title: How to select a root Object3D using Raycaster
body: <p>I have a parent <code>Object3D</code> that has child meshes. How can I use <code>Raycaster</code> to select only the root parent object?</p>
  
  <p><a href="http://neftek.legko.ufanet.ru/MyWebGL/three.js/examples/webgl_interactive_draggablecubes.html" rel="nofollow">my example</a></p>