three.js/examples/js/loaders/OBJLoader.js

/**
 * @author mrdoob / http://mrdoob.com/
 */

THREE.OBJLoader = function ( manager ) {

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

};

THREE.OBJLoader.prototype = {

	constructor: THREE.OBJLoader,

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

		var scope = this;

		var loader = new THREE.XHRLoader( scope.manager );
		loader.setCrossOrigin( this.crossOrigin );
		loader.load( url, function ( text ) {

			onLoad( scope.parse( text ) );

		} );

	},

	parse: function ( text ) {

		// fixes

		text = text.replace( /\ \\\r\n/g, '' ); // rhino adds ' \\r\n' some times.

		var replacement = '/f$1$2$4\n/f$2$3$4'; // quads to tris
		text = text.replace( /f( +\d+)( +\d+)( +\d+)( +\d+)/g, replacement );
		text = text.replace( /f( +\d+\/\d+)( +\d+\/\d+)( +\d+\/\d+)( +\d+\/\d+)/g, replacement );
		text = text.replace( /f( +\d+\/\d+\/\d+)( +\d+\/\d+\/\d+)( +\d+\/\d+\/\d+)( +\d+\/\d+\/\d+)/g, replacement );
		text = text.replace( /f( +\d+\/\/\d+)( +\d+\/\/\d+)( +\d+\/\/\d+)( +\d+\/\/\d+)/g, replacement );

		//

		function vector( x, y, z ) {

			return new THREE.Vector3( x, y, z );

		}

		function uv( u, v ) {

			return new THREE.Vector2( u, v );

		}

		function face3( a, b, c, normals ) {

			return new THREE.Face3( a, b, c, normals );

		}

		var object = new THREE.Object3D();
		var geometry, material, mesh;

		// create mesh if no objects in text

		if ( /^o /gm.test( text ) === false ) {

			geometry = new THREE.Geometry();
			material = new THREE.MeshLambertMaterial();
			mesh = new THREE.Mesh( geometry, material );
			object.add( mesh );

		}

		var vertices = [];
		var verticesCount = 0;
		var normals = [];
		var uvs = [];

		// v float float float

		var vertex_pattern = /v( +[\d|\.|\+|\-|e]+)( +[\d|\.|\+|\-|e]+)( +[\d|\.|\+|\-|e]+)/;

		// vn float float float

		var normal_pattern = /vn( +[\d|\.|\+|\-|e]+)( +[\d|\.|\+|\-|e]+)( +[\d|\.|\+|\-|e]+)/;

		// vt float float

		var uv_pattern = /vt( +[\d|\.|\+|\-|e]+)( +[\d|\.|\+|\-|e]+)/;

		// f vertex vertex vertex

		var face_pattern1 = /f( +\d+)( +\d+)( +\d+)/;

		// f vertex/uv vertex/uv vertex/uv

		var face_pattern2 = /f( +(\d+)\/(\d+))( +(\d+)\/(\d+))( +(\d+)\/(\d+))/;

		// f vertex/uv/normal vertex/uv/normal vertex/uv/normal

		var face_pattern3 = /f( +(\d+)\/(\d+)\/(\d+))( +(\d+)\/(\d+)\/(\d+))( +(\d+)\/(\d+)\/(\d+))/;

		// f vertex//normal vertex//normal vertex//normal

		var face_pattern4 = /f( +(\d+)\/\/(\d+))( +(\d+)\/\/(\d+))( +(\d+)\/\/(\d+))/;

		//

		var lines = text.split( '\n' );

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

			var line = lines[ i ];
			line = line.trim();

			var result;

			if ( line.length === 0 || line.charAt( 0 ) === '#' ) {

				continue;

			} else if ( ( result = vertex_pattern.exec( line ) ) !== null ) {

				// ["v 1.0 2.0 3.0", "1.0", "2.0", "3.0"]

				vertices.push( vector(
					parseFloat( result[ 1 ] ),
					parseFloat( result[ 2 ] ),
					parseFloat( result[ 3 ] )
				) );

			} else if ( ( result = normal_pattern.exec( line ) ) !== null ) {

				// ["vn 1.0 2.0 3.0", "1.0", "2.0", "3.0"]

				normals.push( vector(
					parseFloat( result[ 1 ] ),
					parseFloat( result[ 2 ] ),
					parseFloat( result[ 3 ] )
				) );

			} else if ( ( result = uv_pattern.exec( line ) ) !== null ) {

				// ["vt 0.1 0.2", "0.1", "0.2"]

				uvs.push( uv(
					parseFloat( result[ 1 ] ),
					parseFloat( result[ 2 ] )
				) );

			} else if ( ( result = face_pattern1.exec( line ) ) !== null ) {

				// ["f 1 2 3", "1", "2", "3"]

				geometry.vertices.push(
					vertices[ parseInt( result[ 1 ] ) - 1 ],
					vertices[ parseInt( result[ 2 ] ) - 1 ],
					vertices[ parseInt( result[ 3 ] ) - 1 ]
				);

				geometry.faces.push( face3(
					verticesCount ++,
					verticesCount ++,
					verticesCount ++
				) );

			} else if ( ( result = face_pattern2.exec( line ) ) !== null ) {

				// ["f 1/1 2/2 3/3", " 1/1", "1", "1", " 2/2", "2", "2", " 3/3", "3", "3"]

				geometry.vertices.push(
					vertices[ parseInt( result[ 2 ] ) - 1 ],
					vertices[ parseInt( result[ 5 ] ) - 1 ],
					vertices[ parseInt( result[ 8 ] ) - 1 ]
				);

				geometry.faces.push( face3(
					verticesCount ++,
					verticesCount ++,
					verticesCount ++
				) );

				geometry.faceVertexUvs[ 0 ].push( [
					uvs[ parseInt( result[ 3 ] ) - 1 ],
					uvs[ parseInt( result[ 6 ] ) - 1 ],
					uvs[ parseInt( result[ 9 ] ) - 1 ]
				] );

			} else if ( ( result = face_pattern3.exec( line ) ) !== null ) {

				// ["f 1/1/1 2/2/2 3/3/3", " 1/1/1", "1", "1", "1", " 2/2/2", "2", "2", "2", " 3/3/3", "3", "3", "3"]

				geometry.vertices.push(
					vertices[ parseInt( result[ 2 ] ) - 1 ],
					vertices[ parseInt( result[ 6 ] ) - 1 ],
					vertices[ parseInt( result[ 10 ] ) - 1 ]
				);

				geometry.faces.push( face3(
					verticesCount ++,
					verticesCount ++,
					verticesCount ++,
					[
						normals[ parseInt( result[ 4 ] ) - 1 ],
						normals[ parseInt( result[ 8 ] ) - 1 ],
						normals[ parseInt( result[ 12 ] ) - 1 ]
					]
				) );

				geometry.faceVertexUvs[ 0 ].push( [
					uvs[ parseInt( result[ 3 ] ) - 1 ],
					uvs[ parseInt( result[ 7 ] ) - 1 ],
					uvs[ parseInt( result[ 11 ] ) - 1 ]
				] );

			} else if ( ( result = face_pattern4.exec( line ) ) !== null ) {

				// ["f 1//1 2//2 3//3", " 1//1", "1", "1", " 2//2", "2", "2", " 3//3", "3", "3"]

				geometry.vertices.push(
					vertices[ parseInt( result[ 2 ] ) - 1 ],
					vertices[ parseInt( result[ 5 ] ) - 1 ],
					vertices[ parseInt( result[ 8 ] ) - 1 ]
				);

				geometry.faces.push( face3(
					verticesCount ++,
					verticesCount ++,
					verticesCount ++,
					[
						normals[ parseInt( result[ 3 ] ) - 1 ],
						normals[ parseInt( result[ 6 ] ) - 1 ],
						normals[ parseInt( result[ 9 ] ) - 1 ]
					]
				) );

			} else if ( /^o /.test( line ) ) {

				// object

				geometry = new THREE.Geometry();
				material = new THREE.MeshLambertMaterial();

				mesh = new THREE.Mesh( geometry, material );
				mesh.name = line.substring( 2 ).trim();
				object.add( mesh );

				verticesCount = 0;

			} else if ( /^g /.test( line ) ) {

				// group

			} else if ( /^usemtl /.test( line ) ) {

				// material

				material.name = line.substring( 7 ).trim();

			} else if ( /^mtllib /.test( line ) ) {

				// mtl file

			} else if ( /^s /.test( line ) ) {

				// smooth shading

			} else {

				// console.log( "THREE.OBJLoader: Unhandled line " + line );

			}

		}

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

			var geometry = object.children[ i ].geometry;

			geometry.computeCentroids();
			geometry.computeFaceNormals();
			geometry.computeBoundingSphere();

		}

		return object;

	}

};