(function (global, factory) {
  if (typeof define === "function" && define.amd) {
    define(["exports", "three"], factory);
  } else if (typeof exports !== "undefined") {
    factory(exports, require("three"));
  } else {
    var mod = {
      exports: {}
    };
    factory(mod.exports, global.three);
    global.GLTFExporter = mod.exports;
  }
})(typeof globalThis !== "undefined" ? globalThis : typeof self !== "undefined" ? self : this, function (_exports, _three) {
  "use strict";

  Object.defineProperty(_exports, "__esModule", {
    value: true
  });
  _exports.GLTFExporter = void 0;

  function asyncGeneratorStep(gen, resolve, reject, _next, _throw, key, arg) { try { var info = gen[key](arg); var value = info.value; } catch (error) { reject(error); return; } if (info.done) { resolve(value); } else { Promise.resolve(value).then(_next, _throw); } }

  function _asyncToGenerator(fn) { return function () { var self = this, args = arguments; return new Promise(function (resolve, reject) { var gen = fn.apply(self, args); function _next(value) { asyncGeneratorStep(gen, resolve, reject, _next, _throw, "next", value); } function _throw(err) { asyncGeneratorStep(gen, resolve, reject, _next, _throw, "throw", err); } _next(undefined); }); }; }

  function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

  function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } }

  function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); Object.defineProperty(Constructor, "prototype", { writable: false }); return Constructor; }

  var GLTFExporter = /*#__PURE__*/function () {
    function GLTFExporter() {
      _classCallCheck(this, GLTFExporter);

      this.pluginCallbacks = [];
      this.register(function (writer) {
        return new GLTFLightExtension(writer);
      });
      this.register(function (writer) {
        return new GLTFMaterialsUnlitExtension(writer);
      });
      this.register(function (writer) {
        return new GLTFMaterialsPBRSpecularGlossiness(writer);
      });
      this.register(function (writer) {
        return new GLTFMaterialsTransmissionExtension(writer);
      });
      this.register(function (writer) {
        return new GLTFMaterialsVolumeExtension(writer);
      });
      this.register(function (writer) {
        return new GLTFMaterialsClearcoatExtension(writer);
      });
    }

    _createClass(GLTFExporter, [{
      key: "register",
      value: function register(callback) {
        if (this.pluginCallbacks.indexOf(callback) === -1) {
          this.pluginCallbacks.push(callback);
        }

        return this;
      }
    }, {
      key: "unregister",
      value: function unregister(callback) {
        if (this.pluginCallbacks.indexOf(callback) !== -1) {
          this.pluginCallbacks.splice(this.pluginCallbacks.indexOf(callback), 1);
        }

        return this;
      }
      /**
       * Parse scenes and generate GLTF output
       * @param  {Scene or [THREE.Scenes]} input   Scene or Array of THREE.Scenes
       * @param  {Function} onDone  Callback on completed
       * @param  {Function} onError  Callback on errors
       * @param  {Object} options options
       */

    }, {
      key: "parse",
      value: function parse(input, onDone, onError, options) {
        if (typeof onError === 'object') {
          console.warn('THREE.GLTFExporter: parse() expects options as the fourth argument now.');
          options = onError;
        }

        var writer = new GLTFWriter();
        var plugins = [];

        for (var i = 0, il = this.pluginCallbacks.length; i < il; i++) {
          plugins.push(this.pluginCallbacks[i](writer));
        }

        writer.setPlugins(plugins);
        writer.write(input, onDone, options).catch(onError);
      }
    }, {
      key: "parseAsync",
      value: function parseAsync(input, options) {
        var scope = this;
        return new Promise(function (resolve, reject) {
          scope.parse(input, resolve, reject, options);
        });
      }
    }]);

    return GLTFExporter;
  }(); //------------------------------------------------------------------------------
  // Constants
  //------------------------------------------------------------------------------


  _exports.GLTFExporter = GLTFExporter;
  var WEBGL_CONSTANTS = {
    POINTS: 0x0000,
    LINES: 0x0001,
    LINE_LOOP: 0x0002,
    LINE_STRIP: 0x0003,
    TRIANGLES: 0x0004,
    TRIANGLE_STRIP: 0x0005,
    TRIANGLE_FAN: 0x0006,
    UNSIGNED_BYTE: 0x1401,
    UNSIGNED_SHORT: 0x1403,
    FLOAT: 0x1406,
    UNSIGNED_INT: 0x1405,
    ARRAY_BUFFER: 0x8892,
    ELEMENT_ARRAY_BUFFER: 0x8893,
    NEAREST: 0x2600,
    LINEAR: 0x2601,
    NEAREST_MIPMAP_NEAREST: 0x2700,
    LINEAR_MIPMAP_NEAREST: 0x2701,
    NEAREST_MIPMAP_LINEAR: 0x2702,
    LINEAR_MIPMAP_LINEAR: 0x2703,
    CLAMP_TO_EDGE: 33071,
    MIRRORED_REPEAT: 33648,
    REPEAT: 10497
  };
  var THREE_TO_WEBGL = {};
  THREE_TO_WEBGL[_three.NearestFilter] = WEBGL_CONSTANTS.NEAREST;
  THREE_TO_WEBGL[_three.NearestMipmapNearestFilter] = WEBGL_CONSTANTS.NEAREST_MIPMAP_NEAREST;
  THREE_TO_WEBGL[_three.NearestMipmapLinearFilter] = WEBGL_CONSTANTS.NEAREST_MIPMAP_LINEAR;
  THREE_TO_WEBGL[_three.LinearFilter] = WEBGL_CONSTANTS.LINEAR;
  THREE_TO_WEBGL[_three.LinearMipmapNearestFilter] = WEBGL_CONSTANTS.LINEAR_MIPMAP_NEAREST;
  THREE_TO_WEBGL[_three.LinearMipmapLinearFilter] = WEBGL_CONSTANTS.LINEAR_MIPMAP_LINEAR;
  THREE_TO_WEBGL[_three.ClampToEdgeWrapping] = WEBGL_CONSTANTS.CLAMP_TO_EDGE;
  THREE_TO_WEBGL[_three.RepeatWrapping] = WEBGL_CONSTANTS.REPEAT;
  THREE_TO_WEBGL[_three.MirroredRepeatWrapping] = WEBGL_CONSTANTS.MIRRORED_REPEAT;
  var PATH_PROPERTIES = {
    scale: 'scale',
    position: 'translation',
    quaternion: 'rotation',
    morphTargetInfluences: 'weights'
  }; // GLB constants
  // https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#glb-file-format-specification

  var GLB_HEADER_BYTES = 12;
  var GLB_HEADER_MAGIC = 0x46546C67;
  var GLB_VERSION = 2;
  var GLB_CHUNK_PREFIX_BYTES = 8;
  var GLB_CHUNK_TYPE_JSON = 0x4E4F534A;
  var GLB_CHUNK_TYPE_BIN = 0x004E4942; //------------------------------------------------------------------------------
  // Utility functions
  //------------------------------------------------------------------------------

  /**
   * Compare two arrays
   * @param  {Array} array1 Array 1 to compare
   * @param  {Array} array2 Array 2 to compare
   * @return {Boolean}        Returns true if both arrays are equal
   */

  function equalArray(array1, array2) {
    return array1.length === array2.length && array1.every(function (element, index) {
      return element === array2[index];
    });
  }
  /**
   * Converts a string to an ArrayBuffer.
   * @param  {string} text
   * @return {ArrayBuffer}
   */


  function stringToArrayBuffer(text) {
    if (window.TextEncoder !== undefined) {
      return new TextEncoder().encode(text).buffer;
    }

    var array = new Uint8Array(new ArrayBuffer(text.length));

    for (var i = 0, il = text.length; i < il; i++) {
      var value = text.charCodeAt(i); // Replacing multi-byte character with space(0x20).

      array[i] = value > 0xFF ? 0x20 : value;
    }

    return array.buffer;
  }
  /**
   * Is identity matrix
   *
   * @param {Matrix4} matrix
   * @returns {Boolean} Returns true, if parameter is identity matrix
   */


  function isIdentityMatrix(matrix) {
    return equalArray(matrix.elements, [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1]);
  }
  /**
   * Get the min and max vectors from the given attribute
   * @param  {BufferAttribute} attribute Attribute to find the min/max in range from start to start + count
   * @param  {Integer} start
   * @param  {Integer} count
   * @return {Object} Object containing the `min` and `max` values (As an array of attribute.itemSize components)
   */


  function getMinMax(attribute, start, count) {
    var output = {
      min: new Array(attribute.itemSize).fill(Number.POSITIVE_INFINITY),
      max: new Array(attribute.itemSize).fill(Number.NEGATIVE_INFINITY)
    };

    for (var i = start; i < start + count; i++) {
      for (var a = 0; a < attribute.itemSize; a++) {
        var value = void 0;

        if (attribute.itemSize > 4) {
          // no support for interleaved data for itemSize > 4
          value = attribute.array[i * attribute.itemSize + a];
        } else {
          if (a === 0) value = attribute.getX(i);else if (a === 1) value = attribute.getY(i);else if (a === 2) value = attribute.getZ(i);else if (a === 3) value = attribute.getW(i);
        }

        output.min[a] = Math.min(output.min[a], value);
        output.max[a] = Math.max(output.max[a], value);
      }
    }

    return output;
  }
  /**
   * Get the required size + padding for a buffer, rounded to the next 4-byte boundary.
   * https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#data-alignment
   *
   * @param {Integer} bufferSize The size the original buffer.
   * @returns {Integer} new buffer size with required padding.
   *
   */


  function getPaddedBufferSize(bufferSize) {
    return Math.ceil(bufferSize / 4) * 4;
  }
  /**
   * Returns a buffer aligned to 4-byte boundary.
   *
   * @param {ArrayBuffer} arrayBuffer Buffer to pad
   * @param {Integer} paddingByte (Optional)
   * @returns {ArrayBuffer} The same buffer if it's already aligned to 4-byte boundary or a new buffer
   */


  function getPaddedArrayBuffer(arrayBuffer) {
    var paddingByte = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 0;
    var paddedLength = getPaddedBufferSize(arrayBuffer.byteLength);

    if (paddedLength !== arrayBuffer.byteLength) {
      var array = new Uint8Array(paddedLength);
      array.set(new Uint8Array(arrayBuffer));

      if (paddingByte !== 0) {
        for (var i = arrayBuffer.byteLength; i < paddedLength; i++) {
          array[i] = paddingByte;
        }
      }

      return array.buffer;
    }

    return arrayBuffer;
  }

  var cachedCanvas = null;
  /**
   * Writer
   */

  var GLTFWriter = /*#__PURE__*/function () {
    function GLTFWriter() {
      _classCallCheck(this, GLTFWriter);

      this.plugins = [];
      this.options = {};
      this.pending = [];
      this.buffers = [];
      this.byteOffset = 0;
      this.buffers = [];
      this.nodeMap = new Map();
      this.skins = [];
      this.extensionsUsed = {};
      this.uids = new Map();
      this.uid = 0;
      this.json = {
        asset: {
          version: '2.0',
          generator: 'THREE.GLTFExporter'
        }
      };
      this.cache = {
        meshes: new Map(),
        attributes: new Map(),
        attributesNormalized: new Map(),
        materials: new Map(),
        textures: new Map(),
        images: new Map()
      };
    }

    _createClass(GLTFWriter, [{
      key: "setPlugins",
      value: function setPlugins(plugins) {
        this.plugins = plugins;
      }
      /**
       * Parse scenes and generate GLTF output
       * @param  {Scene or [THREE.Scenes]} input   Scene or Array of THREE.Scenes
       * @param  {Function} onDone  Callback on completed
       * @param  {Object} options options
       */

    }, {
      key: "write",
      value: function () {
        var _write = _asyncToGenerator( /*#__PURE__*/regeneratorRuntime.mark(function _callee(input, onDone, options) {
          var writer, buffers, json, extensionsUsed, blob, extensionsUsedList, reader, _reader;

          return regeneratorRuntime.wrap(function _callee$(_context) {
            while (1) {
              switch (_context.prev = _context.next) {
                case 0:
                  this.options = Object.assign({}, {
                    // default options
                    binary: false,
                    trs: false,
                    onlyVisible: true,
                    truncateDrawRange: true,
                    embedImages: true,
                    maxTextureSize: Infinity,
                    animations: [],
                    includeCustomExtensions: false
                  }, options);

                  if (this.options.animations.length > 0) {
                    // Only TRS properties, and not matrices, may be targeted by animation.
                    this.options.trs = true;
                  }

                  this.processInput(input);
                  _context.next = 5;
                  return Promise.all(this.pending);

                case 5:
                  writer = this;
                  buffers = writer.buffers;
                  json = writer.json;
                  options = writer.options;
                  extensionsUsed = writer.extensionsUsed; // Merge buffers.

                  blob = new Blob(buffers, {
                    type: 'application/octet-stream'
                  }); // Declare extensions.

                  extensionsUsedList = Object.keys(extensionsUsed);
                  if (extensionsUsedList.length > 0) json.extensionsUsed = extensionsUsedList; // Update bytelength of the single buffer.

                  if (json.buffers && json.buffers.length > 0) json.buffers[0].byteLength = blob.size;

                  if (options.binary === true) {
                    // https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#glb-file-format-specification
                    reader = new window.FileReader();
                    reader.readAsArrayBuffer(blob);

                    reader.onloadend = function () {
                      // Binary chunk.
                      var binaryChunk = getPaddedArrayBuffer(reader.result);
                      var binaryChunkPrefix = new DataView(new ArrayBuffer(GLB_CHUNK_PREFIX_BYTES));
                      binaryChunkPrefix.setUint32(0, binaryChunk.byteLength, true);
                      binaryChunkPrefix.setUint32(4, GLB_CHUNK_TYPE_BIN, true); // JSON chunk.

                      var jsonChunk = getPaddedArrayBuffer(stringToArrayBuffer(JSON.stringify(json)), 0x20);
                      var jsonChunkPrefix = new DataView(new ArrayBuffer(GLB_CHUNK_PREFIX_BYTES));
                      jsonChunkPrefix.setUint32(0, jsonChunk.byteLength, true);
                      jsonChunkPrefix.setUint32(4, GLB_CHUNK_TYPE_JSON, true); // GLB header.

                      var header = new ArrayBuffer(GLB_HEADER_BYTES);
                      var headerView = new DataView(header);
                      headerView.setUint32(0, GLB_HEADER_MAGIC, true);
                      headerView.setUint32(4, GLB_VERSION, true);
                      var totalByteLength = GLB_HEADER_BYTES + jsonChunkPrefix.byteLength + jsonChunk.byteLength + binaryChunkPrefix.byteLength + binaryChunk.byteLength;
                      headerView.setUint32(8, totalByteLength, true);
                      var glbBlob = new Blob([header, jsonChunkPrefix, jsonChunk, binaryChunkPrefix, binaryChunk], {
                        type: 'application/octet-stream'
                      });
                      var glbReader = new window.FileReader();
                      glbReader.readAsArrayBuffer(glbBlob);

                      glbReader.onloadend = function () {
                        onDone(glbReader.result);
                      };
                    };
                  } else {
                    if (json.buffers && json.buffers.length > 0) {
                      _reader = new window.FileReader();

                      _reader.readAsDataURL(blob);

                      _reader.onloadend = function () {
                        var base64data = _reader.result;
                        json.buffers[0].uri = base64data;
                        onDone(json);
                      };
                    } else {
                      onDone(json);
                    }
                  }

                case 15:
                case "end":
                  return _context.stop();
              }
            }
          }, _callee, this);
        }));

        function write(_x, _x2, _x3) {
          return _write.apply(this, arguments);
        }

        return write;
      }()
      /**
       * Serializes a userData.
       *
       * @param {THREE.Object3D|THREE.Material} object
       * @param {Object} objectDef
       */

    }, {
      key: "serializeUserData",
      value: function serializeUserData(object, objectDef) {
        if (Object.keys(object.userData).length === 0) return;
        var options = this.options;
        var extensionsUsed = this.extensionsUsed;

        try {
          var json = JSON.parse(JSON.stringify(object.userData));

          if (options.includeCustomExtensions && json.gltfExtensions) {
            if (objectDef.extensions === undefined) objectDef.extensions = {};

            for (var extensionName in json.gltfExtensions) {
              objectDef.extensions[extensionName] = json.gltfExtensions[extensionName];
              extensionsUsed[extensionName] = true;
            }

            delete json.gltfExtensions;
          }

          if (Object.keys(json).length > 0) objectDef.extras = json;
        } catch (error) {
          console.warn('THREE.GLTFExporter: userData of \'' + object.name + '\' ' + 'won\'t be serialized because of JSON.stringify error - ' + error.message);
        }
      }
      /**
       * Assign and return a temporal unique id for an object
       * especially which doesn't have .uuid
       * @param  {Object} object
       * @return {Integer}
       */

    }, {
      key: "getUID",
      value: function getUID(object) {
        if (!this.uids.has(object)) this.uids.set(object, this.uid++);
        return this.uids.get(object);
      }
      /**
       * Checks if normal attribute values are normalized.
       *
       * @param {BufferAttribute} normal
       * @returns {Boolean}
       */

    }, {
      key: "isNormalizedNormalAttribute",
      value: function isNormalizedNormalAttribute(normal) {
        var cache = this.cache;
        if (cache.attributesNormalized.has(normal)) return false;
        var v = new _three.Vector3();

        for (var i = 0, il = normal.count; i < il; i++) {
          // 0.0005 is from glTF-validator
          if (Math.abs(v.fromBufferAttribute(normal, i).length() - 1.0) > 0.0005) return false;
        }

        return true;
      }
      /**
       * Creates normalized normal buffer attribute.
       *
       * @param {BufferAttribute} normal
       * @returns {BufferAttribute}
       *
       */

    }, {
      key: "createNormalizedNormalAttribute",
      value: function createNormalizedNormalAttribute(normal) {
        var cache = this.cache;
        if (cache.attributesNormalized.has(normal)) return cache.attributesNormalized.get(normal);
        var attribute = normal.clone();
        var v = new _three.Vector3();

        for (var i = 0, il = attribute.count; i < il; i++) {
          v.fromBufferAttribute(attribute, i);

          if (v.x === 0 && v.y === 0 && v.z === 0) {
            // if values can't be normalized set (1, 0, 0)
            v.setX(1.0);
          } else {
            v.normalize();
          }

          attribute.setXYZ(i, v.x, v.y, v.z);
        }

        cache.attributesNormalized.set(normal, attribute);
        return attribute;
      }
      /**
       * Applies a texture transform, if present, to the map definition. Requires
       * the KHR_texture_transform extension.
       *
       * @param {Object} mapDef
       * @param {THREE.Texture} texture
       */

    }, {
      key: "applyTextureTransform",
      value: function applyTextureTransform(mapDef, texture) {
        var didTransform = false;
        var transformDef = {};

        if (texture.offset.x !== 0 || texture.offset.y !== 0) {
          transformDef.offset = texture.offset.toArray();
          didTransform = true;
        }

        if (texture.rotation !== 0) {
          transformDef.rotation = texture.rotation;
          didTransform = true;
        }

        if (texture.repeat.x !== 1 || texture.repeat.y !== 1) {
          transformDef.scale = texture.repeat.toArray();
          didTransform = true;
        }

        if (didTransform) {
          mapDef.extensions = mapDef.extensions || {};
          mapDef.extensions['KHR_texture_transform'] = transformDef;
          this.extensionsUsed['KHR_texture_transform'] = true;
        }
      }
      /**
       * Process a buffer to append to the default one.
       * @param  {ArrayBuffer} buffer
       * @return {Integer}
       */

    }, {
      key: "processBuffer",
      value: function processBuffer(buffer) {
        var json = this.json;
        var buffers = this.buffers;
        if (!json.buffers) json.buffers = [{
          byteLength: 0
        }]; // All buffers are merged before export.

        buffers.push(buffer);
        return 0;
      }
      /**
       * Process and generate a BufferView
       * @param  {BufferAttribute} attribute
       * @param  {number} componentType
       * @param  {number} start
       * @param  {number} count
       * @param  {number} target (Optional) Target usage of the BufferView
       * @return {Object}
       */

    }, {
      key: "processBufferView",
      value: function processBufferView(attribute, componentType, start, count, target) {
        var json = this.json;
        if (!json.bufferViews) json.bufferViews = []; // Create a new dataview and dump the attribute's array into it

        var componentSize;

        if (componentType === WEBGL_CONSTANTS.UNSIGNED_BYTE) {
          componentSize = 1;
        } else if (componentType === WEBGL_CONSTANTS.UNSIGNED_SHORT) {
          componentSize = 2;
        } else {
          componentSize = 4;
        }

        var byteLength = getPaddedBufferSize(count * attribute.itemSize * componentSize);
        var dataView = new DataView(new ArrayBuffer(byteLength));
        var offset = 0;

        for (var i = start; i < start + count; i++) {
          for (var a = 0; a < attribute.itemSize; a++) {
            var value = void 0;

            if (attribute.itemSize > 4) {
              // no support for interleaved data for itemSize > 4
              value = attribute.array[i * attribute.itemSize + a];
            } else {
              if (a === 0) value = attribute.getX(i);else if (a === 1) value = attribute.getY(i);else if (a === 2) value = attribute.getZ(i);else if (a === 3) value = attribute.getW(i);
            }

            if (componentType === WEBGL_CONSTANTS.FLOAT) {
              dataView.setFloat32(offset, value, true);
            } else if (componentType === WEBGL_CONSTANTS.UNSIGNED_INT) {
              dataView.setUint32(offset, value, true);
            } else if (componentType === WEBGL_CONSTANTS.UNSIGNED_SHORT) {
              dataView.setUint16(offset, value, true);
            } else if (componentType === WEBGL_CONSTANTS.UNSIGNED_BYTE) {
              dataView.setUint8(offset, value);
            }

            offset += componentSize;
          }
        }

        var bufferViewDef = {
          buffer: this.processBuffer(dataView.buffer),
          byteOffset: this.byteOffset,
          byteLength: byteLength
        };
        if (target !== undefined) bufferViewDef.target = target;

        if (target === WEBGL_CONSTANTS.ARRAY_BUFFER) {
          // Only define byteStride for vertex attributes.
          bufferViewDef.byteStride = attribute.itemSize * componentSize;
        }

        this.byteOffset += byteLength;
        json.bufferViews.push(bufferViewDef); // @TODO Merge bufferViews where possible.

        var output = {
          id: json.bufferViews.length - 1,
          byteLength: 0
        };
        return output;
      }
      /**
       * Process and generate a BufferView from an image Blob.
       * @param {Blob} blob
       * @return {Promise<Integer>}
       */

    }, {
      key: "processBufferViewImage",
      value: function processBufferViewImage(blob) {
        var writer = this;
        var json = writer.json;
        if (!json.bufferViews) json.bufferViews = [];
        return new Promise(function (resolve) {
          var reader = new window.FileReader();
          reader.readAsArrayBuffer(blob);

          reader.onloadend = function () {
            var buffer = getPaddedArrayBuffer(reader.result);
            var bufferViewDef = {
              buffer: writer.processBuffer(buffer),
              byteOffset: writer.byteOffset,
              byteLength: buffer.byteLength
            };
            writer.byteOffset += buffer.byteLength;
            resolve(json.bufferViews.push(bufferViewDef) - 1);
          };
        });
      }
      /**
       * Process attribute to generate an accessor
       * @param  {BufferAttribute} attribute Attribute to process
       * @param  {THREE.BufferGeometry} geometry (Optional) Geometry used for truncated draw range
       * @param  {Integer} start (Optional)
       * @param  {Integer} count (Optional)
       * @return {Integer|null} Index of the processed accessor on the "accessors" array
       */

    }, {
      key: "processAccessor",
      value: function processAccessor(attribute, geometry, start, count) {
        var options = this.options;
        var json = this.json;
        var types = {
          1: 'SCALAR',
          2: 'VEC2',
          3: 'VEC3',
          4: 'VEC4',
          16: 'MAT4'
        };
        var componentType; // Detect the component type of the attribute array (float, uint or ushort)

        if (attribute.array.constructor === Float32Array) {
          componentType = WEBGL_CONSTANTS.FLOAT;
        } else if (attribute.array.constructor === Uint32Array) {
          componentType = WEBGL_CONSTANTS.UNSIGNED_INT;
        } else if (attribute.array.constructor === Uint16Array) {
          componentType = WEBGL_CONSTANTS.UNSIGNED_SHORT;
        } else if (attribute.array.constructor === Uint8Array) {
          componentType = WEBGL_CONSTANTS.UNSIGNED_BYTE;
        } else {
          throw new Error('THREE.GLTFExporter: Unsupported bufferAttribute component type.');
        }

        if (start === undefined) start = 0;
        if (count === undefined) count = attribute.count; // @TODO Indexed buffer geometry with drawRange not supported yet

        if (options.truncateDrawRange && geometry !== undefined && geometry.index === null) {
          var end = start + count;
          var end2 = geometry.drawRange.count === Infinity ? attribute.count : geometry.drawRange.start + geometry.drawRange.count;
          start = Math.max(start, geometry.drawRange.start);
          count = Math.min(end, end2) - start;
          if (count < 0) count = 0;
        } // Skip creating an accessor if the attribute doesn't have data to export


        if (count === 0) return null;
        var minMax = getMinMax(attribute, start, count);
        var bufferViewTarget; // If geometry isn't provided, don't infer the target usage of the bufferView. For
        // animation samplers, target must not be set.

        if (geometry !== undefined) {
          bufferViewTarget = attribute === geometry.index ? WEBGL_CONSTANTS.ELEMENT_ARRAY_BUFFER : WEBGL_CONSTANTS.ARRAY_BUFFER;
        }

        var bufferView = this.processBufferView(attribute, componentType, start, count, bufferViewTarget);
        var accessorDef = {
          bufferView: bufferView.id,
          byteOffset: bufferView.byteOffset,
          componentType: componentType,
          count: count,
          max: minMax.max,
          min: minMax.min,
          type: types[attribute.itemSize]
        };
        if (attribute.normalized === true) accessorDef.normalized = true;
        if (!json.accessors) json.accessors = [];
        return json.accessors.push(accessorDef) - 1;
      }
      /**
       * Process image
       * @param  {Image} image to process
       * @param  {Integer} format of the image (e.g. RGBFormat, RGBAFormat etc)
       * @param  {Boolean} flipY before writing out the image
       * @return {Integer}     Index of the processed texture in the "images" array
       */

    }, {
      key: "processImage",
      value: function processImage(image, format, flipY) {
        var writer = this;
        var cache = writer.cache;
        var json = writer.json;
        var options = writer.options;
        var pending = writer.pending;
        if (!cache.images.has(image)) cache.images.set(image, {});
        var cachedImages = cache.images.get(image);
        var mimeType = format === _three.RGBAFormat ? 'image/png' : 'image/jpeg';
        var key = mimeType + ':flipY/' + flipY.toString();
        if (cachedImages[key] !== undefined) return cachedImages[key];
        if (!json.images) json.images = [];
        var imageDef = {
          mimeType: mimeType
        };

        if (options.embedImages) {
          var canvas = cachedCanvas = cachedCanvas || document.createElement('canvas');
          canvas.width = Math.min(image.width, options.maxTextureSize);
          canvas.height = Math.min(image.height, options.maxTextureSize);
          var ctx = canvas.getContext('2d');

          if (flipY === true) {
            ctx.translate(0, canvas.height);
            ctx.scale(1, -1);
          }

          if (typeof HTMLImageElement !== 'undefined' && image instanceof HTMLImageElement || typeof HTMLCanvasElement !== 'undefined' && image instanceof HTMLCanvasElement || typeof OffscreenCanvas !== 'undefined' && image instanceof OffscreenCanvas || typeof ImageBitmap !== 'undefined' && image instanceof ImageBitmap) {
            ctx.drawImage(image, 0, 0, canvas.width, canvas.height);
          } else {
            if (format !== _three.RGBAFormat && format !== _three.RGBFormat) {
              console.error('GLTFExporter: Only RGB and RGBA formats are supported.');
            }

            if (image.width > options.maxTextureSize || image.height > options.maxTextureSize) {
              console.warn('GLTFExporter: Image size is bigger than maxTextureSize', image);
            }

            var data = new Uint8ClampedArray(image.height * image.width * 4);

            if (format === _three.RGBAFormat) {
              for (var i = 0; i < data.length; i += 4) {
                data[i + 0] = image.data[i + 0];
                data[i + 1] = image.data[i + 1];
                data[i + 2] = image.data[i + 2];
                data[i + 3] = image.data[i + 3];
              }
            } else {
              for (var _i = 0, j = 0; _i < data.length; _i += 4, j += 3) {
                data[_i + 0] = image.data[j + 0];
                data[_i + 1] = image.data[j + 1];
                data[_i + 2] = image.data[j + 2];
                data[_i + 3] = 255;
              }
            }

            ctx.putImageData(new ImageData(data, image.width, image.height), 0, 0);
          }

          if (options.binary === true) {
            pending.push(new Promise(function (resolve) {
              canvas.toBlob(function (blob) {
                writer.processBufferViewImage(blob).then(function (bufferViewIndex) {
                  imageDef.bufferView = bufferViewIndex;
                  resolve();
                });
              }, mimeType);
            }));
          } else {
            imageDef.uri = canvas.toDataURL(mimeType);
          }
        } else {
          imageDef.uri = image.src;
        }

        var index = json.images.push(imageDef) - 1;
        cachedImages[key] = index;
        return index;
      }
      /**
       * Process sampler
       * @param  {Texture} map Texture to process
       * @return {Integer}     Index of the processed texture in the "samplers" array
       */

    }, {
      key: "processSampler",
      value: function processSampler(map) {
        var json = this.json;
        if (!json.samplers) json.samplers = [];
        var samplerDef = {
          magFilter: THREE_TO_WEBGL[map.magFilter],
          minFilter: THREE_TO_WEBGL[map.minFilter],
          wrapS: THREE_TO_WEBGL[map.wrapS],
          wrapT: THREE_TO_WEBGL[map.wrapT]
        };
        return json.samplers.push(samplerDef) - 1;
      }
      /**
       * Process texture
       * @param  {Texture} map Map to process
       * @return {Integer} Index of the processed texture in the "textures" array
       */

    }, {
      key: "processTexture",
      value: function processTexture(map) {
        var cache = this.cache;
        var json = this.json;
        if (cache.textures.has(map)) return cache.textures.get(map);
        if (!json.textures) json.textures = [];
        var textureDef = {
          sampler: this.processSampler(map),
          source: this.processImage(map.image, map.format, map.flipY)
        };
        if (map.name) textureDef.name = map.name;

        this._invokeAll(function (ext) {
          ext.writeTexture && ext.writeTexture(map, textureDef);
        });

        var index = json.textures.push(textureDef) - 1;
        cache.textures.set(map, index);
        return index;
      }
      /**
       * Process material
       * @param  {THREE.Material} material Material to process
       * @return {Integer|null} Index of the processed material in the "materials" array
       */

    }, {
      key: "processMaterial",
      value: function processMaterial(material) {
        var cache = this.cache;
        var json = this.json;
        if (cache.materials.has(material)) return cache.materials.get(material);

        if (material.isShaderMaterial) {
          console.warn('GLTFExporter: THREE.ShaderMaterial not supported.');
          return null;
        }

        if (!json.materials) json.materials = []; // @QUESTION Should we avoid including any attribute that has the default value?

        var materialDef = {
          pbrMetallicRoughness: {}
        };

        if (material.isMeshStandardMaterial !== true && material.isMeshBasicMaterial !== true) {
          console.warn('GLTFExporter: Use MeshStandardMaterial or MeshBasicMaterial for best results.');
        } // pbrMetallicRoughness.baseColorFactor


        var color = material.color.toArray().concat([material.opacity]);

        if (!equalArray(color, [1, 1, 1, 1])) {
          materialDef.pbrMetallicRoughness.baseColorFactor = color;
        }

        if (material.isMeshStandardMaterial) {
          materialDef.pbrMetallicRoughness.metallicFactor = material.metalness;
          materialDef.pbrMetallicRoughness.roughnessFactor = material.roughness;
        } else {
          materialDef.pbrMetallicRoughness.metallicFactor = 0.5;
          materialDef.pbrMetallicRoughness.roughnessFactor = 0.5;
        } // pbrMetallicRoughness.metallicRoughnessTexture


        if (material.metalnessMap || material.roughnessMap) {
          if (material.metalnessMap === material.roughnessMap) {
            var metalRoughMapDef = {
              index: this.processTexture(material.metalnessMap)
            };
            this.applyTextureTransform(metalRoughMapDef, material.metalnessMap);
            materialDef.pbrMetallicRoughness.metallicRoughnessTexture = metalRoughMapDef;
          } else {
            console.warn('THREE.GLTFExporter: Ignoring metalnessMap and roughnessMap because they are not the same Texture.');
          }
        } // pbrMetallicRoughness.baseColorTexture or pbrSpecularGlossiness diffuseTexture


        if (material.map) {
          var baseColorMapDef = {
            index: this.processTexture(material.map)
          };
          this.applyTextureTransform(baseColorMapDef, material.map);
          materialDef.pbrMetallicRoughness.baseColorTexture = baseColorMapDef;
        }

        if (material.emissive) {
          // note: emissive components are limited to stay within the 0 - 1 range to accommodate glTF spec. see #21849 and #22000.
          var emissive = material.emissive.clone().multiplyScalar(material.emissiveIntensity);
          var maxEmissiveComponent = Math.max(emissive.r, emissive.g, emissive.b);

          if (maxEmissiveComponent > 1) {
            emissive.multiplyScalar(1 / maxEmissiveComponent);
            console.warn('THREE.GLTFExporter: Some emissive components exceed 1; emissive has been limited');
          }

          if (maxEmissiveComponent > 0) {
            materialDef.emissiveFactor = emissive.toArray();
          } // emissiveTexture


          if (material.emissiveMap) {
            var emissiveMapDef = {
              index: this.processTexture(material.emissiveMap)
            };
            this.applyTextureTransform(emissiveMapDef, material.emissiveMap);
            materialDef.emissiveTexture = emissiveMapDef;
          }
        } // normalTexture


        if (material.normalMap) {
          var normalMapDef = {
            index: this.processTexture(material.normalMap)
          };

          if (material.normalScale && material.normalScale.x !== 1) {
            // glTF normal scale is univariate. Ignore `y`, which may be flipped.
            // Context: https://github.com/mrdoob/three.js/issues/11438#issuecomment-507003995
            normalMapDef.scale = material.normalScale.x;
          }

          this.applyTextureTransform(normalMapDef, material.normalMap);
          materialDef.normalTexture = normalMapDef;
        } // occlusionTexture


        if (material.aoMap) {
          var occlusionMapDef = {
            index: this.processTexture(material.aoMap),
            texCoord: 1
          };

          if (material.aoMapIntensity !== 1.0) {
            occlusionMapDef.strength = material.aoMapIntensity;
          }

          this.applyTextureTransform(occlusionMapDef, material.aoMap);
          materialDef.occlusionTexture = occlusionMapDef;
        } // alphaMode


        if (material.transparent) {
          materialDef.alphaMode = 'BLEND';
        } else {
          if (material.alphaTest > 0.0) {
            materialDef.alphaMode = 'MASK';
            materialDef.alphaCutoff = material.alphaTest;
          }
        } // doubleSided


        if (material.side === _three.DoubleSide) materialDef.doubleSided = true;
        if (material.name !== '') materialDef.name = material.name;
        this.serializeUserData(material, materialDef);

        this._invokeAll(function (ext) {
          ext.writeMaterial && ext.writeMaterial(material, materialDef);
        });

        var index = json.materials.push(materialDef) - 1;
        cache.materials.set(material, index);
        return index;
      }
      /**
       * Process mesh
       * @param  {THREE.Mesh} mesh Mesh to process
       * @return {Integer|null} Index of the processed mesh in the "meshes" array
       */

    }, {
      key: "processMesh",
      value: function processMesh(mesh) {
        var cache = this.cache;
        var json = this.json;
        var meshCacheKeyParts = [mesh.geometry.uuid];

        if (Array.isArray(mesh.material)) {
          for (var i = 0, l = mesh.material.length; i < l; i++) {
            meshCacheKeyParts.push(mesh.material[i].uuid);
          }
        } else {
          meshCacheKeyParts.push(mesh.material.uuid);
        }

        var meshCacheKey = meshCacheKeyParts.join(':');
        if (cache.meshes.has(meshCacheKey)) return cache.meshes.get(meshCacheKey);
        var geometry = mesh.geometry;
        var mode; // Use the correct mode

        if (mesh.isLineSegments) {
          mode = WEBGL_CONSTANTS.LINES;
        } else if (mesh.isLineLoop) {
          mode = WEBGL_CONSTANTS.LINE_LOOP;
        } else if (mesh.isLine) {
          mode = WEBGL_CONSTANTS.LINE_STRIP;
        } else if (mesh.isPoints) {
          mode = WEBGL_CONSTANTS.POINTS;
        } else {
          mode = mesh.material.wireframe ? WEBGL_CONSTANTS.LINES : WEBGL_CONSTANTS.TRIANGLES;
        }

        if (geometry.isBufferGeometry !== true) {
          throw new Error('THREE.GLTFExporter: Geometry is not of type THREE.BufferGeometry.');
        }

        var meshDef = {};
        var attributes = {};
        var primitives = [];
        var targets = []; // Conversion between attributes names in threejs and gltf spec

        var nameConversion = {
          uv: 'TEXCOORD_0',
          uv2: 'TEXCOORD_1',
          color: 'COLOR_0',
          skinWeight: 'WEIGHTS_0',
          skinIndex: 'JOINTS_0'
        };
        var originalNormal = geometry.getAttribute('normal');

        if (originalNormal !== undefined && !this.isNormalizedNormalAttribute(originalNormal)) {
          console.warn('THREE.GLTFExporter: Creating normalized normal attribute from the non-normalized one.');
          geometry.setAttribute('normal', this.createNormalizedNormalAttribute(originalNormal));
        } // @QUESTION Detect if .vertexColors = true?
        // For every attribute create an accessor


        var modifiedAttribute = null;

        for (var attributeName in geometry.attributes) {
          // Ignore morph target attributes, which are exported later.
          if (attributeName.substr(0, 5) === 'morph') continue;
          var attribute = geometry.attributes[attributeName];
          attributeName = nameConversion[attributeName] || attributeName.toUpperCase(); // Prefix all geometry attributes except the ones specifically
          // listed in the spec; non-spec attributes are considered custom.

          var validVertexAttributes = /^(POSITION|NORMAL|TANGENT|TEXCOORD_\d+|COLOR_\d+|JOINTS_\d+|WEIGHTS_\d+)$/;
          if (!validVertexAttributes.test(attributeName)) attributeName = '_' + attributeName;

          if (cache.attributes.has(this.getUID(attribute))) {
            attributes[attributeName] = cache.attributes.get(this.getUID(attribute));
            continue;
          } // JOINTS_0 must be UNSIGNED_BYTE or UNSIGNED_SHORT.


          modifiedAttribute = null;
          var array = attribute.array;

          if (attributeName === 'JOINTS_0' && !(array instanceof Uint16Array) && !(array instanceof Uint8Array)) {
            console.warn('GLTFExporter: Attribute "skinIndex" converted to type UNSIGNED_SHORT.');
            modifiedAttribute = new _three.BufferAttribute(new Uint16Array(array), attribute.itemSize, attribute.normalized);
          }

          var accessor = this.processAccessor(modifiedAttribute || attribute, geometry);

          if (accessor !== null) {
            attributes[attributeName] = accessor;
            cache.attributes.set(this.getUID(attribute), accessor);
          }
        }

        if (originalNormal !== undefined) geometry.setAttribute('normal', originalNormal); // Skip if no exportable attributes found

        if (Object.keys(attributes).length === 0) return null; // Morph targets

        if (mesh.morphTargetInfluences !== undefined && mesh.morphTargetInfluences.length > 0) {
          var weights = [];
          var targetNames = [];
          var reverseDictionary = {};

          if (mesh.morphTargetDictionary !== undefined) {
            for (var key in mesh.morphTargetDictionary) {
              reverseDictionary[mesh.morphTargetDictionary[key]] = key;
            }
          }

          for (var _i2 = 0; _i2 < mesh.morphTargetInfluences.length; ++_i2) {
            var target = {};
            var warned = false;

            for (var _attributeName in geometry.morphAttributes) {
              // glTF 2.0 morph supports only POSITION/NORMAL/TANGENT.
              // Three.js doesn't support TANGENT yet.
              if (_attributeName !== 'position' && _attributeName !== 'normal') {
                if (!warned) {
                  console.warn('GLTFExporter: Only POSITION and NORMAL morph are supported.');
                  warned = true;
                }

                continue;
              }

              var _attribute = geometry.morphAttributes[_attributeName][_i2];

              var gltfAttributeName = _attributeName.toUpperCase(); // Three.js morph attribute has absolute values while the one of glTF has relative values.
              //
              // glTF 2.0 Specification:
              // https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#morph-targets


              var baseAttribute = geometry.attributes[_attributeName];

              if (cache.attributes.has(this.getUID(_attribute))) {
                target[gltfAttributeName] = cache.attributes.get(this.getUID(_attribute));
                continue;
              } // Clones attribute not to override


              var relativeAttribute = _attribute.clone();

              if (!geometry.morphTargetsRelative) {
                for (var j = 0, jl = _attribute.count; j < jl; j++) {
                  relativeAttribute.setXYZ(j, _attribute.getX(j) - baseAttribute.getX(j), _attribute.getY(j) - baseAttribute.getY(j), _attribute.getZ(j) - baseAttribute.getZ(j));
                }
              }

              target[gltfAttributeName] = this.processAccessor(relativeAttribute, geometry);
              cache.attributes.set(this.getUID(baseAttribute), target[gltfAttributeName]);
            }

            targets.push(target);
            weights.push(mesh.morphTargetInfluences[_i2]);
            if (mesh.morphTargetDictionary !== undefined) targetNames.push(reverseDictionary[_i2]);
          }

          meshDef.weights = weights;

          if (targetNames.length > 0) {
            meshDef.extras = {};
            meshDef.extras.targetNames = targetNames;
          }
        }

        var isMultiMaterial = Array.isArray(mesh.material);
        if (isMultiMaterial && geometry.groups.length === 0) return null;
        var materials = isMultiMaterial ? mesh.material : [mesh.material];
        var groups = isMultiMaterial ? geometry.groups : [{
          materialIndex: 0,
          start: undefined,
          count: undefined
        }];

        for (var _i3 = 0, il = groups.length; _i3 < il; _i3++) {
          var primitive = {
            mode: mode,
            attributes: attributes
          };
          this.serializeUserData(geometry, primitive);
          if (targets.length > 0) primitive.targets = targets;

          if (geometry.index !== null) {
            var cacheKey = this.getUID(geometry.index);

            if (groups[_i3].start !== undefined || groups[_i3].count !== undefined) {
              cacheKey += ':' + groups[_i3].start + ':' + groups[_i3].count;
            }

            if (cache.attributes.has(cacheKey)) {
              primitive.indices = cache.attributes.get(cacheKey);
            } else {
              primitive.indices = this.processAccessor(geometry.index, geometry, groups[_i3].start, groups[_i3].count);
              cache.attributes.set(cacheKey, primitive.indices);
            }

            if (primitive.indices === null) delete primitive.indices;
          }

          var material = this.processMaterial(materials[groups[_i3].materialIndex]);
          if (material !== null) primitive.material = material;
          primitives.push(primitive);
        }

        meshDef.primitives = primitives;
        if (!json.meshes) json.meshes = [];

        this._invokeAll(function (ext) {
          ext.writeMesh && ext.writeMesh(mesh, meshDef);
        });

        var index = json.meshes.push(meshDef) - 1;
        cache.meshes.set(meshCacheKey, index);
        return index;
      }
      /**
       * Process camera
       * @param  {THREE.Camera} camera Camera to process
       * @return {Integer}      Index of the processed mesh in the "camera" array
       */

    }, {
      key: "processCamera",
      value: function processCamera(camera) {
        var json = this.json;
        if (!json.cameras) json.cameras = [];
        var isOrtho = camera.isOrthographicCamera;
        var cameraDef = {
          type: isOrtho ? 'orthographic' : 'perspective'
        };

        if (isOrtho) {
          cameraDef.orthographic = {
            xmag: camera.right * 2,
            ymag: camera.top * 2,
            zfar: camera.far <= 0 ? 0.001 : camera.far,
            znear: camera.near < 0 ? 0 : camera.near
          };
        } else {
          cameraDef.perspective = {
            aspectRatio: camera.aspect,
            yfov: _three.MathUtils.degToRad(camera.fov),
            zfar: camera.far <= 0 ? 0.001 : camera.far,
            znear: camera.near < 0 ? 0 : camera.near
          };
        } // Question: Is saving "type" as name intentional?


        if (camera.name !== '') cameraDef.name = camera.type;
        return json.cameras.push(cameraDef) - 1;
      }
      /**
       * Creates glTF animation entry from AnimationClip object.
       *
       * Status:
       * - Only properties listed in PATH_PROPERTIES may be animated.
       *
       * @param {THREE.AnimationClip} clip
       * @param {THREE.Object3D} root
       * @return {number|null}
       */

    }, {
      key: "processAnimation",
      value: function processAnimation(clip, root) {
        var json = this.json;
        var nodeMap = this.nodeMap;
        if (!json.animations) json.animations = [];
        clip = GLTFExporter.Utils.mergeMorphTargetTracks(clip.clone(), root);
        var tracks = clip.tracks;
        var channels = [];
        var samplers = [];

        for (var i = 0; i < tracks.length; ++i) {
          var track = tracks[i];

          var trackBinding = _three.PropertyBinding.parseTrackName(track.name);

          var trackNode = _three.PropertyBinding.findNode(root, trackBinding.nodeName);

          var trackProperty = PATH_PROPERTIES[trackBinding.propertyName];

          if (trackBinding.objectName === 'bones') {
            if (trackNode.isSkinnedMesh === true) {
              trackNode = trackNode.skeleton.getBoneByName(trackBinding.objectIndex);
            } else {
              trackNode = undefined;
            }
          }

          if (!trackNode || !trackProperty) {
            console.warn('THREE.GLTFExporter: Could not export animation track "%s".', track.name);
            return null;
          }

          var inputItemSize = 1;
          var outputItemSize = track.values.length / track.times.length;

          if (trackProperty === PATH_PROPERTIES.morphTargetInfluences) {
            outputItemSize /= trackNode.morphTargetInfluences.length;
          }

          var interpolation = void 0; // @TODO export CubicInterpolant(InterpolateSmooth) as CUBICSPLINE
          // Detecting glTF cubic spline interpolant by checking factory method's special property
          // GLTFCubicSplineInterpolant is a custom interpolant and track doesn't return
          // valid value from .getInterpolation().

          if (track.createInterpolant.isInterpolantFactoryMethodGLTFCubicSpline === true) {
            interpolation = 'CUBICSPLINE'; // itemSize of CUBICSPLINE keyframe is 9
            // (VEC3 * 3: inTangent, splineVertex, and outTangent)
            // but needs to be stored as VEC3 so dividing by 3 here.

            outputItemSize /= 3;
          } else if (track.getInterpolation() === _three.InterpolateDiscrete) {
            interpolation = 'STEP';
          } else {
            interpolation = 'LINEAR';
          }

          samplers.push({
            input: this.processAccessor(new _three.BufferAttribute(track.times, inputItemSize)),
            output: this.processAccessor(new _three.BufferAttribute(track.values, outputItemSize)),
            interpolation: interpolation
          });
          channels.push({
            sampler: samplers.length - 1,
            target: {
              node: nodeMap.get(trackNode),
              path: trackProperty
            }
          });
        }

        json.animations.push({
          name: clip.name || 'clip_' + json.animations.length,
          samplers: samplers,
          channels: channels
        });
        return json.animations.length - 1;
      }
      /**
       * @param {THREE.Object3D} object
       * @return {number|null}
       */

    }, {
      key: "processSkin",
      value: function processSkin(object) {
        var json = this.json;
        var nodeMap = this.nodeMap;
        var node = json.nodes[nodeMap.get(object)];
        var skeleton = object.skeleton;
        if (skeleton === undefined) return null;
        var rootJoint = object.skeleton.bones[0];
        if (rootJoint === undefined) return null;
        var joints = [];
        var inverseBindMatrices = new Float32Array(skeleton.bones.length * 16);
        var temporaryBoneInverse = new _three.Matrix4();

        for (var i = 0; i < skeleton.bones.length; ++i) {
          joints.push(nodeMap.get(skeleton.bones[i]));
          temporaryBoneInverse.copy(skeleton.boneInverses[i]);
          temporaryBoneInverse.multiply(object.bindMatrix).toArray(inverseBindMatrices, i * 16);
        }

        if (json.skins === undefined) json.skins = [];
        json.skins.push({
          inverseBindMatrices: this.processAccessor(new _three.BufferAttribute(inverseBindMatrices, 16)),
          joints: joints,
          skeleton: nodeMap.get(rootJoint)
        });
        var skinIndex = node.skin = json.skins.length - 1;
        return skinIndex;
      }
      /**
       * Process Object3D node
       * @param  {THREE.Object3D} node Object3D to processNode
       * @return {Integer} Index of the node in the nodes list
       */

    }, {
      key: "processNode",
      value: function processNode(object) {
        var json = this.json;
        var options = this.options;
        var nodeMap = this.nodeMap;
        if (!json.nodes) json.nodes = [];
        var nodeDef = {};

        if (options.trs) {
          var rotation = object.quaternion.toArray();
          var position = object.position.toArray();
          var scale = object.scale.toArray();

          if (!equalArray(rotation, [0, 0, 0, 1])) {
            nodeDef.rotation = rotation;
          }

          if (!equalArray(position, [0, 0, 0])) {
            nodeDef.translation = position;
          }

          if (!equalArray(scale, [1, 1, 1])) {
            nodeDef.scale = scale;
          }
        } else {
          if (object.matrixAutoUpdate) {
            object.updateMatrix();
          }

          if (isIdentityMatrix(object.matrix) === false) {
            nodeDef.matrix = object.matrix.elements;
          }
        } // We don't export empty strings name because it represents no-name in Three.js.


        if (object.name !== '') nodeDef.name = String(object.name);
        this.serializeUserData(object, nodeDef);

        if (object.isMesh || object.isLine || object.isPoints) {
          var meshIndex = this.processMesh(object);
          if (meshIndex !== null) nodeDef.mesh = meshIndex;
        } else if (object.isCamera) {
          nodeDef.camera = this.processCamera(object);
        }

        if (object.isSkinnedMesh) this.skins.push(object);

        if (object.children.length > 0) {
          var children = [];

          for (var i = 0, l = object.children.length; i < l; i++) {
            var child = object.children[i];

            if (child.visible || options.onlyVisible === false) {
              var _nodeIndex = this.processNode(child);

              if (_nodeIndex !== null) children.push(_nodeIndex);
            }
          }

          if (children.length > 0) nodeDef.children = children;
        }

        this._invokeAll(function (ext) {
          ext.writeNode && ext.writeNode(object, nodeDef);
        });

        var nodeIndex = json.nodes.push(nodeDef) - 1;
        nodeMap.set(object, nodeIndex);
        return nodeIndex;
      }
      /**
       * Process Scene
       * @param  {Scene} node Scene to process
       */

    }, {
      key: "processScene",
      value: function processScene(scene) {
        var json = this.json;
        var options = this.options;

        if (!json.scenes) {
          json.scenes = [];
          json.scene = 0;
        }

        var sceneDef = {};
        if (scene.name !== '') sceneDef.name = scene.name;
        json.scenes.push(sceneDef);
        var nodes = [];

        for (var i = 0, l = scene.children.length; i < l; i++) {
          var child = scene.children[i];

          if (child.visible || options.onlyVisible === false) {
            var nodeIndex = this.processNode(child);
            if (nodeIndex !== null) nodes.push(nodeIndex);
          }
        }

        if (nodes.length > 0) sceneDef.nodes = nodes;
        this.serializeUserData(scene, sceneDef);
      }
      /**
       * Creates a Scene to hold a list of objects and parse it
       * @param  {Array} objects List of objects to process
       */

    }, {
      key: "processObjects",
      value: function processObjects(objects) {
        var scene = new _three.Scene();
        scene.name = 'AuxScene';

        for (var i = 0; i < objects.length; i++) {
          // We push directly to children instead of calling `add` to prevent
          // modify the .parent and break its original scene and hierarchy
          scene.children.push(objects[i]);
        }

        this.processScene(scene);
      }
      /**
       * @param {THREE.Object3D|Array<THREE.Object3D>} input
       */

    }, {
      key: "processInput",
      value: function processInput(input) {
        var options = this.options;
        input = input instanceof Array ? input : [input];

        this._invokeAll(function (ext) {
          ext.beforeParse && ext.beforeParse(input);
        });

        var objectsWithoutScene = [];

        for (var i = 0; i < input.length; i++) {
          if (input[i] instanceof _three.Scene) {
            this.processScene(input[i]);
          } else {
            objectsWithoutScene.push(input[i]);
          }
        }

        if (objectsWithoutScene.length > 0) this.processObjects(objectsWithoutScene);

        for (var _i4 = 0; _i4 < this.skins.length; ++_i4) {
          this.processSkin(this.skins[_i4]);
        }

        for (var _i5 = 0; _i5 < options.animations.length; ++_i5) {
          this.processAnimation(options.animations[_i5], input[0]);
        }

        this._invokeAll(function (ext) {
          ext.afterParse && ext.afterParse(input);
        });
      }
    }, {
      key: "_invokeAll",
      value: function _invokeAll(func) {
        for (var i = 0, il = this.plugins.length; i < il; i++) {
          func(this.plugins[i]);
        }
      }
    }]);

    return GLTFWriter;
  }();
  /**
   * Punctual Lights Extension
   *
   * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_lights_punctual
   */


  var GLTFLightExtension = /*#__PURE__*/function () {
    function GLTFLightExtension(writer) {
      _classCallCheck(this, GLTFLightExtension);

      this.writer = writer;
      this.name = 'KHR_lights_punctual';
    }

    _createClass(GLTFLightExtension, [{
      key: "writeNode",
      value: function writeNode(light, nodeDef) {
        if (!light.isLight) return;

        if (!light.isDirectionalLight && !light.isPointLight && !light.isSpotLight) {
          console.warn('THREE.GLTFExporter: Only directional, point, and spot lights are supported.', light);
          return;
        }

        var writer = this.writer;
        var json = writer.json;
        var extensionsUsed = writer.extensionsUsed;
        var lightDef = {};
        if (light.name) lightDef.name = light.name;
        lightDef.color = light.color.toArray();
        lightDef.intensity = light.intensity;

        if (light.isDirectionalLight) {
          lightDef.type = 'directional';
        } else if (light.isPointLight) {
          lightDef.type = 'point';
          if (light.distance > 0) lightDef.range = light.distance;
        } else if (light.isSpotLight) {
          lightDef.type = 'spot';
          if (light.distance > 0) lightDef.range = light.distance;
          lightDef.spot = {};
          lightDef.spot.innerConeAngle = (light.penumbra - 1.0) * light.angle * -1.0;
          lightDef.spot.outerConeAngle = light.angle;
        }

        if (light.decay !== undefined && light.decay !== 2) {
          console.warn('THREE.GLTFExporter: Light decay may be lost. glTF is physically-based, ' + 'and expects light.decay=2.');
        }

        if (light.target && (light.target.parent !== light || light.target.position.x !== 0 || light.target.position.y !== 0 || light.target.position.z !== -1)) {
          console.warn('THREE.GLTFExporter: Light direction may be lost. For best results, ' + 'make light.target a child of the light with position 0,0,-1.');
        }

        if (!extensionsUsed[this.name]) {
          json.extensions = json.extensions || {};
          json.extensions[this.name] = {
            lights: []
          };
          extensionsUsed[this.name] = true;
        }

        var lights = json.extensions[this.name].lights;
        lights.push(lightDef);
        nodeDef.extensions = nodeDef.extensions || {};
        nodeDef.extensions[this.name] = {
          light: lights.length - 1
        };
      }
    }]);

    return GLTFLightExtension;
  }();
  /**
   * Unlit Materials Extension
   *
   * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_materials_unlit
   */


  var GLTFMaterialsUnlitExtension = /*#__PURE__*/function () {
    function GLTFMaterialsUnlitExtension(writer) {
      _classCallCheck(this, GLTFMaterialsUnlitExtension);

      this.writer = writer;
      this.name = 'KHR_materials_unlit';
    }

    _createClass(GLTFMaterialsUnlitExtension, [{
      key: "writeMaterial",
      value: function writeMaterial(material, materialDef) {
        if (!material.isMeshBasicMaterial) return;
        var writer = this.writer;
        var extensionsUsed = writer.extensionsUsed;
        materialDef.extensions = materialDef.extensions || {};
        materialDef.extensions[this.name] = {};
        extensionsUsed[this.name] = true;
        materialDef.pbrMetallicRoughness.metallicFactor = 0.0;
        materialDef.pbrMetallicRoughness.roughnessFactor = 0.9;
      }
    }]);

    return GLTFMaterialsUnlitExtension;
  }();
  /**
   * Specular-Glossiness Extension
   *
   * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_materials_pbrSpecularGlossiness
   */


  var GLTFMaterialsPBRSpecularGlossiness = /*#__PURE__*/function () {
    function GLTFMaterialsPBRSpecularGlossiness(writer) {
      _classCallCheck(this, GLTFMaterialsPBRSpecularGlossiness);

      this.writer = writer;
      this.name = 'KHR_materials_pbrSpecularGlossiness';
    }

    _createClass(GLTFMaterialsPBRSpecularGlossiness, [{
      key: "writeMaterial",
      value: function writeMaterial(material, materialDef) {
        if (!material.isGLTFSpecularGlossinessMaterial) return;
        var writer = this.writer;
        var extensionsUsed = writer.extensionsUsed;
        var extensionDef = {};

        if (materialDef.pbrMetallicRoughness.baseColorFactor) {
          extensionDef.diffuseFactor = materialDef.pbrMetallicRoughness.baseColorFactor;
        }

        var specularFactor = [1, 1, 1];
        material.specular.toArray(specularFactor, 0);
        extensionDef.specularFactor = specularFactor;
        extensionDef.glossinessFactor = material.glossiness;

        if (materialDef.pbrMetallicRoughness.baseColorTexture) {
          extensionDef.diffuseTexture = materialDef.pbrMetallicRoughness.baseColorTexture;
        }

        if (material.specularMap) {
          var specularMapDef = {
            index: writer.processTexture(material.specularMap)
          };
          writer.applyTextureTransform(specularMapDef, material.specularMap);
          extensionDef.specularGlossinessTexture = specularMapDef;
        }

        materialDef.extensions = materialDef.extensions || {};
        materialDef.extensions[this.name] = extensionDef;
        extensionsUsed[this.name] = true;
      }
    }]);

    return GLTFMaterialsPBRSpecularGlossiness;
  }();
  /**
   * Clearcoat Materials Extension
   *
   * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_materials_clearcoat
   */


  var GLTFMaterialsClearcoatExtension = /*#__PURE__*/function () {
    function GLTFMaterialsClearcoatExtension(writer) {
      _classCallCheck(this, GLTFMaterialsClearcoatExtension);

      this.writer = writer;
      this.name = 'KHR_materials_clearcoat';
    }

    _createClass(GLTFMaterialsClearcoatExtension, [{
      key: "writeMaterial",
      value: function writeMaterial(material, materialDef) {
        if (!material.isMeshPhysicalMaterial) return;
        var writer = this.writer;
        var extensionsUsed = writer.extensionsUsed;
        var extensionDef = {};
        extensionDef.clearcoatFactor = material.clearcoat;

        if (material.clearcoatMap) {
          var clearcoatMapDef = {
            index: writer.processTexture(material.clearcoatMap)
          };
          writer.applyTextureTransform(clearcoatMapDef, material.clearcoatMap);
          extensionDef.clearcoatTexture = clearcoatMapDef;
        }

        extensionDef.clearcoatRoughnessFactor = material.clearcoatRoughness;

        if (material.clearcoatRoughnessMap) {
          var clearcoatRoughnessMapDef = {
            index: writer.processTexture(material.clearcoatRoughnessMap)
          };
          writer.applyTextureTransform(clearcoatRoughnessMapDef, material.clearcoatRoughnessMap);
          extensionDef.clearcoatRoughnessTexture = clearcoatRoughnessMapDef;
        }

        if (material.clearcoatNormalMap) {
          var clearcoatNormalMapDef = {
            index: writer.processTexture(material.clearcoatNormalMap)
          };
          writer.applyTextureTransform(clearcoatNormalMapDef, material.clearcoatNormalMap);
          extensionDef.clearcoatNormalTexture = clearcoatNormalMapDef;
        }

        materialDef.extensions = materialDef.extensions || {};
        materialDef.extensions[this.name] = extensionDef;
        extensionsUsed[this.name] = true;
      }
    }]);

    return GLTFMaterialsClearcoatExtension;
  }();
  /**
   * Transmission Materials Extension
   *
   * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_materials_transmission
   */


  var GLTFMaterialsTransmissionExtension = /*#__PURE__*/function () {
    function GLTFMaterialsTransmissionExtension(writer) {
      _classCallCheck(this, GLTFMaterialsTransmissionExtension);

      this.writer = writer;
      this.name = 'KHR_materials_transmission';
    }

    _createClass(GLTFMaterialsTransmissionExtension, [{
      key: "writeMaterial",
      value: function writeMaterial(material, materialDef) {
        if (!material.isMeshPhysicalMaterial || material.transmission === 0) return;
        var writer = this.writer;
        var extensionsUsed = writer.extensionsUsed;
        var extensionDef = {};
        extensionDef.transmissionFactor = material.transmission;

        if (material.transmissionMap) {
          var transmissionMapDef = {
            index: writer.processTexture(material.transmissionMap)
          };
          writer.applyTextureTransform(transmissionMapDef, material.transmissionMap);
          extensionDef.transmissionTexture = transmissionMapDef;
        }

        materialDef.extensions = materialDef.extensions || {};
        materialDef.extensions[this.name] = extensionDef;
        extensionsUsed[this.name] = true;
      }
    }]);

    return GLTFMaterialsTransmissionExtension;
  }();
  /**
   * Materials Volume Extension
   *
   * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_materials_volume
   */


  var GLTFMaterialsVolumeExtension = /*#__PURE__*/function () {
    function GLTFMaterialsVolumeExtension(writer) {
      _classCallCheck(this, GLTFMaterialsVolumeExtension);

      this.writer = writer;
      this.name = 'KHR_materials_volume';
    }

    _createClass(GLTFMaterialsVolumeExtension, [{
      key: "writeMaterial",
      value: function writeMaterial(material, materialDef) {
        if (!material.isMeshPhysicalMaterial || material.transmission === 0) return;
        var writer = this.writer;
        var extensionsUsed = writer.extensionsUsed;
        var extensionDef = {};
        extensionDef.thicknessFactor = material.thickness;

        if (material.thicknessMap) {
          var thicknessMapDef = {
            index: writer.processTexture(material.thicknessMap)
          };
          writer.applyTextureTransform(thicknessMapDef, material.thicknessMap);
          extensionDef.thicknessTexture = thicknessMapDef;
        }

        extensionDef.attenuationDistance = material.attenuationDistance;
        extensionDef.attenuationColor = material.attenuationColor.toArray();
        materialDef.extensions = materialDef.extensions || {};
        materialDef.extensions[this.name] = extensionDef;
        extensionsUsed[this.name] = true;
      }
    }]);

    return GLTFMaterialsVolumeExtension;
  }();
  /**
   * Static utility functions
   */


  GLTFExporter.Utils = {
    insertKeyframe: function insertKeyframe(track, time) {
      var tolerance = 0.001; // 1ms

      var valueSize = track.getValueSize();
      var times = new track.TimeBufferType(track.times.length + 1);
      var values = new track.ValueBufferType(track.values.length + valueSize);
      var interpolant = track.createInterpolant(new track.ValueBufferType(valueSize));
      var index;

      if (track.times.length === 0) {
        times[0] = time;

        for (var i = 0; i < valueSize; i++) {
          values[i] = 0;
        }

        index = 0;
      } else if (time < track.times[0]) {
        if (Math.abs(track.times[0] - time) < tolerance) return 0;
        times[0] = time;
        times.set(track.times, 1);
        values.set(interpolant.evaluate(time), 0);
        values.set(track.values, valueSize);
        index = 0;
      } else if (time > track.times[track.times.length - 1]) {
        if (Math.abs(track.times[track.times.length - 1] - time) < tolerance) {
          return track.times.length - 1;
        }

        times[times.length - 1] = time;
        times.set(track.times, 0);
        values.set(track.values, 0);
        values.set(interpolant.evaluate(time), track.values.length);
        index = times.length - 1;
      } else {
        for (var _i6 = 0; _i6 < track.times.length; _i6++) {
          if (Math.abs(track.times[_i6] - time) < tolerance) return _i6;

          if (track.times[_i6] < time && track.times[_i6 + 1] > time) {
            times.set(track.times.slice(0, _i6 + 1), 0);
            times[_i6 + 1] = time;
            times.set(track.times.slice(_i6 + 1), _i6 + 2);
            values.set(track.values.slice(0, (_i6 + 1) * valueSize), 0);
            values.set(interpolant.evaluate(time), (_i6 + 1) * valueSize);
            values.set(track.values.slice((_i6 + 1) * valueSize), (_i6 + 2) * valueSize);
            index = _i6 + 1;
            break;
          }
        }
      }

      track.times = times;
      track.values = values;
      return index;
    },
    mergeMorphTargetTracks: function mergeMorphTargetTracks(clip, root) {
      var tracks = [];
      var mergedTracks = {};
      var sourceTracks = clip.tracks;

      for (var i = 0; i < sourceTracks.length; ++i) {
        var sourceTrack = sourceTracks[i];

        var sourceTrackBinding = _three.PropertyBinding.parseTrackName(sourceTrack.name);

        var sourceTrackNode = _three.PropertyBinding.findNode(root, sourceTrackBinding.nodeName);

        if (sourceTrackBinding.propertyName !== 'morphTargetInfluences' || sourceTrackBinding.propertyIndex === undefined) {
          // Tracks that don't affect morph targets, or that affect all morph targets together, can be left as-is.
          tracks.push(sourceTrack);
          continue;
        }

        if (sourceTrack.createInterpolant !== sourceTrack.InterpolantFactoryMethodDiscrete && sourceTrack.createInterpolant !== sourceTrack.InterpolantFactoryMethodLinear) {
          if (sourceTrack.createInterpolant.isInterpolantFactoryMethodGLTFCubicSpline) {
            // This should never happen, because glTF morph target animations
            // affect all targets already.
            throw new Error('THREE.GLTFExporter: Cannot merge tracks with glTF CUBICSPLINE interpolation.');
          }

          console.warn('THREE.GLTFExporter: Morph target interpolation mode not yet supported. Using LINEAR instead.');
          sourceTrack = sourceTrack.clone();
          sourceTrack.setInterpolation(_three.InterpolateLinear);
        }

        var targetCount = sourceTrackNode.morphTargetInfluences.length;
        var targetIndex = sourceTrackNode.morphTargetDictionary[sourceTrackBinding.propertyIndex];

        if (targetIndex === undefined) {
          throw new Error('THREE.GLTFExporter: Morph target name not found: ' + sourceTrackBinding.propertyIndex);
        }

        var mergedTrack = void 0; // If this is the first time we've seen this object, create a new
        // track to store merged keyframe data for each morph target.

        if (mergedTracks[sourceTrackNode.uuid] === undefined) {
          mergedTrack = sourceTrack.clone();
          var values = new mergedTrack.ValueBufferType(targetCount * mergedTrack.times.length);

          for (var j = 0; j < mergedTrack.times.length; j++) {
            values[j * targetCount + targetIndex] = mergedTrack.values[j];
          } // We need to take into consideration the intended target node
          // of our original un-merged morphTarget animation.


          mergedTrack.name = (sourceTrackBinding.nodeName || '') + '.morphTargetInfluences';
          mergedTrack.values = values;
          mergedTracks[sourceTrackNode.uuid] = mergedTrack;
          tracks.push(mergedTrack);
          continue;
        }

        var sourceInterpolant = sourceTrack.createInterpolant(new sourceTrack.ValueBufferType(1));
        mergedTrack = mergedTracks[sourceTrackNode.uuid]; // For every existing keyframe of the merged track, write a (possibly
        // interpolated) value from the source track.

        for (var _j = 0; _j < mergedTrack.times.length; _j++) {
          mergedTrack.values[_j * targetCount + targetIndex] = sourceInterpolant.evaluate(mergedTrack.times[_j]);
        } // For every existing keyframe of the source track, write a (possibly
        // new) keyframe to the merged track. Values from the previous loop may
        // be written again, but keyframes are de-duplicated.


        for (var _j2 = 0; _j2 < sourceTrack.times.length; _j2++) {
          var keyframeIndex = this.insertKeyframe(mergedTrack, sourceTrack.times[_j2]);
          mergedTrack.values[keyframeIndex * targetCount + targetIndex] = sourceTrack.values[_j2];
        }
      }

      clip.tracks = tracks;
      return clip;
    }
  };
});