three.js/examples/js/loaders/LDrawLoader.js

( function () {

	// Note: "MATERIAL" tag (e.g. GLITTER, SPECKLE) is not implemented

	const FINISH_TYPE_DEFAULT = 0;
	const FINISH_TYPE_CHROME = 1;
	const FINISH_TYPE_PEARLESCENT = 2;
	const FINISH_TYPE_RUBBER = 3;
	const FINISH_TYPE_MATTE_METALLIC = 4;
	const FINISH_TYPE_METAL = 5; // State machine to search a subobject path.
	// The LDraw standard establishes these various possible subfolders.

	const FILE_LOCATION_AS_IS = 0;
	const FILE_LOCATION_TRY_PARTS = 1;
	const FILE_LOCATION_TRY_P = 2;
	const FILE_LOCATION_TRY_MODELS = 3;
	const FILE_LOCATION_TRY_RELATIVE = 4;
	const FILE_LOCATION_TRY_ABSOLUTE = 5;
	const FILE_LOCATION_NOT_FOUND = 6;

	const _tempVec0 = new THREE.Vector3();

	const _tempVec1 = new THREE.Vector3();

	class LDrawConditionalLineMaterial extends THREE.ShaderMaterial {

		constructor( parameters ) {

			super( {
				uniforms: THREE.UniformsUtils.merge( [ THREE.UniformsLib.fog, {
					diffuse: {
						value: new THREE.Color()
					},
					opacity: {
						value: 1.0
					}
				} ] ),
				vertexShader:
      /* glsl */
      `
				attribute vec3 control0;
				attribute vec3 control1;
				attribute vec3 direction;
				varying float discardFlag;

				#include <common>
				#include <color_pars_vertex>
				#include <fog_pars_vertex>
				#include <logdepthbuf_pars_vertex>
				#include <clipping_planes_pars_vertex>
				void main() {
					#include <color_vertex>

					vec4 mvPosition = modelViewMatrix * vec4( position, 1.0 );
					gl_Position = projectionMatrix * mvPosition;

					// Transform the line segment ends and control points into camera clip space
					vec4 c0 = projectionMatrix * modelViewMatrix * vec4( control0, 1.0 );
					vec4 c1 = projectionMatrix * modelViewMatrix * vec4( control1, 1.0 );
					vec4 p0 = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
					vec4 p1 = projectionMatrix * modelViewMatrix * vec4( position + direction, 1.0 );

					c0.xy /= c0.w;
					c1.xy /= c1.w;
					p0.xy /= p0.w;
					p1.xy /= p1.w;

					// Get the direction of the segment and an orthogonal vector
					vec2 dir = p1.xy - p0.xy;
					vec2 norm = vec2( -dir.y, dir.x );

					// Get control point directions from the line
					vec2 c0dir = c0.xy - p1.xy;
					vec2 c1dir = c1.xy - p1.xy;

					// If the vectors to the controls points are pointed in different directions away
					// from the line segment then the line should not be drawn.
					float d0 = dot( normalize( norm ), normalize( c0dir ) );
					float d1 = dot( normalize( norm ), normalize( c1dir ) );
					discardFlag = float( sign( d0 ) != sign( d1 ) );

					#include <logdepthbuf_vertex>
					#include <clipping_planes_vertex>
					#include <fog_vertex>
				}
			`,
				fragmentShader:
      /* glsl */
      `
			uniform vec3 diffuse;
			uniform float opacity;
			varying float discardFlag;

			#include <common>
			#include <color_pars_fragment>
			#include <fog_pars_fragment>
			#include <logdepthbuf_pars_fragment>
			#include <clipping_planes_pars_fragment>
			void main() {

				if ( discardFlag > 0.5 ) discard;

				#include <clipping_planes_fragment>
				vec3 outgoingLight = vec3( 0.0 );
				vec4 diffuseColor = vec4( diffuse, opacity );
				#include <logdepthbuf_fragment>
				#include <color_fragment>
				outgoingLight = diffuseColor.rgb; // simple shader
				gl_FragColor = vec4( outgoingLight, diffuseColor.a );
				#include <tonemapping_fragment>
				#include <encodings_fragment>
				#include <fog_fragment>
				#include <premultiplied_alpha_fragment>
			}
			`
			} );
			Object.defineProperties( this, {
				opacity: {
					get: function () {

						return this.uniforms.opacity.value;

					},
					set: function ( value ) {

						this.uniforms.opacity.value = value;

					}
				},
				color: {
					get: function () {

						return this.uniforms.diffuse.value;

					}
				}
			} );
			this.setValues( parameters );
			this.isLDrawConditionalLineMaterial = true;

		}

	}

	function smoothNormals( faces, lineSegments ) {

		function hashVertex( v ) {

			// NOTE: 1e2 is pretty coarse but was chosen because it allows edges
			// to be smoothed as expected (see minifig arms). The errors between edges
			// could be due to matrix multiplication.
			const x = ~ ~ ( v.x * 1e2 );
			const y = ~ ~ ( v.y * 1e2 );
			const z = ~ ~ ( v.z * 1e2 );
			return `${x},${y},${z}`;

		}

		function hashEdge( v0, v1 ) {

			return `${hashVertex( v0 )}_${hashVertex( v1 )}`;

		}

		const hardEdges = new Set();
		const halfEdgeList = {};
		const normals = []; // Save the list of hard edges by hash

		for ( let i = 0, l = lineSegments.length; i < l; i ++ ) {

			const ls = lineSegments[ i ];
			const vertices = ls.vertices;
			const v0 = vertices[ 0 ];
			const v1 = vertices[ 1 ];
			hardEdges.add( hashEdge( v0, v1 ) );
			hardEdges.add( hashEdge( v1, v0 ) );

		} // track the half edges associated with each triangle


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

			const tri = faces[ i ];
			const vertices = tri.vertices;
			const vertCount = vertices.length;

			for ( let i2 = 0; i2 < vertCount; i2 ++ ) {

				const index = i2;
				const next = ( i2 + 1 ) % vertCount;
				const v0 = vertices[ index ];
				const v1 = vertices[ next ];
				const hash = hashEdge( v0, v1 ); // don't add the triangle if the edge is supposed to be hard

				if ( hardEdges.has( hash ) ) continue;
				const info = {
					index: index,
					tri: tri
				};
				halfEdgeList[ hash ] = info;

			}

		} // Iterate until we've tried to connect all faces to share normals


		while ( true ) {

			// Stop if there are no more faces left
			let halfEdge = null;

			for ( const key in halfEdgeList ) {

				halfEdge = halfEdgeList[ key ];
				break;

			}

			if ( halfEdge === null ) {

				break;

			} // Exhaustively find all connected faces


			const queue = [ halfEdge ];

			while ( queue.length > 0 ) {

				// initialize all vertex normals in this triangle
				const tri = queue.pop().tri;
				const vertices = tri.vertices;
				const vertNormals = tri.normals;
				const faceNormal = tri.faceNormal; // Check if any edge is connected to another triangle edge

				const vertCount = vertices.length;

				for ( let i2 = 0; i2 < vertCount; i2 ++ ) {

					const index = i2;
					const next = ( i2 + 1 ) % vertCount;
					const v0 = vertices[ index ];
					const v1 = vertices[ next ]; // delete this triangle from the list so it won't be found again

					const hash = hashEdge( v0, v1 );
					delete halfEdgeList[ hash ];
					const reverseHash = hashEdge( v1, v0 );
					const otherInfo = halfEdgeList[ reverseHash ];

					if ( otherInfo ) {

						const otherTri = otherInfo.tri;
						const otherIndex = otherInfo.index;
						const otherNormals = otherTri.normals;
						const otherVertCount = otherNormals.length;
						const otherFaceNormal = otherTri.faceNormal; // NOTE: If the angle between faces is > 67.5 degrees then assume it's
						// hard edge. There are some cases where the line segments do not line up exactly
						// with or span multiple triangle edges (see Lunar Vehicle wheels).

						if ( Math.abs( otherTri.faceNormal.dot( tri.faceNormal ) ) < 0.25 ) {

							continue;

						} // if this triangle has already been traversed then it won't be in
						// the halfEdgeList. If it has not then add it to the queue and delete
						// it so it won't be found again.


						if ( reverseHash in halfEdgeList ) {

							queue.push( otherInfo );
							delete halfEdgeList[ reverseHash ];

						} // share the first normal


						const otherNext = ( otherIndex + 1 ) % otherVertCount;

						if ( vertNormals[ index ] && otherNormals[ otherNext ] && vertNormals[ index ] !== otherNormals[ otherNext ] ) {

							otherNormals[ otherNext ].norm.add( vertNormals[ index ].norm );
							vertNormals[ index ].norm = otherNormals[ otherNext ].norm;

						}

						let sharedNormal1 = vertNormals[ index ] || otherNormals[ otherNext ];

						if ( sharedNormal1 === null ) {

							// it's possible to encounter an edge of a triangle that has already been traversed meaning
							// both edges already have different normals defined and shared. To work around this we create
							// a wrapper object so when those edges are merged the normals can be updated everywhere.
							sharedNormal1 = {
								norm: new THREE.Vector3()
							};
							normals.push( sharedNormal1.norm );

						}

						if ( vertNormals[ index ] === null ) {

							vertNormals[ index ] = sharedNormal1;
							sharedNormal1.norm.add( faceNormal );

						}

						if ( otherNormals[ otherNext ] === null ) {

							otherNormals[ otherNext ] = sharedNormal1;
							sharedNormal1.norm.add( otherFaceNormal );

						} // share the second normal


						if ( vertNormals[ next ] && otherNormals[ otherIndex ] && vertNormals[ next ] !== otherNormals[ otherIndex ] ) {

							otherNormals[ otherIndex ].norm.add( vertNormals[ next ].norm );
							vertNormals[ next ].norm = otherNormals[ otherIndex ].norm;

						}

						let sharedNormal2 = vertNormals[ next ] || otherNormals[ otherIndex ];

						if ( sharedNormal2 === null ) {

							sharedNormal2 = {
								norm: new THREE.Vector3()
							};
							normals.push( sharedNormal2.norm );

						}

						if ( vertNormals[ next ] === null ) {

							vertNormals[ next ] = sharedNormal2;
							sharedNormal2.norm.add( faceNormal );

						}

						if ( otherNormals[ otherIndex ] === null ) {

							otherNormals[ otherIndex ] = sharedNormal2;
							sharedNormal2.norm.add( otherFaceNormal );

						}

					}

				}

			}

		} // The normals of each face have been added up so now we average them by normalizing the vector.


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

			normals[ i ].normalize();

		}

	}

	function isPartType( type ) {

		return type === 'Part';

	}

	function isModelType( type ) {

		return type === 'Model' || type === 'Unofficial_Model';

	}

	function isPrimitiveType( type ) {

		return /primitive/i.test( type ) || type === 'Subpart';

	}

	class LineParser {

		constructor( line, lineNumber ) {

			this.line = line;
			this.lineLength = line.length;
			this.currentCharIndex = 0;
			this.currentChar = ' ';
			this.lineNumber = lineNumber;

		}

		seekNonSpace() {

			while ( this.currentCharIndex < this.lineLength ) {

				this.currentChar = this.line.charAt( this.currentCharIndex );

				if ( this.currentChar !== ' ' && this.currentChar !== '\t' ) {

					return;

				}

				this.currentCharIndex ++;

			}

		}

		getToken() {

			const pos0 = this.currentCharIndex ++; // Seek space

			while ( this.currentCharIndex < this.lineLength ) {

				this.currentChar = this.line.charAt( this.currentCharIndex );

				if ( this.currentChar === ' ' || this.currentChar === '\t' ) {

					break;

				}

				this.currentCharIndex ++;

			}

			const pos1 = this.currentCharIndex;
			this.seekNonSpace();
			return this.line.substring( pos0, pos1 );

		}

		getRemainingString() {

			return this.line.substring( this.currentCharIndex, this.lineLength );

		}

		isAtTheEnd() {

			return this.currentCharIndex >= this.lineLength;

		}

		setToEnd() {

			this.currentCharIndex = this.lineLength;

		}

		getLineNumberString() {

			return this.lineNumber >= 0 ? ' at line ' + this.lineNumber : '';

		}

	}

	class LDrawFileCache {

		constructor( loader ) {

			this.cache = {};
			this.loader = loader;

		}

		setData( key, contents ) {

			this.cache[ key.toLowerCase() ] = contents;

		}

		async loadData( fileName ) {

			const key = fileName.toLowerCase();

			if ( key in this.cache ) {

				return this.cache[ key ];

			}

			this.cache[ fileName ] = new Promise( async ( resolve, reject ) => {

				let triedLowerCase = false;
				let locationState = FILE_LOCATION_AS_IS;

				while ( locationState !== FILE_LOCATION_NOT_FOUND ) {

					let subobjectURL = fileName;

					switch ( locationState ) {

						case FILE_LOCATION_AS_IS:
							locationState = locationState + 1;
							break;

						case FILE_LOCATION_TRY_PARTS:
							subobjectURL = 'parts/' + subobjectURL;
							locationState = locationState + 1;
							break;

						case FILE_LOCATION_TRY_P:
							subobjectURL = 'p/' + subobjectURL;
							locationState = locationState + 1;
							break;

						case FILE_LOCATION_TRY_MODELS:
							subobjectURL = 'models/' + subobjectURL;
							locationState = locationState + 1;
							break;

						case FILE_LOCATION_TRY_RELATIVE:
							subobjectURL = fileName.substring( 0, fileName.lastIndexOf( '/' ) + 1 ) + subobjectURL;
							locationState = locationState + 1;
							break;

						case FILE_LOCATION_TRY_ABSOLUTE:
							if ( triedLowerCase ) {

								// Try absolute path
								locationState = FILE_LOCATION_NOT_FOUND;

							} else {

								// Next attempt is lower case
								fileName = fileName.toLowerCase();
								subobjectURL = fileName;
								triedLowerCase = true;
								locationState = FILE_LOCATION_AS_IS;

							}

							break;

					}

					const loader = this.loader;
					const fileLoader = new THREE.FileLoader( loader.manager );
					fileLoader.setPath( loader.partsLibraryPath );
					fileLoader.setRequestHeader( loader.requestHeader );
					fileLoader.setWithCredentials( loader.withCredentials );

					try {

						const text = await fileLoader.loadAsync( subobjectURL );
						this.setData( fileName, text );
						resolve( text );
						return;

					} catch {

						continue;

					}

				}

				reject();

			} );
			return this.cache[ fileName ];

		}

	}

	function sortByMaterial( a, b ) {

		if ( a.colourCode === b.colourCode ) {

			return 0;

		}

		if ( a.colourCode < b.colourCode ) {

			return - 1;

		}

		return 1;

	}

	function createObject( elements, elementSize, isConditionalSegments = false, totalElements = null ) {

		// Creates a THREE.LineSegments (elementSize = 2) or a THREE.Mesh (elementSize = 3 )
		// With per face / segment material, implemented with mesh groups and materials array
		// Sort the faces or line segments by colour code to make later the mesh groups
		elements.sort( sortByMaterial );

		if ( totalElements === null ) {

			totalElements = elements.length;

		}

		const positions = new Float32Array( elementSize * totalElements * 3 );
		const normals = elementSize === 3 ? new Float32Array( elementSize * totalElements * 3 ) : null;
		const materials = [];
		const quadArray = new Array( 6 );
		const bufferGeometry = new THREE.BufferGeometry();
		let prevMaterial = null;
		let index0 = 0;
		let numGroupVerts = 0;
		let offset = 0;

		for ( let iElem = 0, nElem = elements.length; iElem < nElem; iElem ++ ) {

			const elem = elements[ iElem ];
			let vertices = elem.vertices;

			if ( vertices.length === 4 ) {

				quadArray[ 0 ] = vertices[ 0 ];
				quadArray[ 1 ] = vertices[ 1 ];
				quadArray[ 2 ] = vertices[ 2 ];
				quadArray[ 3 ] = vertices[ 0 ];
				quadArray[ 4 ] = vertices[ 2 ];
				quadArray[ 5 ] = vertices[ 3 ];
				vertices = quadArray;

			}

			for ( let j = 0, l = vertices.length; j < l; j ++ ) {

				const v = vertices[ j ];
				const index = offset + j * 3;
				positions[ index + 0 ] = v.x;
				positions[ index + 1 ] = v.y;
				positions[ index + 2 ] = v.z;

			}

			if ( elementSize === 3 ) {

				let elemNormals = elem.normals;

				if ( elemNormals.length === 4 ) {

					quadArray[ 0 ] = elemNormals[ 0 ];
					quadArray[ 1 ] = elemNormals[ 1 ];
					quadArray[ 2 ] = elemNormals[ 2 ];
					quadArray[ 3 ] = elemNormals[ 0 ];
					quadArray[ 4 ] = elemNormals[ 2 ];
					quadArray[ 5 ] = elemNormals[ 3 ];
					elemNormals = quadArray;

				}

				for ( let j = 0, l = elemNormals.length; j < l; j ++ ) {

					let n = elem.faceNormal;

					if ( elemNormals[ j ] ) {

						n = elemNormals[ j ].norm;

					}

					const index = offset + j * 3;
					normals[ index + 0 ] = n.x;
					normals[ index + 1 ] = n.y;
					normals[ index + 2 ] = n.z;

				}

			}

			if ( prevMaterial !== elem.material ) {

				if ( prevMaterial !== null ) {

					bufferGeometry.addGroup( index0, numGroupVerts, materials.length - 1 );

				}

				materials.push( elem.material );
				prevMaterial = elem.material;
				index0 = offset / 3;
				numGroupVerts = vertices.length;

			} else {

				numGroupVerts += vertices.length;

			}

			offset += 3 * vertices.length;

		}

		if ( numGroupVerts > 0 ) {

			bufferGeometry.addGroup( index0, Infinity, materials.length - 1 );

		}

		bufferGeometry.setAttribute( 'position', new THREE.BufferAttribute( positions, 3 ) );

		if ( normals !== null ) {

			bufferGeometry.setAttribute( 'normal', new THREE.BufferAttribute( normals, 3 ) );

		}

		let object3d = null;

		if ( elementSize === 2 ) {

			object3d = new THREE.LineSegments( bufferGeometry, materials.length === 1 ? materials[ 0 ] : materials );

		} else if ( elementSize === 3 ) {

			object3d = new THREE.Mesh( bufferGeometry, materials.length === 1 ? materials[ 0 ] : materials );

		}

		if ( isConditionalSegments ) {

			object3d.isConditionalLine = true;
			const controlArray0 = new Float32Array( elements.length * 3 * 2 );
			const controlArray1 = new Float32Array( elements.length * 3 * 2 );
			const directionArray = new Float32Array( elements.length * 3 * 2 );

			for ( let i = 0, l = elements.length; i < l; i ++ ) {

				const os = elements[ i ];
				const vertices = os.vertices;
				const controlPoints = os.controlPoints;
				const c0 = controlPoints[ 0 ];
				const c1 = controlPoints[ 1 ];
				const v0 = vertices[ 0 ];
				const v1 = vertices[ 1 ];
				const index = i * 3 * 2;
				controlArray0[ index + 0 ] = c0.x;
				controlArray0[ index + 1 ] = c0.y;
				controlArray0[ index + 2 ] = c0.z;
				controlArray0[ index + 3 ] = c0.x;
				controlArray0[ index + 4 ] = c0.y;
				controlArray0[ index + 5 ] = c0.z;
				controlArray1[ index + 0 ] = c1.x;
				controlArray1[ index + 1 ] = c1.y;
				controlArray1[ index + 2 ] = c1.z;
				controlArray1[ index + 3 ] = c1.x;
				controlArray1[ index + 4 ] = c1.y;
				controlArray1[ index + 5 ] = c1.z;
				directionArray[ index + 0 ] = v1.x - v0.x;
				directionArray[ index + 1 ] = v1.y - v0.y;
				directionArray[ index + 2 ] = v1.z - v0.z;
				directionArray[ index + 3 ] = v1.x - v0.x;
				directionArray[ index + 4 ] = v1.y - v0.y;
				directionArray[ index + 5 ] = v1.z - v0.z;

			}

			bufferGeometry.setAttribute( 'control0', new THREE.BufferAttribute( controlArray0, 3, false ) );
			bufferGeometry.setAttribute( 'control1', new THREE.BufferAttribute( controlArray1, 3, false ) );
			bufferGeometry.setAttribute( 'direction', new THREE.BufferAttribute( directionArray, 3, false ) );

		}

		return object3d;

	} //


	class LDrawLoader extends THREE.Loader {

		constructor( manager ) {

			super( manager ); // Array of THREE.Material

			this.materials = []; // Not using THREE.Cache here because it returns the previous HTML error response instead of calling onError()
			// This also allows to handle the embedded text files ("0 FILE" lines)

			this.cache = new LDrawFileCache( this ); // This object is a map from file names to paths. It agilizes the paths search. If it is not set then files will be searched by trial and error.

			this.fileMap = null;
			this.rootParseScope = this.newParseScopeLevel(); // Add default main triangle and line edge materials (used in pieces that can be coloured with a main color)

			this.setMaterials( [ this.parseColourMetaDirective( new LineParser( 'Main_Colour CODE 16 VALUE #FF8080 EDGE #333333' ) ), this.parseColourMetaDirective( new LineParser( 'Edge_Colour CODE 24 VALUE #A0A0A0 EDGE #333333' ) ) ] ); // If this flag is set to true, each subobject will be a Object.
			// If not (the default), only one object which contains all the merged primitives will be created.

			this.separateObjects = false; // If this flag is set to true the vertex normals will be smoothed.

			this.smoothNormals = true; // The path to load parts from the LDraw parts library from.

			this.partsLibraryPath = '';

		}

		setPartsLibraryPath( path ) {

			this.partsLibraryPath = path;
			return this;

		}

		async preloadMaterials( url ) {

			const fileLoader = new THREE.FileLoader( this.manager );
			fileLoader.setPath( this.path );
			fileLoader.setRequestHeader( this.requestHeader );
			fileLoader.setWithCredentials( this.withCredentials );
			const text = await fileLoader.loadAsync( url );
			const colorLineRegex = /^0 !COLOUR/;
			const lines = text.split( /[\n\r]/g );
			const materials = [];

			for ( let i = 0, l = lines.length; i < l; i ++ ) {

				const line = lines[ i ];

				if ( colorLineRegex.test( line ) ) {

					const directive = line.replace( colorLineRegex, '' );
					const material = this.parseColourMetaDirective( new LineParser( directive ) );
					materials.push( material );

				}

			}

			this.setMaterials( materials );

		}

		load( url, onLoad, onProgress, onError ) {

			if ( ! this.fileMap ) {

				this.fileMap = {};

			}

			const fileLoader = new THREE.FileLoader( this.manager );
			fileLoader.setPath( this.path );
			fileLoader.setRequestHeader( this.requestHeader );
			fileLoader.setWithCredentials( this.withCredentials );
			fileLoader.load( url, text => {

				this.processObject( text, null, url, this.rootParseScope ).then( function ( result ) {

					onLoad( result.groupObject );

				} );

			}, onProgress, onError );

		}

		parse( text, path, onLoad ) {

			// Async parse.  This function calls onParse with the parsed THREE.Object3D as parameter
			this.processObject( text, null, path, this.rootParseScope ).then( function ( result ) {

				onLoad( result.groupObject );

			} );

		}

		setMaterials( materials ) {

			// Clears parse scopes stack, adds new scope with material library
			this.rootParseScope = this.newParseScopeLevel( materials );
			this.rootParseScope.isFromParse = false;
			this.materials = materials;
			return this;

		}

		setFileMap( fileMap ) {

			this.fileMap = fileMap;
			return this;

		}

		newParseScopeLevel( materials = null, parentScope = null ) {

			// Adds a new scope level, assign materials to it and returns it
			const matLib = {};

			if ( materials ) {

				for ( let i = 0, n = materials.length; i < n; i ++ ) {

					const material = materials[ i ];
					matLib[ material.userData.code ] = material;

				}

			}

			const newParseScope = {
				parentScope: parentScope,
				lib: matLib,
				url: null,
				// Subobjects
				subobjects: null,
				numSubobjects: 0,
				subobjectIndex: 0,
				inverted: false,
				category: null,
				keywords: null,
				// Current subobject
				currentFileName: null,
				mainColourCode: parentScope ? parentScope.mainColourCode : '16',
				mainEdgeColourCode: parentScope ? parentScope.mainEdgeColourCode : '24',
				currentMatrix: new THREE.Matrix4(),
				matrix: new THREE.Matrix4(),
				type: 'Model',
				// If false, it is a root material scope previous to parse
				isFromParse: true,
				faces: [],
				lineSegments: [],
				conditionalSegments: [],
				totalFaces: 0,
				// If true, this object is the start of a construction step
				startingConstructionStep: false
			};
			return newParseScope;

		}

		addMaterial( material, parseScope ) {

			// Adds a material to the material library which is on top of the parse scopes stack. And also to the materials array
			const matLib = parseScope.lib;

			if ( ! matLib[ material.userData.code ] ) {

				this.materials.push( material );

			}

			matLib[ material.userData.code ] = material;
			return this;

		}

		getMaterial( colourCode, parseScope = this.rootParseScope ) {

			// Given a colour code search its material in the parse scopes stack
			if ( colourCode.startsWith( '0x2' ) ) {

				// Special 'direct' material value (RGB colour)
				const colour = colourCode.substring( 3 );
				return this.parseColourMetaDirective( new LineParser( 'Direct_Color_' + colour + ' CODE -1 VALUE #' + colour + ' EDGE #' + colour + '' ) );

			}

			while ( parseScope ) {

				const material = parseScope.lib[ colourCode ];

				if ( material ) {

					return material;

				} else {

					parseScope = parseScope.parentScope;

				}

			} // Material was not found


			return null;

		}

		parseColourMetaDirective( lineParser ) {

			// Parses a colour definition and returns a THREE.Material
			let code = null; // Triangle and line colours

			let colour = 0xFF00FF;
			let edgeColour = 0xFF00FF; // Transparency

			let alpha = 1;
			let isTransparent = false; // Self-illumination:

			let luminance = 0;
			let finishType = FINISH_TYPE_DEFAULT;
			let edgeMaterial = null;
			const name = lineParser.getToken();

			if ( ! name ) {

				throw 'LDrawLoader: Material name was expected after "!COLOUR tag' + lineParser.getLineNumberString() + '.';

			} // Parse tag tokens and their parameters


			let token = null;

			while ( true ) {

				token = lineParser.getToken();

				if ( ! token ) {

					break;

				}

				switch ( token.toUpperCase() ) {

					case 'CODE':
						code = lineParser.getToken();
						break;

					case 'VALUE':
						colour = lineParser.getToken();

						if ( colour.startsWith( '0x' ) ) {

							colour = '#' + colour.substring( 2 );

						} else if ( ! colour.startsWith( '#' ) ) {

							throw 'LDrawLoader: Invalid colour while parsing material' + lineParser.getLineNumberString() + '.';

						}

						break;

					case 'EDGE':
						edgeColour = lineParser.getToken();

						if ( edgeColour.startsWith( '0x' ) ) {

							edgeColour = '#' + edgeColour.substring( 2 );

						} else if ( ! edgeColour.startsWith( '#' ) ) {

							// Try to see if edge colour is a colour code
							edgeMaterial = this.getMaterial( edgeColour );

							if ( ! edgeMaterial ) {

								throw 'LDrawLoader: Invalid edge colour while parsing material' + lineParser.getLineNumberString() + '.';

							} // Get the edge material for this triangle material


							edgeMaterial = edgeMaterial.userData.edgeMaterial;

						}

						break;

					case 'ALPHA':
						alpha = parseInt( lineParser.getToken() );

						if ( isNaN( alpha ) ) {

							throw 'LDrawLoader: Invalid alpha value in material definition' + lineParser.getLineNumberString() + '.';

						}

						alpha = Math.max( 0, Math.min( 1, alpha / 255 ) );

						if ( alpha < 1 ) {

							isTransparent = true;

						}

						break;

					case 'LUMINANCE':
						luminance = parseInt( lineParser.getToken() );

						if ( isNaN( luminance ) ) {

							throw 'LDrawLoader: Invalid luminance value in material definition' + LineParser.getLineNumberString() + '.';

						}

						luminance = Math.max( 0, Math.min( 1, luminance / 255 ) );
						break;

					case 'CHROME':
						finishType = FINISH_TYPE_CHROME;
						break;

					case 'PEARLESCENT':
						finishType = FINISH_TYPE_PEARLESCENT;
						break;

					case 'RUBBER':
						finishType = FINISH_TYPE_RUBBER;
						break;

					case 'MATTE_METALLIC':
						finishType = FINISH_TYPE_MATTE_METALLIC;
						break;

					case 'METAL':
						finishType = FINISH_TYPE_METAL;
						break;

					case 'MATERIAL':
						// Not implemented
						lineParser.setToEnd();
						break;

					default:
						throw 'LDrawLoader: Unknown token "' + token + '" while parsing material' + lineParser.getLineNumberString() + '.';
						break;

				}

			}

			let material = null;

			switch ( finishType ) {

				case FINISH_TYPE_DEFAULT:
					material = new THREE.MeshStandardMaterial( {
						color: colour,
						roughness: 0.3,
						metalness: 0
					} );
					break;

				case FINISH_TYPE_PEARLESCENT:
					// Try to imitate pearlescency by making the surface glossy
					material = new THREE.MeshStandardMaterial( {
						color: colour,
						roughness: 0.3,
						metalness: 0.25
					} );
					break;

				case FINISH_TYPE_CHROME:
					// Mirror finish surface
					material = new THREE.MeshStandardMaterial( {
						color: colour,
						roughness: 0,
						metalness: 1
					} );
					break;

				case FINISH_TYPE_RUBBER:
					// Rubber finish
					material = new THREE.MeshStandardMaterial( {
						color: colour,
						roughness: 0.9,
						metalness: 0
					} );
					break;

				case FINISH_TYPE_MATTE_METALLIC:
					// Brushed metal finish
					material = new THREE.MeshStandardMaterial( {
						color: colour,
						roughness: 0.8,
						metalness: 0.4
					} );
					break;

				case FINISH_TYPE_METAL:
					// Average metal finish
					material = new THREE.MeshStandardMaterial( {
						color: colour,
						roughness: 0.2,
						metalness: 0.85
					} );
					break;

				default:
					// Should not happen
					break;

			}

			material.transparent = isTransparent;
			material.premultipliedAlpha = true;
			material.opacity = alpha;
			material.depthWrite = ! isTransparent;
			material.polygonOffset = true;
			material.polygonOffsetFactor = 1;

			if ( luminance !== 0 ) {

				material.emissive.set( material.color ).multiplyScalar( luminance );

			}

			if ( ! edgeMaterial ) {

				// This is the material used for edges
				edgeMaterial = new THREE.LineBasicMaterial( {
					color: edgeColour,
					transparent: isTransparent,
					opacity: alpha,
					depthWrite: ! isTransparent
				} );
				edgeMaterial.userData.code = code;
				edgeMaterial.name = name + ' - Edge'; // This is the material used for conditional edges

				edgeMaterial.userData.conditionalEdgeMaterial = new LDrawConditionalLineMaterial( {
					fog: true,
					transparent: isTransparent,
					depthWrite: ! isTransparent,
					color: edgeColour,
					opacity: alpha
				} );

			}

			material.userData.code = code;
			material.name = name;
			material.userData.edgeMaterial = edgeMaterial;
			return material;

		} //


		objectParse( text, parseScope ) {

			// Retrieve data from the parent parse scope
			const currentParseScope = parseScope;
			const parentParseScope = currentParseScope.parentScope; // Main colour codes passed to this subobject (or default codes 16 and 24 if it is the root object)

			const mainColourCode = currentParseScope.mainColourCode;
			const mainEdgeColourCode = currentParseScope.mainEdgeColourCode; // Parse result variables

			let faces;
			let lineSegments;
			let conditionalSegments;
			const subobjects = [];
			let category = null;
			let keywords = null;

			if ( text.indexOf( '\r\n' ) !== - 1 ) {

				// This is faster than String.split with regex that splits on both
				text = text.replace( /\r\n/g, '\n' );

			}

			const lines = text.split( '\n' );
			const numLines = lines.length;
			let parsingEmbeddedFiles = false;
			let currentEmbeddedFileName = null;
			let currentEmbeddedText = null;
			let bfcCertified = false;
			let bfcCCW = true;
			let bfcInverted = false;
			let bfcCull = true;
			let type = '';
			let startingConstructionStep = false;
			const scope = this;

			function parseColourCode( lineParser, forEdge ) {

				// Parses next colour code and returns a THREE.Material
				let colourCode = lineParser.getToken();

				if ( ! forEdge && colourCode === '16' ) {

					colourCode = mainColourCode;

				}

				if ( forEdge && colourCode === '24' ) {

					colourCode = mainEdgeColourCode;

				}

				const material = scope.getMaterial( colourCode, currentParseScope );

				if ( ! material ) {

					throw 'LDrawLoader: Unknown colour code "' + colourCode + '" is used' + lineParser.getLineNumberString() + ' but it was not defined previously.';

				}

				return material;

			}

			function parseVector( lp ) {

				const v = new THREE.Vector3( parseFloat( lp.getToken() ), parseFloat( lp.getToken() ), parseFloat( lp.getToken() ) );

				if ( ! scope.separateObjects ) {

					v.applyMatrix4( currentParseScope.currentMatrix );

				}

				return v;

			} // Parse all line commands


			for ( let lineIndex = 0; lineIndex < numLines; lineIndex ++ ) {

				const line = lines[ lineIndex ];
				if ( line.length === 0 ) continue;

				if ( parsingEmbeddedFiles ) {

					if ( line.startsWith( '0 FILE ' ) ) {

						// Save previous embedded file in the cache
						this.cache.setData( currentEmbeddedFileName.toLowerCase(), currentEmbeddedText ); // New embedded text file

						currentEmbeddedFileName = line.substring( 7 );
						currentEmbeddedText = '';

					} else {

						currentEmbeddedText += line + '\n';

					}

					continue;

				}

				const lp = new LineParser( line, lineIndex + 1 );
				lp.seekNonSpace();

				if ( lp.isAtTheEnd() ) {

					// Empty line
					continue;

				} // Parse the line type


				const lineType = lp.getToken();
				let material;
				let segment;
				let inverted;
				let ccw;
				let doubleSided;
				let v0, v1, v2, v3, c0, c1, faceNormal;

				switch ( lineType ) {

					// Line type 0: Comment or META
					case '0':
						// Parse meta directive
						const meta = lp.getToken();

						if ( meta ) {

							switch ( meta ) {

								case '!LDRAW_ORG':
									type = lp.getToken();
									currentParseScope.type = type;
									const isRoot = ! parentParseScope.isFromParse;

									if ( isRoot || scope.separateObjects && ! isPrimitiveType( type ) ) {

										currentParseScope.groupObject = new THREE.Group();
										currentParseScope.groupObject.userData.startingConstructionStep = currentParseScope.startingConstructionStep;

									} // If the scale of the object is negated then the triangle winding order
									// needs to be flipped.


									if ( currentParseScope.matrix.determinant() < 0 && ( scope.separateObjects && isPrimitiveType( type ) || ! scope.separateObjects ) ) {

										currentParseScope.inverted = ! currentParseScope.inverted;

									}

									faces = currentParseScope.faces;
									lineSegments = currentParseScope.lineSegments;
									conditionalSegments = currentParseScope.conditionalSegments;
									break;

								case '!COLOUR':
									material = this.parseColourMetaDirective( lp );

									if ( material ) {

										this.addMaterial( material, parseScope );

									} else {

										console.warn( 'LDrawLoader: Error parsing material' + lp.getLineNumberString() );

									}

									break;

								case '!CATEGORY':
									category = lp.getToken();
									break;

								case '!KEYWORDS':
									const newKeywords = lp.getRemainingString().split( ',' );

									if ( newKeywords.length > 0 ) {

										if ( ! keywords ) {

											keywords = [];

										}

										newKeywords.forEach( function ( keyword ) {

											keywords.push( keyword.trim() );

										} );

									}

									break;

								case 'FILE':
									if ( lineIndex > 0 ) {

										// Start embedded text files parsing
										parsingEmbeddedFiles = true;
										currentEmbeddedFileName = lp.getRemainingString();
										currentEmbeddedText = '';
										bfcCertified = false;
										bfcCCW = true;

									}

									break;

								case 'BFC':
									// Changes to the backface culling state
									while ( ! lp.isAtTheEnd() ) {

										const token = lp.getToken();

										switch ( token ) {

											case 'CERTIFY':
											case 'NOCERTIFY':
												bfcCertified = token === 'CERTIFY';
												bfcCCW = true;
												break;

											case 'CW':
											case 'CCW':
												bfcCCW = token === 'CCW';
												break;

											case 'INVERTNEXT':
												bfcInverted = true;
												break;

											case 'CLIP':
											case 'NOCLIP':
												bfcCull = token === 'CLIP';
												break;

											default:
												console.warn( 'THREE.LDrawLoader: BFC directive "' + token + '" is unknown.' );
												break;

										}

									}

									break;

								case 'STEP':
									startingConstructionStep = true;
									break;

								default:
									// Other meta directives are not implemented
									break;

							}

						}

						break;
						// Line type 1: Sub-object file

					case '1':
						material = parseColourCode( lp );
						const posX = parseFloat( lp.getToken() );
						const posY = parseFloat( lp.getToken() );
						const posZ = parseFloat( lp.getToken() );
						const m0 = parseFloat( lp.getToken() );
						const m1 = parseFloat( lp.getToken() );
						const m2 = parseFloat( lp.getToken() );
						const m3 = parseFloat( lp.getToken() );
						const m4 = parseFloat( lp.getToken() );
						const m5 = parseFloat( lp.getToken() );
						const m6 = parseFloat( lp.getToken() );
						const m7 = parseFloat( lp.getToken() );
						const m8 = parseFloat( lp.getToken() );
						const matrix = new THREE.Matrix4().set( m0, m1, m2, posX, m3, m4, m5, posY, m6, m7, m8, posZ, 0, 0, 0, 1 );
						let fileName = lp.getRemainingString().trim().replace( /\\/g, '/' );

						if ( scope.fileMap[ fileName ] ) {

							// Found the subobject path in the preloaded file path map
							fileName = scope.fileMap[ fileName ];

						} else {

							// Standardized subfolders
							if ( fileName.startsWith( 's/' ) ) {

								fileName = 'parts/' + fileName;

							} else if ( fileName.startsWith( '48/' ) ) {

								fileName = 'p/' + fileName;

							}

						}

						subobjects.push( {
							material: material,
							matrix: matrix,
							fileName: fileName,
							inverted: bfcInverted !== currentParseScope.inverted,
							startingConstructionStep: startingConstructionStep
						} );
						bfcInverted = false;
						break;
						// Line type 2: Line segment

					case '2':
						material = parseColourCode( lp, true );
						v0 = parseVector( lp );
						v1 = parseVector( lp );
						segment = {
							material: material.userData.edgeMaterial,
							colourCode: material.userData.code,
							v0: v0,
							v1: v1,
							vertices: [ v0, v1 ]
						};
						lineSegments.push( segment );
						break;
						// Line type 5: Conditional Line segment

					case '5':
						material = parseColourCode( lp, true );
						v0 = parseVector( lp );
						v1 = parseVector( lp );
						c0 = parseVector( lp );
						c1 = parseVector( lp );
						segment = {
							material: material.userData.edgeMaterial.userData.conditionalEdgeMaterial,
							colourCode: material.userData.code,
							vertices: [ v0, v1 ],
							controlPoints: [ c0, c1 ]
						};
						conditionalSegments.push( segment );
						break;
						// Line type 3: Triangle

					case '3':
						material = parseColourCode( lp );
						inverted = currentParseScope.inverted;
						ccw = bfcCCW !== inverted;
						doubleSided = ! bfcCertified || ! bfcCull;

						if ( ccw === true ) {

							v0 = parseVector( lp );
							v1 = parseVector( lp );
							v2 = parseVector( lp );

						} else {

							v2 = parseVector( lp );
							v1 = parseVector( lp );
							v0 = parseVector( lp );

						}

						_tempVec0.subVectors( v1, v0 );

						_tempVec1.subVectors( v2, v1 );

						faceNormal = new THREE.Vector3().crossVectors( _tempVec0, _tempVec1 ).normalize();
						faces.push( {
							material: material,
							colourCode: material.userData.code,
							faceNormal: faceNormal,
							vertices: [ v0, v1, v2 ],
							normals: [ null, null, null ]
						} );
						currentParseScope.totalFaces ++;

						if ( doubleSided === true ) {

							faces.push( {
								material: material,
								colourCode: material.userData.code,
								faceNormal: faceNormal,
								vertices: [ v2, v1, v0 ],
								normals: [ null, null, null ]
							} );
							currentParseScope.totalFaces ++;

						}

						break;
						// Line type 4: Quadrilateral

					case '4':
						material = parseColourCode( lp );
						inverted = currentParseScope.inverted;
						ccw = bfcCCW !== inverted;
						doubleSided = ! bfcCertified || ! bfcCull;

						if ( ccw === true ) {

							v0 = parseVector( lp );
							v1 = parseVector( lp );
							v2 = parseVector( lp );
							v3 = parseVector( lp );

						} else {

							v3 = parseVector( lp );
							v2 = parseVector( lp );
							v1 = parseVector( lp );
							v0 = parseVector( lp );

						}

						_tempVec0.subVectors( v1, v0 );

						_tempVec1.subVectors( v2, v1 );

						faceNormal = new THREE.Vector3().crossVectors( _tempVec0, _tempVec1 ).normalize(); // specifically place the triangle diagonal in the v0 and v1 slots so we can
						// account for the doubling of vertices later when smoothing normals.

						faces.push( {
							material: material,
							colourCode: material.userData.code,
							faceNormal: faceNormal,
							vertices: [ v0, v1, v2, v3 ],
							normals: [ null, null, null, null ]
						} );
						currentParseScope.totalFaces += 2;

						if ( doubleSided === true ) {

							faces.push( {
								material: material,
								colourCode: material.userData.code,
								faceNormal: faceNormal,
								vertices: [ v3, v2, v1, v0 ],
								normals: [ null, null, null, null ]
							} );
							currentParseScope.totalFaces += 2;

						}

						break;

					default:
						throw 'LDrawLoader: Unknown line type "' + lineType + '"' + lp.getLineNumberString() + '.';
						break;

				}

			}

			if ( parsingEmbeddedFiles ) {

				this.cache.setData( currentEmbeddedFileName.toLowerCase(), currentEmbeddedText );

			}

			currentParseScope.category = category;
			currentParseScope.keywords = keywords;
			currentParseScope.subobjects = subobjects;
			currentParseScope.numSubobjects = subobjects.length;
			currentParseScope.subobjectIndex = 0;

		}

		computeConstructionSteps( model ) {

			// Sets userdata.constructionStep number in THREE.Group objects and userData.numConstructionSteps number in the root THREE.Group object.
			let stepNumber = 0;
			model.traverse( c => {

				if ( c.isGroup ) {

					if ( c.userData.startingConstructionStep ) {

						stepNumber ++;

					}

					c.userData.constructionStep = stepNumber;

				}

			} );
			model.userData.numConstructionSteps = stepNumber + 1;

		}

		finalizeObject( subobjectParseScope ) {

			// fail gracefully if an object could not be loaded
			if ( subobjectParseScope === null ) {

				return;

			}

			const parentParseScope = subobjectParseScope.parentScope; // Smooth the normals if this is a part or if this is a case where the subpart
			// is added directly into the parent model (meaning it will never get smoothed by
			// being added to a part)

			const doSmooth = isPartType( subobjectParseScope.type ) || ! isPartType( subobjectParseScope.type ) && ! isModelType( subobjectParseScope.type ) && isModelType( subobjectParseScope.parentScope.type );

			if ( this.smoothNormals && doSmooth ) {

				smoothNormals( subobjectParseScope.faces, subobjectParseScope.lineSegments );

			}

			const isRoot = ! parentParseScope.isFromParse;

			if ( this.separateObjects && ! isPrimitiveType( subobjectParseScope.type ) || isRoot ) {

				const objGroup = subobjectParseScope.groupObject;

				if ( subobjectParseScope.faces.length > 0 ) {

					objGroup.add( createObject( subobjectParseScope.faces, 3, false, subobjectParseScope.totalFaces ) );

				}

				if ( subobjectParseScope.lineSegments.length > 0 ) {

					objGroup.add( createObject( subobjectParseScope.lineSegments, 2 ) );

				}

				if ( subobjectParseScope.conditionalSegments.length > 0 ) {

					objGroup.add( createObject( subobjectParseScope.conditionalSegments, 2, true ) );

				}

				if ( parentParseScope.groupObject ) {

					objGroup.name = subobjectParseScope.fileName;
					objGroup.userData.category = subobjectParseScope.category;
					objGroup.userData.keywords = subobjectParseScope.keywords;
					subobjectParseScope.matrix.decompose( objGroup.position, objGroup.quaternion, objGroup.scale );
					parentParseScope.groupObject.add( objGroup );

				}

			} else {

				const separateObjects = this.separateObjects;
				const parentLineSegments = parentParseScope.lineSegments;
				const parentConditionalSegments = parentParseScope.conditionalSegments;
				const parentFaces = parentParseScope.faces;
				const lineSegments = subobjectParseScope.lineSegments;
				const conditionalSegments = subobjectParseScope.conditionalSegments;
				const faces = subobjectParseScope.faces;

				for ( let i = 0, l = lineSegments.length; i < l; i ++ ) {

					const ls = lineSegments[ i ];

					if ( separateObjects ) {

						const vertices = ls.vertices;
						vertices[ 0 ].applyMatrix4( subobjectParseScope.matrix );
						vertices[ 1 ].applyMatrix4( subobjectParseScope.matrix );

					}

					parentLineSegments.push( ls );

				}

				for ( let i = 0, l = conditionalSegments.length; i < l; i ++ ) {

					const os = conditionalSegments[ i ];

					if ( separateObjects ) {

						const vertices = os.vertices;
						const controlPoints = os.controlPoints;
						vertices[ 0 ].applyMatrix4( subobjectParseScope.matrix );
						vertices[ 1 ].applyMatrix4( subobjectParseScope.matrix );
						controlPoints[ 0 ].applyMatrix4( subobjectParseScope.matrix );
						controlPoints[ 1 ].applyMatrix4( subobjectParseScope.matrix );

					}

					parentConditionalSegments.push( os );

				}

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

					const tri = faces[ i ];

					if ( separateObjects ) {

						const vertices = tri.vertices;

						for ( let i = 0, l = vertices.length; i < l; i ++ ) {

							vertices[ i ] = vertices[ i ].clone().applyMatrix4( subobjectParseScope.matrix );

						}

						_tempVec0.subVectors( vertices[ 1 ], vertices[ 0 ] );

						_tempVec1.subVectors( vertices[ 2 ], vertices[ 1 ] );

						tri.faceNormal.crossVectors( _tempVec0, _tempVec1 ).normalize();

					}

					parentFaces.push( tri );

				}

				parentParseScope.totalFaces += subobjectParseScope.totalFaces;

			}

		}

		async processObject( text, subobject, url, parentScope ) {

			const scope = this;
			const parseScope = this.newParseScopeLevel( null, parentScope );
			parseScope.url = url;
			const parentParseScope = parseScope.parentScope; // Set current matrix

			if ( subobject ) {

				parseScope.currentMatrix.multiplyMatrices( parentParseScope.currentMatrix, subobject.matrix );
				parseScope.matrix.copy( subobject.matrix );
				parseScope.inverted = subobject.inverted;
				parseScope.startingConstructionStep = subobject.startingConstructionStep;
				parseScope.mainColourCode = subobject.material.userData.code;
				parseScope.mainEdgeColourCode = subobject.material.userData.edgeMaterial.userData.code;
				parseScope.fileName = subobject.fileName;

			} // Parse the object


			this.objectParse( text, parseScope );
			const subobjects = parseScope.subobjects;
			const promises = [];

			for ( let i = 0, l = subobjects.length; i < l; i ++ ) {

				promises.push( loadSubobject( parseScope.subobjects[ i ] ) );

			} // Kick off of the downloads in parallel but process all the subobjects
			// in order so all the assembly instructions are correct


			const subobjectScopes = await Promise.all( promises );

			for ( let i = 0, l = subobjectScopes.length; i < l; i ++ ) {

				this.finalizeObject( subobjectScopes[ i ] );

			} // If it is root object then finalize this object and compute construction steps


			if ( ! parentParseScope.isFromParse ) {

				this.finalizeObject( parseScope );
				this.computeConstructionSteps( parseScope.groupObject );

			}

			return parseScope;

			function loadSubobject( subobject ) {

				return scope.cache.loadData( subobject.fileName ).then( function ( text ) {

					return scope.processObject( text, subobject, url, parseScope );

				} ).catch( function () {

					console.warn( 'LDrawLoader: Subobject "' + subobject.fileName + '" could not be found.' );
					return null;

				} );

			}

		}

	}

	THREE.LDrawLoader = LDrawLoader;

} )();