BinaryLoader.js

/**
 * @author alteredq / http://alteredqualia.com/
 */

THREE.BinaryLoader = function ( showStatus ) {

	THREE.Loader.call( this, showStatus );

};

THREE.BinaryLoader.prototype = Object.create( THREE.Loader.prototype );
THREE.BinaryLoader.prototype.constructor = THREE.BinaryLoader;

// Load models generated by slim OBJ converter with BINARY option (converter_obj_three_slim.py -t binary)
//  - binary models consist of two files: JS and BIN
//  - parameters
//		- url (required)
//		- callback (required)
//		- texturePath (optional: if not specified, textures will be assumed to be in the same folder as JS model file)
//		- binaryPath (optional: if not specified, binary file will be assumed to be in the same folder as JS model file)

THREE.BinaryLoader.prototype.load = function ( url, callback, texturePath, binaryPath ) {

	// todo: unify load API to for easier SceneLoader use

	texturePath = texturePath || this.extractUrlBase( url );
	binaryPath = binaryPath || this.extractUrlBase( url );

	var callbackProgress = this.showProgress ? THREE.Loader.prototype.updateProgress : undefined;

	this.onLoadStart();

	// #1 load JS part via web worker

	this.loadAjaxJSON( this, url, callback, texturePath, binaryPath, callbackProgress );

};

THREE.BinaryLoader.prototype.loadAjaxJSON = function ( context, url, callback, texturePath, binaryPath, callbackProgress ) {

	var xhr = new XMLHttpRequest();

	texturePath = texturePath && ( typeof texturePath === "string" ) ? texturePath : this.extractUrlBase( url );
	binaryPath = binaryPath && ( typeof binaryPath === "string" ) ? binaryPath : this.extractUrlBase( url );

	xhr.onreadystatechange = function () {

		if ( xhr.readyState == 4 ) {

			if ( xhr.status == 200 || xhr.status == 0 ) {

				var json = JSON.parse( xhr.responseText );
				context.loadAjaxBuffers( json, callback, binaryPath, texturePath, callbackProgress );

			} else {

				console.error( "THREE.BinaryLoader: Couldn't load [" + url + "] [" + xhr.status + "]" );

			}

		}

	};

	xhr.open( "GET", url, true );
	xhr.send( null );

};

THREE.BinaryLoader.prototype.loadAjaxBuffers = function ( json, callback, binaryPath, texturePath, callbackProgress ) {

	var scope = this;

	var xhr = new XMLHttpRequest(),
		url = binaryPath + json.buffers;

	xhr.addEventListener( 'load', function ( event ) {

		var buffer = xhr.response;

		if ( buffer === undefined ) {

			// IEWEBGL needs this
			buffer = ( new Uint8Array( xhr.responseBody ) ).buffer;

		}

		if ( buffer.byteLength == 0 ) {  // iOS and other XMLHttpRequest level 1

			var buffer = new ArrayBuffer( xhr.responseText.length );

			var bufView = new Uint8Array( buffer );

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

				bufView[ i ] = xhr.responseText.charCodeAt( i ) & 0xff;

			}

		}

		scope.createBinModel( buffer, callback, texturePath, json.materials );

	}, false );

	if ( callbackProgress !== undefined ) {

		xhr.addEventListener( 'progress', function ( event ) {

			if ( event.lengthComputable ) {

				callbackProgress( event );

			}

		}, false );

	}

	xhr.addEventListener( 'error', function ( event ) {

		console.error( "THREE.BinaryLoader: Couldn't load [" + url + "] [" + xhr.status + "]" );

	}, false );


	xhr.open( "GET", url, true );
	xhr.responseType = "arraybuffer";
	if ( xhr.overrideMimeType ) xhr.overrideMimeType( "text/plain; charset=x-user-defined" );
	xhr.send( null );

};

// Binary AJAX parser

THREE.BinaryLoader.prototype.createBinModel = function ( data, callback, texturePath, jsonMaterials ) {

	var Model = function ( texturePath ) {

		var scope = this,
			currentOffset = 0,
			md,
			normals = [],
			uvs = [],
			start_tri_flat, start_tri_smooth, start_tri_flat_uv, start_tri_smooth_uv,
			start_quad_flat, start_quad_smooth, start_quad_flat_uv, start_quad_smooth_uv,
			tri_size, quad_size,
			len_tri_flat, len_tri_smooth, len_tri_flat_uv, len_tri_smooth_uv,
			len_quad_flat, len_quad_smooth, len_quad_flat_uv, len_quad_smooth_uv;


		THREE.Geometry.call( this );

		md = parseMetaData( data, currentOffset );

		currentOffset += md.header_bytes;
/*
		md.vertex_index_bytes = Uint32Array.BYTES_PER_ELEMENT;
		md.material_index_bytes = Uint16Array.BYTES_PER_ELEMENT;
		md.normal_index_bytes = Uint32Array.BYTES_PER_ELEMENT;
		md.uv_index_bytes = Uint32Array.BYTES_PER_ELEMENT;
*/
		// buffers sizes

		tri_size =  md.vertex_index_bytes * 3 + md.material_index_bytes;
		quad_size = md.vertex_index_bytes * 4 + md.material_index_bytes;

		len_tri_flat      = md.ntri_flat      * ( tri_size );
		len_tri_smooth    = md.ntri_smooth    * ( tri_size + md.normal_index_bytes * 3 );
		len_tri_flat_uv   = md.ntri_flat_uv   * ( tri_size + md.uv_index_bytes * 3 );
		len_tri_smooth_uv = md.ntri_smooth_uv * ( tri_size + md.normal_index_bytes * 3 + md.uv_index_bytes * 3 );

		len_quad_flat      = md.nquad_flat      * ( quad_size );
		len_quad_smooth    = md.nquad_smooth    * ( quad_size + md.normal_index_bytes * 4 );
		len_quad_flat_uv   = md.nquad_flat_uv   * ( quad_size + md.uv_index_bytes * 4 );
		len_quad_smooth_uv = md.nquad_smooth_uv * ( quad_size + md.normal_index_bytes * 4 + md.uv_index_bytes * 4 );

		// read buffers

		currentOffset += init_vertices( currentOffset );

		currentOffset += init_normals( currentOffset );
		currentOffset += handlePadding( md.nnormals * 3 );

		currentOffset += init_uvs( currentOffset );

		start_tri_flat 		= currentOffset;
		start_tri_smooth    = start_tri_flat    + len_tri_flat    + handlePadding( md.ntri_flat * 2 );
		start_tri_flat_uv   = start_tri_smooth  + len_tri_smooth  + handlePadding( md.ntri_smooth * 2 );
		start_tri_smooth_uv = start_tri_flat_uv + len_tri_flat_uv + handlePadding( md.ntri_flat_uv * 2 );

		start_quad_flat     = start_tri_smooth_uv + len_tri_smooth_uv  + handlePadding( md.ntri_smooth_uv * 2 );
		start_quad_smooth   = start_quad_flat     + len_quad_flat	   + handlePadding( md.nquad_flat * 2 );
		start_quad_flat_uv  = start_quad_smooth   + len_quad_smooth    + handlePadding( md.nquad_smooth * 2 );
		start_quad_smooth_uv = start_quad_flat_uv  + len_quad_flat_uv   + handlePadding( md.nquad_flat_uv * 2 );

		// have to first process faces with uvs
		// so that face and uv indices match

		init_triangles_flat_uv( start_tri_flat_uv );
		init_triangles_smooth_uv( start_tri_smooth_uv );

		init_quads_flat_uv( start_quad_flat_uv );
		init_quads_smooth_uv( start_quad_smooth_uv );

		// now we can process untextured faces

		init_triangles_flat( start_tri_flat );
		init_triangles_smooth( start_tri_smooth );

		init_quads_flat( start_quad_flat );
		init_quads_smooth( start_quad_smooth );

		this.computeFaceNormals();

		function handlePadding( n ) {

			return ( n % 4 ) ? ( 4 - n % 4 ) : 0;

		};

		function parseMetaData( data, offset ) {

			var metaData = {

				'signature'               :parseString( data, offset,  12 ),
				'header_bytes'            :parseUChar8( data, offset + 12 ),

				'vertex_coordinate_bytes' :parseUChar8( data, offset + 13 ),
				'normal_coordinate_bytes' :parseUChar8( data, offset + 14 ),
				'uv_coordinate_bytes'     :parseUChar8( data, offset + 15 ),

				'vertex_index_bytes'      :parseUChar8( data, offset + 16 ),
				'normal_index_bytes'      :parseUChar8( data, offset + 17 ),
				'uv_index_bytes'          :parseUChar8( data, offset + 18 ),
				'material_index_bytes'    :parseUChar8( data, offset + 19 ),

				'nvertices'    :parseUInt32( data, offset + 20 ),
				'nnormals'     :parseUInt32( data, offset + 20 + 4 * 1 ),
				'nuvs'         :parseUInt32( data, offset + 20 + 4 * 2 ),

				'ntri_flat'      :parseUInt32( data, offset + 20 + 4 * 3 ),
				'ntri_smooth'    :parseUInt32( data, offset + 20 + 4 * 4 ),
				'ntri_flat_uv'   :parseUInt32( data, offset + 20 + 4 * 5 ),
				'ntri_smooth_uv' :parseUInt32( data, offset + 20 + 4 * 6 ),

				'nquad_flat'      :parseUInt32( data, offset + 20 + 4 * 7 ),
				'nquad_smooth'    :parseUInt32( data, offset + 20 + 4 * 8 ),
				'nquad_flat_uv'   :parseUInt32( data, offset + 20 + 4 * 9 ),
				'nquad_smooth_uv' :parseUInt32( data, offset + 20 + 4 * 10 )

			};
/*
			console.log( "signature: " + metaData.signature );

			console.log( "header_bytes: " + metaData.header_bytes );
			console.log( "vertex_coordinate_bytes: " + metaData.vertex_coordinate_bytes );
			console.log( "normal_coordinate_bytes: " + metaData.normal_coordinate_bytes );
			console.log( "uv_coordinate_bytes: " + metaData.uv_coordinate_bytes );

			console.log( "vertex_index_bytes: " + metaData.vertex_index_bytes );
			console.log( "normal_index_bytes: " + metaData.normal_index_bytes );
			console.log( "uv_index_bytes: " + metaData.uv_index_bytes );
			console.log( "material_index_bytes: " + metaData.material_index_bytes );

			console.log( "nvertices: " + metaData.nvertices );
			console.log( "nnormals: " + metaData.nnormals );
			console.log( "nuvs: " + metaData.nuvs );

			console.log( "ntri_flat: " + metaData.ntri_flat );
			console.log( "ntri_smooth: " + metaData.ntri_smooth );
			console.log( "ntri_flat_uv: " + metaData.ntri_flat_uv );
			console.log( "ntri_smooth_uv: " + metaData.ntri_smooth_uv );

			console.log( "nquad_flat: " + metaData.nquad_flat );
			console.log( "nquad_smooth: " + metaData.nquad_smooth );
			console.log( "nquad_flat_uv: " + metaData.nquad_flat_uv );
			console.log( "nquad_smooth_uv: " + metaData.nquad_smooth_uv );

			var total = metaData.header_bytes
					  + metaData.nvertices * metaData.vertex_coordinate_bytes * 3
					  + metaData.nnormals * metaData.normal_coordinate_bytes * 3
					  + metaData.nuvs * metaData.uv_coordinate_bytes * 2
					  + metaData.ntri_flat * ( metaData.vertex_index_bytes*3 + metaData.material_index_bytes )
					  + metaData.ntri_smooth * ( metaData.vertex_index_bytes*3 + metaData.material_index_bytes + metaData.normal_index_bytes*3 )
					  + metaData.ntri_flat_uv * ( metaData.vertex_index_bytes*3 + metaData.material_index_bytes + metaData.uv_index_bytes*3 )
					  + metaData.ntri_smooth_uv * ( metaData.vertex_index_bytes*3 + metaData.material_index_bytes + metaData.normal_index_bytes*3 + metaData.uv_index_bytes*3 )
					  + metaData.nquad_flat * ( metaData.vertex_index_bytes*4 + metaData.material_index_bytes )
					  + metaData.nquad_smooth * ( metaData.vertex_index_bytes*4 + metaData.material_index_bytes + metaData.normal_index_bytes*4 )
					  + metaData.nquad_flat_uv * ( metaData.vertex_index_bytes*4 + metaData.material_index_bytes + metaData.uv_index_bytes*4 )
					  + metaData.nquad_smooth_uv * ( metaData.vertex_index_bytes*4 + metaData.material_index_bytes + metaData.normal_index_bytes*4 + metaData.uv_index_bytes*4 );
			console.log( "total bytes: " + total );
*/

			return metaData;

		};

		function parseString( data, offset, length ) {

			var charArray = new Uint8Array( data, offset, length );

			var text = "";

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

				text += String.fromCharCode( charArray[ offset + i ] );

			}

			return text;

		};

		function parseUChar8( data, offset ) {

			var charArray = new Uint8Array( data, offset, 1 );

			return charArray[ 0 ];

		};

		function parseUInt32( data, offset ) {

			var intArray = new Uint32Array( data, offset, 1 );

			return intArray[ 0 ];

		};

		function init_vertices( start ) {

			var nElements = md.nvertices;

			var coordArray = new Float32Array( data, start, nElements * 3 );

			var i, x, y, z;

			for ( i = 0; i < nElements; i ++ ) {

				x = coordArray[ i * 3 ];
				y = coordArray[ i * 3 + 1 ];
				z = coordArray[ i * 3 + 2 ];

				scope.vertices.push( new THREE.Vector3( x, y, z ) );

			}

			return nElements * 3 * Float32Array.BYTES_PER_ELEMENT;

		};

		function init_normals( start ) {

			var nElements = md.nnormals;

			if ( nElements ) {

				var normalArray = new Int8Array( data, start, nElements * 3 );

				var i, x, y, z;

				for ( i = 0; i < nElements; i ++ ) {

					x = normalArray[ i * 3 ];
					y = normalArray[ i * 3 + 1 ];
					z = normalArray[ i * 3 + 2 ];

					normals.push( x / 127, y / 127, z / 127 );

				}

			}

			return nElements * 3 * Int8Array.BYTES_PER_ELEMENT;

		};

		function init_uvs( start ) {

			var nElements = md.nuvs;

			if ( nElements ) {

				var uvArray = new Float32Array( data, start, nElements * 2 );

				var i, u, v;

				for ( i = 0; i < nElements; i ++ ) {

					u = uvArray[ i * 2 ];
					v = uvArray[ i * 2 + 1 ];

					uvs.push( u, v );

				}

			}

			return nElements * 2 * Float32Array.BYTES_PER_ELEMENT;

		};

		function init_uvs3( nElements, offset ) {

			var i, uva, uvb, uvc, u1, u2, u3, v1, v2, v3;

			var uvIndexBuffer = new Uint32Array( data, offset, 3 * nElements );

			for ( i = 0; i < nElements; i ++ ) {

				uva = uvIndexBuffer[ i * 3 ];
				uvb = uvIndexBuffer[ i * 3 + 1 ];
				uvc = uvIndexBuffer[ i * 3 + 2 ];

				u1 = uvs[ uva * 2 ];
				v1 = uvs[ uva * 2 + 1 ];

				u2 = uvs[ uvb * 2 ];
				v2 = uvs[ uvb * 2 + 1 ];

				u3 = uvs[ uvc * 2 ];
				v3 = uvs[ uvc * 2 + 1 ];

				scope.faceVertexUvs[ 0 ].push( [
					new THREE.Vector2( u1, v1 ),
					new THREE.Vector2( u2, v2 ),
					new THREE.Vector2( u3, v3 )
				] );

			}

		};

		function init_uvs4( nElements, offset ) {

			var i, uva, uvb, uvc, uvd, u1, u2, u3, u4, v1, v2, v3, v4;

			var uvIndexBuffer = new Uint32Array( data, offset, 4 * nElements );

			for ( i = 0; i < nElements; i ++ ) {

				uva = uvIndexBuffer[ i * 4 ];
				uvb = uvIndexBuffer[ i * 4 + 1 ];
				uvc = uvIndexBuffer[ i * 4 + 2 ];
				uvd = uvIndexBuffer[ i * 4 + 3 ];

				u1 = uvs[ uva * 2 ];
				v1 = uvs[ uva * 2 + 1 ];

				u2 = uvs[ uvb * 2 ];
				v2 = uvs[ uvb * 2 + 1 ];

				u3 = uvs[ uvc * 2 ];
				v3 = uvs[ uvc * 2 + 1 ];

				u4 = uvs[ uvd * 2 ];
				v4 = uvs[ uvd * 2 + 1 ];

				scope.faceVertexUvs[ 0 ].push( [
					new THREE.Vector2( u1, v1 ),
					new THREE.Vector2( u2, v2 ),
					new THREE.Vector2( u4, v4 )
				] );

				scope.faceVertexUvs[ 0 ].push( [
					new THREE.Vector2( u2, v2 ),
					new THREE.Vector2( u3, v3 ),
					new THREE.Vector2( u4, v4 )
				] );

			}

		};

		function init_faces3_flat( nElements, offsetVertices, offsetMaterials ) {

			var i, a, b, c, m;

			var vertexIndexBuffer = new Uint32Array( data, offsetVertices, 3 * nElements );
			var materialIndexBuffer = new Uint16Array( data, offsetMaterials, nElements );

			for ( i = 0; i < nElements; i ++ ) {

				a = vertexIndexBuffer[ i * 3 ];
				b = vertexIndexBuffer[ i * 3 + 1 ];
				c = vertexIndexBuffer[ i * 3 + 2 ];

				m = materialIndexBuffer[ i ];

				scope.faces.push( new THREE.Face3( a, b, c, null, null, m ) );

			}

		};

		function init_faces4_flat( nElements, offsetVertices, offsetMaterials ) {

			var i, a, b, c, d, m;

			var vertexIndexBuffer = new Uint32Array( data, offsetVertices, 4 * nElements );
			var materialIndexBuffer = new Uint16Array( data, offsetMaterials, nElements );

			for ( i = 0; i < nElements; i ++ ) {

				a = vertexIndexBuffer[ i * 4 ];
				b = vertexIndexBuffer[ i * 4 + 1 ];
				c = vertexIndexBuffer[ i * 4 + 2 ];
				d = vertexIndexBuffer[ i * 4 + 3 ];

				m = materialIndexBuffer[ i ];

				scope.faces.push( new THREE.Face3( a, b, d, null, null, m ) );
				scope.faces.push( new THREE.Face3( b, c, d, null, null, m ) );

			}

		};

		function init_faces3_smooth( nElements, offsetVertices, offsetNormals, offsetMaterials ) {

			var i, a, b, c, m;
			var na, nb, nc;

			var vertexIndexBuffer = new Uint32Array( data, offsetVertices, 3 * nElements );
			var normalIndexBuffer = new Uint32Array( data, offsetNormals, 3 * nElements );
			var materialIndexBuffer = new Uint16Array( data, offsetMaterials, nElements );

			for ( i = 0; i < nElements; i ++ ) {

				a = vertexIndexBuffer[ i * 3 ];
				b = vertexIndexBuffer[ i * 3 + 1 ];
				c = vertexIndexBuffer[ i * 3 + 2 ];

				na = normalIndexBuffer[ i * 3 ];
				nb = normalIndexBuffer[ i * 3 + 1 ];
				nc = normalIndexBuffer[ i * 3 + 2 ];

				m = materialIndexBuffer[ i ];

				var nax = normals[ na * 3     ],
					nay = normals[ na * 3 + 1 ],
					naz = normals[ na * 3 + 2 ],

					nbx = normals[ nb * 3     ],
					nby = normals[ nb * 3 + 1 ],
					nbz = normals[ nb * 3 + 2 ],

					ncx = normals[ nc * 3     ],
					ncy = normals[ nc * 3 + 1 ],
					ncz = normals[ nc * 3 + 2 ];

				scope.faces.push( new THREE.Face3( a, b, c, [
					new THREE.Vector3( nax, nay, naz ),
					new THREE.Vector3( nbx, nby, nbz ),
					new THREE.Vector3( ncx, ncy, ncz )
				], null, m ) );

			}

		};

		function init_faces4_smooth( nElements, offsetVertices, offsetNormals, offsetMaterials ) {

			var i, a, b, c, d, m;
			var na, nb, nc, nd;

			var vertexIndexBuffer = new Uint32Array( data, offsetVertices, 4 * nElements );
			var normalIndexBuffer = new Uint32Array( data, offsetNormals, 4 * nElements );
			var materialIndexBuffer = new Uint16Array( data, offsetMaterials, nElements );

			for ( i = 0; i < nElements; i ++ ) {

				a = vertexIndexBuffer[ i * 4 ];
				b = vertexIndexBuffer[ i * 4 + 1 ];
				c = vertexIndexBuffer[ i * 4 + 2 ];
				d = vertexIndexBuffer[ i * 4 + 3 ];

				na = normalIndexBuffer[ i * 4 ];
				nb = normalIndexBuffer[ i * 4 + 1 ];
				nc = normalIndexBuffer[ i * 4 + 2 ];
				nd = normalIndexBuffer[ i * 4 + 3 ];

				m = materialIndexBuffer[ i ];

				var nax = normals[ na * 3     ],
					nay = normals[ na * 3 + 1 ],
					naz = normals[ na * 3 + 2 ],

					nbx = normals[ nb * 3     ],
					nby = normals[ nb * 3 + 1 ],
					nbz = normals[ nb * 3 + 2 ],

					ncx = normals[ nc * 3     ],
					ncy = normals[ nc * 3 + 1 ],
					ncz = normals[ nc * 3 + 2 ],

					ndx = normals[ nd * 3     ],
					ndy = normals[ nd * 3 + 1 ],
					ndz = normals[ nd * 3 + 2 ];

				scope.faces.push( new THREE.Face3( a, b, d, [
					new THREE.Vector3( nax, nay, naz ),
					new THREE.Vector3( nbx, nby, nbz ),
					new THREE.Vector3( ndx, ndy, ndz )
				], null, m ) );

				scope.faces.push( new THREE.Face3( b, c, d, [
					new THREE.Vector3( nbx, nby, nbz ),
					new THREE.Vector3( ncx, ncy, ncz ),
					new THREE.Vector3( ndx, ndy, ndz )
				], null, m ) );

			}

		};

		function init_triangles_flat( start ) {

			var nElements = md.ntri_flat;

			if ( nElements ) {

				var offsetMaterials = start + nElements * Uint32Array.BYTES_PER_ELEMENT * 3;
				init_faces3_flat( nElements, start, offsetMaterials );

			}

		};

		function init_triangles_flat_uv( start ) {

			var nElements = md.ntri_flat_uv;

			if ( nElements ) {

				var offsetUvs = start + nElements * Uint32Array.BYTES_PER_ELEMENT * 3;
				var offsetMaterials = offsetUvs + nElements * Uint32Array.BYTES_PER_ELEMENT * 3;

				init_faces3_flat( nElements, start, offsetMaterials );
				init_uvs3( nElements, offsetUvs );

			}

		};

		function init_triangles_smooth( start ) {

			var nElements = md.ntri_smooth;

			if ( nElements ) {

				var offsetNormals = start + nElements * Uint32Array.BYTES_PER_ELEMENT * 3;
				var offsetMaterials = offsetNormals + nElements * Uint32Array.BYTES_PER_ELEMENT * 3;

				init_faces3_smooth( nElements, start, offsetNormals, offsetMaterials );

			}

		};

		function init_triangles_smooth_uv( start ) {

			var nElements = md.ntri_smooth_uv;

			if ( nElements ) {

				var offsetNormals = start + nElements * Uint32Array.BYTES_PER_ELEMENT * 3;
				var offsetUvs = offsetNormals + nElements * Uint32Array.BYTES_PER_ELEMENT * 3;
				var offsetMaterials = offsetUvs + nElements * Uint32Array.BYTES_PER_ELEMENT * 3;

				init_faces3_smooth( nElements, start, offsetNormals, offsetMaterials );
				init_uvs3( nElements, offsetUvs );

			}

		};

		function init_quads_flat( start ) {

			var nElements = md.nquad_flat;

			if ( nElements ) {

				var offsetMaterials = start + nElements * Uint32Array.BYTES_PER_ELEMENT * 4;
				init_faces4_flat( nElements, start, offsetMaterials );

			}

		};

		function init_quads_flat_uv( start ) {

			var nElements = md.nquad_flat_uv;

			if ( nElements ) {

				var offsetUvs = start + nElements * Uint32Array.BYTES_PER_ELEMENT * 4;
				var offsetMaterials = offsetUvs + nElements * Uint32Array.BYTES_PER_ELEMENT * 4;

				init_faces4_flat( nElements, start, offsetMaterials );
				init_uvs4( nElements, offsetUvs );

			}

		};

		function init_quads_smooth( start ) {

			var nElements = md.nquad_smooth;

			if ( nElements ) {

				var offsetNormals = start + nElements * Uint32Array.BYTES_PER_ELEMENT * 4;
				var offsetMaterials = offsetNormals + nElements * Uint32Array.BYTES_PER_ELEMENT * 4;

				init_faces4_smooth( nElements, start, offsetNormals, offsetMaterials );

			}

		};

		function init_quads_smooth_uv( start ) {

			var nElements = md.nquad_smooth_uv;

			if ( nElements ) {

				var offsetNormals = start + nElements * Uint32Array.BYTES_PER_ELEMENT * 4;
				var offsetUvs = offsetNormals + nElements * Uint32Array.BYTES_PER_ELEMENT * 4;
				var offsetMaterials = offsetUvs + nElements * Uint32Array.BYTES_PER_ELEMENT * 4;

				init_faces4_smooth( nElements, start, offsetNormals, offsetMaterials );
				init_uvs4( nElements, offsetUvs );

			}

		};

	};

	Model.prototype = Object.create( THREE.Geometry.prototype );
	Model.prototype.constructor = Model;

	var geometry = new Model( texturePath );
	var materials = this.initMaterials( jsonMaterials, texturePath );

	if ( this.needsTangents( materials ) ) geometry.computeTangents();

	callback( geometry, materials );

};