title: threejs raycast incorrect after group rotate
body: <p>I take all mesh adding to a Three.group</p>
  
  <p>when I rotation the Three.group it's really do it by view but inner mesh's value are incorrect (such as rotation &amp; position etc...)</p>
  
  <p>so after rotate to do raycast get incorrect result(actually befor rotate value   )</p>
  
  <p>see code: </p>
  
  <pre><code>init{       
    _group = new THREE.Group();
     _scene.add(_group);
  
    _group.add(mesh1);
    _group.add(mesh2);
    _group.add(mesh.....);
   }
  
  rotateClick{
  
    _group.rotateX(90 * Math.PI / 180)
  }
  
  dbClick{
  
     var intersections = rayCaster.intersectObjects( _group.children);
  }
  </code></pre>