetU || 0, technique.offsetV || 0 );
							texture.repeat.set( technique.repeatU || 1, technique.repeatV || 1 );

						} else {

							texture.wrapS = RepeatWrapping;
							texture.wrapT = RepeatWrapping;

						}

						if ( encoding !== null ) {

							texture.encoding = encoding;

						}

						return texture;

					} else {

						console.warn( 'THREE.ColladaLoader: Loader for texture %s not found.', image );

						return null;

					}

				} else {

					console.warn( 'THREE.ColladaLoader: Couldn\'t create texture with ID:', textureObject.id );

					return null;

				}

			}

			const parameters = technique.parameters;

			for ( const key in parameters ) {

				const parameter = parameters[ key ];

				switch ( key ) {

					case 'diffuse':
						if ( parameter.color ) material.color.fromArray( parameter.color );
						if ( parameter.texture ) material.map = getTexture( parameter.texture, sRGBEncoding );
						break;
					case 'specular':
						if ( parameter.color && material.specular ) material.specular.fromArray( parameter.color );
						if ( parameter.texture ) material.specularMap = getTexture( parameter.texture );
						break;
					case 'bump':
						if ( parameter.texture ) material.normalMap = getTexture( parameter.texture );
						break;
					case 'ambient':
						if ( parameter.texture ) material.lightMap = getTexture( parameter.texture, sRGBEncoding );
						break;
					case 'shininess':
						if ( parameter.float && material.shininess ) material.shininess = parameter.float;
						break;
					case 'emission':
						if ( parameter.color && material.emissive ) material.emissive.fromArray( parameter.color );
						if ( parameter.texture ) material.emissiveMap = getTexture( parameter.texture, sRGBEncoding );
						break;

				}

			}

			material.color.convertSRGBToLinear();
			if ( material.specular ) material.specular.convertSRGBToLinear();
			if ( material.emissive ) material.emissive.convertSRGBToLinear();

			//

			let transparent = parameters[ 'transparent' ];
			let transparency = parameters[ 'transparency' ];

			// <transparency> does not exist but <transparent>

			if ( transparency === undefined && transparent ) {

				transparency = {
					float: 1
				};

			}

			// <transparent> does not exist but <transparency>

			if ( transparent === undefined && transparency ) {

				transparent = {
					opaque: 'A_ONE',
					data: {
						color: [ 1, 1, 1, 1 ]
					} };

			}

			if ( transparent && transparency ) {

				// handle case if a texture exists but no color

				if ( transparent.data.texture ) {

					// we do not set an alpha map (see #13792)

					material.transparent = true;

				} else {

					const color = transparent.data.color;

					switch ( transparent.opaque ) {

						case 'A_ONE':
							material.opacity = color[ 3 ] * transparency.float;
							break;
						case 'RGB_ZERO':
							material.opacity = 1 - ( color[ 0 ] * transparency.float );
							break;
						case 'A_ZERO':
							material.opacity = 1 - ( color[ 3 ] * transparency.float );
							break;
						case 'RGB_ONE':
							material.opacity = color[ 0 ] * transparency.float;
							break;
						default:
							console.warn( 'THREE.ColladaLoader: Invalid opaque type "%s" of transparent tag.', transparent.opaque );

					}

					if ( material.opacity < 1 ) material.transparent = true;

				}

			}

			//


			if ( technique.extra !== undefined && technique.extra.technique !== undefined ) {

				const techniques = technique.extra.technique;

				for ( const k in techniques ) {

					const v = techniques[ k ];

					switch ( k ) {

						case 'double_sided':
							material.side = ( v === 1 ? DoubleSide : FrontSide );
							break;

						case 'bump':
							material.normalMap = getTexture( v.texture );
							material.normalScale = new Vector2( 1, 1 );
							break;

					}

				}

			}

			return material;

		}

		function getMaterial( id ) {

			return getBuild( library.materials[ id ], buildMaterial );

		}

		// camera

		function parseCamera( xml ) {

			const data = {
				name: xml.getAttribute( 'name' )
			};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'optics':
						data.optics = parseCameraOptics( child );
						break;

				}

			}

			library.cameras[ xml.getAttribute( 'id' ) ] = data;

		}

		function parseCameraOptics( xml ) {

			for ( let i = 0; i < xml.childNodes.length; i ++ ) {

				const child = xml.childNodes[ i ];

				switch ( child.nodeName ) {

					case 'technique_common':
						return parseCameraTechnique( child );

				}

			}

			return {};

		}

		function parseCameraTechnique( xml ) {

			const data = {};

			for ( let i = 0; i < xml.childNodes.length; i ++ ) {

				const child = xml.childNodes[ i ];

				switch ( child.nodeName ) {

					case 'perspective':
					case 'orthographic':

						data.technique = child.nodeName;
						data.parameters = parseCameraParameters( child );

						break;

				}

			}

			return data;

		}

		function parseCameraParameters( xml ) {

			const data = {};

			for ( let i = 0; i < xml.childNodes.length; i ++ ) {

				const child = xml.childNodes[ i ];

				switch ( child.nodeName ) {

					case 'xfov':
					case 'yfov':
					case 'xmag':
					case 'ymag':
					case 'znear':
					case 'zfar':
					case 'aspect_ratio':
						data[ child.nodeName ] = parseFloat( child.textContent );
						break;

				}

			}

			return data;

		}

		function buildCamera( data ) {

			let camera;

			switch ( data.optics.technique ) {

				case 'perspective':
					camera = new PerspectiveCamera(
						data.optics.parameters.yfov,
						data.optics.parameters.aspect_ratio,
						data.optics.parameters.znear,
						data.optics.parameters.zfar
					);
					break;

				case 'orthographic':
					let ymag = data.optics.parameters.ymag;
					let xmag = data.optics.parameters.xmag;
					const aspectRatio = data.optics.parameters.aspect_ratio;

					xmag = ( xmag === undefined ) ? ( ymag * aspectRatio ) : xmag;
					ymag = ( ymag === undefined ) ? ( xmag / aspectRatio ) : ymag;

					xmag *= 0.5;
					ymag *= 0.5;

					camera = new OrthographicCamera(
						- xmag, xmag, ymag, - ymag, // left, right, top, bottom
						data.optics.parameters.znear,
						data.optics.parameters.zfar
					);
					break;

				default:
					camera = new PerspectiveCamera();
					break;

			}

			camera.name = data.name || '';

			return camera;

		}

		function getCamera( id ) {

			const data = library.cameras[ id ];

			if ( data !== undefined ) {

				return getBuild( data, buildCamera );

			}

			console.warn( 'THREE.ColladaLoader: Couldn\'t find camera with ID:', id );

			return null;

		}

		// light

		function parseLight( xml ) {

			let data = {};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'technique_common':
						data = parseLightTechnique( child );
						break;

				}

			}

			library.lights[ xml.getAttribute( 'id' ) ] = data;

		}

		function parseLightTechnique( xml ) {

			const data = {};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'directional':
					case 'point':
					case 'spot':
					case 'ambient':

						data.technique = child.nodeName;
						data.parameters = parseLightParameters( child );

				}

			}

			return data;

		}

		function parseLightParameters( xml ) {

			const data = {};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'color':
						const array = parseFloats( child.textContent );
						data.color = new Color().fromArray( array ).convertSRGBToLinear();
						break;

					case 'falloff_angle':
						data.falloffAngle = parseFloat( child.textContent );
						break;

					case 'quadratic_attenuation':
						const f = parseFloat( child.textContent );
						data.distance = f ? Math.sqrt( 1 / f ) : 0;
						break;

				}

			}

			return data;

		}

		function buildLight( data ) {

			let light;

			switch ( data.technique ) {

				case 'directional':
					light = new DirectionalLight();
					break;

				case 'point':
					light = new PointLight();
					break;

				case 'spot':
					light = new SpotLight();
					break;

				case 'ambient':
					light = new AmbientLight();
					break;

			}

			if ( data.parameters.color ) light.color.copy( data.parameters.color );
			if ( data.parameters.distance ) light.distance = data.parameters.distance;

			return light;

		}

		function getLight( id ) {

			const data = library.lights[ id ];

			if ( data !== undefined ) {

				return getBuild( data, buildLight );

			}

			console.warn( 'THREE.ColladaLoader: Couldn\'t find light with ID:', id );

			return null;

		}

		// geometry

		function parseGeometry( xml ) {

			const data = {
				name: xml.getAttribute( 'name' ),
				sources: {},
				vertices: {},
				primitives: []
			};

			const mesh = getElementsByTagName( xml, 'mesh' )[ 0 ];

			// the following tags inside geometry are not supported yet (see https://github.com/mrdoob/three.js/pull/12606): convex_mesh, spline, brep
			if ( mesh === undefined ) return;

			for ( let i = 0; i < mesh.childNodes.length; i ++ ) {

				const child = mesh.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				const id = child.getAttribute( 'id' );

				switch ( child.nodeName ) {

					case 'source':
						data.sources[ id ] = parseSource( child );
						break;

					case 'vertices':
						// data.sources[ id ] = data.sources[ parseId( getElementsByTagName( child, 'input' )[ 0 ].getAttribute( 'source' ) ) ];
						data.vertices = parseGeometryVertices( child );
						break;

					case 'polygons':
						console.warn( 'THREE.ColladaLoader: Unsupported primitive type: ', child.nodeName );
						break;

					case 'lines':
					case 'linestrips':
					case 'polylist':
					case 'triangles':
						data.primitives.push( parseGeometryPrimitive( child ) );
						break;

					default:
						console.log( child );

				}

			}

			library.geometries[ xml.getAttribute( 'id' ) ] = data;

		}

		function parseSource( xml ) {

			const data = {
				array: [],
				stride: 3
			};

			for ( let i = 0; i < xml.childNodes.length; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'float_array':
						data.array = parseFloats( child.textContent );
						break;

					case 'Name_array':
						data.array = parseStrings( child.textContent );
						break;

					case 'technique_common':
						const accessor = getElementsByTagName( child, 'accessor' )[ 0 ];

						if ( accessor !== undefined ) {

							data.stride = parseInt( accessor.getAttribute( 'stride' ) );

						}

						break;

				}

			}

			return data;

		}

		function parseGeometryVertices( xml ) {

			const data = {};

			for ( let i = 0; i < xml.childNodes.length; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				data[ child.getAttribute( 'semantic' ) ] = parseId( child.getAttribute( 'source' ) );

			}

			return data;

		}

		function parseGeometryPrimitive( xml ) {

			const primitive = {
				type: xml.nodeName,
				material: xml.getAttribute( 'material' ),
				count: parseInt( xml.getAttribute( 'count' ) ),
				inputs: {},
				stride: 0,
				hasUV: false
			};

			for ( let i = 0, l = xml.childNodes.length; i < l; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'input':
						const id = parseId( child.getAttribute( 'source' ) );
						const semantic = child.getAttribute( 'semantic' );
						const offset = parseInt( child.getAttribute( 'offset' ) );
						const set = parseInt( child.getAttribute( 'set' ) );
						const inputname = ( set > 0 ? semantic + set : semantic );
						primitive.inputs[ inputname ] = { id: id, offset: offset };
						primitive.stride = Math.max( primitive.stride, offset + 1 );
						if ( semantic === 'TEXCOORD' ) primitive.hasUV = true;
						break;

					case 'vcount':
						primitive.vcount = parseInts( child.textContent );
						break;

					case 'p':
						primitive.p = parseInts( child.textContent );
						break;

				}

			}

			return primitive;

		}

		function groupPrimitives( primitives ) {

			const build = {};

			for ( let i = 0; i < primitives.length; i ++ ) {

				const primitive = primitives[ i ];

				if ( build[ primitive.type ] === undefined ) build[ primitive.type ] = [];

				build[ primitive.type ].push( primitive );

			}

			return build;

		}

		function checkUVCoordinates( primitives ) {

			let count = 0;

			for ( let i = 0, l = primitives.length; i < l; i ++ ) {

				const primitive = primitives[ i ];

				if ( primitive.hasUV === true ) {

					count ++;

				}

			}

			if ( count > 0 && count < primitives.length ) {

				primitives.uvsNeedsFix = true;

			}

		}

		function buildGeometry( data ) {

			const build = {};

			const sources = data.sources;
			const vertices = data.vertices;
			const primitives = data.primitives;

			if ( primitives.length === 0 ) return {};

			// our goal is to create one buffer geometry for a single type of primitives
			// first, we group all primitives by their type

			const groupedPrimitives = groupPrimitives( primitives );

			for ( const type in groupedPrimitives ) {

				const primitiveType = groupedPrimitives[ type ];

				// second, ensure consistent uv coordinates for each type of primitives (polylist,triangles or lines)

				checkUVCoordinates( primitiveType );

				// third, create a buffer geometry for each type of primitives

				build[ type ] = buildGeometryType( primitiveType, sources, vertices );

			}

			return build;

		}

		function buildGeometryType( primitives, sources, vertices ) {

			const build = {};

			const position = { array: [], stride: 0 };
			const normal = { array: [], stride: 0 };
			const uv = { array: [], stride: 0 };
			const uv2 = { array: [], stride: 0 };
			const color = { array: [], stride: 0 };

			const skinIndex = { array: [], stride: 4 };
			const skinWeight = { array: [], stride: 4 };

			const geometry = new BufferGeometry();

			const materialKeys = [];

			let start = 0;

			for ( let p = 0; p < primitives.length; p ++ ) {

				const primitive = primitives[ p ];
				const inputs = primitive.inputs;

				// groups

				let count = 0;

				switch ( primitive.type ) {

					case 'lines':
					case 'linestrips':
						count = primitive.count * 2;
						break;

					case 'triangles':
						count = primitive.count * 3;
						break;

					case 'polylist':

						for ( let g = 0; g < primitive.count; g ++ ) {

							const vc = primitive.vcount[ g ];

							switch ( vc ) {

								case 3:
									count += 3; // single triangle
									break;

								case 4:
									count += 6; // quad, subdivided into two triangles
									break;

								default:
									count += ( vc - 2 ) * 3; // polylist with more than four vertices
									break;

							}

						}

						break;

					default:
						console.warn( 'THREE.ColladaLoader: Unknow primitive type:', primitive.type );

				}

				geometry.addGroup( start, count, p );
				start += count;

				// material

				if ( primitive.material ) {

					materialKeys.push( primitive.material );

				}

				// geometry data

				for ( const name in inputs ) {

					const input = inputs[ name ];

					switch ( name )	{

						case 'VERTEX':
							for ( const key in vertices ) {

								const id = vertices[ key ];

								switch ( key ) {

									case 'POSITION':
										const prevLength = position.array.length;
										buildGeometryData( primitive, sources[ id ], input.offset, position.array );
										position.stride = sources[ id ].stride;

										if ( sources.skinWeights && sources.skinIndices ) {

											buildGeometryData( primitive, sources.skinIndices, input.offset, skinIndex.array );
											buildGeometryData( primitive, sources.skinWeights, input.offset, skinWeight.array );

										}

										// see #3803

										if ( primitive.hasUV === false && primitives.uvsNeedsFix === true ) {

											const count = ( position.array.length - prevLength ) / position.stride;

											for ( let i = 0; i < count; i ++ ) {

												// fill missing uv coordinates

												uv.array.push( 0, 0 );

											}

										}

										break;

									case 'NORMAL':
										buildGeometryData( primitive, sources[ id ], input.offset, normal.array );
										normal.stride = sources[ id ].stride;
										break;

									case 'COLOR':
										buildGeometryData( primitive, sources[ id ], input.offset, color.array );
										color.stride = sources[ id ].stride;
										break;

									case 'TEXCOORD':
										buildGeometryData( primitive, sources[ id ], input.offset, uv.array );
										uv.stride = sources[ id ].stride;
										break;

									case 'TEXCOORD1':
										buildGeometryData( primitive, sources[ id ], input.offset, uv2.array );
										uv.stride = sources[ id ].stride;
										break;

									default:
										console.warn( 'THREE.ColladaLoader: Semantic "%s" not handled in geometry build process.', key );

								}

							}

							break;

						case 'NORMAL':
							buildGeometryData( primitive, sources[ input.id ], input.offset, normal.array );
							normal.stride = sources[ input.id ].stride;
							break;

						case 'COLOR':
							buildGeometryData( primitive, sources[ input.id ], input.offset, color.array, true );
							color.stride = sources[ input.id ].stride;
							break;

						case 'TEXCOORD':
							buildGeometryData( primitive, sources[ input.id ], input.offset, uv.array );
							uv.stride = sources[ input.id ].stride;
							break;

						case 'TEXCOORD1':
							buildGeometryData( primitive, sources[ input.id ], input.offset, uv2.array );
							uv2.stride = sources[ input.id ].stride;
							break;

					}

				}

			}

			// build geometry

			if ( position.array.length > 0 ) geometry.setAttribute( 'position', new Float32BufferAttribute( position.array, position.stride ) );
			if ( normal.array.length > 0 ) geometry.setAttribute( 'normal', new Float32BufferAttribute( normal.array, normal.stride ) );
			if ( color.array.length > 0 ) geometry.setAttribute( 'color', new Float32BufferAttribute( color.array, color.stride ) );
			if ( uv.array.length > 0 ) geometry.setAttribute( 'uv', new Float32BufferAttribute( uv.array, uv.stride ) );
			if ( uv2.array.length > 0 ) geometry.setAttribute( 'uv2', new Float32BufferAttribute( uv2.array, uv2.stride ) );

			if ( skinIndex.array.length > 0 ) geometry.setAttribute( 'skinIndex', new Float32BufferAttribute( skinIndex.array, skinIndex.stride ) );
			if ( skinWeight.array.length > 0 ) geometry.setAttribute( 'skinWeight', new Float32BufferAttribute( skinWeight.array, skinWeight.stride ) );

			build.data = geometry;
			build.type = primitives[ 0 ].type;
			build.materialKeys = materialKeys;

			return build;

		}

		function buildGeometryData( primitive, source, offset, array, isColor = false ) {

			const indices = primitive.p;
			const stride = primitive.stride;
			const vcount = primitive.vcount;

			function pushVector( i ) {

				let index = indices[ i + offset ] * sourceStride;
				const length = index + sourceStride;

				for ( ; index < length; index ++ ) {

					array.push( sourceArray[ index ] );

				}

				if ( isColor ) {

					// convert the vertex colors from srgb to linear if present
					const startIndex = array.length - sourceStride - 1;
					tempColor.setRGB(
						array[ startIndex + 0 ],
						array[ startIndex + 1 ],
						array[ startIndex + 2 ]
					).convertSRGBToLinear();

					array[ startIndex + 0 ] = tempColor.r;
					array[ startIndex + 1 ] = tempColor.g;
					array[ startIndex + 2 ] = tempColor.b;

				}

			}

			const sourceArray = source.array;
			const sourceStride = source.stride;

			if ( primitive.vcount !== undefined ) {

				let index = 0;

				for ( let i = 0, l = vcount.length; i < l; i ++ ) {

					const count = vcount[ i ];

					if ( count === 4 ) {

						const a = index + stride * 0;
						const b = index + stride * 1;
						const c = index + stride * 2;
						const d = index + stride * 3;

						pushVector( a ); pushVector( b ); pushVector( d );
						pushVector( b ); pushVector( c ); pushVector( d );

					} else if ( count === 3 ) {

						const a = index + stride * 0;
						const b = index + stride * 1;
						const c = index + stride * 2;

						pushVector( a ); pushVector( b ); pushVector( c );

					} else if ( count > 4 ) {

						for ( let k = 1, kl = ( count - 2 ); k <= kl; k ++ ) {

							const a = index + stride * 0;
							const b = index + stride * k;
							const c = index + stride * ( k + 1 );

							pushVector( a ); pushVector( b ); pushVector( c );

						}

					}

					index += stride * count;

				}

			} else {

				for ( let i = 0, l = indices.length; i < l; i += stride ) {

					pushVector( i );

				}

			}

		}

		function getGeometry( id ) {

			return getBuild( library.geometries[ id ], buildGeometry );

		}

		// kinematics

		function parseKinematicsModel( xml ) {

			const data = {
				name: xml.getAttribute( 'name' ) || '',
				joints: {},
				links: []
			};

			for ( let i = 0; i < xml.childNodes.length; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'technique_common':
						parseKinematicsTechniqueCommon( child, data );
						break;

				}

			}

			library.kinematicsModels[ xml.getAttribute( 'id' ) ] = data;

		}

		function buildKinematicsModel( data ) {

			if ( data.build !== undefined ) return data.build;

			return data;

		}

		function getKinematicsModel( id ) {

			return getBuild( library.kinematicsModels[ id ], buildKinematicsModel );

		}

		function parseKinematicsTechniqueCommon( xml, data ) {

			for ( let i = 0; i < xml.childNodes.length; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'joint':
						data.joints[ child.getAttribute( 'sid' ) ] = parseKinematicsJoint( child );
						break;

					case 'link':
						data.links.push( parseKinematicsLink( child ) );
						break;

				}

			}

		}

		function parseKinematicsJoint( xml ) {

			let data;

			for ( let i = 0; i < xml.childNodes.length; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'prismatic':
					case 'revolute':
						data = parseKinematicsJointParameter( child );
						break;

				}

			}

			return data;

		}

		function parseKinematicsJointParameter( xml ) {

			const data = {
				sid: xml.getAttribute( 'sid' ),
				name: xml.getAttribute( 'name' ) || '',
				axis: new Vector3(),
				limits: {
					min: 0,
					max: 0
				},
				type: xml.nodeName,
				static: false,
				zeroPosition: 0,
				middlePosition: 0
			};

			for ( let i = 0; i < xml.childNodes.length; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'axis':
						const array = parseFloats( child.textContent );
						data.axis.fromArray( array );
						break;
					case 'limits':
						const max = child.getElementsByTagName( 'max' )[ 0 ];
						const min = child.getElementsByTagName( 'min' )[ 0 ];

						data.limits.max = parseFloat( max.textContent );
						data.limits.min = parseFloat( min.textContent );
						break;

				}

			}

			// if min is equal to or greater than max, consider the joint static

			if ( data.limits.min >= data.limits.max ) {

				data.static = true;

			}

			// calculate middle position

			data.middlePosition = ( data.limits.min + data.limits.max ) / 2.0;

			return data;

		}

		function parseKinematicsLink( xml ) {

			const data = {
				sid: xml.getAttribute( 'sid' ),
				name: xml.getAttribute( 'name' ) || '',
				attachments: [],
				transforms: []
			};

			for ( let i = 0; i < xml.childNodes.length; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'attachment_full':
						data.attachments.push( parseKinematicsAttachment( child ) );
						break;

					case 'matrix':
					case 'translate':
					case 'rotate':
						data.transforms.push( parseKinematicsTransform( child ) );
						break;

				}

			}

			return data;

		}

		function parseKinematicsAttachment( xml ) {

			const data = {
				joint: xml.getAttribute( 'joint' ).split( '/' ).pop(),
				transforms: [],
				links: []
			};

			for ( let i = 0; i < xml.childNodes.length; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'link':
						data.links.push( parseKinematicsLink( child ) );
						break;

					case 'matrix':
					case 'translate':
					case 'rotate':
						data.transforms.push( parseKinematicsTransform( child ) );
						break;

				}

			}

			return data;

		}

		function parseKinematicsTransform( xml ) {

			const data = {
				type: xml.nodeName
			};

			const array = parseFloats( xml.textContent );

			switch ( data.type ) {

				case 'matrix':
					data.obj = new Matrix4();
					data.obj.fromArray( array ).transpose();
					break;

				case 'translate':
					data.obj = new Vector3();
					data.obj.fromArray( array );
					break;

				case 'rotate':
					data.obj = new Vector3();
					data.obj.fromArray( array );
					data.angle = MathUtils.degToRad( array[ 3 ] );
					break;

			}

			return data;

		}

		// physics

		function parsePhysicsModel( xml ) {

			const data = {
				name: xml.getAttribute( 'name' ) || '',
				rigidBodies: {}
			};

			for ( let i = 0; i < xml.childNodes.length; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'rigid_body':
						data.rigidBodies[ child.getAttribute( 'name' ) ] = {};
						parsePhysicsRigidBody( child, data.rigidBodies[ child.getAttribute( 'name' ) ] );
						break;

				}

			}

			library.physicsModels[ xml.getAttribute( 'id' ) ] = data;

		}

		function parsePhysicsRigidBody( xml, data ) {

			for ( let i = 0; i < xml.childNodes.length; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'technique_common':
						parsePhysicsTechniqueCommon( child, data );
						break;

				}

			}

		}

		function parsePhysicsTechniqueCommon( xml, data ) {

			for ( let i = 0; i < xml.childNodes.length; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'inertia':
						data.inertia = parseFloats( child.textContent );
						break;

					case 'mass':
						data.mass = parseFloats( child.textContent )[ 0 ];
						break;

				}

			}

		}

		// scene

		function parseKinematicsScene( xml ) {

			const data = {
				bindJointAxis: []
			};

			for ( let i = 0; i < xml.childNodes.length; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'bind_joint_axis':
						data.bindJointAxis.push( parseKinematicsBindJointAxis( child ) );
						break;

				}

			}

			library.kinematicsScenes[ parseId( xml.getAttribute( 'url' ) ) ] = data;

		}

		function parseKinematicsBindJointAxis( xml ) {

			const data = {
				target: xml.getAttribute( 'target' ).split( '/' ).pop()
			};

			for ( let i = 0; i < xml.childNodes.length; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				switch ( child.nodeName ) {

					case 'axis':
						const param = child.getElementsByTagName( 'param' )[ 0 ];
						data.axis = param.textContent;
						const tmpJointIndex = data.axis.split( 'inst_' ).pop().split( 'axis' )[ 0 ];
						data.jointIndex = tmpJointIndex.substr( 0, tmpJointIndex.length - 1 );
						break;

				}

			}

			return data;

		}

		function buildKinematicsScene( data ) {

			if ( data.build !== undefined ) return data.build;

			return data;

		}

		function getKinematicsScene( id ) {

			return getBuild( library.kinematicsScenes[ id ], buildKinematicsScene );

		}

		function setupKinematics() {

			const kinematicsModelId = Object.keys( library.kinematicsModels )[ 0 ];
			const kinematicsSceneId = Object.keys( library.kinematicsScenes )[ 0 ];
			const visualSceneId = Object.keys( library.visualScenes )[ 0 ];

			if ( kinematicsModelId === undefined || kinematicsSceneId === undefined ) return;

			const kinematicsModel = getKinematicsModel( kinematicsModelId );
			const kinematicsScene = getKinematicsScene( kinematicsSceneId );
			const visualScene = getVisualScene( visualSceneId );

			const bindJointAxis = kinematicsScene.bindJointAxis;
			const jointMap = {};

			for ( let i = 0, l = bindJointAxis.length; i < l; i ++ ) {

				const axis = bindJointAxis[ i ];

				// the result of the following query is an element of type 'translate', 'rotate','scale' or 'matrix'

				const targetElement = collada.querySelector( '[sid="' + axis.target + '"]' );

				if ( targetElement ) {

					// get the parent of the transform element

					const parentVisualElement = targetElement.parentElement;

					// connect the joint of the kinematics model with the element in the visual scene

					connect( axis.jointIndex, parentVisualElement );

				}

			}

			function connect( jointIndex, visualElement ) {

				const visualElementName = visualElement.getAttribute( 'name' );
				const joint = kinematicsModel.joints[ jointIndex ];

				visualScene.traverse( function ( object ) {

					if ( object.name === visualElementName ) {

						jointMap[ jointIndex ] = {
							object: object,
							transforms: buildTransformList( visualElement ),
							joint: joint,
							position: joint.zeroPosition
						};

					}

				} );

			}

			const m0 = new Matrix4();

			kinematics = {

				joints: kinematicsModel && kinematicsModel.joints,

				getJointValue: function ( jointIndex ) {

					const jointData = jointMap[ jointIndex ];

					if ( jointData ) {

						return jointData.position;

					} else {

						console.warn( 'THREE.ColladaLoader: Joint ' + jointIndex + ' doesn\'t exist.' );

					}

				},

				setJointValue: function ( jointIndex, value ) {

					const jointData = jointMap[ jointIndex ];

					if ( jointData ) {

						const joint = jointData.joint;

						if ( value > joint.limits.max || value < joint.limits.min ) {

							console.warn( 'THREE.ColladaLoader: Joint ' + jointIndex + ' value ' + value + ' outside of limits (min: ' + joint.limits.min + ', max: ' + joint.limits.max + ').' );

						} else if ( joint.static ) {

							console.warn( 'THREE.ColladaLoader: Joint ' + jointIndex + ' is static.' );

						} else {

							const object = jointData.object;
							const axis = joint.axis;
							const transforms = jointData.transforms;

							matrix.identity();

							// each update, we have to apply all transforms in the correct order

							for ( let i = 0; i < transforms.length; i ++ ) {

								const transform = transforms[ i ];

								// if there is a connection of the transform node with a joint, apply the joint value

								if ( transform.sid && transform.sid.indexOf( jointIndex ) !== - 1 ) {

									switch ( joint.type ) {

										case 'revolute':
											matrix.multiply( m0.makeRotationAxis( axis, MathUtils.degToRad( value ) ) );
											break;

										case 'prismatic':
											matrix.multiply( m0.makeTranslation( axis.x * value, axis.y * value, axis.z * value ) );
											break;

										default:
											console.warn( 'THREE.ColladaLoader: Unknown joint type: ' + joint.type );
											break;

									}

								} else {

									switch ( transform.type ) {

										case 'matrix':
											matrix.multiply( transform.obj );
											break;

										case 'translate':
											matrix.multiply( m0.makeTranslation( transform.obj.x, transform.obj.y, transform.obj.z ) );
											break;

										case 'scale':
											matrix.scale( transform.obj );
											break;

										case 'rotate':
											matrix.multiply( m0.makeRotationAxis( transform.obj, transform.angle ) );
											break;

									}

								}

							}

							object.matrix.copy( matrix );
							object.matrix.decompose( object.position, object.quaternion, object.scale );

							jointMap[ jointIndex ].position = value;

						}

					} else {

						console.log( 'THREE.ColladaLoader: ' + jointIndex + ' does not exist.' );

					}

				}

			};

		}

		function buildTransformList( node ) {

			const transforms = [];

			const xml = collada.querySelector( '[id="' + node.id + '"]' );

			for ( let i = 0; i < xml.childNodes.length; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				let array, vector;

				switch ( child.nodeName ) {

					case 'matrix':
						array = parseFloats( child.textContent );
						const matrix = new Matrix4().fromArray( array ).transpose();
						transforms.push( {
							sid: child.getAttribute( 'sid' ),
							type: child.nodeName,
							obj: matrix
						} );
						break;

					case 'translate':
					case 'scale':
						array = parseFloats( child.textContent );
						vector = new Vector3().fromArray( array );
						transforms.push( {
							sid: child.getAttribute( 'sid' ),
							type: child.nodeName,
							obj: vector
						} );
						break;

					case 'rotate':
						array = parseFloats( child.textContent );
						vector = new Vector3().fromArray( array );
						const angle = MathUtils.degToRad( array[ 3 ] );
						transforms.push( {
							sid: child.getAttribute( 'sid' ),
							type: child.nodeName,
							obj: vector,
							angle: angle
						} );
						break;

				}

			}

			return transforms;

		}

		// nodes

		function prepareNodes( xml ) {

			const elements = xml.getElementsByTagName( 'node' );

			// ensure all node elements have id attributes

			for ( let i = 0; i < elements.length; i ++ ) {

				const element = elements[ i ];

				if ( element.hasAttribute( 'id' ) === false ) {

					element.setAttribute( 'id', generateId() );

				}

			}

		}

		const matrix = new Matrix4();
		const vector = new Vector3();

		function parseNode( xml ) {

			const data = {
				name: xml.getAttribute( 'name' ) || '',
				type: xml.getAttribute( 'type' ),
				id: xml.getAttribute( 'id' ),
				sid: xml.getAttribute( 'sid' ),
				matrix: new Matrix4(),
				nodes: [],
				instanceCameras: [],
				instanceControllers: [],
				instanceLights: [],
				instanceGeometries: [],
				instanceNodes: [],
				transforms: {}
			};

			for ( let i = 0; i < xml.childNodes.length; i ++ ) {

				const child = xml.childNodes[ i ];

				if ( child.nodeType !== 1 ) continue;

				let array;

				switch ( child.nodeName ) {

					case 'node':
						data.nodes.push( child.getAttribute( 'id' ) );
						parseNode( child );
						break;

					case 'instance_camera':
						data.instanceCameras.push( parseId( child.getAttribute( 'url' ) ) );
						break;

					case 'instance_controller':
						data.instanceControllers.push( parseNodeInstance( child ) );
						break;

					case 'instance_light':
						data.instanceLights.push( parseId( child.getAttribute( 'url' ) ) );
						break;

					case 'instance_geometry':
						data.instanceGeometries.push( parseNodeInstance( child ) );
						break;

					case 'instance_node':
						data.instanceNodes.push( parseId( child.getAttribute( 'url' ) ) );
						break;

					case 'matrix':
						array = parseFloats( child.textContent );
						data.matrix.multiply( matrix.fromArray( array ).transpose() );
						data.transforms[ child.getAttribute( 'sid' ) ] = child.nodeName;
						break;

					case 'translate':
						array = parseFloats( child.textContent );
						vector.fromArray( array );
						data.matrix.multiply( matrix.makeTranslation( vector.x, vector.y, vector.z ) );
						data.transforms[ child.getAttribute( 'sid' ) ] = child.nodeName;
						break;

					case 'rotate':
						array = parseFloats( child.textContent );
						const angle = MathUtils.degToRad( array[ 3 ] );
						data.matrix.multiply( matrix.makeRotationAxis( vector.fromArray( array ), angle ) );
						data.transforms[ child.getAttribute( 'sid' ) ] = child.nodeName;
						break;

					case 'scale':
						array = parseFloats( child.textContent );
						data.matrix.scale( vector.fromArray( array ) );
						data.transforms[ child.getAttribute( 'sid' ) ] = child.nodeName;
						break;

					case 'extra':
						break;

					default:
						console.log( child );

				}

			}

			if ( hasNode( data.id ) ) {

				console.warn( 'THREE.ColladaLoader: There is already a node with ID %s. Exclude current node from further processing.', data.id );

			} else {

				library.nodes[ data.id ] = data;

			}

			return data;

		}

		function parseNodeInstance( xml ) {

			const data = {
				id: parseId( xml.getAttribute( 'url' ) ),
				materials: {},
				skeletons: []
			};

			for ( let i = 0; i < xml.childNodes.length; i ++ ) {

				const child = xml.childNodes[ i ];

				switch ( child.nodeName ) {

					case 'bind_material':
						const instances = child.getElementsByTagName( 'instance_material' );

						for ( let j = 0; j < instances.length; j ++ ) {

							const instance = instances[ j ];
							const symbol = instance.getAttribute( 'symbol' );
							const target = instance.getAttribute( 'target' );

							data.materials[ symbol ] = parseId( target );

						}

						break;

					case 'skeleton':
						data.skeletons.push( parseId( child.textContent ) );
						break;

					default:
						break;

				}

			}

			return data;

		}

		function buildSkeleton( skeletons, joints ) {

			const boneData = [];
			const sortedBoneData = [];

			let i, j, data;

			// a skeleton can have multiple root bones. collada expresses this
			// situtation with multiple "skeleton" tags per controller instance

			for ( i = 0; i < skeletons.length; i ++ ) {

				const skeleton = skeletons[ i ];

				let root;

				if ( hasNode( skeleton ) ) {

					root = getNode( skeleton );
					buildBoneHierarchy( root, joints, boneData );

				} else if ( hasVisualScene( skeleton ) ) {

					// handle case where the skeleton refers to the visual scene (#13335)

					const visualScene = library.visualScenes[ skeleton ];
					const children = visualScene.children;

					for ( let j = 0; j < children.length; j ++ ) {

						const child = children[ j ];

						if ( child.type === 'JOINT' ) {

							const root = getNode( child.id );
							buildBoneHierarchy( root, joints, boneData );

						}

					}

				} else {

					console.error( 'THREE.ColladaLoader: Unable to find root bone of skeleton with ID:', skeleton );

				}

			}

			// sort bone data (the order is defined in the corresponding controller)

			for ( i = 0; i < joints.length; i ++ ) {

				for ( j = 0; j < boneData.length; j ++ ) {

					data = boneData[ j ];

					if ( data.bone.name === joints[ i ].name ) {

						sortedBoneData[ i ] = data;
						data.processed = true;
						break;

					}

				}

			}

			// add unprocessed bone data at the end of the list

			for ( i = 0; i < boneData.length; i ++ ) {

				data = boneData[ i ];

				if ( data.processed === false ) {

					sortedBoneData.push( data );
					data.processed = true;

				}

			}

			// setup arrays for skeleton creation

			const bones = [];
			const boneInverses = [];

			for ( i = 0; i < sortedBoneData.length; i ++ ) {

				data = sortedBoneData[ i ];

				bones.push( data.bone );
				boneInverses.push( data.boneInverse );

			}

			return new Skeleton( bones, boneInverses );

		}

		function buildBoneHierarchy( root, joints, boneData ) {

			// setup bone data from visual scene

			root.traverse( function ( object ) {

				if ( object.isBone === true ) {

					let boneInverse;

					// retrieve the boneInverse from the controller data

					for ( let i = 0; i < joints.length; i ++ ) {

						const joint = joints[ i ];

						if ( joint.name === object.name ) {

							boneInverse = joint.boneInverse;
							break;

						}

					}

					if ( boneInverse === undefined ) {

						// Unfortunately, there can be joints in the visual scene that are not part of the
						// corresponding controller. In this case, we have to create a dummy boneInverse matrix
						// for the respective bone. This bone won't affect any vertices, because there are no skin indices
						// and weights defined for it. But we still have to add the bone to the sorted bone list in order to
						// ensure a correct animation of the model.

						boneInverse = new Matrix4();

					}

					boneData.push( { bone: object, boneInverse: boneInverse, processed: false } );

				}

			} );

		}

		function buildNode( data ) {

			const objects = [];

			const matrix = data.matrix;
			const nodes = data.nodes;
			const type = data.type;
			const instanceCameras = data.instanceCameras;
			const instanceControllers = data.instanceControllers;
			const instanceLights = data.instanceLights;
			const instanceGeometries = data.instanceGeometries;
			const instanceNodes = data.instanceNodes;

			// nodes

			for ( let i = 0, l = nodes.length; i < l; i ++ ) {

				objects.push( getNode( nodes[ i ] ) );

			}

			// instance cameras

			for ( let i = 0, l = instanceCameras.length; i < l; i ++ ) {

				const instanceCamera = getCamera( instanceCameras[ i ] );

				if ( instanceCamera !== null ) {

					objects.push( instanceCamera.clone() );

				}

			}

			// instance controllers

			for ( let i = 0, l = instanceControllers.length; i < l; i ++ ) {

				const instance = instanceControllers[ i ];
				const controller = getController( instance.id );
				const geometries = getGeometry( controller.id );
				const newObjects = buildObjects( geometries, instance.materials );

				const skeletons = instance.skeletons;
				const joints = controller.skin.joints;

				const skeleton = buildSkeleton( skeletons, joints );

				for ( let j = 0, jl = newObjects.length; j < jl; j ++ ) {

					const object = newObjects[ j ];

					if ( object.isSkinnedMesh ) {

						object.bind( skeleton, controller.skin.bindMatrix );
						object.normalizeSkinWeights();

					}

					objects.push( object );

				}

			}

			// instance lights

			for ( let i = 0, l = instanceLights.length; i < l; i ++ ) {

				const instanceLight = getLight( instanceLights[ i ] );

				if ( instanceLight !== null ) {

					objects.push( instanceLight.clone() );

				}

			}

			// instance geometries

			for ( let i = 0, l = instanceGeometries.length; i < l; i ++ ) {

				const instance = instanceGeometries[ i ];

				// a single geometry instance in collada can lead to multiple object3Ds.
				// this is the case when primitives are combined like triangles and lines

				const geometries = getGeometry( instance.id );
				const newObjects = buildObjects( geometries, instance.materials );

				for ( let j = 0, jl = newObjects.length; j < jl; j ++ ) {

					objects.push( newObjects[ j ] );

				}

			}

			// instance nodes

			for ( let i = 0, l = instanceNodes.length; i < l; i ++ ) {

				objects.push( getNode( instanceNodes[ i ] ).clone() );

			}

			let object;

			if ( nodes.length === 0 && objects.length === 1 ) {

				object = objects[ 0 ];

			} else {

				object = ( type === 'JOINT' ) ? new Bone() : new Group();

				for ( let i = 0; i < objects.length; i ++ ) {

					object.add( objects[ i ] );

				}

			}

			object.name = ( type === 'JOINT' ) ? data.sid : data.name;
			object.matrix.copy( matrix );
			object.matrix.decompose( object.position, object.quaternion, object.scale );

			return object;

		}

		const fallbackMaterial = new MeshBasicMaterial( { color: 0xff00ff } );

		function resolveMaterialBinding( keys, instanceMaterials ) {

			const materials = [];

			for ( let i = 0, l = keys.length; i < l; i ++ ) {

				const id = instanceMaterials[ keys[ i ] ];

				if ( id === undefined ) {

					console.warn( 'THREE.ColladaLoader: Material with key %s not found. Apply fallback material.', keys[ i ] );
					materials.push( fallbackMaterial );

				} else {

					materials.push( getMaterial( id ) );

				}

			}

			return materials;

		}

		function buildObjects( geometries, instanceMaterials ) {

			const objects = [];

			for ( const type in geometries ) {

				const geometry = geometries[ type ];

				const materials = resolveMaterialBinding( geometry.materialKeys, instanceMaterials );

				// handle case if no materials are defined

				if ( materials.length === 0 ) {

					if ( type === 'lines' || type === 'linestrips' ) {

						materials.push( new LineBasicMaterial() );

					} else {

						materials.push( new MeshPhongMaterial() );

					}

				}

				// regard skinning

				const skinning = ( geometry.data.attributes.skinIndex !== undefined );

				// choose between a single or multi materials (material array)

				const material = ( materials.length === 1 ) ? materials[ 0 ] : materials;

				// now create a specific 3D object

				let object;

				switch ( type ) {

					case 'lines':
						object = new LineSegments( geometry.data, material );
						break;

					case 'linestrips':
						object = new Line( geometry.data, material );
						break;

					case 'triangles':
					case 'polylist':
						if ( skinning ) {

							object = new SkinnedMesh( geometry.data, material );

						} else {

							object = new Mesh( geometry.data, material );

						}

						break;

				}

				objects.push( object );

			}

			return objects;

		}

		function hasNode( id ) {

			return library.nodes[ id ] !== undefined;

		}

		function getNode( id ) {

			return getBuild( library.nodes[ id ], buildNode );

		}

		// visual scenes

		function parseVisualScene( xml ) {

			const data = {
				name: xml.getAttribute( 'name' ),
				children: []
			};

			prepareNodes( xml );

			const elements = getElementsByTagName( xml, 'node' );

			for ( let i = 0; i < elements.length; i ++ ) {

				data.children.push( parseNode( elements[ i ] ) );

			}

			library.visualScenes[ xml.getAttribute( 'id' ) ] = data;

		}

		function buildVisualScene( data ) {

			const group = new Group();
			group.name = data.name;

			const children = data.children;

			for ( let i = 0; i < children.length; i ++ ) {

				const child = children[ i ];

				group.add( getNode( child.id ) );

			}

			return group;

		}

		function hasVisualScene( id ) {

			return library.visualScenes[ id ] !== undefined;

		}

		function getVisualScene( id ) {

			return getBuild( library.visualScenes[ id ], buildVisualScene );

		}

		// scenes

		function parseScene( xml ) {

			const instance = getElementsByTagName( xml, 'instance_visual_scene' )[ 0 ];
			return getVisualScene( parseId( instance.getAttribute( 'url' ) ) );

		}

		function setupAnimations() {

			const clips = library.clips;

			if ( isEmpty( clips ) === true ) {

				if ( isEmpty( library.animations ) === false ) {

					// if there are animations but no clips, we create a default clip for playback

					const tracks = [];

					for ( const id in library.animations ) {

						const animationTracks = getAnimation( id );

						for ( let i = 0, l = animationTracks.length; i < l; i ++ ) {

							tracks.push( animationTracks[ i ] );

						}

					}

					animations.push( new AnimationClip( 'default', - 1, tracks ) );

				}

			} else {

				for ( const id in clips ) {

					animations.push( getAnimationClip( id ) );

				}

			}

		}

		// convert the parser error element into text with each child elements text
		// separated by new lines.

		function parserErrorToText( parserError ) {

			let result = '';
			const stack = [ parserError ];

			while ( stack.length ) {

				const node = stack.shift();

				if ( node.nodeType === Node.TEXT_NODE ) {

					result += node.textContent;

				} else {

					result += '\n';
					stack.push.apply( stack, node.childNodes );

				}

			}

			return result.trim();

		}

		if ( text.length === 0 ) {

			return { scene: new Scene() };

		}

		const xml = new DOMParser().parseFromString( text, 'application/xml' );

		const collada = getElementsByTagName( xml, 'COLLADA' )[ 0 ];

		const parserError = xml.getElementsByTagName( 'parsererror' )[ 0 ];
		if ( parserError !== undefined ) {

			// Chrome will return parser error with a div in it

			const errorElement = getElementsByTagName( parserError, 'div' )[ 0 ];
			let errorText;

			if ( errorElement ) {

				errorText = errorElement.textContent;

			} else {

				errorText = parserErrorToText( parserError );

			}

			console.error( 'THREE.ColladaLoader: Failed to parse collada file.\n', errorText );

			return null;

		}

		// metadata

		const version = collada.getAttribute( 'version' );
		console.log( 'THREE.ColladaLoader: File version', version );

		const asset = parseAsset( getElementsByTagName( collada, 'asset' )[ 0 ] );
		const textureLoader = new TextureLoader( this.manager );
		textureLoader.setPath( this.resourcePath || path ).setCrossOrigin( this.crossOrigin );

		let tgaLoader;

		if ( TGALoader ) {

			tgaLoader = new TGALoader( this.manager );
			tgaLoader.setPath( this.resourcePath || path );

		}

		//

		const tempColor = new Color();
		const animations = [];
		let kinematics = {};
		let count = 0;

		//

		const library = {
			animations: {},
			clips: {},
			controllers: {},
			images: {},
			effects: {},
			materials: {},
			cameras: {},
			lights: {},
			geometries: {},
			nodes: {},
			visualScenes: {},
			kinematicsModels: {},
			physicsModels: {},
			kinematicsScenes: {}
		};

		parseLibrary( collada, 'library_animations', 'animation', parseAnimation );
		parseLibrary( collada, 'library_animation_clips', 'animation_clip', parseAnimationClip );
		parseLibrary( collada, 'library_controllers', 'controller', parseController );
		parseLibrary( collada, 'library_images', 'image', parseImage );
		parseLibrary( collada, 'library_effects', 'effect', parseEffect );
		parseLibrary( collada, 'library_materials', 'material', parseMaterial );
		parseLibrary( collada, 'library_cameras', 'camera', parseCamera );
		parseLibrary( collada, 'library_lights', 'light', parseLight );
		parseLibrary( collada, 'library_geometries', 'geometry', parseGeometry );
		parseLibrary( collada, 'library_nodes', 'node', parseNode );
		parseLibrary( collada, 'library_visual_scenes', 'visual_scene', parseVisualScene );
		parseLibrary( collada, 'library_kinematics_models', 'kinematics_model', parseKinematicsModel );
		parseLibrary( collada, 'library_physics_models', 'physics_model', parsePhysicsModel );
		parseLibrary( collada, 'scene', 'instance_kinematics_scene', parseKinematicsScene );

		buildLibrary( library.animations, buildAnimation );
		buildLibrary( library.clips, buildAnimationClip );
		buildLibrary( library.controllers, buildController );
		buildLibrary( library.images, buildImage );
		buildLibrary( library.effects, buildEffect );
		buildLibrary( library.materials, buildMaterial );
		buildLibrary( library.cameras, buildCamera );
		buildLibrary( library.lights, buildLight );
		buildLibrary( library.geometries, buildGeometry );
		buildLibrary( library.visualScenes, buildVisualScene );

		setupAnimations();
		setupKinematics();

		const scene = parseScene( getElementsByTagName( collada, 'scene' )[ 0 ] );
		scene.animations = animations;

		if ( asset.upAxis === 'Z_UP' ) {

			scene.quaternion.setFromEuler( new Euler( - Math.PI / 2, 0, 0 ) );

		}

		scene.scale.multiplyScalar( asset.unit );

		return {
			get animations() {

				console.warn( 'THREE.ColladaLoader: Please access animations over scene.animations now.' );
				return animations;

			},
			kinematics: kinematics,
			library: library,
			scene: scene
		};

	}