three.js/src/core/Geometry.js

/**
 * @author mrdoob / http://mrdoob.com/
 * @author kile / http://kile.stravaganza.org/
 * @author alteredq / http://alteredqualia.com/
 * @author mikael emtinger / http://gomo.se/
 * @author zz85 / http://www.lab4games.net/zz85/blog
 * @author bhouston / http://exocortex.com
 */

THREE.Geometry = function () {

	Object.defineProperty( this, 'id', { value: THREE.GeometryIdCount ++ } );

	this.uuid = THREE.Math.generateUUID();

	this.name = '';
	this.type = 'Geometry';

	this.vertices = [];
	this.colors = [];  // one-to-one vertex colors, used in Points and Line

	this.faces = [];

	this.faceVertexUvs = [ [] ];

	this.morphTargets = [];
	this.morphColors = [];
	this.morphNormals = [];

	this.skinWeights = [];
	this.skinIndices = [];

	this.lineDistances = [];

	this.boundingBox = null;
	this.boundingSphere = null;

	this.hasTangents = false;

	this.dynamic = true; // the intermediate typed arrays will be deleted when set to false

	// update flags

	this.verticesNeedUpdate = false;
	this.elementsNeedUpdate = false;
	this.uvsNeedUpdate = false;
	this.normalsNeedUpdate = false;
	this.tangentsNeedUpdate = false;
	this.colorsNeedUpdate = false;
	this.lineDistancesNeedUpdate = false;

	this.groupsNeedUpdate = false;

};

THREE.Geometry.prototype = {

	constructor: THREE.Geometry,

	applyMatrix: function ( matrix ) {

		var normalMatrix = new THREE.Matrix3().getNormalMatrix( matrix );

		for ( var i = 0, il = this.vertices.length; i < il; i ++ ) {

			var vertex = this.vertices[ i ];
			vertex.applyMatrix4( matrix );

		}

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

			var face = this.faces[ i ];
			face.normal.applyMatrix3( normalMatrix ).normalize();

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

				face.vertexNormals[ j ].applyMatrix3( normalMatrix ).normalize();

			}

		}

		if ( this.boundingBox !== null ) {

			this.computeBoundingBox();

		}

		if ( this.boundingSphere !== null ) {

			this.computeBoundingSphere();

		}

		this.verticesNeedUpdate = true;
		this.normalsNeedUpdate = true;

	},

	fromBufferGeometry: function ( geometry ) {

		var scope = this;

		var attributes = geometry.attributes;

		var vertices = attributes.position.array;
		var indices = attributes.index !== undefined ? attributes.index.array : undefined;
		var normals = attributes.normal !== undefined ? attributes.normal.array : undefined;
		var colors = attributes.color !== undefined ? attributes.color.array : undefined;
		var uvs = attributes.uv !== undefined ? attributes.uv.array : undefined;

		var tempNormals = [];
		var tempUVs = [];

		for ( var i = 0, j = 0; i < vertices.length; i += 3, j += 2 ) {

			scope.vertices.push( new THREE.Vector3( vertices[ i ], vertices[ i + 1 ], vertices[ i + 2 ] ) );

			if ( normals !== undefined ) {

				tempNormals.push( new THREE.Vector3( normals[ i ], normals[ i + 1 ], normals[ i + 2 ] ) );

			}

			if ( colors !== undefined ) {

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

			}

			if ( uvs !== undefined ) {

				tempUVs.push( new THREE.Vector2( uvs[ j ], uvs[ j + 1 ] ) );

			}

		}

		var addFace = function ( a, b, c ) {

			var vertexNormals = normals !== undefined ? [ tempNormals[ a ].clone(), tempNormals[ b ].clone(), tempNormals[ c ].clone() ] : [];
			var vertexColors = colors !== undefined ? [ scope.colors[ a ].clone(), scope.colors[ b ].clone(), scope.colors[ c ].clone() ] : [];

			scope.faces.push( new THREE.Face3( a, b, c, vertexNormals, vertexColors ) );

			if ( uvs !== undefined ) {

				scope.faceVertexUvs[ 0 ].push( [ tempUVs[ a ].clone(), tempUVs[ b ].clone(), tempUVs[ c ].clone() ] );

			}

		};

		if ( indices !== undefined ) {

			var drawcalls = geometry.drawcalls;

			if ( drawcalls.length > 0 ) {

				for ( var i = 0; i < drawcalls.length; i ++ ) {

					var drawcall = drawcalls[ i ];

					var start = drawcall.start;
					var count = drawcall.count;
					var index = drawcall.index;

					for ( var j = start, jl = start + count; j < jl; j += 3 ) {

						addFace( index + indices[ j ], index + indices[ j + 1 ], index + indices[ j + 2 ] );

					}

				}

			} else {

				for ( var i = 0; i < indices.length; i += 3 ) {

					addFace( indices[ i ], indices[ i + 1 ], indices[ i + 2 ] );

				}

			}

		} else {

			for ( var i = 0; i < vertices.length / 3; i += 3 ) {

				addFace( i, i + 1, i + 2 );

			}

		}

		this.computeFaceNormals();

		if ( geometry.boundingBox !== null ) {

			this.boundingBox = geometry.boundingBox.clone();

		}

		if ( geometry.boundingSphere !== null ) {

			this.boundingSphere = geometry.boundingSphere.clone();

		}

		return this;

	},

	center: function () {

		this.computeBoundingBox();

		var offset = this.boundingBox.center().negate();

		this.applyMatrix( new THREE.Matrix4().setPosition( offset ) );

		return offset;

	},

	computeFaceNormals: function () {

		var cb = new THREE.Vector3(), ab = new THREE.Vector3();

		for ( var f = 0, fl = this.faces.length; f < fl; f ++ ) {

			var face = this.faces[ f ];

			var vA = this.vertices[ face.a ];
			var vB = this.vertices[ face.b ];
			var vC = this.vertices[ face.c ];

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

			cb.normalize();

			face.normal.copy( cb );

		}

	},

	computeVertexNormals: function ( areaWeighted ) {

		var v, vl, f, fl, face, vertices;

		vertices = new Array( this.vertices.length );

		for ( v = 0, vl = this.vertices.length; v < vl; v ++ ) {

			vertices[ v ] = new THREE.Vector3();

		}

		if ( areaWeighted ) {

			// vertex normals weighted by triangle areas
			// http://www.iquilezles.org/www/articles/normals/normals.htm

			var vA, vB, vC;
			var cb = new THREE.Vector3(), ab = new THREE.Vector3();

			for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

				face = this.faces[ f ];

				vA = this.vertices[ face.a ];
				vB = this.vertices[ face.b ];
				vC = this.vertices[ face.c ];

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

				vertices[ face.a ].add( cb );
				vertices[ face.b ].add( cb );
				vertices[ face.c ].add( cb );

			}

		} else {

			for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

				face = this.faces[ f ];

				vertices[ face.a ].add( face.normal );
				vertices[ face.b ].add( face.normal );
				vertices[ face.c ].add( face.normal );

			}

		}

		for ( v = 0, vl = this.vertices.length; v < vl; v ++ ) {

			vertices[ v ].normalize();

		}

		for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

			face = this.faces[ f ];

			face.vertexNormals[ 0 ] = vertices[ face.a ].clone();
			face.vertexNormals[ 1 ] = vertices[ face.b ].clone();
			face.vertexNormals[ 2 ] = vertices[ face.c ].clone();

		}

	},

	computeMorphNormals: function () {

		var i, il, f, fl, face;

		// save original normals
		// - create temp variables on first access
		//   otherwise just copy (for faster repeated calls)

		for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

			face = this.faces[ f ];

			if ( ! face.__originalFaceNormal ) {

				face.__originalFaceNormal = face.normal.clone();

			} else {

				face.__originalFaceNormal.copy( face.normal );

			}

			if ( ! face.__originalVertexNormals ) face.__originalVertexNormals = [];

			for ( i = 0, il = face.vertexNormals.length; i < il; i ++ ) {

				if ( ! face.__originalVertexNormals[ i ] ) {

					face.__originalVertexNormals[ i ] = face.vertexNormals[ i ].clone();

				} else {

					face.__originalVertexNormals[ i ].copy( face.vertexNormals[ i ] );

				}

			}

		}

		// use temp geometry to compute face and vertex normals for each morph

		var tmpGeo = new THREE.Geometry();
		tmpGeo.faces = this.faces;

		for ( i = 0, il = this.morphTargets.length; i < il; i ++ ) {

			// create on first access

			if ( ! this.morphNormals[ i ] ) {

				this.morphNormals[ i ] = {};
				this.morphNormals[ i ].faceNormals = [];
				this.morphNormals[ i ].vertexNormals = [];

				var dstNormalsFace = this.morphNormals[ i ].faceNormals;
				var dstNormalsVertex = this.morphNormals[ i ].vertexNormals;

				var faceNormal, vertexNormals;

				for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

					faceNormal = new THREE.Vector3();
					vertexNormals = { a: new THREE.Vector3(), b: new THREE.Vector3(), c: new THREE.Vector3() };

					dstNormalsFace.push( faceNormal );
					dstNormalsVertex.push( vertexNormals );

				}

			}

			var morphNormals = this.morphNormals[ i ];

			// set vertices to morph target

			tmpGeo.vertices = this.morphTargets[ i ].vertices;

			// compute morph normals

			tmpGeo.computeFaceNormals();
			tmpGeo.computeVertexNormals();

			// store morph normals

			var faceNormal, vertexNormals;

			for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

				face = this.faces[ f ];

				faceNormal = morphNormals.faceNormals[ f ];
				vertexNormals = morphNormals.vertexNormals[ f ];

				faceNormal.copy( face.normal );

				vertexNormals.a.copy( face.vertexNormals[ 0 ] );
				vertexNormals.b.copy( face.vertexNormals[ 1 ] );
				vertexNormals.c.copy( face.vertexNormals[ 2 ] );

			}

		}

		// restore original normals

		for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

			face = this.faces[ f ];

			face.normal = face.__originalFaceNormal;
			face.vertexNormals = face.__originalVertexNormals;

		}

	},

	computeTangents: function () {

		// based on http://www.terathon.com/code/tangent.html
		// tangents go to vertices

		var f, fl, v, vl, i, vertexIndex,
			face, uv, vA, vB, vC, uvA, uvB, uvC,
			x1, x2, y1, y2, z1, z2,
			s1, s2, t1, t2, r, t, test,
			tan1 = [], tan2 = [],
			sdir = new THREE.Vector3(), tdir = new THREE.Vector3(),
			tmp = new THREE.Vector3(), tmp2 = new THREE.Vector3(),
			n = new THREE.Vector3(), w;

		for ( v = 0, vl = this.vertices.length; v < vl; v ++ ) {

			tan1[ v ] = new THREE.Vector3();
			tan2[ v ] = new THREE.Vector3();

		}

		function handleTriangle( context, a, b, c, ua, ub, uc ) {

			vA = context.vertices[ a ];
			vB = context.vertices[ b ];
			vC = context.vertices[ c ];

			uvA = uv[ ua ];
			uvB = uv[ ub ];
			uvC = uv[ uc ];

			x1 = vB.x - vA.x;
			x2 = vC.x - vA.x;
			y1 = vB.y - vA.y;
			y2 = vC.y - vA.y;
			z1 = vB.z - vA.z;
			z2 = vC.z - vA.z;

			s1 = uvB.x - uvA.x;
			s2 = uvC.x - uvA.x;
			t1 = uvB.y - uvA.y;
			t2 = uvC.y - uvA.y;

			r = 1.0 / ( s1 * t2 - s2 * t1 );
			sdir.set( ( t2 * x1 - t1 * x2 ) * r,
					  ( t2 * y1 - t1 * y2 ) * r,
					  ( t2 * z1 - t1 * z2 ) * r );
			tdir.set( ( s1 * x2 - s2 * x1 ) * r,
					  ( s1 * y2 - s2 * y1 ) * r,
					  ( s1 * z2 - s2 * z1 ) * r );

			tan1[ a ].add( sdir );
			tan1[ b ].add( sdir );
			tan1[ c ].add( sdir );

			tan2[ a ].add( tdir );
			tan2[ b ].add( tdir );
			tan2[ c ].add( tdir );

		}

		for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

			face = this.faces[ f ];
			uv = this.faceVertexUvs[ 0 ][ f ]; // use UV layer 0 for tangents

			handleTriangle( this, face.a, face.b, face.c, 0, 1, 2 );

		}

		var faceIndex = [ 'a', 'b', 'c', 'd' ];

		for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

			face = this.faces[ f ];

			for ( i = 0; i < Math.min( face.vertexNormals.length, 3 ); i ++ ) {

				n.copy( face.vertexNormals[ i ] );

				vertexIndex = face[ faceIndex[ i ] ];

				t = tan1[ vertexIndex ];

				// Gram-Schmidt orthogonalize

				tmp.copy( t );
				tmp.sub( n.multiplyScalar( n.dot( t ) ) ).normalize();

				// Calculate handedness

				tmp2.crossVectors( face.vertexNormals[ i ], t );
				test = tmp2.dot( tan2[ vertexIndex ] );
				w = ( test < 0.0 ) ? - 1.0 : 1.0;

				face.vertexTangents[ i ] = new THREE.Vector4( tmp.x, tmp.y, tmp.z, w );

			}

		}

		this.hasTangents = true;

	},

	computeLineDistances: function () {

		var d = 0;
		var vertices = this.vertices;

		for ( var i = 0, il = vertices.length; i < il; i ++ ) {

			if ( i > 0 ) {

				d += vertices[ i ].distanceTo( vertices[ i - 1 ] );

			}

			this.lineDistances[ i ] = d;

		}

	},

	computeBoundingBox: function () {

		if ( this.boundingBox === null ) {

			this.boundingBox = new THREE.Box3();

		}

		this.boundingBox.setFromPoints( this.vertices );

	},

	computeBoundingSphere: function () {

		if ( this.boundingSphere === null ) {

			this.boundingSphere = new THREE.Sphere();

		}

		this.boundingSphere.setFromPoints( this.vertices );

	},

	merge: function ( geometry, matrix, materialIndexOffset ) {

		if ( geometry instanceof THREE.Geometry === false ) {

			THREE.error( 'THREE.Geometry.merge(): geometry not an instance of THREE.Geometry.', geometry );
			return;

		}

		var normalMatrix,
		vertexOffset = this.vertices.length,
		vertices1 = this.vertices,
		vertices2 = geometry.vertices,
		faces1 = this.faces,
		faces2 = geometry.faces,
		uvs1 = this.faceVertexUvs[ 0 ],
		uvs2 = geometry.faceVertexUvs[ 0 ];

		if ( materialIndexOffset === undefined ) materialIndexOffset = 0;

		if ( matrix !== undefined ) {

			normalMatrix = new THREE.Matrix3().getNormalMatrix( matrix );

		}

		// vertices

		for ( var i = 0, il = vertices2.length; i < il; i ++ ) {

			var vertex = vertices2[ i ];

			var vertexCopy = vertex.clone();

			if ( matrix !== undefined ) vertexCopy.applyMatrix4( matrix );

			vertices1.push( vertexCopy );

		}

		// faces

		for ( i = 0, il = faces2.length; i < il; i ++ ) {

			var face = faces2[ i ], faceCopy, normal, color,
			faceVertexNormals = face.vertexNormals,
			faceVertexColors = face.vertexColors;

			faceCopy = new THREE.Face3( face.a + vertexOffset, face.b + vertexOffset, face.c + vertexOffset );
			faceCopy.normal.copy( face.normal );

			if ( normalMatrix !== undefined ) {

				faceCopy.normal.applyMatrix3( normalMatrix ).normalize();

			}

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

				normal = faceVertexNormals[ j ].clone();

				if ( normalMatrix !== undefined ) {

					normal.applyMatrix3( normalMatrix ).normalize();

				}

				faceCopy.vertexNormals.push( normal );

			}

			faceCopy.color.copy( face.color );

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

				color = faceVertexColors[ j ];
				faceCopy.vertexColors.push( color.clone() );

			}

			faceCopy.materialIndex = face.materialIndex + materialIndexOffset;

			faces1.push( faceCopy );

		}

		// uvs

		for ( i = 0, il = uvs2.length; i < il; i ++ ) {

			var uv = uvs2[ i ], uvCopy = [];

			if ( uv === undefined ) {

				continue;

			}

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

				uvCopy.push( uv[ j ].clone() );

			}

			uvs1.push( uvCopy );

		}

	},

	mergeMesh: function ( mesh ) {

		if ( mesh instanceof THREE.Mesh === false ) {

			THREE.error( 'THREE.Geometry.mergeMesh(): mesh not an instance of THREE.Mesh.', mesh );
			return;

		}

		mesh.matrixAutoUpdate && mesh.updateMatrix();

		this.merge( mesh.geometry, mesh.matrix );

	},

	/*
	 * Checks for duplicate vertices with hashmap.
	 * Duplicated vertices are removed
	 * and faces' vertices are updated.
	 */

	mergeVertices: function () {

		var verticesMap = {}; // Hashmap for looking up vertice by position coordinates (and making sure they are unique)
		var unique = [], changes = [];

		var v, key;
		var precisionPoints = 4; // number of decimal points, eg. 4 for epsilon of 0.0001
		var precision = Math.pow( 10, precisionPoints );
		var i, il, face;
		var indices, j, jl;

		for ( i = 0, il = this.vertices.length; i < il; i ++ ) {

			v = this.vertices[ i ];
			key = Math.round( v.x * precision ) + '_' + Math.round( v.y * precision ) + '_' + Math.round( v.z * precision );

			if ( verticesMap[ key ] === undefined ) {

				verticesMap[ key ] = i;
				unique.push( this.vertices[ i ] );
				changes[ i ] = unique.length - 1;

			} else {

				//console.log('Duplicate vertex found. ', i, ' could be using ', verticesMap[key]);
				changes[ i ] = changes[ verticesMap[ key ] ];

			}

		};


		// if faces are completely degenerate after merging vertices, we
		// have to remove them from the geometry.
		var faceIndicesToRemove = [];

		for ( i = 0, il = this.faces.length; i < il; i ++ ) {

			face = this.faces[ i ];

			face.a = changes[ face.a ];
			face.b = changes[ face.b ];
			face.c = changes[ face.c ];

			indices = [ face.a, face.b, face.c ];

			var dupIndex = - 1;

			// if any duplicate vertices are found in a Face3
			// we have to remove the face as nothing can be saved
			for ( var n = 0; n < 3; n ++ ) {
				if ( indices[ n ] == indices[ ( n + 1 ) % 3 ] ) {

					dupIndex = n;
					faceIndicesToRemove.push( i );
					break;

				}
			}

		}

		for ( i = faceIndicesToRemove.length - 1; i >= 0; i -- ) {
			var idx = faceIndicesToRemove[ i ];

			this.faces.splice( idx, 1 );

			for ( j = 0, jl = this.faceVertexUvs.length; j < jl; j ++ ) {

				this.faceVertexUvs[ j ].splice( idx, 1 );

			}

		}

		// Use unique set of vertices

		var diff = this.vertices.length - unique.length;
		this.vertices = unique;
		return diff;

	},

	toJSON: function () {

		var output = {
			metadata: {
				version: 4.0,
				type: 'BufferGeometry',
				generator: 'BufferGeometryExporter'
			},
			uuid: this.uuid,
			type: this.type
		};

		if ( this.name !== "" ) output.name = this.name;

		if ( this.parameters !== undefined ) {

			var parameters = this.parameters;

			for ( var key in parameters ) {

				if ( parameters[ key ] !== undefined ) output[ key ] = parameters[ key ];

			}

			return output;

		}

		var vertices = [];

		for ( var i = 0; i < this.vertices.length; i ++ ) {

			var vertex = this.vertices[ i ];
			vertices.push( vertex.x, vertex.y, vertex.z );

		}

		var faces = [];
		var normals = [];
		var normalsHash = {};
		var colors = [];
		var colorsHash = {};
		var uvs = [];
		var uvsHash = {};

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

			var face = this.faces[ i ];

			var hasMaterial = false; // face.materialIndex !== undefined;
			var hasFaceUv = false; // deprecated
			var hasFaceVertexUv = this.faceVertexUvs[ 0 ][ i ] !== undefined;
			var hasFaceNormal = face.normal.length() > 0;
			var hasFaceVertexNormal = face.vertexNormals.length > 0;
			var hasFaceColor = face.color.r !== 1 || face.color.g !== 1 || face.color.b !== 1;
			var hasFaceVertexColor = face.vertexColors.length > 0;

			var faceType = 0;

			faceType = setBit( faceType, 0, 0 );
			faceType = setBit( faceType, 1, hasMaterial );
			faceType = setBit( faceType, 2, hasFaceUv );
			faceType = setBit( faceType, 3, hasFaceVertexUv );
			faceType = setBit( faceType, 4, hasFaceNormal );
			faceType = setBit( faceType, 5, hasFaceVertexNormal );
			faceType = setBit( faceType, 6, hasFaceColor );
			faceType = setBit( faceType, 7, hasFaceVertexColor );

			faces.push( faceType );
			faces.push( face.a, face.b, face.c );


			/*
			if ( hasMaterial ) {

				faces.push( face.materialIndex );

			}
			*/

			if ( hasFaceVertexUv ) {

				var faceVertexUvs = this.faceVertexUvs[ 0 ][ i ];

				faces.push(
					getUvIndex( faceVertexUvs[ 0 ] ),
					getUvIndex( faceVertexUvs[ 1 ] ),
					getUvIndex( faceVertexUvs[ 2 ] )
				);

			}

			if ( hasFaceNormal ) {

				faces.push( getNormalIndex( face.normal ) );

			}

			if ( hasFaceVertexNormal ) {

				var vertexNormals = face.vertexNormals;

				faces.push(
					getNormalIndex( vertexNormals[ 0 ] ),
					getNormalIndex( vertexNormals[ 1 ] ),
					getNormalIndex( vertexNormals[ 2 ] )
				);

			}

			if ( hasFaceColor ) {

				faces.push( getColorIndex( face.color ) );

			}

			if ( hasFaceVertexColor ) {

				var vertexColors = face.vertexColors;

				faces.push(
					getColorIndex( vertexColors[ 0 ] ),
					getColorIndex( vertexColors[ 1 ] ),
					getColorIndex( vertexColors[ 2 ] )
				);

			}

		}

		function setBit( value, position, enabled ) {

			return enabled ? value | ( 1 << position ) : value & ( ~ ( 1 << position) );

		}

		function getNormalIndex( normal ) {

			var hash = normal.x.toString() + normal.y.toString() + normal.z.toString();

			if ( normalsHash[ hash ] !== undefined ) {

				return normalsHash[ hash ];

			}

			normalsHash[ hash ] = normals.length / 3;
			normals.push( normal.x, normal.y, normal.z );

			return normalsHash[ hash ];

		}

		function getColorIndex( color ) {

			var hash = color.r.toString() + color.g.toString() + color.b.toString();

			if ( colorsHash[ hash ] !== undefined ) {

				return colorsHash[ hash ];

			}

			colorsHash[ hash ] = colors.length;
			colors.push( color.getHex() );

			return colorsHash[ hash ];

		}

		function getUvIndex( uv ) {

			var hash = uv.x.toString() + uv.y.toString();

			if ( uvsHash[ hash ] !== undefined ) {

				return uvsHash[ hash ];

			}

			uvsHash[ hash ] = uvs.length / 2;
			uvs.push( uv.x, uv.y );

			return uvsHash[ hash ];

		}

		output.data = {};

		output.data.vertices = vertices;
		output.data.normals = normals;
		if ( colors.length > 0 ) output.data.colors = colors;
		if ( uvs.length > 0 ) output.data.uvs = [ uvs ]; // temporal backward compatibility
		output.data.faces = faces;

		//

		return output;

	},

	clone: function () {

		var geometry = new THREE.Geometry();

		var vertices = this.vertices;

		for ( var i = 0, il = vertices.length; i < il; i ++ ) {

			geometry.vertices.push( vertices[ i ].clone() );

		}

		var faces = this.faces;

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

			geometry.faces.push( faces[ i ].clone() );

		}

		for ( var i = 0, il = this.faceVertexUvs.length; i < il; i ++ ) {

			var faceVertexUvs = this.faceVertexUvs[ i ];

			if ( geometry.faceVertexUvs[ i ] === undefined ) {

				geometry.faceVertexUvs[ i ] = [];

			}

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

				var uvs = faceVertexUvs[ j ], uvsCopy = [];

				for ( var k = 0, kl = uvs.length; k < kl; k ++ ) {

					var uv = uvs[ k ];

					uvsCopy.push( uv.clone() );

				}

				geometry.faceVertexUvs[ i ].push( uvsCopy );

			}

		}

		return geometry;

	},

	dispose: function () {

		this.dispatchEvent( { type: 'dispose' } );

	}

};

THREE.EventDispatcher.prototype.apply( THREE.Geometry.prototype );

THREE.GeometryIdCount = 0;