three.js/examples/js/loaders/VTKLoader.js

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

THREE.VTKLoader = function () {

	THREE.EventTarget.call( this );

};

THREE.VTKLoader.prototype = {

	constructor: THREE.VTKLoader,

	load: function ( url ) {

		var scope = this;
		var xhr = new XMLHttpRequest();

		xhr.onreadystatechange = function () {

			if ( xhr.readyState == 4 ) {

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

					scope.dispatchEvent( { type: 'complete', content: scope.parse( xhr.responseText ) } );

				} else {

					scope.dispatchEvent( { type: 'error', status: xhr.status } );

				}

			}

		};

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

	},

	parse: function ( data ) {

		var geometry = new THREE.Geometry();

		function vertex( x, y, z ) {

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

		}

		function face3( a, b, c ) {

			geometry.faces.push( new THREE.Face3( a, b, c ) );

		}

		function face4( a, b, c, d ) {

			geometry.faces.push( new THREE.Face4( a, b, c, d ) );

		}

		var pattern, result;

		// float float float

		pattern = /([\d|\.|\+|\-|e]+)[ ]+([\d|\.|\+|\-|e]+)[ ]+([\d|\.|\+|\-|e]+)/g;

		while ( ( result = pattern.exec( data ) ) != null ) {

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

			vertex( parseFloat( result[ 1 ] ), parseFloat( result[ 2 ] ), parseFloat( result[ 3 ] ) );

		}

		// 3 int int int

		pattern = /3[ ]+([\d]+)[ ]+([\d]+)[ ]+([\d]+)/g;

		while ( ( result = pattern.exec( data ) ) != null ) {

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

			face3( parseInt( result[ 1 ] ), parseInt( result[ 2 ] ), parseInt( result[ 3 ] ) );

		}

		// 4 int int int int

		pattern = /4[ ]+([\d]+)[ ]+([\d]+)[ ]+([\d]+)[ ]+([\d]+)/g;

		while ( ( result = pattern.exec( data ) ) != null ) {

			// ["4 1 2 3 4", "1", "2", "3", "4"]

			face4( parseInt( result[ 1 ] ), parseInt( result[ 2 ] ), parseInt( result[ 3 ] ), parseInt( result[ 4 ] ) );

		}

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

		return geometry;

	}

}