GLTFLoader.js

;(function () {
  class GLTFLoader extends THREE.Loader {
    constructor(manager) {
      super(manager)
      this.dracoLoader = null
      this.ktx2Loader = null
      this.meshoptDecoder = null
      this.pluginCallbacks = []
      this.register(function (parser) {
        return new GLTFMaterialsClearcoatExtension(parser)
      })
      this.register(function (parser) {
        return new GLTFTextureBasisUExtension(parser)
      })
      this.register(function (parser) {
        return new GLTFTextureWebPExtension(parser)
      })
      this.register(function (parser) {
        return new GLTFMaterialsSheenExtension(parser)
      })
      this.register(function (parser) {
        return new GLTFMaterialsTransmissionExtension(parser)
      })
      this.register(function (parser) {
        return new GLTFMaterialsVolumeExtension(parser)
      })
      this.register(function (parser) {
        return new GLTFMaterialsIorExtension(parser)
      })
      this.register(function (parser) {
        return new GLTFMaterialsSpecularExtension(parser)
      })
      this.register(function (parser) {
        return new GLTFLightsExtension(parser)
      })
      this.register(function (parser) {
        return new GLTFMeshoptCompression(parser)
      })
    }

    load(url, onLoad, onProgress, onError) {
      const scope = this
      let resourcePath

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

      this.manager.itemStart(url)

      const _onError = function (e) {
        if (onError) {
          onError(e)
        } else {
          console.error(e)
        }

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

      const loader = new THREE.FileLoader(this.manager)
      loader.setPath(this.path)
      loader.setResponseType('arraybuffer')
      loader.setRequestHeader(this.requestHeader)
      loader.setWithCredentials(this.withCredentials)
      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(dracoLoader) {
      this.dracoLoader = dracoLoader
      return this
    }

    setDDSLoader() {
      throw new Error('THREE.GLTFLoader: "MSFT_texture_dds" no longer supported. Please update to "KHR_texture_basisu".')
    }

    setKTX2Loader(ktx2Loader) {
      this.ktx2Loader = ktx2Loader
      return this
    }

    setMeshoptDecoder(meshoptDecoder) {
      this.meshoptDecoder = meshoptDecoder
      return this
    }

    register(callback) {
      if (this.pluginCallbacks.indexOf(callback) === -1) {
        this.pluginCallbacks.push(callback)
      }

      return this
    }

    unregister(callback) {
      if (this.pluginCallbacks.indexOf(callback) !== -1) {
        this.pluginCallbacks.splice(this.pluginCallbacks.indexOf(callback), 1)
      }

      return this
    }

    parse(data, path, onLoad, onError) {
      let content
      const extensions = {}
      const plugins = {}

      if (typeof data === 'string') {
        content = data
      } else {
        const magic = THREE.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 = THREE.LoaderUtils.decodeText(new Uint8Array(data))
        }
      }

      const 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
      }

      const parser = new GLTFParser(json, {
        path: path || this.resourcePath || '',
        crossOrigin: this.crossOrigin,
        requestHeader: this.requestHeader,
        manager: this.manager,
        ktx2Loader: this.ktx2Loader,
        meshoptDecoder: this.meshoptDecoder
      })
      parser.fileLoader.setRequestHeader(this.requestHeader)

      for (let i = 0; i < this.pluginCallbacks.length; i++) {
        const plugin = this.pluginCallbacks[i](parser)
        plugins[plugin.name] = plugin // Workaround to avoid determining as unknown extension
        // in addUnknownExtensionsToUserData().
        // Remove this workaround if we move all the existing
        // extension handlers to plugin system

        extensions[plugin.name] = true
      }

      if (json.extensionsUsed) {
        for (let i = 0; i < json.extensionsUsed.length; ++i) {
          const extensionName = json.extensionsUsed[i]
          const extensionsRequired = json.extensionsRequired || []

          switch (extensionName) {
            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.KHR_TEXTURE_TRANSFORM:
              extensions[extensionName] = new GLTFTextureTransformExtension()
              break

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

            default:
              if (extensionsRequired.indexOf(extensionName) >= 0 && plugins[extensionName] === undefined) {
                console.warn('THREE.GLTFLoader: Unknown extension "' + extensionName + '".')
              }
          }
        }
      }

      parser.setExtensions(extensions)
      parser.setPlugins(plugins)
      parser.parse(onLoad, onError)
    }

    parseAsync(data, path) {
      const scope = this
      return new Promise(function (resolve, reject) {
        scope.parse(data, path, resolve, reject)
      })
    }
  }
  /* GLTFREGISTRY */

  function GLTFRegistry() {
    let 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 ***********/

  /*********************************/

  const 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_IOR: 'KHR_materials_ior',
    KHR_MATERIALS_PBR_SPECULAR_GLOSSINESS: 'KHR_materials_pbrSpecularGlossiness',
    KHR_MATERIALS_SHEEN: 'KHR_materials_sheen',
    KHR_MATERIALS_SPECULAR: 'KHR_materials_specular',
    KHR_MATERIALS_TRANSMISSION: 'KHR_materials_transmission',
    KHR_MATERIALS_UNLIT: 'KHR_materials_unlit',
    KHR_MATERIALS_VOLUME: 'KHR_materials_volume',
    KHR_TEXTURE_BASISU: 'KHR_texture_basisu',
    KHR_TEXTURE_TRANSFORM: 'KHR_texture_transform',
    KHR_MESH_QUANTIZATION: 'KHR_mesh_quantization',
    EXT_TEXTURE_WEBP: 'EXT_texture_webp',
    EXT_MESHOPT_COMPRESSION: 'EXT_meshopt_compression'
  }
  /**
   * Punctual Lights Extension
   *
   * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_lights_punctual
   */

  class GLTFLightsExtension {
    constructor(parser) {
      this.parser = parser
      this.name = EXTENSIONS.KHR_LIGHTS_PUNCTUAL // THREE.Object3D instance caches

      this.cache = {
        refs: {},
        uses: {}
      }
    }

    _markDefs() {
      const parser = this.parser
      const nodeDefs = this.parser.json.nodes || []

      for (let nodeIndex = 0, nodeLength = nodeDefs.length; nodeIndex < nodeLength; nodeIndex++) {
        const nodeDef = nodeDefs[nodeIndex]

        if (nodeDef.extensions && nodeDef.extensions[this.name] && nodeDef.extensions[this.name].light !== undefined) {
          parser._addNodeRef(this.cache, nodeDef.extensions[this.name].light)
        }
      }
    }

    _loadLight(lightIndex) {
      const parser = this.parser
      const cacheKey = 'light:' + lightIndex
      let dependency = parser.cache.get(cacheKey)
      if (dependency) return dependency
      const json = parser.json
      const extensions = (json.extensions && json.extensions[this.name]) || {}
      const lightDefs = extensions.lights || []
      const lightDef = lightDefs[lightIndex]
      let lightNode
      const color = new THREE.Color(0xffffff)
      if (lightDef.color !== undefined) color.fromArray(lightDef.color)
      const range = lightDef.range !== undefined ? lightDef.range : 0

      switch (lightDef.type) {
        case 'directional':
          lightNode = new THREE.DirectionalLight(color)
          lightNode.target.position.set(0, 0, -1)
          lightNode.add(lightNode.target)
          break

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

        case 'spot':
          lightNode = new THREE.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 = parser.createUniqueName(lightDef.name || 'light_' + lightIndex)
      dependency = Promise.resolve(lightNode)
      parser.cache.add(cacheKey, dependency)
      return dependency
    }

    createNodeAttachment(nodeIndex) {
      const self = this
      const parser = this.parser
      const json = parser.json
      const nodeDef = json.nodes[nodeIndex]
      const lightDef = (nodeDef.extensions && nodeDef.extensions[this.name]) || {}
      const lightIndex = lightDef.light
      if (lightIndex === undefined) return null
      return this._loadLight(lightIndex).then(function (light) {
        return parser._getNodeRef(self.cache, lightIndex, light)
      })
    }
  }
  /**
   * Unlit Materials Extension
   *
   * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_materials_unlit
   */

  class GLTFMaterialsUnlitExtension {
    constructor() {
      this.name = EXTENSIONS.KHR_MATERIALS_UNLIT
    }

    getMaterialType() {
      return THREE.MeshBasicMaterial
    }

    extendParams(materialParams, materialDef, parser) {
      const pending = []
      materialParams.color = new THREE.Color(1.0, 1.0, 1.0)
      materialParams.opacity = 1.0
      const metallicRoughness = materialDef.pbrMetallicRoughness

      if (metallicRoughness) {
        if (Array.isArray(metallicRoughness.baseColorFactor)) {
          const 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
   */

  class GLTFMaterialsClearcoatExtension {
    constructor(parser) {
      this.parser = parser
      this.name = EXTENSIONS.KHR_MATERIALS_CLEARCOAT
    }

    getMaterialType(materialIndex) {
      const parser = this.parser
      const materialDef = parser.json.materials[materialIndex]
      if (!materialDef.extensions || !materialDef.extensions[this.name]) return null
      return THREE.MeshPhysicalMaterial
    }

    extendMaterialParams(materialIndex, materialParams) {
      const parser = this.parser
      const materialDef = parser.json.materials[materialIndex]

      if (!materialDef.extensions || !materialDef.extensions[this.name]) {
        return Promise.resolve()
      }

      const pending = []
      const 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) {
          const scale = extension.clearcoatNormalTexture.scale
          materialParams.clearcoatNormalScale = new THREE.Vector2(scale, scale)
        }
      }

      return Promise.all(pending)
    }
  }
  /**
   * Sheen Materials Extension
   *
   * Specification: https://github.com/KhronosGroup/glTF/tree/main/extensions/2.0/Khronos/KHR_materials_sheen
   */

  class GLTFMaterialsSheenExtension {
    constructor(parser) {
      this.parser = parser
      this.name = EXTENSIONS.KHR_MATERIALS_SHEEN
    }

    getMaterialType(materialIndex) {
      const parser = this.parser
      const materialDef = parser.json.materials[materialIndex]
      if (!materialDef.extensions || !materialDef.extensions[this.name]) return null
      return THREE.MeshPhysicalMaterial
    }

    extendMaterialParams(materialIndex, materialParams) {
      const parser = this.parser
      const materialDef = parser.json.materials[materialIndex]

      if (!materialDef.extensions || !materialDef.extensions[this.name]) {
        return Promise.resolve()
      }

      const pending = []
      materialParams.sheenColor = new THREE.Color(0, 0, 0)
      materialParams.sheenRoughness = 0
      materialParams.sheen = 1
      const extension = materialDef.extensions[this.name]

      if (extension.sheenColorFactor !== undefined) {
        materialParams.sheenColor.fromArray(extension.sheenColorFactor)
      }

      if (extension.sheenRoughnessFactor !== undefined) {
        materialParams.sheenRoughness = extension.sheenRoughnessFactor
      }

      if (extension.sheenColorTexture !== undefined) {
        pending.push(parser.assignTexture(materialParams, 'sheenColorMap', extension.sheenColorTexture))
      }

      if (extension.sheenRoughnessTexture !== undefined) {
        pending.push(parser.assignTexture(materialParams, 'sheenRoughnessMap', extension.sheenRoughnessTexture))
      }

      return Promise.all(pending)
    }
  }
  /**
   * Transmission Materials Extension
   *
   * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_materials_transmission
   * Draft: https://github.com/KhronosGroup/glTF/pull/1698
   */

  class GLTFMaterialsTransmissionExtension {
    constructor(parser) {
      this.parser = parser
      this.name = EXTENSIONS.KHR_MATERIALS_TRANSMISSION
    }

    getMaterialType(materialIndex) {
      const parser = this.parser
      const materialDef = parser.json.materials[materialIndex]
      if (!materialDef.extensions || !materialDef.extensions[this.name]) return null
      return THREE.MeshPhysicalMaterial
    }

    extendMaterialParams(materialIndex, materialParams) {
      const parser = this.parser
      const materialDef = parser.json.materials[materialIndex]

      if (!materialDef.extensions || !materialDef.extensions[this.name]) {
        return Promise.resolve()
      }

      const pending = []
      const extension = materialDef.extensions[this.name]

      if (extension.transmissionFactor !== undefined) {
        materialParams.transmission = extension.transmissionFactor
      }

      if (extension.transmissionTexture !== undefined) {
        pending.push(parser.assignTexture(materialParams, 'transmissionMap', extension.transmissionTexture))
      }

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

  class GLTFMaterialsVolumeExtension {
    constructor(parser) {
      this.parser = parser
      this.name = EXTENSIONS.KHR_MATERIALS_VOLUME
    }

    getMaterialType(materialIndex) {
      const parser = this.parser
      const materialDef = parser.json.materials[materialIndex]
      if (!materialDef.extensions || !materialDef.extensions[this.name]) return null
      return THREE.MeshPhysicalMaterial
    }

    extendMaterialParams(materialIndex, materialParams) {
      const parser = this.parser
      const materialDef = parser.json.materials[materialIndex]

      if (!materialDef.extensions || !materialDef.extensions[this.name]) {
        return Promise.resolve()
      }

      const pending = []
      const extension = materialDef.extensions[this.name]
      materialParams.thickness = extension.thicknessFactor !== undefined ? extension.thicknessFactor : 0

      if (extension.thicknessTexture !== undefined) {
        pending.push(parser.assignTexture(materialParams, 'thicknessMap', extension.thicknessTexture))
      }

      materialParams.attenuationDistance = extension.attenuationDistance || 0
      const colorArray = extension.attenuationColor || [1, 1, 1]
      materialParams.attenuationColor = new THREE.Color(colorArray[0], colorArray[1], colorArray[2])
      return Promise.all(pending)
    }
  }
  /**
   * Materials ior Extension
   *
   * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_materials_ior
   */

  class GLTFMaterialsIorExtension {
    constructor(parser) {
      this.parser = parser
      this.name = EXTENSIONS.KHR_MATERIALS_IOR
    }

    getMaterialType(materialIndex) {
      const parser = this.parser
      const materialDef = parser.json.materials[materialIndex]
      if (!materialDef.extensions || !materialDef.extensions[this.name]) return null
      return THREE.MeshPhysicalMaterial
    }

    extendMaterialParams(materialIndex, materialParams) {
      const parser = this.parser
      const materialDef = parser.json.materials[materialIndex]

      if (!materialDef.extensions || !materialDef.extensions[this.name]) {
        return Promise.resolve()
      }

      const extension = materialDef.extensions[this.name]
      materialParams.ior = extension.ior !== undefined ? extension.ior : 1.5
      return Promise.resolve()
    }
  }
  /**
   * Materials specular Extension
   *
   * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_materials_specular
   */

  class GLTFMaterialsSpecularExtension {
    constructor(parser) {
      this.parser = parser
      this.name = EXTENSIONS.KHR_MATERIALS_SPECULAR
    }

    getMaterialType(materialIndex) {
      const parser = this.parser
      const materialDef = parser.json.materials[materialIndex]
      if (!materialDef.extensions || !materialDef.extensions[this.name]) return null
      return THREE.MeshPhysicalMaterial
    }

    extendMaterialParams(materialIndex, materialParams) {
      const parser = this.parser
      const materialDef = parser.json.materials[materialIndex]

      if (!materialDef.extensions || !materialDef.extensions[this.name]) {
        return Promise.resolve()
      }

      const pending = []
      const extension = materialDef.extensions[this.name]
      materialParams.specularIntensity = extension.specularFactor !== undefined ? extension.specularFactor : 1.0

      if (extension.specularTexture !== undefined) {
        pending.push(parser.assignTexture(materialParams, 'specularIntensityMap', extension.specularTexture))
      }

      const colorArray = extension.specularColorFactor || [1, 1, 1]
      materialParams.specularColor = new THREE.Color(colorArray[0], colorArray[1], colorArray[2])

      if (extension.specularColorTexture !== undefined) {
        pending.push(
          parser.assignTexture(materialParams, 'specularColorMap', extension.specularColorTexture).then(function (texture) {
            texture.encoding = THREE.sRGBEncoding
          })
        )
      }

      return Promise.all(pending)
    }
  }
  /**
   * BasisU THREE.Texture Extension
   *
   * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_texture_basisu
   */

  class GLTFTextureBasisUExtension {
    constructor(parser) {
      this.parser = parser
      this.name = EXTENSIONS.KHR_TEXTURE_BASISU
    }

    loadTexture(textureIndex) {
      const parser = this.parser
      const json = parser.json
      const textureDef = json.textures[textureIndex]

      if (!textureDef.extensions || !textureDef.extensions[this.name]) {
        return null
      }

      const extension = textureDef.extensions[this.name]
      const source = json.images[extension.source]
      const loader = parser.options.ktx2Loader

      if (!loader) {
        if (json.extensionsRequired && json.extensionsRequired.indexOf(this.name) >= 0) {
          throw new Error('THREE.GLTFLoader: setKTX2Loader must be called before loading KTX2 textures')
        } else {
          // Assumes that the extension is optional and that a fallback texture is present
          return null
        }
      }

      return parser.loadTextureImage(textureIndex, source, loader)
    }
  }
  /**
   * WebP THREE.Texture Extension
   *
   * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Vendor/EXT_texture_webp
   */

  class GLTFTextureWebPExtension {
    constructor(parser) {
      this.parser = parser
      this.name = EXTENSIONS.EXT_TEXTURE_WEBP
      this.isSupported = null
    }

    loadTexture(textureIndex) {
      const name = this.name
      const parser = this.parser
      const json = parser.json
      const textureDef = json.textures[textureIndex]

      if (!textureDef.extensions || !textureDef.extensions[name]) {
        return null
      }

      const extension = textureDef.extensions[name]
      const source = json.images[extension.source]
      let loader = parser.textureLoader

      if (source.uri) {
        const handler = parser.options.manager.getHandler(source.uri)
        if (handler !== null) loader = handler
      }

      return this.detectSupport().then(function (isSupported) {
        if (isSupported) return parser.loadTextureImage(textureIndex, source, loader)

        if (json.extensionsRequired && json.extensionsRequired.indexOf(name) >= 0) {
          throw new Error('THREE.GLTFLoader: WebP required by asset but unsupported.')
        } // Fall back to PNG or JPEG.

        return parser.loadTexture(textureIndex)
      })
    }

    detectSupport() {
      if (!this.isSupported) {
        this.isSupported = new Promise(function (resolve) {
          const image = new Image() // Lossy test image. Support for lossy images doesn't guarantee support for all
          // WebP images, unfortunately.

          image.src = 'data:image/webp;base64,UklGRiIAAABXRUJQVlA4IBYAAAAwAQCdASoBAAEADsD+JaQAA3AAAAAA'

          image.onload = image.onerror = function () {
            resolve(image.height === 1)
          }
        })
      }

      return this.isSupported
    }
  }
  /**
   * meshopt BufferView Compression Extension
   *
   * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Vendor/EXT_meshopt_compression
   */

  class GLTFMeshoptCompression {
    constructor(parser) {
      this.name = EXTENSIONS.EXT_MESHOPT_COMPRESSION
      this.parser = parser
    }

    loadBufferView(index) {
      const json = this.parser.json
      const bufferView = json.bufferViews[index]

      if (bufferView.extensions && bufferView.extensions[this.name]) {
        const extensionDef = bufferView.extensions[this.name]
        const buffer = this.parser.getDependency('buffer', extensionDef.buffer)
        const decoder = this.parser.options.meshoptDecoder

        if (!decoder || !decoder.supported) {
          if (json.extensionsRequired && json.extensionsRequired.indexOf(this.name) >= 0) {
            throw new Error('THREE.GLTFLoader: setMeshoptDecoder must be called before loading compressed files')
          } else {
            // Assumes that the extension is optional and that fallback buffer data is present
            return null
          }
        }

        return Promise.all([buffer, decoder.ready]).then(function (res) {
          const byteOffset = extensionDef.byteOffset || 0
          const byteLength = extensionDef.byteLength || 0
          const count = extensionDef.count
          const stride = extensionDef.byteStride
          const result = new ArrayBuffer(count * stride)
          const source = new Uint8Array(res[0], byteOffset, byteLength)
          decoder.decodeGltfBuffer(new Uint8Array(result), count, stride, source, extensionDef.mode, extensionDef.filter)
          return result
        })
      } else {
        return null
      }
    }
  }
  /* BINARY EXTENSION */

  const BINARY_EXTENSION_HEADER_MAGIC = 'glTF'
  const BINARY_EXTENSION_HEADER_LENGTH = 12
  const BINARY_EXTENSION_CHUNK_TYPES = {
    JSON: 0x4e4f534a,
    BIN: 0x004e4942
  }

  class GLTFBinaryExtension {
    constructor(data) {
      this.name = EXTENSIONS.KHR_BINARY_GLTF
      this.content = null
      this.body = null
      const headerView = new DataView(data, 0, BINARY_EXTENSION_HEADER_LENGTH)
      this.header = {
        magic: THREE.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.')
      }

      const chunkContentsLength = this.header.length - BINARY_EXTENSION_HEADER_LENGTH
      const chunkView = new DataView(data, BINARY_EXTENSION_HEADER_LENGTH)
      let chunkIndex = 0

      while (chunkIndex < chunkContentsLength) {
        const chunkLength = chunkView.getUint32(chunkIndex, true)
        chunkIndex += 4
        const chunkType = chunkView.getUint32(chunkIndex, true)
        chunkIndex += 4

        if (chunkType === BINARY_EXTENSION_CHUNK_TYPES.JSON) {
          const contentArray = new Uint8Array(data, BINARY_EXTENSION_HEADER_LENGTH + chunkIndex, chunkLength)
          this.content = THREE.LoaderUtils.decodeText(contentArray)
        } else if (chunkType === BINARY_EXTENSION_CHUNK_TYPES.BIN) {
          const 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 THREE.Mesh Compression Extension
   *
   * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_draco_mesh_compression
   */

  class GLTFDracoMeshCompressionExtension {
    constructor(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()
    }

    decodePrimitive(primitive, parser) {
      const json = this.json
      const dracoLoader = this.dracoLoader
      const bufferViewIndex = primitive.extensions[this.name].bufferView
      const gltfAttributeMap = primitive.extensions[this.name].attributes
      const threeAttributeMap = {}
      const attributeNormalizedMap = {}
      const attributeTypeMap = {}

      for (const attributeName in gltfAttributeMap) {
        const threeAttributeName = ATTRIBUTES[attributeName] || attributeName.toLowerCase()
        threeAttributeMap[threeAttributeName] = gltfAttributeMap[attributeName]
      }

      for (const attributeName in primitive.attributes) {
        const threeAttributeName = ATTRIBUTES[attributeName] || attributeName.toLowerCase()

        if (gltfAttributeMap[attributeName] !== undefined) {
          const accessorDef = json.accessors[primitive.attributes[attributeName]]
          const 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 (const attributeName in geometry.attributes) {
                const attribute = geometry.attributes[attributeName]
                const normalized = attributeNormalizedMap[attributeName]
                if (normalized !== undefined) attribute.normalized = normalized
              }

              resolve(geometry)
            },
            threeAttributeMap,
            attributeTypeMap
          )
        })
      })
    }
  }
  /**
   * THREE.Texture Transform Extension
   *
   * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_texture_transform
   */

  class GLTFTextureTransformExtension {
    constructor() {
      this.name = EXTENSIONS.KHR_TEXTURE_TRANSFORM
    }

    extendTexture(texture, transform) {
      if (transform.texCoord !== undefined) {
        // WARNING SUPPRESSED BY LOCAL PATCH
        // console.warn( 'THREE.GLTFLoader: Custom UV sets in "' + this.name + '" extension not yet supported.' );
      }

      if (transform.offset === undefined && transform.rotation === undefined && transform.scale === undefined) {
        // See https://github.com/mrdoob/three.js/issues/21819.
        return texture
      }

      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)
      }

      texture.needsUpdate = true
      return texture
    }
  }
  /**
   * Specular-Glossiness Extension
   *
   * Specification: https://github.com/KhronosGroup/glTF/tree/main/extensions/2.0/Archived/KHR_materials_pbrSpecularGlossiness
   */

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

  class GLTFMeshStandardSGMaterial extends THREE.MeshStandardMaterial {
    constructor(params) {
      super()
      this.isGLTFSpecularGlossinessMaterial = true //various chunks that need replacing

      const specularMapParsFragmentChunk = ['#ifdef USE_SPECULARMAP', '	uniform sampler2D specularMap;', '#endif'].join('\n')
      const glossinessMapParsFragmentChunk = ['#ifdef USE_GLOSSINESSMAP', '	uniform sampler2D glossinessMap;', '#endif'].join('\n')
      const 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')
      const 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')
      const lightPhysicalFragmentChunk = [
        'PhysicalMaterial material;',
        'material.diffuseColor = diffuseColor.rgb * ( 1. - max( specularFactor.r, max( specularFactor.g, specularFactor.b ) ) );',
        'vec3 dxy = max( abs( dFdx( geometryNormal ) ), abs( dFdy( geometryNormal ) ) );',
        'float geometryRoughness = max( max( dxy.x, dxy.y ), dxy.z );',
        'material.roughness = max( 1.0 - glossinessFactor, 0.0525 ); // 0.0525 corresponds to the base mip of a 256 cubemap.',
        'material.roughness += geometryRoughness;',
        'material.roughness = min( material.roughness, 1.0 );',
        'material.specularColor = specularFactor;'
      ].join('\n')
      const uniforms = {
        specular: {
          value: new THREE.Color().setHex(0xffffff)
        },
        glossiness: {
          value: 1
        },
        specularMap: {
          value: null
        },
        glossinessMap: {
          value: null
        }
      }
      this._extraUniforms = uniforms

      this.onBeforeCompile = function (shader) {
        for (const uniformName in uniforms) {
          shader.uniforms[uniformName] = uniforms[uniformName]
        }

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

      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

            if (v) {
              this.defines.USE_SPECULARMAP = '' // USE_UV is set by the renderer for specular maps
            } else {
              delete this.defines.USE_SPECULARMAP
            }
          }
        },
        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

            if (v) {
              this.defines.USE_GLOSSINESSMAP = ''
              this.defines.USE_UV = ''
            } else {
              delete this.defines.USE_GLOSSINESSMAP
              delete this.defines.USE_UV
            }
          }
        }
      })
      delete this.metalness
      delete this.roughness
      delete this.metalnessMap
      delete this.roughnessMap
      this.setValues(params)
    }

    copy(source) {
      super.copy(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
    }
  }

  class GLTFMaterialsPbrSpecularGlossinessExtension {
    constructor() {
      this.name = EXTENSIONS.KHR_MATERIALS_PBR_SPECULAR_GLOSSINESS
      this.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() {
      return GLTFMeshStandardSGMaterial
    }

    extendParams(materialParams, materialDef, parser) {
      const pbrSpecularGlossiness = materialDef.extensions[this.name]
      materialParams.color = new THREE.Color(1.0, 1.0, 1.0)
      materialParams.opacity = 1.0
      const pending = []

      if (Array.isArray(pbrSpecularGlossiness.diffuseFactor)) {
        const 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 THREE.Color(0.0, 0.0, 0.0)
      materialParams.glossiness = pbrSpecularGlossiness.glossinessFactor !== undefined ? pbrSpecularGlossiness.glossinessFactor : 1.0
      materialParams.specular = new THREE.Color(1.0, 1.0, 1.0)

      if (Array.isArray(pbrSpecularGlossiness.specularFactor)) {
        materialParams.specular.fromArray(pbrSpecularGlossiness.specularFactor)
      }

      if (pbrSpecularGlossiness.specularGlossinessTexture !== undefined) {
        const specGlossMapDef = pbrSpecularGlossiness.specularGlossinessTexture
        pending.push(parser.assignTexture(materialParams, 'glossinessMap', specGlossMapDef))
        pending.push(parser.assignTexture(materialParams, 'specularMap', specGlossMapDef))
      }

      return Promise.all(pending)
    }

    createMaterial(materialParams) {
      const 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 = THREE.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
    }
  }
  /**
   * THREE.Mesh Quantization Extension
   *
   * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_mesh_quantization
   */

  class GLTFMeshQuantizationExtension {
    constructor() {
      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

  class GLTFCubicSplineInterpolant extends THREE.Interpolant {
    constructor(parameterPositions, sampleValues, sampleSize, resultBuffer) {
      super(parameterPositions, sampleValues, sampleSize, resultBuffer)
    }

    copySampleValue_(index) {
      // Copies a sample value to the result buffer. See description of glTF
      // CUBICSPLINE values layout in interpolate_() function below.
      const result = this.resultBuffer,
        values = this.sampleValues,
        valueSize = this.valueSize,
        offset = index * valueSize * 3 + valueSize

      for (let 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) {
    const result = this.resultBuffer
    const values = this.sampleValues
    const stride = this.valueSize
    const stride2 = stride * 2
    const stride3 = stride * 3
    const td = t1 - t0
    const p = (t - t0) / td
    const pp = p * p
    const ppp = pp * p
    const offset1 = i1 * stride3
    const offset0 = offset1 - stride3
    const s2 = -2 * ppp + 3 * pp
    const s3 = ppp - pp
    const s0 = 1 - s2
    const s1 = s3 - pp + p // Layout of keyframe output values for CUBICSPLINE animations:
    //   [ inTangent_1, splineVertex_1, outTangent_1, inTangent_2, splineVertex_2, ... ]

    for (let i = 0; i !== stride; i++) {
      const p0 = values[offset0 + i + stride] // splineVertex_k

      const m0 = values[offset0 + i + stride2] * td // outTangent_k * (t_k+1 - t_k)

      const p1 = values[offset1 + i + stride] // splineVertex_k+1

      const 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
  }

  const _q = new THREE.Quaternion()

  class GLTFCubicSplineQuaternionInterpolant extends GLTFCubicSplineInterpolant {
    interpolate_(i1, t0, t, t1) {
      const result = super.interpolate_(i1, t0, t, t1)

      _q.fromArray(result).normalize().toArray(result)

      return result
    }
  }
  /*********************************/

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

  /*********************************/

  /* CONSTANTS */

  const 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
  }
  const WEBGL_COMPONENT_TYPES = {
    5120: Int8Array,
    5121: Uint8Array,
    5122: Int16Array,
    5123: Uint16Array,
    5125: Uint32Array,
    5126: Float32Array
  }
  const WEBGL_FILTERS = {
    9728: THREE.NearestFilter,
    9729: THREE.LinearFilter,
    9984: THREE.NearestMipmapNearestFilter,
    9985: THREE.LinearMipmapNearestFilter,
    9986: THREE.NearestMipmapLinearFilter,
    9987: THREE.LinearMipmapLinearFilter
  }
  const WEBGL_WRAPPINGS = {
    33071: THREE.ClampToEdgeWrapping,
    33648: THREE.MirroredRepeatWrapping,
    10497: THREE.RepeatWrapping
  }
  const WEBGL_TYPE_SIZES = {
    SCALAR: 1,
    VEC2: 2,
    VEC3: 3,
    VEC4: 4,
    MAT2: 4,
    MAT3: 9,
    MAT4: 16
  }
  const ATTRIBUTES = {
    POSITION: 'position',
    NORMAL: 'normal',
    TANGENT: 'tangent',
    TEXCOORD_0: 'uv',
    TEXCOORD_1: 'uv2',
    COLOR_0: 'color',
    WEIGHTS_0: 'skinWeight',
    JOINTS_0: 'skinIndex'
  }
  const PATH_PROPERTIES = {
    scale: 'scale',
    translation: 'position',
    rotation: 'quaternion',
    weights: 'morphTargetInfluences'
  }
  const 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: THREE.InterpolateLinear,
    STEP: THREE.InterpolateDiscrete
  }
  const ALPHA_MODES = {
    OPAQUE: 'OPAQUE',
    MASK: 'MASK',
    BLEND: 'BLEND'
  }
  /**
   * 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 THREE.MeshStandardMaterial({
        color: 0xffffff,
        emissive: 0x000000,
        metalness: 1,
        roughness: 1,
        transparent: false,
        depthTest: true,
        side: THREE.FrontSide
      })
    }

    return cache['DefaultMaterial']
  }

  function addUnknownExtensionsToUserData(knownExtensions, object, objectDef) {
    // Add unknown glTF extensions to an object's userData.
    for (const 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) {
    let hasMorphPosition = false
    let hasMorphNormal = false

    for (let i = 0, il = targets.length; i < il; i++) {
      const 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)
    const pendingPositionAccessors = []
    const pendingNormalAccessors = []

    for (let i = 0, il = targets.length; i < il; i++) {
      const target = targets[i]

      if (hasMorphPosition) {
        const pendingAccessor = target.POSITION !== undefined ? parser.getDependency('accessor', target.POSITION) : geometry.attributes.position
        pendingPositionAccessors.push(pendingAccessor)
      }

      if (hasMorphNormal) {
        const 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) {
      const morphPositions = accessors[0]
      const 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 (let 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)) {
      const targetNames = meshDef.extras.targetNames

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

        for (let 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) {
    const dracoExtension = primitiveDef.extensions && primitiveDef.extensions[EXTENSIONS.KHR_DRACO_MESH_COMPRESSION]
    let 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) {
    let attributesKey = ''
    const keys = Object.keys(attributes).sort()

    for (let i = 0, il = keys.length; i < il; i++) {
      attributesKey += keys[i] + ':' + attributes[keys[i]] + ';'
    }

    return attributesKey
  }

  function getNormalizedComponentScale(constructor) {
    // Reference:
    // https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_mesh_quantization#encoding-quantized-data
    switch (constructor) {
      case Int8Array:
        return 1 / 127

      case Uint8Array:
        return 1 / 255

      case Int16Array:
        return 1 / 32767

      case Uint16Array:
        return 1 / 65535

      default:
        throw new Error('THREE.GLTFLoader: Unsupported normalized accessor component type.')
    }
  }
  /* GLTF PARSER */

  class GLTFParser {
    constructor(json = {}, options = {}) {
      this.json = json
      this.extensions = {}
      this.plugins = {}
      this.options = options // loader object cache

      this.cache = new GLTFRegistry() // associations between Three.js objects and glTF elements

      this.associations = new Map() // THREE.BufferGeometry caching

      this.primitiveCache = {} // THREE.Object3D instance caches

      this.meshCache = {
        refs: {},
        uses: {}
      }
      this.cameraCache = {
        refs: {},
        uses: {}
      }
      this.lightCache = {
        refs: {},
        uses: {}
      }
      this.textureCache = {} // Track node names, to ensure no duplicates

      this.nodeNamesUsed = {} // Use an THREE.ImageBitmapLoader if imageBitmaps are supported. Moves much of the
      // expensive work of uploading a texture to the GPU off the main thread.

      if (typeof createImageBitmap !== 'undefined' && /Firefox|Safari/.test(navigator.userAgent) === false) {
        this.textureLoader = new THREE.ImageBitmapLoader(this.options.manager)
      } else {
        this.textureLoader = new THREE.TextureLoader(this.options.manager)
      }

      this.textureLoader.setCrossOrigin(this.options.crossOrigin)
      this.textureLoader.setRequestHeader(this.options.requestHeader)
      this.fileLoader = new THREE.FileLoader(this.options.manager)
      this.fileLoader.setResponseType('arraybuffer')

      if (this.options.crossOrigin === 'use-credentials') {
        this.fileLoader.setWithCredentials(true)
      }
    }

    setExtensions(extensions) {
      this.extensions = extensions
    }

    setPlugins(plugins) {
      this.plugins = plugins
    }

    parse(onLoad, onError) {
      const parser = this
      const json = this.json
      const extensions = this.extensions // Clear the loader cache

      this.cache.removeAll() // Mark the special nodes/meshes in json for efficient parse

      this._invokeAll(function (ext) {
        return ext._markDefs && ext._markDefs()
      })

      Promise.all(
        this._invokeAll(function (ext) {
          return ext.beforeRoot && ext.beforeRoot()
        })
      )
        .then(function () {
          return Promise.all([parser.getDependencies('scene'), parser.getDependencies('animation'), parser.getDependencies('camera')])
        })
        .then(function (dependencies) {
          const 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)
          Promise.all(
            parser._invokeAll(function (ext) {
              return ext.afterRoot && ext.afterRoot(result)
            })
          ).then(function () {
            onLoad(result)
          })
        })
        .catch(onError)
    }
    /**
     * Marks the special nodes/meshes in json for efficient parse.
     */

    _markDefs() {
      const nodeDefs = this.json.nodes || []
      const skinDefs = this.json.skins || []
      const meshDefs = this.json.meshes || [] // Nothing in the node definition indicates whether it is a THREE.Bone or an
      // THREE.Object3D. Use the skins' joint references to mark bones.

      for (let skinIndex = 0, skinLength = skinDefs.length; skinIndex < skinLength; skinIndex++) {
        const joints = skinDefs[skinIndex].joints

        for (let i = 0, il = joints.length; i < il; i++) {
          nodeDefs[joints[i]].isBone = true
        }
      } // Iterate over all nodes, marking references to shared resources,
      // as well as skeleton joints.

      for (let nodeIndex = 0, nodeLength = nodeDefs.length; nodeIndex < nodeLength; nodeIndex++) {
        const nodeDef = nodeDefs[nodeIndex]

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

          if (nodeDef.skin !== undefined) {
            meshDefs[nodeDef.mesh].isSkinnedMesh = true
          }
        }

        if (nodeDef.camera !== undefined) {
          this._addNodeRef(this.cameraCache, nodeDef.camera)
        }
      }
    }
    /**
     * Counts references to shared node / THREE.Object3D resources. These resources
     * can be reused, or "instantiated", at multiple nodes in the scene
     * hierarchy. THREE.Mesh, Camera, and Light instances are instantiated and must
     * be marked. Non-scenegraph resources (like Materials, Geometries, and
     * Textures) can be reused directly and are not marked here.
     *
     * Example: CesiumMilkTruck sample model reuses "Wheel" meshes.
     */

    _addNodeRef(cache, index) {
      if (index === undefined) return

      if (cache.refs[index] === undefined) {
        cache.refs[index] = cache.uses[index] = 0
      }

      cache.refs[index]++
    }
    /** Returns a reference to a shared resource, cloning it if necessary. */

    _getNodeRef(cache, index, object) {
      if (cache.refs[index] <= 1) return object
      const ref = object.clone() // Propagates mappings to the cloned object, prevents mappings on the
      // original object from being lost.

      const updateMappings = (original, clone) => {
        const mappings = this.associations.get(original)

        if (mappings != null) {
          this.associations.set(clone, mappings)
        }

        for (const [i, child] of original.children.entries()) {
          updateMappings(child, clone.children[i])
        }
      }

      updateMappings(object, ref)
      ref.name += '_instance_' + cache.uses[index]++
      return ref
    }

    _invokeOne(func) {
      const extensions = Object.values(this.plugins)
      extensions.push(this)

      for (let i = 0; i < extensions.length; i++) {
        const result = func(extensions[i])
        if (result) return result
      }

      return null
    }

    _invokeAll(func) {
      const extensions = Object.values(this.plugins)
      extensions.unshift(this)
      const pending = []

      for (let i = 0; i < extensions.length; i++) {
        const result = func(extensions[i])
        if (result) pending.push(result)
      }

      return pending
    }
    /**
     * Requests the specified dependency asynchronously, with caching.
     * @param {string} type
     * @param {number} index
     * @return {Promise<Object3D|Material|THREE.Texture|AnimationClip|ArrayBuffer|Object>}
     */

    getDependency(type, index) {
      const cacheKey = type + ':' + index
      let 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._invokeOne(function (ext) {
              return ext.loadMesh && ext.loadMesh(index)
            })
            break

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

          case 'bufferView':
            dependency = this._invokeOne(function (ext) {
              return ext.loadBufferView && ext.loadBufferView(index)
            })
            break

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

          case 'material':
            dependency = this._invokeOne(function (ext) {
              return ext.loadMaterial && ext.loadMaterial(index)
            })
            break

          case 'texture':
            dependency = this._invokeOne(function (ext) {
              return ext.loadTexture && ext.loadTexture(index)
            })
            break

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

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

          case 'camera':
            dependency = this.loadCamera(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>>}
     */

    getDependencies(type) {
      let dependencies = this.cache.get(type)

      if (!dependencies) {
        const parser = this
        const 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>}
     */

    loadBuffer(bufferIndex) {
      const bufferDef = this.json.buffers[bufferIndex]
      const 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)
      }

      const options = this.options
      return new Promise(function (resolve, reject) {
        loader.load(THREE.LoaderUtils.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>}
     */

    loadBufferView(bufferViewIndex) {
      const bufferViewDef = this.json.bufferViews[bufferViewIndex]
      return this.getDependency('buffer', bufferViewDef.buffer).then(function (buffer) {
        const byteLength = bufferViewDef.byteLength || 0
        const 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>}
     */

    loadAccessor(accessorIndex) {
      const parser = this
      const json = this.json
      const 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)
      }

      const 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) {
        const bufferView = bufferViews[0]
        const itemSize = WEBGL_TYPE_SIZES[accessorDef.type]
        const TypedArray = WEBGL_COMPONENT_TYPES[accessorDef.componentType] // For VEC3: itemSize is 3, elementBytes is 4, itemBytes is 12.

        const elementBytes = TypedArray.BYTES_PER_ELEMENT
        const itemBytes = elementBytes * itemSize
        const byteOffset = accessorDef.byteOffset || 0
        const byteStride = accessorDef.bufferView !== undefined ? json.bufferViews[accessorDef.bufferView].byteStride : undefined
        const normalized = accessorDef.normalized === true
        let 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 THREE.InterleavedBuffer
          // This makes sure that IBA.count reflects accessor.count properly
          const ibSlice = Math.floor(byteOffset / byteStride)
          const ibCacheKey = 'InterleavedBuffer:' + accessorDef.bufferView + ':' + accessorDef.componentType + ':' + ibSlice + ':' + accessorDef.count
          let 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 THREE.InterleavedBuffer(array, byteStride / elementBytes)
            parser.cache.add(ibCacheKey, ib)
          }

          bufferAttribute = new THREE.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 THREE.BufferAttribute(array, itemSize, normalized)
        } // https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#sparse-accessors

        if (accessorDef.sparse !== undefined) {
          const itemSizeIndices = WEBGL_TYPE_SIZES.SCALAR
          const TypedArrayIndices = WEBGL_COMPONENT_TYPES[accessorDef.sparse.indices.componentType]
          const byteOffsetIndices = accessorDef.sparse.indices.byteOffset || 0
          const byteOffsetValues = accessorDef.sparse.values.byteOffset || 0
          const sparseIndices = new TypedArrayIndices(bufferViews[1], byteOffsetIndices, accessorDef.sparse.count * itemSizeIndices)
          const 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 THREE.BufferAttribute(bufferAttribute.array.slice(), bufferAttribute.itemSize, bufferAttribute.normalized)
          }

          for (let i = 0, il = sparseIndices.length; i < il; i++) {
            const 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 THREE.BufferAttribute.')
          }
        }

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

    loadTexture(textureIndex) {
      const json = this.json
      const options = this.options
      const textureDef = json.textures[textureIndex]
      const source = json.images[textureDef.source]
      let loader = this.textureLoader

      if (source.uri) {
        const handler = options.manager.getHandler(source.uri)
        if (handler !== null) loader = handler
      }

      return this.loadTextureImage(textureIndex, source, loader)
    }

    loadTextureImage(textureIndex, source, loader) {
      const parser = this
      const json = this.json
      const options = this.options
      const textureDef = json.textures[textureIndex]
      const cacheKey = (source.uri || source.bufferView) + ':' + textureDef.sampler

      if (this.textureCache[cacheKey]) {
        // See https://github.com/mrdoob/three.js/issues/21559.
        return this.textureCache[cacheKey]
      }

      const URL = self.URL || self.webkitURL
      let sourceURI = source.uri || ''
      let 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
          const blob = new Blob([bufferView], {
            type: source.mimeType
          })
          sourceURI = URL.createObjectURL(blob)
          return sourceURI
        })
      } else if (source.uri === undefined) {
        throw new Error('THREE.GLTFLoader: Image ' + textureIndex + ' is missing URI and bufferView')
      }

      const promise = Promise.resolve(sourceURI)
        .then(function (sourceURI) {
          return new Promise(function (resolve, reject) {
            let onLoad = resolve

            if (loader.isImageBitmapLoader === true) {
              onLoad = function (imageBitmap) {
                const texture = new THREE.Texture(imageBitmap)
                texture.needsUpdate = true
                resolve(texture)
              }
            }

            loader.load(THREE.LoaderUtils.resolveURL(sourceURI, options.path), onLoad, undefined, reject)
          })
        })
        .then(function (texture) {
          // Clean up resources and configure THREE.Texture.
          if (isObjectURL === true) {
            URL.revokeObjectURL(sourceURI)
          }

          texture.flipY = false
          if (textureDef.name) texture.name = textureDef.name
          const samplers = json.samplers || {}
          const sampler = samplers[textureDef.sampler] || {}
          texture.magFilter = WEBGL_FILTERS[sampler.magFilter] || THREE.LinearFilter
          texture.minFilter = WEBGL_FILTERS[sampler.minFilter] || THREE.LinearMipmapLinearFilter
          texture.wrapS = WEBGL_WRAPPINGS[sampler.wrapS] || THREE.RepeatWrapping
          texture.wrapT = WEBGL_WRAPPINGS[sampler.wrapT] || THREE.RepeatWrapping
          parser.associations.set(texture, {
            textures: textureIndex
          })
          return texture
        })
        .catch(function () {
          console.error("THREE.GLTFLoader: Couldn't load texture", sourceURI)
          return null
        })
      this.textureCache[cacheKey] = promise
      return promise
    }
    /**
     * Asynchronously assigns a texture to the given material parameters.
     * @param {Object} materialParams
     * @param {string} mapName
     * @param {Object} mapDef
     * @return {Promise<Texture>}
     */

    assignTexture(materialParams, mapName, mapDef) {
      const parser = this
      return this.getDependency('texture', mapDef.index).then(function (texture) {
        // 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]) {
          const transform = mapDef.extensions !== undefined ? mapDef.extensions[EXTENSIONS.KHR_TEXTURE_TRANSFORM] : undefined

          if (transform) {
            const gltfReference = parser.associations.get(texture)
            texture = parser.extensions[EXTENSIONS.KHR_TEXTURE_TRANSFORM].extendTexture(texture, transform)
            parser.associations.set(texture, gltfReference)
          }
        }

        materialParams[mapName] = texture
        return texture
      })
    }
    /**
     * Assigns final material to a THREE.Mesh, THREE.Line, or THREE.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 accommodate different primitive types, defines, etc. New materials will
     * be created if necessary, and reused from a cache.
     * @param  {Object3D} mesh THREE.Mesh, THREE.Line, or THREE.Points instance.
     */

    assignFinalMaterial(mesh) {
      const geometry = mesh.geometry
      let material = mesh.material
      const useDerivativeTangents = geometry.attributes.tangent === undefined
      const useVertexColors = geometry.attributes.color !== undefined
      const useFlatShading = geometry.attributes.normal === undefined

      if (mesh.isPoints) {
        const cacheKey = 'PointsMaterial:' + material.uuid
        let pointsMaterial = this.cache.get(cacheKey)

        if (!pointsMaterial) {
          pointsMaterial = new THREE.PointsMaterial()
          THREE.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) {
        const cacheKey = 'LineBasicMaterial:' + material.uuid
        let lineMaterial = this.cache.get(cacheKey)

        if (!lineMaterial) {
          lineMaterial = new THREE.LineBasicMaterial()
          THREE.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 (useDerivativeTangents || useVertexColors || useFlatShading) {
        let cacheKey = 'ClonedMaterial:' + material.uuid + ':'
        if (material.isGLTFSpecularGlossinessMaterial) cacheKey += 'specular-glossiness:'
        if (useDerivativeTangents) cacheKey += 'derivative-tangents:'
        if (useVertexColors) cacheKey += 'vertex-colors:'
        if (useFlatShading) cacheKey += 'flat-shading:'
        let cachedMaterial = this.cache.get(cacheKey)

        if (!cachedMaterial) {
          cachedMaterial = material.clone()
          if (useVertexColors) cachedMaterial.vertexColors = true
          if (useFlatShading) cachedMaterial.flatShading = true

          if (useDerivativeTangents) {
            // https://github.com/mrdoob/three.js/issues/11438#issuecomment-507003995
            if (cachedMaterial.normalScale) cachedMaterial.normalScale.y *= -1
            if (cachedMaterial.clearcoatNormalScale) cachedMaterial.clearcoatNormalScale.y *= -1
          }

          this.cache.add(cacheKey, cachedMaterial)
          this.associations.set(cachedMaterial, this.associations.get(material))
        }

        material = cachedMaterial
      } // workarounds for mesh and geometry

      if (material.aoMap && geometry.attributes.uv2 === undefined && geometry.attributes.uv !== undefined) {
        geometry.setAttribute('uv2', geometry.attributes.uv)
      }

      mesh.material = material
    }

    getMaterialType() {
      return THREE.MeshStandardMaterial
    }
    /**
     * Specification: https://github.com/KhronosGroup/glTF/blob/master/specification/2.0/README.md#materials
     * @param {number} materialIndex
     * @return {Promise<Material>}
     */

    loadMaterial(materialIndex) {
      const parser = this
      const json = this.json
      const extensions = this.extensions
      const materialDef = json.materials[materialIndex]
      let materialType
      const materialParams = {}
      const materialExtensions = materialDef.extensions || {}
      const pending = []

      if (materialExtensions[EXTENSIONS.KHR_MATERIALS_PBR_SPECULAR_GLOSSINESS]) {
        const 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]) {
        const 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
        const metallicRoughness = materialDef.pbrMetallicRoughness || {}
        materialParams.color = new THREE.Color(1.0, 1.0, 1.0)
        materialParams.opacity = 1.0

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

        materialType = this._invokeOne(function (ext) {
          return ext.getMaterialType && ext.getMaterialType(materialIndex)
        })
        pending.push(
          Promise.all(
            this._invokeAll(function (ext) {
              return ext.extendMaterialParams && ext.extendMaterialParams(materialIndex, materialParams)
            })
          )
        )
      }

      if (materialDef.doubleSided === true) {
        materialParams.side = THREE.DoubleSide
      }

      const 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.format = THREE.RGBFormat
        materialParams.transparent = false

        if (alphaMode === ALPHA_MODES.MASK) {
          materialParams.alphaTest = materialDef.alphaCutoff !== undefined ? materialDef.alphaCutoff : 0.5
        }
      }

      if (materialDef.normalTexture !== undefined && materialType !== THREE.MeshBasicMaterial) {
        pending.push(parser.assignTexture(materialParams, 'normalMap', materialDef.normalTexture))
        materialParams.normalScale = new THREE.Vector2(1, 1)

        if (materialDef.normalTexture.scale !== undefined) {
          const scale = materialDef.normalTexture.scale
          materialParams.normalScale.set(scale, scale)
        }
      }

      if (materialDef.occlusionTexture !== undefined && materialType !== THREE.MeshBasicMaterial) {
        pending.push(parser.assignTexture(materialParams, 'aoMap', materialDef.occlusionTexture))

        if (materialDef.occlusionTexture.strength !== undefined) {
          materialParams.aoMapIntensity = materialDef.occlusionTexture.strength
        }
      }

      if (materialDef.emissiveFactor !== undefined && materialType !== THREE.MeshBasicMaterial) {
        materialParams.emissive = new THREE.Color().fromArray(materialDef.emissiveFactor)
      }

      if (materialDef.emissiveTexture !== undefined && materialType !== THREE.MeshBasicMaterial) {
        pending.push(parser.assignTexture(materialParams, 'emissiveMap', materialDef.emissiveTexture))
      }

      return Promise.all(pending).then(function () {
        let 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 = THREE.sRGBEncoding
        if (material.emissiveMap) material.emissiveMap.encoding = THREE.sRGBEncoding
        assignExtrasToUserData(material, materialDef)
        parser.associations.set(material, {
          materials: materialIndex
        })
        if (materialDef.extensions) addUnknownExtensionsToUserData(extensions, material, materialDef)
        return material
      })
    }
    /** When THREE.Object3D instances are targeted by animation, they need unique names. */

    createUniqueName(originalName) {
      const sanitizedName = THREE.PropertyBinding.sanitizeNodeName(originalName || '')
      let name = sanitizedName

      for (let i = 1; this.nodeNamesUsed[name]; ++i) {
        name = sanitizedName + '_' + i
      }

      this.nodeNamesUsed[name] = true
      return name
    }
    /**
     * 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>>}
     */

    loadGeometries(primitives) {
      const parser = this
      const extensions = this.extensions
      const cache = this.primitiveCache

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

      const pending = []

      for (let i = 0, il = primitives.length; i < il; i++) {
        const primitive = primitives[i]
        const cacheKey = createPrimitiveKey(primitive) // See if we've already created this geometry

        const cached = cache[cacheKey]

        if (cached) {
          // Use the cached geometry if it exists
          pending.push(cached.promise)
        } else {
          let 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 THREE.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>}
     */

    loadMesh(meshIndex) {
      const parser = this
      const json = this.json
      const extensions = this.extensions
      const meshDef = json.meshes[meshIndex]
      const primitives = meshDef.primitives
      const pending = []

      for (let i = 0, il = primitives.length; i < il; i++) {
        const 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) {
        const materials = results.slice(0, results.length - 1)
        const geometries = results[results.length - 1]
        const meshes = []

        for (let i = 0, il = geometries.length; i < il; i++) {
          const geometry = geometries[i]
          const primitive = primitives[i] // 1. create THREE.Mesh

          let mesh
          const 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 THREE.SkinnedMesh(geometry, material) : new THREE.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, THREE.TriangleStripDrawMode)
            } else if (primitive.mode === WEBGL_CONSTANTS.TRIANGLE_FAN) {
              mesh.geometry = toTrianglesDrawMode(mesh.geometry, THREE.TriangleFanDrawMode)
            }
          } else if (primitive.mode === WEBGL_CONSTANTS.LINES) {
            mesh = new THREE.LineSegments(geometry, material)
          } else if (primitive.mode === WEBGL_CONSTANTS.LINE_STRIP) {
            mesh = new THREE.Line(geometry, material)
          } else if (primitive.mode === WEBGL_CONSTANTS.LINE_LOOP) {
            mesh = new THREE.LineLoop(geometry, material)
          } else if (primitive.mode === WEBGL_CONSTANTS.POINTS) {
            mesh = new THREE.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 = parser.createUniqueName(meshDef.name || 'mesh_' + meshIndex)
          assignExtrasToUserData(mesh, meshDef)
          if (primitive.extensions) addUnknownExtensionsToUserData(extensions, mesh, primitive)
          parser.assignFinalMaterial(mesh)
          meshes.push(mesh)
        }

        for (let i = 0, il = meshes.length; i < il; i++) {
          parser.associations.set(meshes[i], {
            meshes: meshIndex,
            primitives: i
          })
        }

        if (meshes.length === 1) {
          return meshes[0]
        }

        const group = new THREE.Group()
        parser.associations.set(group, {
          meshes: meshIndex
        })

        for (let 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>}
     */

    loadCamera(cameraIndex) {
      let camera
      const cameraDef = this.json.cameras[cameraIndex]
      const params = cameraDef[cameraDef.type]

      if (!params) {
        console.warn('THREE.GLTFLoader: Missing camera parameters.')
        return
      }

      if (cameraDef.type === 'perspective') {
        camera = new THREE.PerspectiveCamera(THREE.MathUtils.radToDeg(params.yfov), params.aspectRatio || 1, params.znear || 1, params.zfar || 2e6)
      } else if (cameraDef.type === 'orthographic') {
        camera = new THREE.OrthographicCamera(-params.xmag, params.xmag, params.ymag, -params.ymag, params.znear, params.zfar)
      }

      if (cameraDef.name) camera.name = this.createUniqueName(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>}
     */

    loadSkin(skinIndex) {
      const skinDef = this.json.skins[skinIndex]
      const 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>}
     */

    loadAnimation(animationIndex) {
      const json = this.json
      const animationDef = json.animations[animationIndex]
      const pendingNodes = []
      const pendingInputAccessors = []
      const pendingOutputAccessors = []
      const pendingSamplers = []
      const pendingTargets = []

      for (let i = 0, il = animationDef.channels.length; i < il; i++) {
        const channel = animationDef.channels[i]
        const sampler = animationDef.samplers[channel.sampler]
        const target = channel.target
        const name = target.node !== undefined ? target.node : target.id // NOTE: target.id is deprecated.

        const input = animationDef.parameters !== undefined ? animationDef.parameters[sampler.input] : sampler.input
        const 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) {
          const nodes = dependencies[0]
          const inputAccessors = dependencies[1]
          const outputAccessors = dependencies[2]
          const samplers = dependencies[3]
          const targets = dependencies[4]
          const tracks = []

          for (let i = 0, il = nodes.length; i < il; i++) {
            const node = nodes[i]
            const inputAccessor = inputAccessors[i]
            const outputAccessor = outputAccessors[i]
            const sampler = samplers[i]
            const target = targets[i]
            if (node === undefined) continue
            node.updateMatrix()
            node.matrixAutoUpdate = true
            let TypedKeyframeTrack

            switch (PATH_PROPERTIES[target.path]) {
              case PATH_PROPERTIES.weights:
                TypedKeyframeTrack = THREE.NumberKeyframeTrack
                break

              case PATH_PROPERTIES.rotation:
                TypedKeyframeTrack = THREE.QuaternionKeyframeTrack
                break

              case PATH_PROPERTIES.position:
              case PATH_PROPERTIES.scale:
              default:
                TypedKeyframeTrack = THREE.VectorKeyframeTrack
                break
            }

            const targetName = node.name ? node.name : node.uuid
            const interpolation = sampler.interpolation !== undefined ? INTERPOLATION[sampler.interpolation] : THREE.InterpolateLinear
            const targetNames = []

            if (PATH_PROPERTIES[target.path] === PATH_PROPERTIES.weights) {
              node.traverse(function (object) {
                if (object.morphTargetInfluences) {
                  targetNames.push(object.name ? object.name : object.uuid)
                }
              })
            } else {
              targetNames.push(targetName)
            }

            let outputArray = outputAccessor.array

            if (outputAccessor.normalized) {
              const scale = getNormalizedComponentScale(outputArray.constructor)
              const scaled = new Float32Array(outputArray.length)

              for (let j = 0, jl = outputArray.length; j < jl; j++) {
                scaled[j] = outputArray[j] * scale
              }

              outputArray = scaled
            }

            for (let j = 0, jl = targetNames.length; j < jl; j++) {
              const 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.
                  const interpolantType = this instanceof THREE.QuaternionKeyframeTrack ? GLTFCubicSplineQuaternionInterpolant : GLTFCubicSplineInterpolant
                  return new interpolantType(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)
            }
          }

          const name = animationDef.name ? animationDef.name : 'animation_' + animationIndex
          return new THREE.AnimationClip(name, undefined, tracks)
        }
      )
    }

    createNodeMesh(nodeIndex) {
      const json = this.json
      const parser = this
      const nodeDef = json.nodes[nodeIndex]
      if (nodeDef.mesh === undefined) return null
      return parser.getDependency('mesh', nodeDef.mesh).then(function (mesh) {
        const node = parser._getNodeRef(parser.meshCache, nodeDef.mesh, 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 (let i = 0, il = nodeDef.weights.length; i < il; i++) {
              o.morphTargetInfluences[i] = nodeDef.weights[i]
            }
          })
        }

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

    loadNode(nodeIndex) {
      const json = this.json
      const extensions = this.extensions
      const parser = this
      const nodeDef = json.nodes[nodeIndex] // reserve node's name before its dependencies, so the root has the intended name.

      const nodeName = nodeDef.name ? parser.createUniqueName(nodeDef.name) : ''
      return (function () {
        const pending = []

        const meshPromise = parser._invokeOne(function (ext) {
          return ext.createNodeMesh && ext.createNodeMesh(nodeIndex)
        })

        if (meshPromise) {
          pending.push(meshPromise)
        }

        if (nodeDef.camera !== undefined) {
          pending.push(
            parser.getDependency('camera', nodeDef.camera).then(function (camera) {
              return parser._getNodeRef(parser.cameraCache, nodeDef.camera, camera)
            })
          )
        }

        parser
          ._invokeAll(function (ext) {
            return ext.createNodeAttachment && ext.createNodeAttachment(nodeIndex)
          })
          .forEach(function (promise) {
            pending.push(promise)
          })

        return Promise.all(pending)
      })().then(function (objects) {
        let node // .isBone isn't in glTF spec. See ._markDefs

        if (nodeDef.isBone === true) {
          node = new THREE.Bone()
        } else if (objects.length > 1) {
          node = new THREE.Group()
        } else if (objects.length === 1) {
          node = objects[0]
        } else {
          node = new THREE.Object3D()
        }

        if (node !== objects[0]) {
          for (let i = 0, il = objects.length; i < il; i++) {
            node.add(objects[i])
          }
        }

        if (nodeDef.name) {
          node.userData.name = nodeDef.name
          node.name = nodeName
        }

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

        if (nodeDef.matrix !== undefined) {
          const matrix = new THREE.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)
          }
        }

        if (!parser.associations.has(node)) {
          parser.associations.set(node, {})
        }

        parser.associations.get(node).nodes = nodeIndex
        return node
      })
    }
    /**
     * Specification: https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#scenes
     * @param {number} sceneIndex
     * @return {Promise<Group>}
     */

    loadScene(sceneIndex) {
      const json = this.json
      const extensions = this.extensions
      const sceneDef = this.json.scenes[sceneIndex]
      const parser = this // THREE.Loader returns THREE.Group, not Scene.
      // See: https://github.com/mrdoob/three.js/issues/18342#issuecomment-578981172

      const scene = new THREE.Group()
      if (sceneDef.name) scene.name = parser.createUniqueName(sceneDef.name)
      assignExtrasToUserData(scene, sceneDef)
      if (sceneDef.extensions) addUnknownExtensionsToUserData(extensions, scene, sceneDef)
      const nodeIds = sceneDef.nodes || []
      const pending = []

      for (let i = 0, il = nodeIds.length; i < il; i++) {
        pending.push(buildNodeHierarchy(nodeIds[i], scene, json, parser))
      }

      return Promise.all(pending).then(function () {
        // Removes dangling associations, associations that reference a node that
        // didn't make it into the scene.
        const reduceAssociations = (node) => {
          const reducedAssociations = new Map()

          for (const [key, value] of parser.associations) {
            if (key instanceof THREE.Material || key instanceof THREE.Texture) {
              reducedAssociations.set(key, value)
            }
          }

          node.traverse((node) => {
            const mappings = parser.associations.get(node)

            if (mappings != null) {
              reducedAssociations.set(node, mappings)
            }
          })
          return reducedAssociations
        }

        parser.associations = reduceAssociations(scene)
        return scene
      })
    }
  }

  function buildNodeHierarchy(nodeId, parentObject, json, parser) {
    const nodeDef = json.nodes[nodeId]
    return parser
      .getDependency('node', nodeId)
      .then(function (node) {
        if (nodeDef.skin === undefined) return node // build skeleton here as well

        let skinEntry
        return parser
          .getDependency('skin', nodeDef.skin)
          .then(function (skin) {
            skinEntry = skin
            const pendingJoints = []

            for (let 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
              const bones = []
              const boneInverses = []

              for (let j = 0, jl = jointNodes.length; j < jl; j++) {
                const jointNode = jointNodes[j]

                if (jointNode) {
                  bones.push(jointNode)
                  const mat = new THREE.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 THREE.Skeleton(bones, boneInverses), mesh.matrixWorld)
            })
            return node
          })
      })
      .then(function (node) {
        // build node hierachy
        parentObject.add(node)
        const pending = []

        if (nodeDef.children) {
          const children = nodeDef.children

          for (let i = 0, il = children.length; i < il; i++) {
            const child = children[i]
            pending.push(buildNodeHierarchy(child, node, json, parser))
          }
        }

        return Promise.all(pending)
      })
  }
  /**
   * @param {BufferGeometry} geometry
   * @param {GLTF.Primitive} primitiveDef
   * @param {GLTFParser} parser
   */

  function computeBounds(geometry, primitiveDef, parser) {
    const attributes = primitiveDef.attributes
    const box = new THREE.Box3()

    if (attributes.POSITION !== undefined) {
      const accessor = parser.json.accessors[attributes.POSITION]
      const min = accessor.min
      const 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 THREE.Vector3(min[0], min[1], min[2]), new THREE.Vector3(max[0], max[1], max[2]))

        if (accessor.normalized) {
          const boxScale = getNormalizedComponentScale(WEBGL_COMPONENT_TYPES[accessor.componentType])
          box.min.multiplyScalar(boxScale)
          box.max.multiplyScalar(boxScale)
        }
      } else {
        console.warn('THREE.GLTFLoader: Missing min/max properties for accessor POSITION.')
        return
      }
    } else {
      return
    }

    const targets = primitiveDef.targets

    if (targets !== undefined) {
      const maxDisplacement = new THREE.Vector3()
      const vector = new THREE.Vector3()

      for (let i = 0, il = targets.length; i < il; i++) {
        const target = targets[i]

        if (target.POSITION !== undefined) {
          const accessor = parser.json.accessors[target.POSITION]
          const min = accessor.min
          const 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])))

            if (accessor.normalized) {
              const boxScale = getNormalizedComponentScale(WEBGL_COMPONENT_TYPES[accessor.componentType])
              vector.multiplyScalar(boxScale)
            } // 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
    const sphere = new THREE.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) {
    const attributes = primitiveDef.attributes
    const pending = []

    function assignAttributeAccessor(accessorIndex, attributeName) {
      return parser.getDependency('accessor', accessorIndex).then(function (accessor) {
        geometry.setAttribute(attributeName, accessor)
      })
    }

    for (const gltfAttributeName in attributes) {
      const 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) {
      const 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) {
    let index = geometry.getIndex() // generate index if not present

    if (index === null) {
      const indices = []
      const position = geometry.getAttribute('position')

      if (position !== undefined) {
        for (let 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
      }
    } //

    const numberOfTriangles = index.count - 2
    const newIndices = []

    if (drawMode === THREE.TriangleFanDrawMode) {
      // gl.TRIANGLE_FAN
      for (let 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 (let 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

    const newGeometry = geometry.clone()
    newGeometry.setIndex(newIndices)
    return newGeometry
  }

  THREE.GLTFLoader = GLTFLoader
})()