text: self.importScripts( '../../../build/three.js' );
  
  self.onmessage = function ( message ) {
  
  	var data = message.data;
  	init( data.drawingSurface, data.width, data.height, data.pixelRatio );
  
  };
  
  var camera, scene, renderer, mesh, clock;
  
  function init( offscreen, width, height, pixelRatio ) {
  
  	camera = new THREE.PerspectiveCamera( 70, width / height, 1, 1000 );
  	camera.position.z = 400;
  
  	scene = new THREE.Scene();
  
  	clock = new THREE.Clock();
  
  	// we don't use ImageLoader since it has a DOM dependency (HTML5 image element)
  
  	var loader = new THREE.ImageBitmapLoader();
  
  	loader.load( '../../textures/crate.gif', function ( imageBitmap ) {
  
  		var texture = new THREE.CanvasTexture( imageBitmap );
  		var material = new THREE.MeshBasicMaterial( { map: texture } );
  		var geometry = new THREE.BoxBufferGeometry( 200, 200, 200 );
  		mesh = new THREE.Mesh( geometry, material );
  		scene.add( mesh );
  
  		animate();
  
  	}, null, function () {
  
  		// Workaround for Firefox
  		// https://bugzilla.mozilla.org/show_bug.cgi?id=1335594
  
  		var material = new THREE.MeshBasicMaterial( { color: 0x00ff00 } );
  		var geometry = new THREE.BoxBufferGeometry( 200, 200, 200 );
  		mesh = new THREE.Mesh( geometry, material );
  		scene.add( mesh );
  
  		animate();
  
  	} );
  
  	renderer = new THREE.WebGLRenderer( { antialias: true, canvas: offscreen } );
  	renderer.setPixelRatio( pixelRatio );
  	renderer.setSize( width, height, false );
  
  }
  
  function animate() {
  
  	var delta = clock.getDelta();
  
  	mesh.rotation.x += delta * 0.2;
  	mesh.rotation.y += delta * 0.5;
  
  	renderer.render( scene, camera );
  
  	if ( self.requestAnimationFrame ) {
  
  		self.requestAnimationFrame( animate );
  
  	} else if ( renderer.context.commit ) {
  
  		// Deprecated
  
  		renderer.context.commit().then( animate );
  
  	}
  
  }
  