three.js/examples/jsm/loaders/VRMLLoader.js

/**
 * @author Mugen87 / https://github.com/Mugen87
 */

import {
	BackSide,
	BoxBufferGeometry,
	BufferAttribute,
	BufferGeometry,
	ClampToEdgeWrapping,
	Color,
	ConeBufferGeometry,
	CylinderBufferGeometry,
	DefaultLoadingManager,
	DoubleSide,
	FileLoader,
	Float32BufferAttribute,
	FrontSide,
	Group,
	LineBasicMaterial,
	LineSegments,
	LoaderUtils,
	Mesh,
	MeshBasicMaterial,
	MeshPhongMaterial,
	Object3D,
	Points,
	PointsMaterial,
	RepeatWrapping,
	Scene,
	SphereBufferGeometry,
	TextureLoader,
	Vector2,
	Vector3,
	VertexColors
} from "../../../build/three.module.js";

/* global chevrotain */

var VRMLLoader = ( function () {

	// dependency check

	if ( typeof chevrotain === 'undefined' ) {

		throw Error( 'THREE.VRMLLoader: External library chevrotain.min.js required.' );

	}

	// class definitions

	function VRMLLoader( manager ) {

		this.manager = ( manager !== undefined ) ? manager : DefaultLoadingManager;

	}

	VRMLLoader.prototype = {

		constructor: VRMLLoader,

		crossOrigin: 'anonymous',

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

			var scope = this;

			var path = ( scope.path === undefined ) ? LoaderUtils.extractUrlBase( url ) : scope.path;

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

				onLoad( scope.parse( text, path ) );

			}, onProgress, onError );

		},

		setPath: function ( value ) {

			this.path = value;
			return this;

		},

		setResourcePath: function ( value ) {

			this.resourcePath = value;
			return this;

		},

		setCrossOrigin: function ( value ) {

			this.crossOrigin = value;
			return this;

		},

		parse: function ( data, path ) {

			var nodeMap = {};

			function generateVRMLTree( data ) {

				// create lexer, parser and visitor

				var tokenData = createTokens();

				var lexer = new VRMLLexer( tokenData.tokens );
				var parser = new VRMLParser( tokenData.tokenVocabulary );
				var visitor = createVisitor( parser.getBaseCstVisitorConstructor() );

				// lexing

				var lexingResult = lexer.lex( data );
				parser.input = lexingResult.tokens;

				// parsing

				var cstOutput = parser.vrml();

				if ( parser.errors.length > 0 ) {

					console.error( parser.errors );

					throw Error( 'THREE.VRMLLoader: Parsing errors detected.' );

				}

				// actions

				var ast = visitor.visit( cstOutput );

				return ast;

			}

			function createTokens() {

				var createToken = chevrotain.createToken;

				// from http://gun.teipir.gr/VRML-amgem/spec/part1/concepts.html#SyntaxBasics

				var RouteIdentifier = createToken( { name: 'RouteIdentifier', pattern: /[^\x30-\x39\0-\x20\x22\x27\x23\x2b\x2c\x2d\x2e\x5b\x5d\x5c\x7b\x7d][^\0-\x20\x22\x27\x23\x2b\x2c\x2d\x2e\x5b\x5d\x5c\x7b\x7d]*[\.][^\x30-\x39\0-\x20\x22\x27\x23\x2b\x2c\x2d\x2e\x5b\x5d\x5c\x7b\x7d][^\0-\x20\x22\x27\x23\x2b\x2c\x2d\x2e\x5b\x5d\x5c\x7b\x7d]*/ } );
				var Identifier = createToken( { name: 'Identifier', pattern: /[^\x30-\x39\0-\x20\x22\x27\x23\x2b\x2c\x2d\x2e\x5b\x5d\x5c\x7b\x7d][^\0-\x20\x22\x27\x23\x2b\x2c\x2d\x2e\x5b\x5d\x5c\x7b\x7d]*/, longer_alt: RouteIdentifier } );

				// from http://gun.teipir.gr/VRML-amgem/spec/part1/nodesRef.html

				var nodeTypes = [
					'Anchor', 'Billboard', 'Collision', 'Group', 'Transform', // grouping nodes
					'Inline', 'LOD', 'Switch', // special groups
					'AudioClip', 'DirectionalLight', 'PointLight', 'Script', 'Shape', 'Sound', 'SpotLight', 'WorldInfo', // common nodes
					'CylinderSensor', 'PlaneSensor', 'ProximitySensor', 'SphereSensor', 'TimeSensor', 'TouchSensor', 'VisibilitySensor', // sensors
					'Box', 'Cone', 'Cylinder', 'ElevationGrid', 'Extrusion', 'IndexedFaceSet', 'IndexedLineSet', 'PointSet', 'Sphere', // geometries
					'Color', 'Coordinate', 'Normal', 'TextureCoordinate', // geometric properties
					'Appearance', 'FontStyle', 'ImageTexture', 'Material', 'MovieTexture', 'PixelTexture', 'TextureTransform', // appearance
					'ColorInterpolator', 'CoordinateInterpolator', 'NormalInterpolator', 'OrientationInterpolator', 'PositionInterpolator', 'ScalarInterpolator', // interpolators
					'Background', 'Fog', 'NavigationInfo', 'Viewpoint', // bindable nodes
					'Text' // Text must be placed at the end of the regex so there are no matches for TextureTransform and TextureCoordinate
				];

				//

				var Version = createToken( {
					name: 'Version',
					pattern: /#VRML.*/,
					longer_alt: Identifier
				} );

				var NodeName = createToken( {
					name: 'NodeName',
					pattern: new RegExp( nodeTypes.join( '|' ) ),
					longer_alt: Identifier
				} );

				var DEF = createToken( {
					name: 'DEF',
					pattern: /DEF/,
					longer_alt: Identifier
				} );

				var USE = createToken( {
					name: 'USE',
					pattern: /USE/,
					longer_alt: Identifier
				} );

				var ROUTE = createToken( {
					name: 'ROUTE',
					pattern: /ROUTE/,
					longer_alt: Identifier
				} );

				var TO = createToken( {
					name: 'TO',
					pattern: /TO/,
					longer_alt: Identifier
				} );

				//

				var StringLiteral = createToken( { name: "StringLiteral", pattern: /"(:?[^\\"\n\r]+|\\(:?[bfnrtv"\\/]|u[0-9a-fA-F]{4}))*"/ } );
				var NumberLiteral = createToken( { name: 'NumberLiteral', pattern: /[-+]?[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?/ } );
				var BooleanLiteral = createToken( { name: 'BooleanLiteral', pattern: /TRUE|FALSE/ } );
				var NullLiteral = createToken( { name: 'NullLiteral', pattern: /NULL/ } );
				var LSquare = createToken( { name: 'LSquare', pattern: /\[/ } );
				var RSquare = createToken( { name: 'RSquare', pattern: /]/ } );
				var LCurly = createToken( { name: 'LCurly', pattern: /{/ } );
				var RCurly = createToken( { name: 'RCurly', pattern: /}/ } );
				var Comment = createToken( {
					name: 'Comment',
					pattern: /#.*/,
					group: chevrotain.Lexer.SKIPPED
				} );

				// commas, blanks, tabs, newlines and carriage returns are whitespace characters wherever they appear outside of string fields

				var WhiteSpace = createToken( {
					name: 'WhiteSpace',
					pattern: /[ ,\s]/,
					group: chevrotain.Lexer.SKIPPED
				} );

				var tokens = [
					WhiteSpace,
					// keywords appear before the Identifier
					NodeName,
					DEF,
					USE,
					ROUTE,
					TO,
					BooleanLiteral,
					NullLiteral,
					// the Identifier must appear after the keywords because all keywords are valid identifiers
					Version,
					Identifier,
					RouteIdentifier,
					StringLiteral,
					NumberLiteral,
					LSquare,
					RSquare,
					LCurly,
					RCurly,
					Comment
				];

				var tokenVocabulary = {};

				for ( var i = 0, l = tokens.length; i < l; i ++ ) {

					var token = tokens[ i ];

					tokenVocabulary[ token.name ] = token;

				}

				return { tokens: tokens, tokenVocabulary: tokenVocabulary };

			}


			function createVisitor( BaseVRMLVisitor ) {

				// the visitor is created dynmaically based on the given base class

				function VRMLToASTVisitor() {

					BaseVRMLVisitor.call( this );

					this.validateVisitor();

				}

				VRMLToASTVisitor.prototype = Object.assign( Object.create( BaseVRMLVisitor.prototype ), {

					constructor: VRMLToASTVisitor,

					vrml: function ( ctx ) {

						var data = {
							version: this.visit( ctx.version ),
							nodes: [],
							routes: []
						};

						for ( var i = 0, l = ctx.node.length; i < l; i ++ ) {

							var node = ctx.node[ i ];

							data.nodes.push( this.visit( node ) );

						}

						if ( ctx.route ) {

							for ( var i = 0, l = ctx.route.length; i < l; i ++ ) {

								var route = ctx.route[ i ];

								data.routes.push( this.visit( route ) );

							}

						}

						return data;

					},

					version: function ( ctx ) {

						return ctx.Version[ 0 ].image;

					},

					node: function ( ctx ) {

						var data = {
							name: ctx.NodeName[ 0 ].image,
							fields: []
						};

						if ( ctx.field ) {

							for ( var i = 0, l = ctx.field.length; i < l; i ++ ) {

								var field = ctx.field[ i ];

								data.fields.push( this.visit( field ) );

							}

						}

						// DEF

						if ( ctx.def ) {

							data.DEF = this.visit( ctx.def[ 0 ] );

						}

						return data;

					},

					field: function ( ctx ) {

						var data = {
							name: ctx.Identifier[ 0 ].image,
							type: null,
							values: null
						};

						var result;

						// SFValue

						if ( ctx.singleFieldValue ) {

							result = this.visit( ctx.singleFieldValue[ 0 ] );

						}

						// MFValue

						if ( ctx.multiFieldValue ) {

							result = this.visit( ctx.multiFieldValue[ 0 ] );

						}

						data.type = result.type;
						data.values = result.values;

						return data;

					},

					def: function ( ctx ) {

						return ctx.Identifier[ 0 ].image;

					},

					use: function ( ctx ) {

						return { USE: ctx.Identifier[ 0 ].image };

					},

					singleFieldValue: function ( ctx ) {

						return processField( this, ctx );

					},

					multiFieldValue: function ( ctx ) {

						return processField( this, ctx );

					},

					route: function ( ctx ) {

						var data = {
							FROM: ctx.RouteIdentifier[ 0 ].image,
							TO: ctx.RouteIdentifier[ 1 ].image
						};

						return data;

					}

				} );

				function processField( scope, ctx ) {

					var field = {
						type: null,
						values: []
					};

					if ( ctx.node ) {

						field.type = 'node';

						for ( var i = 0, l = ctx.node.length; i < l; i ++ ) {

							var node = ctx.node[ i ];

							field.values.push( scope.visit( node ) );

						}

					}

					if ( ctx.use ) {

						field.type = 'use';

						for ( var i = 0, l = ctx.use.length; i < l; i ++ ) {

							var use = ctx.use[ i ];

							field.values.push( scope.visit( use ) );

						}

					}

					if ( ctx.StringLiteral ) {

						field.type = 'string';

						for ( var i = 0, l = ctx.StringLiteral.length; i < l; i ++ ) {

							var stringLiteral = ctx.StringLiteral[ i ];

							field.values.push( stringLiteral.image.replace( /'|"/g, '' ) );

						}

					}

					if ( ctx.NumberLiteral ) {

						field.type = 'number';

						for ( var i = 0, l = ctx.NumberLiteral.length; i < l; i ++ ) {

							var numberLiteral = ctx.NumberLiteral[ i ];

							field.values.push( parseFloat( numberLiteral.image ) );

						}

					}

					if ( ctx.BooleanLiteral ) {

						field.type = 'boolean';

						for ( var i = 0, l = ctx.BooleanLiteral.length; i < l; i ++ ) {

							var booleanLiteral = ctx.BooleanLiteral[ i ];

							field.values.push( booleanLiteral.image === 'TRUE' );

						}

					}

					if ( ctx.NullLiteral ) {

						field.type = 'null';

						ctx.NullLiteral.forEach( function () {

							field.values.push( null );

						} );

					}

					return field;

				}

				return new VRMLToASTVisitor();

			}

			function parseTree( tree ) {

				// console.log( JSON.stringify( tree, null, 2 ) );

				var nodes = tree.nodes;
				var scene = new Scene();

				// first iteration: build nodemap based on DEF statements

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

					var node = nodes[ i ];

					buildNodeMap( node );

				}

				// second iteration: build nodes

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

					var node = nodes[ i ];
					var object = getNode( node );

					if ( object instanceof Object3D ) scene.add( object );

				}

				return scene;

			}

			function buildNodeMap( node ) {

				if ( node.DEF ) {

					nodeMap[ node.DEF ] = node;

				}

				var fields = node.fields;

				for ( var i = 0, l = fields.length; i < l; i ++ ) {

					var field = fields[ i ];

					if ( field.type === 'node' ) {

						var fieldValues = field.values;

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

							buildNodeMap( fieldValues[ j ] );

						}

					}


				}

			}


			function getNode( node ) {

				// handle case where a node refers to a different one

				if ( node.USE ) {

					return resolveUSE( node.USE );

				}

				if ( node.build !== undefined ) return node.build;

				node.build = buildNode( node );

				return node.build;

			}

			// node builder

			function buildNode( node ) {

				var nodeName = node.name;
				var build;

				switch ( nodeName ) {

					case 'Group':
					case 'Transform':
						build = buildGroupingNode( node );
						break;

					case 'Background':
						build = buildBackgroundNode( node );
						break;

					case 'Shape':
						build = buildShapeNode( node );
						break;

					case 'Appearance':
						build = buildApperanceNode( node );
						break;

					case 'Material':
						build = buildMaterialNode( node );
						break;

					case 'ImageTexture':
						build = buildImageTextureNode( node );
						break;

					case 'TextureTransform':
						build = buildTextureTransformNode( node );
						break;

					case 'IndexedFaceSet':
						build = buildIndexedFaceSetNode( node );
						break;

					case 'IndexedLineSet':
						build = buildIndexedLineSetNode( node );
						break;

					case 'PointSet':
						build = buildPointSetNode( node );
						break;

					case 'Box':
						build = buildBoxNode( node );
						break;

					case 'Cone':
						build = buildConeNode( node );
						break;

					case 'Cylinder':
						build = buildCylinderNode( node );
						break;

					case 'Sphere':
						build = buildSphereNode( node );
						break;

					case 'Color':
					case 'Coordinate':
					case 'Normal':
					case 'TextureCoordinate':
						build = buildGeometricNode( node );
						break;

					case 'Anchor':
					case 'Billboard':
					case 'Collision':

					case 'Inline':
					case 'LOD':
					case 'Switch':

					case 'AudioClip':
					case 'DirectionalLight':
					case 'PointLight':
					case 'Script':
					case 'Sound':
					case 'SpotLight':
					case 'WorldInfo':

					case 'CylinderSensor':
					case 'PlaneSensor':
					case 'ProximitySensor':
					case 'SphereSensor':
					case 'TimeSensor':
					case 'TouchSensor':
					case 'VisibilitySensor':

					case 'ElevationGrid':
					case 'Extrusion':
					case 'Text':

					case 'FontStyle':
					case 'MovieTexture':
					case 'PixelTexture':

					case 'ColorInterpolator':
					case 'CoordinateInterpolator':
					case 'NormalInterpolator':
					case 'OrientationInterpolator':
					case 'PositionInterpolator':
					case 'ScalarInterpolator':

					case 'Fog':
					case 'NavigationInfo':
					case 'Viewpoint':
						// node not supported yet
						break;

					default:
						console.warn( 'THREE.VRMLLoader: Unknown node:', nodeName );
						break;

				}

				return build;

			}

			function buildGroupingNode( node ) {

				var object = new Group();

				//

				var fields = node.fields;

				for ( var i = 0, l = fields.length; i < l; i ++ ) {

					var field = fields[ i ];
					var fieldName = field.name;
					var fieldValues = field.values;

					switch ( fieldName ) {

						case 'center':
							// field not supported
							break;

						case 'children':
							parseFieldChildren( fieldValues, object );
							break;

						case 'rotation':
							var axis = new Vector3( fieldValues[ 0 ], fieldValues[ 1 ], fieldValues[ 2 ] );
							var angle = fieldValues[ 3 ];
							object.quaternion.setFromAxisAngle( axis, angle );
							break;

						case 'scale':
							object.scale.set( fieldValues[ 0 ], fieldValues[ 1 ], fieldValues[ 2 ] );
							break;

						case 'scaleOrientation':
							// field not supported
							break;

						case 'translation':
							object.position.set( fieldValues[ 0 ], fieldValues[ 1 ], fieldValues[ 2 ] );
							break;

						case 'bboxCenter':
							// field not supported
							break;

						case 'bboxSize':
							// field not supported
							break;

						default:
							console.warn( 'THREE.VRMLLoader: Unknown field:', fieldName );
							break;

					}

				}

				return object;

			}

			function buildBackgroundNode( node ) {

				var group = new Group();

				var groundAngle, groundColor;
				var skyAngle, skyColor;

				var fields = node.fields;

				for ( var i = 0, l = fields.length; i < l; i ++ ) {

					var field = fields[ i ];
					var fieldName = field.name;
					var fieldValues = field.values;

					switch ( fieldName ) {

						case 'groundAngle':
							groundAngle = fieldValues;
							break;

						case 'groundColor':
							groundColor = fieldValues;
							break;

						case 'backUrl':
							// field not supported
							break;

						case 'bottomUrl':
							// field not supported
							break;

						case 'frontUrl':
							// field not supported
							break;

						case 'leftUrl':
							// field not supported
							break;

						case 'rightUrl':
							// field not supported
							break;

						case 'topUrl':
							// field not supported
							break;

						case 'skyAngle':
							skyAngle = fieldValues;
							break;

						case 'skyColor':
							skyColor = fieldValues;
							break;

						default:
							console.warn( 'THREE.VRMLLoader: Unknown field:', fieldName );
							break;

					}

				}

				// sky

				if ( skyColor ) {

					var radius = 10000;

					var skyGeometry = new SphereBufferGeometry( radius, 32, 16 );
					var skyMaterial = new MeshBasicMaterial( { fog: false, side: BackSide, depthWrite: false, depthTest: false } );

					if ( skyColor.length > 3 ) {

						paintFaces( skyGeometry, radius, skyAngle, toColorArray( skyColor ), true );
						skyMaterial.vertexColors = VertexColors;

					} else {

						skyMaterial.color.setRGB( skyColor[ 0 ], skyColor[ 1 ], skyColor[ 2 ] );

					}

					var sky = new Mesh( skyGeometry, skyMaterial );
					group.add( sky );

				}

				// ground

				if ( groundColor ) {

					if ( groundColor.length > 0 ) {

						var groundGeometry = new SphereBufferGeometry( radius, 32, 16, 0, 2 * Math.PI, 0.5 * Math.PI, 1.5 * Math.PI );
						var groundMaterial = new MeshBasicMaterial( { fog: false, side: BackSide, vertexColors: VertexColors, depthWrite: false, depthTest: false } );

						paintFaces( groundGeometry, radius, groundAngle, toColorArray( groundColor ), false );

						var ground = new Mesh( groundGeometry, groundMaterial );
						group.add( ground );

					}

				}

				// render background group first

				group.renderOrder = - Infinity;

				return group;

			}

			function buildShapeNode( node ) {

				var fields = node.fields;

				// if the appearance field is NULL or unspecified, lighting is off and the unlit object color is (0, 0, 0)

				var material = new MeshBasicMaterial( { color: 0x000000 } );
				var geometry;

				for ( var i = 0, l = fields.length; i < l; i ++ ) {

					var field = fields[ i ];
					var fieldName = field.name;
					var fieldValues = field.values;

					switch ( fieldName ) {

						case 'appearance':
							if ( fieldValues[ 0 ] !== null ) {

								material = getNode( fieldValues[ 0 ] );

							}
							break;

						case 'geometry':
							if ( fieldValues[ 0 ] !== null ) {

								geometry = getNode( fieldValues[ 0 ] );

							}
							break;

						default:
							console.warn( 'THREE.VRMLLoader: Unknown field:', fieldName );
							break;

					}

				}

				// build 3D object

				var object;

				if ( geometry ) {

					var type = geometry._type;

					if ( type === 'points' ) { // points

						var pointsMaterial = new PointsMaterial( { color: 0xffffff } );

						if ( geometry.attributes.color !== undefined ) {

							pointsMaterial.vertexColors = VertexColors;

						} else {

							// if the color field is NULL and there is a material defined for the appearance affecting this PointSet, then use the emissiveColor of the material to draw the points

							if ( material.isMeshPhongMaterial ) {

								pointsMaterial.color.copy( material.emissive );

							}

						}

						object = new Points( geometry, pointsMaterial );

					} else if ( type === 'line' ) { // lines

						var lineMaterial = new LineBasicMaterial( { color: 0xffffff } );

						if ( geometry.attributes.color !== undefined ) {

							lineMaterial.vertexColors = VertexColors;

						} else {

							// if the color field is NULL and there is a material defined for the appearance affecting this IndexedLineSet, then use the emissiveColor of the material to draw the lines

							if ( material.isMeshPhongMaterial ) {

								lineMaterial.color.copy( material.emissive );

							}

						}

						object = new LineSegments( geometry, lineMaterial );

					} else { // consider meshes

						// check "solid" hint (it's placed in the geometry but affects the material)

						if ( geometry._solid !== undefined ) {

							material.side = ( geometry._solid ) ? FrontSide : DoubleSide;

						}

						// check for vertex colors

						if ( geometry.attributes.color !== undefined ) {

							material.vertexColors = VertexColors;

						}

						object = new Mesh( geometry, material );

					}

				} else {

					object = new Object3D();

					// if the geometry field is NULL the object is not drawn

					object.visible = false;

				}

				return object;

			}

			function buildApperanceNode( node ) {

				var material = new MeshPhongMaterial();
				var transformData;

				var fields = node.fields;

				for ( var i = 0, l = fields.length; i < l; i ++ ) {

					var field = fields[ i ];
					var fieldName = field.name;
					var fieldValues = field.values;

					switch ( fieldName ) {

						case 'material':
							if ( fieldValues[ 0 ] !== null ) {

								var materialData = getNode( fieldValues[ 0 ] );

								if ( materialData.diffuseColor ) material.color.copy( materialData.diffuseColor );
								if ( materialData.emissiveColor ) material.emissive.copy( materialData.emissiveColor );
								if ( materialData.shininess ) material.shininess = materialData.shininess;
								if ( materialData.specularColor ) material.specular.copy( materialData.specularColor );
								if ( materialData.transparency ) material.opacity = 1 - materialData.transparency;
								if ( materialData.transparency > 0 ) material.transparent = true;

							} else {

								// if the material field is NULL or unspecified, lighting is off and the unlit object color is (0, 0, 0)

								material = new MeshBasicMaterial( { color: 0x000000 } );

							}
							break;

						case 'texture':
							var textureNode = fieldValues[ 0 ];
							if ( textureNode !== null ) {

								if ( textureNode.name === 'ImageTexture' ) {

									material.map = getNode( textureNode );

								} else {

									// MovieTexture and PixelTexture not supported yet

								}

							}
							break;

						case 'textureTransform':
							if ( fieldValues[ 0 ] !== null ) {

								transformData = getNode( fieldValues[ 0 ] );

							}
							break;

						default:
							console.warn( 'THREE.VRMLLoader: Unknown field:', fieldName );
							break;

					}

				}

				// only apply texture transform data if a texture was defined

				if ( material.map && transformData ) {

					material.map.center.copy( transformData.center );
					material.map.rotation = transformData.rotation;
					material.map.repeat.copy( transformData.scale );
					material.map.offset.copy( transformData.translation );

				}

				return material;

			}

			function buildMaterialNode( node ) {

				var materialData = {};

				var fields = node.fields;

				for ( var i = 0, l = fields.length; i < l; i ++ ) {

					var field = fields[ i ];
					var fieldName = field.name;
					var fieldValues = field.values;

					switch ( fieldName ) {

						case 'ambientIntensity':
							// field not supported
							break;

						case 'diffuseColor':
							materialData.diffuseColor = new Color( fieldValues[ 0 ], fieldValues[ 1 ], fieldValues[ 2 ] );
							break;

						case 'emissiveColor':
							materialData.emissiveColor = new Color( fieldValues[ 0 ], fieldValues[ 1 ], fieldValues[ 2 ] );
							break;

						case 'shininess':
							materialData.shininess = fieldValues[ 0 ];
							break;

						case 'specularColor':
							materialData.emissiveColor = new Color( fieldValues[ 0 ], fieldValues[ 1 ], fieldValues[ 2 ] );
							break;

						case 'transparency':
							materialData.transparency = fieldValues[ 0 ];
							break;

						default:
							console.warn( 'THREE.VRMLLoader: Unknown field:', fieldName );
							break;

					}

				}

				return materialData;

			}

			function buildImageTextureNode( node ) {

				var texture;
				var wrapS = RepeatWrapping;
				var wrapT = RepeatWrapping;

				var fields = node.fields;

				for ( var i = 0, l = fields.length; i < l; i ++ ) {

					var field = fields[ i ];
					var fieldName = field.name;
					var fieldValues = field.values;

					switch ( fieldName ) {

						case 'url':
							var url = fieldValues[ 0 ];
							if ( url ) texture = textureLoader.load( url );
							break;

						case 'repeatS':
							if ( fieldValues[ 0 ] === false ) wrapS = ClampToEdgeWrapping;
							break;

						case 'repeatT':
							if ( fieldValues[ 0 ] === false ) wrapT = ClampToEdgeWrapping;
							break;

						default:
							console.warn( 'THREE.VRMLLoader: Unknown field:', fieldName );
							break;

					}

				}

				if ( texture ) {

					texture.wrapS = wrapS;
					texture.wrapT = wrapT;

				}

				return texture;

			}

			function buildTextureTransformNode( node ) {

				var transformData = {
					center: new Vector2(),
					rotation: new Vector2(),
					scale: new Vector2(),
					translation: new Vector2()
				};

				var fields = node.fields;

				for ( var i = 0, l = fields.length; i < l; i ++ ) {

					var field = fields[ i ];
					var fieldName = field.name;
					var fieldValues = field.values;

					switch ( fieldName ) {

						case 'center':
							transformData.center.set( fieldValues[ 0 ], fieldValues[ 1 ] );
							break;

						case 'rotation':
							transformData.rotation = fieldValues[ 0 ];
							break;

						case 'scale':
							transformData.scale.set( fieldValues[ 0 ], fieldValues[ 1 ] );
							break;

						case 'translation':
							transformData.translation.set( fieldValues[ 0 ], fieldValues[ 1 ] );
							break;

						default:
							console.warn( 'THREE.VRMLLoader: Unknown field:', fieldName );
							break;

					}

				}

				return transformData;

			}

			function buildGeometricNode( node ) {

				return node.fields[ 0 ].values;

			}

			function buildIndexedFaceSetNode( node ) {

				var color, coord, normal, texCoord;
				var ccw = true, solid = true, creaseAngle;
				var colorIndex, coordIndex, normalIndex, texCoordIndex;
				var colorPerVertex = true, normalPerVertex = true;

				var fields = node.fields;

				for ( var i = 0, l = fields.length; i < l; i ++ ) {

					var field = fields[ i ];
					var fieldName = field.name;
					var fieldValues = field.values;

					switch ( fieldName ) {

						case 'color':
							var colorNode = fieldValues[ 0 ];

							if ( colorNode !== null ) {

								color = getNode( colorNode );

							}
							break;

						case 'coord':
							var coordNode = fieldValues[ 0 ];

							if ( coordNode !== null ) {

								coord = getNode( coordNode );

							}
							break;

						case 'normal':
							var normalNode = fieldValues[ 0 ];

							if ( normalNode !== null ) {

								normal = getNode( normalNode );

							}
							break;

						case 'texCoord':
							var texCoordNode = fieldValues[ 0 ];

							if ( texCoordNode !== null ) {

								texCoord = getNode( texCoordNode );

							}
							break;

						case 'ccw':
							ccw = fieldValues[ 0 ];
							break;

						case 'colorIndex':
							colorIndex = fieldValues;
							break;

						case 'colorPerVertex':
							colorPerVertex = fieldValues[ 0 ];
							break;

						case 'convex':
							// field not supported
							break;

						case 'coordIndex':
							coordIndex = fieldValues;
							break;

						case 'creaseAngle':
							creaseAngle = fieldValues[ 0 ];
							break;

						case 'normalIndex':
							normalIndex = fieldValues;
							break;

						case 'normalPerVertex':
							normalPerVertex = fieldValues[ 0 ];
							break;

						case 'solid':
							solid = fieldValues[ 0 ];
							break;

						case 'texCoordIndex':
							texCoordIndex = fieldValues;
							break;

						default:
							console.warn( 'THREE.VRMLLoader: Unknown field:', fieldName );
							break;

					}

				}

				var triangulatedCoordIndex = triangulateFaceIndex( coordIndex, ccw );

				var positionAttribute;
				var colorAttribute;
				var normalAttribute;
				var uvAttribute;

				if ( color ) {

					if ( colorPerVertex === true ) {

						if ( colorIndex.length > 0 ) {

							// if the colorIndex field is not empty, then it is used to choose colors for each vertex of the IndexedFaceSet.

							var triangulatedColorIndex = triangulateFaceIndex( colorIndex, ccw );
							colorAttribute = computeAttributeFromIndexedData( triangulatedCoordIndex, triangulatedColorIndex, color, 3 );

						} else {

							// if the colorIndex field is empty, then the coordIndex field is used to choose colors from the Color node

							colorAttribute = toNonIndexedAttribute( triangulatedCoordIndex, new Float32BufferAttribute( color, 3 ) );

						}

					} else {

						if ( colorIndex.length > 0 ) {

							// if the colorIndex field is not empty, then they are used to choose one color for each face of the IndexedFaceSet

							var flattenFaceColors = flattenData( color, colorIndex );
							var triangulatedFaceColors = triangulateFaceData( flattenFaceColors, coordIndex );
							colorAttribute = computeAttributeFromFaceData( triangulatedCoordIndex, triangulatedFaceColors );

						} else {

							// if the colorIndex field is empty, then the color are applied to each face of the IndexedFaceSet in order

							var triangulatedFaceColors = triangulateFaceData( color, coordIndex );
							colorAttribute = computeAttributeFromFaceData( triangulatedCoordIndex, triangulatedFaceColors );


						}

					}

				}

				if ( normal ) {

					if ( normalPerVertex === true ) {

						// consider vertex normals

						if ( normalIndex.length > 0 ) {

							// if the normalIndex field is not empty, then it is used to choose normals for each vertex of the IndexedFaceSet.

							var triangulatedNormalIndex = triangulateFaceIndex( normalIndex, ccw );
							normalAttribute = computeAttributeFromIndexedData( triangulatedCoordIndex, triangulatedNormalIndex, normal, 3 );

						} else {

							// if the normalIndex field is empty, then the coordIndex field is used to choose normals from the Normal node

							normalAttribute = toNonIndexedAttribute( triangulatedCoordIndex, new Float32BufferAttribute( normal, 3 ) );

						}

					} else {

						// consider face normals

						if ( normalIndex.length > 0 ) {

							// if the normalIndex field is not empty, then they are used to choose one normal for each face of the IndexedFaceSet

							var flattenFaceNormals = flattenData( normal, normalIndex );
							var triangulatedFaceNormals = triangulateFaceData( flattenFaceNormals, coordIndex );
							normalAttribute = computeAttributeFromFaceData( triangulatedCoordIndex, triangulatedFaceNormals );

						} else {

							// if the normalIndex field is empty, then the normals are applied to each face of the IndexedFaceSet in order

							var triangulatedFaceNormals = triangulateFaceData( normal, coordIndex );
							normalAttribute = computeAttributeFromFaceData( triangulatedCoordIndex, triangulatedFaceNormals );

						}

					}

				} else {

					// if the normal field is NULL, then the loader should automatically generate normals, using creaseAngle to determine if and how normals are smoothed across shared vertices

					normalAttribute = computeNormalAttribute( triangulatedCoordIndex, coord, creaseAngle );

				}

				if ( texCoord ) {

					// texture coordinates are always defined on vertex level

					if ( texCoordIndex.length > 0 ) {

						// if the texCoordIndex field is not empty, then it is used to choose texture coordinates for each vertex of the IndexedFaceSet.

						var triangulatedTexCoordIndex = triangulateFaceIndex( texCoordIndex, ccw );
						uvAttribute = computeAttributeFromIndexedData( triangulatedCoordIndex, triangulatedTexCoordIndex, texCoord, 2 );


					} else {

						// if the texCoordIndex field is empty, then the coordIndex array is used to choose texture coordinates from the TextureCoordinate node

						uvAttribute = toNonIndexedAttribute( triangulatedCoordIndex, new Float32BufferAttribute( texCoord, 2 ) );

					}

				}

				var geometry = new BufferGeometry();
				positionAttribute = toNonIndexedAttribute( triangulatedCoordIndex, new Float32BufferAttribute( coord, 3 ) );

				geometry.addAttribute( 'position', positionAttribute );
				geometry.addAttribute( 'normal', normalAttribute );

				// optional attributes

				if ( colorAttribute ) geometry.addAttribute( 'color', colorAttribute );
				if ( uvAttribute ) geometry.addAttribute( 'uv', uvAttribute );

				// "solid" influences the material so let's store it for later use

				geometry._solid = solid;
				geometry._type = 'mesh';

				return geometry;

			}

			function buildIndexedLineSetNode( node ) {

				var color, coord;
				var colorIndex, coordIndex;
				var colorPerVertex = true;

				var fields = node.fields;

				for ( var i = 0, l = fields.length; i < l; i ++ ) {

					var field = fields[ i ];
					var fieldName = field.name;
					var fieldValues = field.values;

					switch ( fieldName ) {

						case 'color':
							var colorNode = fieldValues[ 0 ];

							if ( colorNode !== null ) {

								color = getNode( colorNode );

							}
							break;

						case 'coord':
							var coordNode = fieldValues[ 0 ];

							if ( coordNode !== null ) {

								coord = getNode( coordNode );

							}
							break;

						case 'colorIndex':
							colorIndex = fieldValues;
							break;

						case 'colorPerVertex':
							colorPerVertex = fieldValues[ 0 ];
							break;

						case 'coordIndex':
							coordIndex = fieldValues;
							break;

						default:
							console.warn( 'THREE.VRMLLoader: Unknown field:', fieldName );
							break;

					}

				}

				// build lines

				var colorAttribute;

				var expandedLineIndex = expandLineIndex( coordIndex ); // create an index for three.js's linesegment primitive

				if ( color ) {

					if ( colorPerVertex === true ) {

						if ( colorIndex.length > 0 ) {

							// if the colorIndex field is not empty, then one color is used for each polyline of the IndexedLineSet.

							var expandedColorIndex = expandLineIndex( colorIndex ); // compute colors for each line segment (rendering primitve)
							colorAttribute = computeAttributeFromIndexedData( expandedLineIndex, expandedColorIndex, color, 3 ); // compute data on vertex level

						} else {

							// if the colorIndex field is empty, then the colors are applied to each polyline of the IndexedLineSet in order.

							colorAttribute = toNonIndexedAttribute( expandedLineIndex, new Float32BufferAttribute( color, 3 ) );

						}

					} else {

						if ( colorIndex.length > 0 ) {

							// if the colorIndex field is not empty, then colors are applied to each vertex of the IndexedLineSet

							var flattenLineColors = flattenData( color, colorIndex ); // compute colors for each VRML primitve
							var expandedLineColors = expandLineData( flattenLineColors, coordIndex ); // compute colors for each line segment (rendering primitve)
							colorAttribute = computeAttributeFromLineData( expandedLineIndex, expandedLineColors ); // compute data on vertex level


						} else {

							// if the colorIndex field is empty, then the coordIndex field is used to choose colors from the Color node

							var expandedLineColors = expandLineData( color, coordIndex ); // compute colors for each line segment (rendering primitve)
							colorAttribute = computeAttributeFromLineData( expandedLineIndex, expandedLineColors ); // compute data on vertex level

						}

					}

				}

				//

				var geometry = new BufferGeometry();

				var positionAttribute = toNonIndexedAttribute( expandedLineIndex, new Float32BufferAttribute( coord, 3 ) );
				geometry.addAttribute( 'position', positionAttribute );

				if ( colorAttribute ) geometry.addAttribute( 'color', colorAttribute );

				geometry._type = 'line';

				return geometry;

			}

			function buildPointSetNode( node ) {

				var geometry;
				var color, coord;

				var fields = node.fields;

				for ( var i = 0, l = fields.length; i < l; i ++ ) {

					var field = fields[ i ];
					var fieldName = field.name;
					var fieldValues = field.values;

					switch ( fieldName ) {

						case 'color':
							var colorNode = fieldValues[ 0 ];

							if ( colorNode !== null ) {

								color = getNode( colorNode );

							}
							break;

						case 'coord':
							var coordNode = fieldValues[ 0 ];

							if ( coordNode !== null ) {

								coord = getNode( coordNode );

							}
							break;


						default:
							console.warn( 'THREE.VRMLLoader: Unknown field:', fieldName );
							break;

					}

				}

				var geometry = new BufferGeometry();

				geometry.addAttribute( 'position', new Float32BufferAttribute( coord, 3 ) );
				if ( color ) geometry.addAttribute( 'color', new Float32BufferAttribute( color, 3 ) );

				geometry._type = 'points';

				return geometry;

			}

			function buildBoxNode( node ) {

				var size = new Vector3( 2, 2, 2 );

				var fields = node.fields;

				for ( var i = 0, l = fields.length; i < l; i ++ ) {

					var field = fields[ i ];
					var fieldName = field.name;
					var fieldValues = field.values;

					switch ( fieldName ) {

						case 'size':
							size.x = fieldValues[ 0 ];
							size.y = fieldValues[ 1 ];
							size.z = fieldValues[ 2 ];
							break;

						default:
							console.warn( 'THREE.VRMLLoader: Unknown field:', fieldName );
							break;

					}

				}

				var geometry = new BoxBufferGeometry( size.x, size.y, size.z );

				return geometry;

			}

			function buildConeNode( node ) {

				var radius = 1, height = 2, openEnded = false;

				var fields = node.fields;

				for ( var i = 0, l = fields.length; i < l; i ++ ) {

					var field = fields[ i ];
					var fieldName = field.name;
					var fieldValues = field.values;

					switch ( fieldName ) {

						case 'bottom':
							openEnded = ! fieldValues[ 0 ];
							break;

						case 'bottomRadius':
							radius = fieldValues[ 0 ];
							break;

						case 'height':
							height = fieldValues[ 0 ];
							break;

						case 'side':
							// field not supported
							break;

						default:
							console.warn( 'THREE.VRMLLoader: Unknown field:', fieldName );
							break;

					}

				}

				var geometry = new ConeBufferGeometry( radius, height, 16, 1, openEnded );

				return geometry;

			}

			function buildCylinderNode( node ) {

				var radius = 1, height = 2;

				var fields = node.fields;

				for ( var i = 0, l = fields.length; i < l; i ++ ) {

					var field = fields[ i ];
					var fieldName = field.name;
					var fieldValues = field.values;

					switch ( fieldName ) {

						case 'bottom':
							// field not supported
							break;

						case 'radius':
							radius = fieldValues[ 0 ];
							break;

						case 'height':
							height = fieldValues[ 0 ];
							break;

						case 'side':
							// field not supported
							break;

						case 'top':
							// field not supported
							break;

						default:
							console.warn( 'THREE.VRMLLoader: Unknown field:', fieldName );
							break;

					}

				}

				var geometry = new CylinderBufferGeometry( radius, radius, height, 16, 1 );

				return geometry;

			}

			function buildSphereNode( node ) {

				var radius = 1;

				var fields = node.fields;

				for ( var i = 0, l = fields.length; i < l; i ++ ) {

					var field = fields[ i ];
					var fieldName = field.name;
					var fieldValues = field.values;

					switch ( fieldName ) {

						case 'radius':
							radius = fieldValues[ 0 ];
							break;

						default:
							console.warn( 'THREE.VRMLLoader: Unknown field:', fieldName );
							break;

					}

				}

				var geometry = new SphereBufferGeometry( radius, 16, 16 );

				return geometry;

			}

			// helper functions

			function resolveUSE( identifier ) {

				var node = nodeMap[ identifier ];
				var build = getNode( node );

				// because the same 3D objects can have different transformations, it's necessary to clone them.
				// materials can be influenced by the geometry (e.g. vertex normals). cloning is necessary to avoid
				// any side effects

				return ( build.isObject3D || build.isMaterial ) ? build.clone() : build;

			}

			function parseFieldChildren( children, owner ) {

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

					var object = getNode( children[ i ] );

					if ( object instanceof Object3D ) owner.add( object );

				}

			}

			function triangulateFaceIndex( index, ccw ) {

				var indices = [];

				// since face defintions can have more than three vertices, it's necessary to
				// perform a simple triangulation

				var start = 0;

				for ( var i = 0, l = index.length; i < l; i ++ ) {

					var i1 = index[ start ];
					var i2 = index[ i + ( ccw ? 1 : 2 ) ];
					var i3 = index[ i + ( ccw ? 2 : 1 ) ];

					indices.push( i1, i2, i3 );

					// an index of -1 indicates that the current face has ended and the next one begins

					if ( index[ i + 3 ] === - 1 || i + 3 >= l ) {

						i += 3;
						start = i + 1;

					}

				}

				return indices;

			}

			function triangulateFaceData( data, index ) {

				var triangulatedData = [];

				var start = 0;

				for ( var i = 0, l = index.length; i < l; i ++ ) {

					var stride = start * 3;

					var x = data[ stride ];
					var y = data[ stride + 1 ];
					var z = data[ stride + 2 ];

					triangulatedData.push( x, y, z );

					// an index of -1 indicates that the current face has ended and the next one begins

					if ( index[ i + 3 ] === - 1 || i + 3 >= l ) {

						i += 3;
						start ++;

					}

				}

				return triangulatedData;

			}

			function flattenData( data, index ) {

				var flattenData = [];

				for ( var i = 0, l = index.length; i < l; i ++ ) {

					var i1 = index[ i ];

					var stride = i1 * 3;

					var x = data[ stride ];
					var y = data[ stride + 1 ];
					var z = data[ stride + 2 ];

					flattenData.push( x, y, z );

				}

				return flattenData;

			}

			function expandLineIndex( index ) {

				var indices = [];

				for ( var i = 0, l = index.length; i < l; i ++ ) {

					var i1 = index[ i ];
					var i2 = index[ i + 1 ];

					indices.push( i1, i2 );

					// an index of -1 indicates that the current line has ended and the next one begins

					if ( index[ i + 2 ] === - 1 || i + 2 >= l ) {

						i += 2;

					}

				}

				return indices;

			}

			function expandLineData( data, index ) {

				var triangulatedData = [];

				var start = 0;

				for ( var i = 0, l = index.length; i < l; i ++ ) {

					var stride = start * 3;

					var x = data[ stride ];
					var y = data[ stride + 1 ];
					var z = data[ stride + 2 ];

					triangulatedData.push( x, y, z );

					// an index of -1 indicates that the current line has ended and the next one begins

					if ( index[ i + 2 ] === - 1 || i + 2 >= l ) {

						i += 2;
						start ++;

					}

				}

				return triangulatedData;

			}

			var vA = new Vector3();
			var vB = new Vector3();
			var vC = new Vector3();

			var uvA = new Vector2();
			var uvB = new Vector2();
			var uvC = new Vector2();

			function computeAttributeFromIndexedData( coordIndex, index, data, itemSize ) {

				var array = [];

				// we use the coordIndex.length as delimiter since normalIndex must contain at least as many indices

				for ( var i = 0, l = coordIndex.length; i < l; i += 3 ) {

					var a = index[ i ];
					var b = index[ i + 1 ];
					var c = index[ i + 2 ];

					if ( itemSize === 2 ) {

						uvA.fromArray( data, a * itemSize );
						uvB.fromArray( data, b * itemSize );
						uvC.fromArray( data, c * itemSize );

						array.push( uvA.x, uvA.y );
						array.push( uvB.x, uvB.y );
						array.push( uvC.x, uvC.y );

					} else {

						vA.fromArray( data, a * itemSize );
						vB.fromArray( data, b * itemSize );
						vC.fromArray( data, c * itemSize );

						array.push( vA.x, vA.y, vA.z );
						array.push( vB.x, vB.y, vB.z );
						array.push( vC.x, vC.y, vC.z );

					}

				}

				return new Float32BufferAttribute( array, itemSize );

			}

			function computeAttributeFromFaceData( index, faceData ) {

				var array = [];

				for ( var i = 0, j = 0, l = index.length; i < l; i += 3, j ++ ) {

					vA.fromArray( faceData, j * 3 );

					array.push( vA.x, vA.y, vA.z );
					array.push( vA.x, vA.y, vA.z );
					array.push( vA.x, vA.y, vA.z );

				}

				return new Float32BufferAttribute( array, 3 );

			}

			function computeAttributeFromLineData( index, lineData ) {

				var array = [];

				for ( var i = 0, j = 0, l = index.length; i < l; i += 2, j ++ ) {

					vA.fromArray( lineData, j * 3 );

					array.push( vA.x, vA.y, vA.z );
					array.push( vA.x, vA.y, vA.z );

				}

				return new Float32BufferAttribute( array, 3 );

			}

			function toNonIndexedAttribute( indices, attribute ) {

				var array = attribute.array;
				var itemSize = attribute.itemSize;

				var array2 = new array.constructor( indices.length * itemSize );

				var index = 0, index2 = 0;

				for ( var i = 0, l = indices.length; i < l; i ++ ) {

					index = indices[ i ] * itemSize;

					for ( var j = 0; j < itemSize; j ++ ) {

						array2[ index2 ++ ] = array[ index ++ ];

					}

				}

				return new Float32BufferAttribute( array2, itemSize );

			}

			var ab = new Vector3();
			var cb = new Vector3();

			function computeNormalAttribute( index, coord, creaseAngle ) {

				var faces = [];
				var vertexNormals = {};

				// prepare face and raw vertex normals

				for ( var i = 0, l = index.length; i < l; i += 3 ) {

					var a = index[ i ];
					var b = index[ i + 1 ];
					var c = index[ i + 2 ];

					var face = new Face( a, b, c );

					vA.fromArray( coord, a * 3 );
					vB.fromArray( coord, b * 3 );
					vC.fromArray( coord, c * 3 );

					cb.subVectors( vC, vB );
					ab.subVectors( vA, vB );
					cb.cross( ab );

					cb.normalize();

					face.normal.copy( cb );

					if ( vertexNormals[ a ] === undefined ) vertexNormals[ a ] = [];
					if ( vertexNormals[ b ] === undefined ) vertexNormals[ b ] = [];
					if ( vertexNormals[ c ] === undefined ) vertexNormals[ c ] = [];

					vertexNormals[ a ].push( face.normal );
					vertexNormals[ b ].push( face.normal );
					vertexNormals[ c ].push( face.normal );

					faces.push( face );

				}

				// compute vertex normals and build final geometry

				var normals = [];

				for ( var i = 0, l = faces.length; i < l; i ++ ) {

					var face = faces[ i ];

					var nA = weightedNormal( vertexNormals[ face.a ], face.normal, creaseAngle );
					var nB = weightedNormal( vertexNormals[ face.b ], face.normal, creaseAngle );
					var nC = weightedNormal( vertexNormals[ face.c ], face.normal, creaseAngle );

					vA.fromArray( coord, face.a * 3 );
					vB.fromArray( coord, face.b * 3 );
					vC.fromArray( coord, face.c * 3 );

					normals.push( nA.x, nA.y, nA.z );
					normals.push( nB.x, nB.y, nB.z );
					normals.push( nC.x, nC.y, nC.z );

				}

				return new Float32BufferAttribute( normals, 3 );

			}

			function weightedNormal( normals, vector, creaseAngle ) {

				var normal = vector.clone();

				for ( var i = 0, l = normals.length; i < l; i ++ ) {

					if ( normals[ i ].angleTo( vector ) < creaseAngle ) {

						normal.add( normals[ i ] );

					}

				}

				return normal.normalize();

			}

			function toColorArray( colors ) {

				var array = [];

				for ( var i = 0, l = colors.length; i < l; i += 3 ) {

					array.push( new Color( colors[ i ], colors[ i + 1 ], colors[ i + 2 ] ) );

				}

				return array;

			}

			/**
			 * Vertically paints the faces interpolating between the
			 * specified colors at the specified angels. This is used for the Background
			 * node, but could be applied to other nodes with multiple faces as well.
			 *
			 * When used with the Background node, default is directionIsDown is true if
			 * interpolating the skyColor down from the Zenith. When interpolationg up from
			 * the Nadir i.e. interpolating the groundColor, the directionIsDown is false.
			 *
			 * The first angle is never specified, it is the Zenith (0 rad). Angles are specified
			 * in radians. The geometry is thought a sphere, but could be anything. The color interpolation
			 * is linear along the Y axis in any case.
			 *
			 * You must specify one more color than you have angles at the beginning of the colors array.
			 * This is the color of the Zenith (the top of the shape).
			 *
			 * @param {BufferGeometry} geometry
			 * @param {number} radius
			 * @param {array} angles
			 * @param {array} colors
			 * @param {boolean} topDown - Whether to work top down or bottom up.
			 */
			function paintFaces( geometry, radius, angles, colors, topDown ) {

				var direction = ( topDown === true ) ? 1 : - 1;

				var coord = [], A = {}, B = {}, applyColor = false;

				for ( var k = 0; k < angles.length; k ++ ) {

					// push the vector at which the color changes

					var vec = {
						x: direction * ( Math.cos( angles[ k ] ) * radius ),
						y: direction * ( Math.sin( angles[ k ] ) * radius )
					};

					coord.push( vec );

				}

				var index = geometry.index;
				var positionAttribute = geometry.attributes.position;
				var colorAttribute = new BufferAttribute( new Float32Array( geometry.attributes.position.count * 3 ), 3 );

				var position = new Vector3();
				var color = new Color();

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

					var vertexIndex = index.getX( i );

					position.fromBufferAttribute( positionAttribute, vertexIndex );

					for ( var j = 0; j < colors.length; j ++ ) {

						// linear interpolation between aColor and bColor, calculate proportion
						// A is previous point (angle)

						if ( j === 0 ) {

							A.x = 0;
							A.y = ( topDown === true ) ? radius : - 1 * radius;

						} else {

							A.x = coord[ j - 1 ].x;
							A.y = coord[ j - 1 ].y;

						}

						// B is current point (angle)

						B = coord[ j ];

						if ( B !== undefined ) {

							// p has to be between the points A and B which we interpolate

							applyColor = ( topDown === true ) ? ( position.y <= A.y && position.y > B.y ) : ( position.y >= A.y && position.y < B.y );

							if ( applyColor === true ) {

								var aColor = colors[ j ];
								var bColor = colors[ j + 1 ];

								// below is simple linear interpolation

								var t = Math.abs( position.y - A.y ) / ( A.y - B.y );

								// to make it faster, you can only calculate this if the y coord changes, the color is the same for points with the same y

								color.copy( aColor ).lerp( bColor, t );

								colorAttribute.setXYZ( vertexIndex, color.r, color.g, color.b );

							} else {

								var colorIndex = ( topDown === true ) ? colors.length - 1 : 0;
								var c = colors[ colorIndex ];
								colorAttribute.setXYZ( vertexIndex, c.r, c.g, c.b );

							}

						}

					}

				}

				geometry.addAttribute( 'color', colorAttribute );

			}

			//

			var textureLoader = new TextureLoader( this.manager );
			textureLoader.setPath( this.resourcePath || path ).setCrossOrigin( this.crossOrigin );

			// create JSON representing the tree structure of the VRML asset

			var tree = generateVRMLTree( data );

			// check version (only 2.0 is supported)

			if ( tree.version.indexOf( 'V2.0' ) === - 1 ) {

				throw Error( 'THREE.VRMLLexer: Version of VRML asset not supported.' );

			}

			// parse the tree structure to a three.js scene

			var scene = parseTree( tree );

			return scene;

		}

	};

	function VRMLLexer( tokens ) {

		this.lexer = new chevrotain.Lexer( tokens );

	}

	VRMLLexer.prototype = {

		constructor: VRMLLexer,

		lex: function ( inputText ) {

			var lexingResult = this.lexer.tokenize( inputText );

			if ( lexingResult.errors.length > 0 ) {

				console.error( lexingResult.errors );

				throw Error( 'THREE.VRMLLexer: Lexing errors detected.' );

			}

			return lexingResult;

		}

	};

	function VRMLParser( tokenVocabulary ) {

		chevrotain.Parser.call( this, tokenVocabulary );

		var $ = this;

		var Version = tokenVocabulary[ 'Version' ];
		var LCurly = tokenVocabulary[ 'LCurly' ];
		var RCurly = tokenVocabulary[ 'RCurly' ];
		var LSquare = tokenVocabulary[ 'LSquare' ];
		var RSquare = tokenVocabulary[ 'RSquare' ];
		var Identifier = tokenVocabulary[ 'Identifier' ];
		var RouteIdentifier = tokenVocabulary[ 'RouteIdentifier' ];
		var StringLiteral = tokenVocabulary[ 'StringLiteral' ];
		var NumberLiteral = tokenVocabulary[ 'NumberLiteral' ];
		var BooleanLiteral = tokenVocabulary[ 'BooleanLiteral' ];
		var NullLiteral = tokenVocabulary[ 'NullLiteral' ];
		var DEF = tokenVocabulary[ 'DEF' ];
		var USE = tokenVocabulary[ 'USE' ];
		var ROUTE = tokenVocabulary[ 'ROUTE' ];
		var TO = tokenVocabulary[ 'TO' ];
		var NodeName = tokenVocabulary[ 'NodeName' ];

		$.RULE( 'vrml', function () {

			$.SUBRULE( $.version );
			$.AT_LEAST_ONE( function () {

				$.SUBRULE( $.node );

			} );
			$.MANY( function () {

				$.SUBRULE( $.route );

			} );

		} );

		$.RULE( 'version', function () {

			$.CONSUME( Version );

		} );

		$.RULE( 'node', function () {

			$.OPTION( function () {

				$.SUBRULE( $.def );

			} );

			$.CONSUME( NodeName );
			$.CONSUME( LCurly );
			$.MANY( function () {

				$.SUBRULE( $.field );

			} );
			$.CONSUME( RCurly );

		} );

		$.RULE( 'field', function () {

			$.CONSUME( Identifier );

			$.OR2( [
				{ ALT: function () {

					$.SUBRULE( $.singleFieldValue );

				} },
				{ ALT: function () {

					$.SUBRULE( $.multiFieldValue );

				} }
			] );

		} );

		$.RULE( 'def', function () {

			$.CONSUME( DEF );
			$.CONSUME( Identifier );

		} );

		$.RULE( 'use', function () {

			$.CONSUME( USE );
			$.CONSUME( Identifier );

		} );

		$.RULE( 'singleFieldValue', function () {

			$.AT_LEAST_ONE( function () {

				$.OR( [
					{ ALT: function () {

						$.SUBRULE( $.node );

					} },
					{ ALT: function () {

						$.SUBRULE( $.use );

					} },
					{ ALT: function () {

						$.CONSUME( StringLiteral );

					} },
					{ ALT: function () {

						$.CONSUME( NumberLiteral );

					} },
					{ ALT: function () {

						$.CONSUME( BooleanLiteral );

					} },
					{ ALT: function () {

						$.CONSUME( NullLiteral );

					} }
				] );


			} );

		} );

		$.RULE( 'multiFieldValue', function () {

			$.CONSUME( LSquare );
			$.MANY( function () {

				$.OR( [
					{ ALT: function () {

						$.SUBRULE( $.node );

					} },
					{ ALT: function () {

						$.SUBRULE( $.use );

					} },
					{ ALT: function () {

						$.CONSUME( StringLiteral );

					} },
					{ ALT: function () {

						$.CONSUME( NumberLiteral );

					} },
					{ ALT: function () {

						$.CONSUME( NullLiteral );

					} }
				] );

			} );
			$.CONSUME( RSquare );

		} );

		$.RULE( 'route', function () {

			$.CONSUME( ROUTE );
			$.CONSUME( RouteIdentifier );
			$.CONSUME( TO );
			$.CONSUME2( RouteIdentifier );

		} );

		this.performSelfAnalysis();

	}

	VRMLParser.prototype = Object.create( chevrotain.Parser.prototype );
	VRMLParser.prototype.constructor = VRMLParser;

	function Face( a, b, c ) {

		this.a = a;
		this.b = b;
		this.c = c;
		this.normal = new Vector3();

	}

	return VRMLLoader;

} )();

export { VRMLLoader };