text: ( function () {
  
  	/**
   * Loads a Wavefront .mtl file specifying materials
   */
  
  	class MTLLoader extends THREE.Loader {
  
  		constructor( manager ) {
  
  			super( manager );
  
  		}
  		/**
     * Loads and parses a MTL asset from a URL.
     *
     * @param {String} url - URL to the MTL file.
     * @param {Function} [onLoad] - Callback invoked with the loaded object.
     * @param {Function} [onProgress] - Callback for download progress.
     * @param {Function} [onError] - Callback for download errors.
     *
     * @see setPath setResourcePath
     *
     * @note In order for relative texture references to resolve correctly
     * you must call setResourcePath() explicitly prior to load.
     */
  
  
  		load( url, onLoad, onProgress, onError ) {
  
  			const scope = this;
  			const path = this.path === '' ? THREE.LoaderUtils.extractUrlBase( url ) : this.path;
  			const loader = new THREE.FileLoader( this.manager );
  			loader.setPath( this.path );
  			loader.setRequestHeader( this.requestHeader );
  			loader.setWithCredentials( this.withCredentials );
  			loader.load( url, function ( text ) {
  
  				try {
  
  					onLoad( scope.parse( text, path ) );
  
  				} catch ( e ) {
  
  					if ( onError ) {
  
  						onError( e );
  
  					} else {
  
  						console.error( e );
  
  					}
  
  					scope.manager.itemError( url );
  
  				}
  
  			}, onProgress, onError );
  
  		}
  
  		setMaterialOptions( value ) {
  
  			this.materialOptions = value;
  			return this;
  
  		}
  		/**
     * Parses a MTL file.
     *
     * @param {String} text - Content of MTL file
     * @return {MaterialCreator}
     *
     * @see setPath setResourcePath
     *
     * @note In order for relative texture references to resolve correctly
     * you must call setResourcePath() explicitly prior to parse.
     */
  
  
  		parse( text, path ) {
  
  			const lines = text.split( '\n' );
  			let info = {};
  			const delimiter_pattern = /\s+/;
  			const materialsInfo = {};
  
  			for ( let i = 0; i < lines.length; i ++ ) {
  
  				let line = lines[ i ];
  				line = line.trim();
  
  				if ( line.length === 0 || line.charAt( 0 ) === '#' ) {
  
  					// Blank line or comment ignore
  					continue;
  
  				}
  
  				const pos = line.indexOf( ' ' );
  				let key = pos >= 0 ? line.substring( 0, pos ) : line;
  				key = key.toLowerCase();
  				let value = pos >= 0 ? line.substring( pos + 1 ) : '';
  				value = value.trim();
  
  				if ( key === 'newmtl' ) {
  
  					// New material
  					info = {
  						name: value
  					};
  					materialsInfo[ value ] = info;
  
  				} else {
  
  					if ( key === 'ka' || key === 'kd' || key === 'ks' || key === 'ke' ) {
  
  						const ss = value.split( delimiter_pattern, 3 );
  						info[ key ] = [ parseFloat( ss[ 0 ] ), parseFloat( ss[ 1 ] ), parseFloat( ss[ 2 ] ) ];
  
  					} else {
  
  						info[ key ] = value;
  
  					}
  
  				}
  
  			}
  
  			const materialCreator = new MaterialCreator( this.resourcePath || path, this.materialOptions );
  			materialCreator.setCrossOrigin( this.crossOrigin );
  			materialCreator.setManager( this.manager );
  			materialCreator.setMaterials( materialsInfo );
  			return materialCreator;
  
  		}
  
  	}
  	/**
   * Create a new MTLLoader.MaterialCreator
   * @param baseUrl - Url relative to which textures are loaded
   * @param options - Set of options on how to construct the materials
   *                  side: Which side to apply the material
   *                        THREE.FrontSide (default), THREE.BackSide, THREE.DoubleSide
   *                  wrap: What type of wrapping to apply for textures
   *                        THREE.RepeatWrapping (default), THREE.ClampToEdgeWrapping, THREE.MirroredRepeatWrapping
   *                  normalizeRGB: RGBs need to be normalized to 0-1 from 0-255
   *                                Default: false, assumed to be already normalized
   *                  ignoreZeroRGBs: Ignore values of RGBs (Ka,Kd,Ks) that are all 0's
   *                                  Default: false
   * @constructor
   */
  
  
  	class MaterialCreator {
  
  		constructor( baseUrl = '', options = {} ) {
  
  			this.baseUrl = baseUrl;
  			this.options = options;
  			this.materialsInfo = {};
  			this.materials = {};
  			this.materialsArray = [];
  			this.nameLookup = {};
  			this.crossOrigin = 'anonymous';
  			this.side = this.options.side !== undefined ? this.options.side : THREE.FrontSide;
  			this.wrap = this.options.wrap !== undefined ? this.options.wrap : THREE.RepeatWrapping;
  
  		}
  
  		setCrossOrigin( value ) {
  
  			this.crossOrigin = value;
  			return this;
  
  		}
  
  		setManager( value ) {
  
  			this.manager = value;
  
  		}
  
  		setMaterials( materialsInfo ) {
  
  			this.materialsInfo = this.convert( materialsInfo );
  			this.materials = {};
  			this.materialsArray = [];
  			this.nameLookup = {};
  
  		}
  
  		convert( materialsInfo ) {
  
  			if ( ! this.options ) return materialsInfo;
  			const converted = {};
  
  			for ( const mn in materialsInfo ) {
  
  				// Convert materials info into normalized form based on options
  				const mat = materialsInfo[ mn ];
  				const covmat = {};
  				converted[ mn ] = covmat;
  
  				for ( const prop in mat ) {
  
  					let save = true;
  					let value = mat[ prop ];
  					const lprop = prop.toLowerCase();
  
  					switch ( lprop ) {
  
  						case 'kd':
  						case 'ka':
  						case 'ks':
  							// Diffuse color (color under white light) using RGB values
  							if ( this.options && this.options.normalizeRGB ) {
  
  								value = [ value[ 0 ] / 255, value[ 1 ] / 255, value[ 2 ] / 255 ];
  
  							}
  
  							if ( this.options && this.options.ignoreZeroRGBs ) {
  
  								if ( value[ 0 ] === 0 && value[ 1 ] === 0 && value[ 2 ] === 0 ) {
  
  									// ignore
  									save = false;
  
  								}
  
  							}
  
  							break;
  
  						default:
  							break;
  
  					}
  
  					if ( save ) {
  
  						covmat[ lprop ] = value;
  
  					}
  
  				}
  
  			}
  
  			return converted;
  
  		}
  
  		preload() {
  
  			for ( const mn in this.materialsInfo ) {
  
  				this.create( mn );
  
  			}
  
  		}
  
  		getIndex( materialName ) {
  
  			return this.nameLookup[ materialName ];
  
  		}
  
  		getAsArray() {
  
  			let index = 0;
  
  			for ( const mn in this.materialsInfo ) {
  
  				this.materialsArray[ index ] = this.create( mn );
  				this.nameLookup[ mn ] = index;
  				index ++;
  
  			}
  
  			return this.materialsArray;
  
  		}
  
  		create( materialName ) {
  
  			if ( this.materials[ materialName ] === undefined ) {
  
  				this.createMaterial_( materialName );
  
  			}
  
  			return this.materials[ materialName ];
  
  		}
  
  		createMaterial_( materialName ) {
  
  			// Create material
  			const scope = this;
  			const mat = this.materialsInfo[ materialName ];
  			const params = {
  				name: materialName,
  				side: this.side
  			};
  
  			function resolveURL( baseUrl, url ) {
  
  				if ( typeof url !== 'string' || url === '' ) return ''; // Absolute URL
  
  				if ( /^https?:\/\//i.test( url ) ) return url;
  				return baseUrl + url;
  
  			}
  
  			function setMapForType( mapType, value ) {
  
  				if ( params[ mapType ] ) return; // Keep the first encountered texture
  
  				const texParams = scope.getTextureParams( value, params );
  				const map = scope.loadTexture( resolveURL( scope.baseUrl, texParams.url ) );
  				map.repeat.copy( texParams.scale );
  				map.offset.copy( texParams.offset );
  				map.wrapS = scope.wrap;
  				map.wrapT = scope.wrap;
  
  				if ( mapType === 'map' || mapType === 'emissiveMap' ) {
  
  					map.encoding = THREE.sRGBEncoding;
  
  				}
  
  				params[ mapType ] = map;
  
  			}
  
  			for ( const prop in mat ) {
  
  				const value = mat[ prop ];
  				let n;
  				if ( value === '' ) continue;
  
  				switch ( prop.toLowerCase() ) {
  
  					// Ns is material specular exponent
  					case 'kd':
  						// Diffuse color (color under white light) using RGB values
  						params.color = new THREE.Color().fromArray( value ).convertSRGBToLinear();
  						break;
  
  					case 'ks':
  						// Specular color (color when light is reflected from shiny surface) using RGB values
  						params.specular = new THREE.Color().fromArray( value ).convertSRGBToLinear();
  						break;
  
  					case 'ke':
  						// Emissive using RGB values
  						params.emissive = new THREE.Color().fromArray( value ).convertSRGBToLinear();
  						break;
  
  					case 'map_kd':
  						// Diffuse texture map
  						setMapForType( 'map', value );
  						break;
  
  					case 'map_ks':
  						// Specular map
  						setMapForType( 'specularMap', value );
  						break;
  
  					case 'map_ke':
  						// Emissive map
  						setMapForType( 'emissiveMap', value );
  						break;
  
  					case 'norm':
  						setMapForType( 'normalMap', value );
  						break;
  
  					case 'map_bump':
  					case 'bump':
  						// Bump texture map
  						setMapForType( 'bumpMap', value );
  						break;
  
  					case 'map_d':
  						// Alpha map
  						setMapForType( 'alphaMap', value );
  						params.transparent = true;
  						break;
  
  					case 'ns':
  						// The specular exponent (defines the focus of the specular highlight)
  						// A high exponent results in a tight, concentrated highlight. Ns values normally range from 0 to 1000.
  						params.shininess = parseFloat( value );
  						break;
  
  					case 'd':
  						n = parseFloat( value );
  
  						if ( n < 1 ) {
  
  							params.opacity = n;
  							params.transparent = true;
  
  						}
  
  						break;
  
  					case 'tr':
  						n = parseFloat( value );
  						if ( this.options && this.options.invertTrProperty ) n = 1 - n;
  
  						if ( n > 0 ) {
  
  							params.opacity = 1 - n;
  							params.transparent = true;
  
  						}
  
  						break;
  
  					default:
  						break;
  
  				}
  
  			}
  
  			this.materials[ materialName ] = new THREE.MeshPhongMaterial( params );
  			return this.materials[ materialName ];
  
  		}
  
  		getTextureParams( value, matParams ) {
  
  			const texParams = {
  				scale: new THREE.Vector2( 1, 1 ),
  				offset: new THREE.Vector2( 0, 0 )
  			};
  			const items = value.split( /\s+/ );
  			let pos;
  			pos = items.indexOf( '-bm' );
  
  			if ( pos >= 0 ) {
  
  				matParams.bumpScale = parseFloat( items[ pos + 1 ] );
  				items.splice( pos, 2 );
  
  			}
  
  			pos = items.indexOf( '-s' );
  
  			if ( pos >= 0 ) {
  
  				texParams.scale.set( parseFloat( items[ pos + 1 ] ), parseFloat( items[ pos + 2 ] ) );
  				items.splice( pos, 4 ); // we expect 3 parameters here!
  
  			}
  
  			pos = items.indexOf( '-o' );
  
  			if ( pos >= 0 ) {
  
  				texParams.offset.set( parseFloat( items[ pos + 1 ] ), parseFloat( items[ pos + 2 ] ) );
  				items.splice( pos, 4 ); // we expect 3 parameters here!
  
  			}
  
  			texParams.url = items.join( ' ' ).trim();
  			return texParams;
  
  		}
  
  		loadTexture( url, mapping, onLoad, onProgress, onError ) {
  
  			const manager = this.manager !== undefined ? this.manager : THREE.DefaultLoadingManager;
  			let loader = manager.getHandler( url );
  
  			if ( loader === null ) {
  
  				loader = new THREE.TextureLoader( manager );
  
  			}
  
  			if ( loader.setCrossOrigin ) loader.setCrossOrigin( this.crossOrigin );
  			const texture = loader.load( url, onLoad, onProgress, onError );
  			if ( mapping !== undefined ) texture.mapping = mapping;
  			return texture;
  
  		}
  
  	}
  
  	THREE.MTLLoader = MTLLoader;
  
  } )();