title: Three.js shadow issue
body: <p>I have a problem with my Three.js script. I have this scene, </p>
  
  <p><a href="http://jsfiddle.net/Rhtr2/7/" rel="nofollow">http://jsfiddle.net/Rhtr2/7/</a></p>
  
  <p>but as soon as I enable shadows (uncomment <code>spot.castShadow=true;</code>) it gets to this:</p>
  
  <p><a href="http://prntscr.com/jx7id" rel="nofollow">http://prntscr.com/jx7id</a></p>
  
  <p>I'm not sure where in my code is the problem, but I think it is something obviously.</p>
  
  <p>Btw: Other Three.js examples with shadow work, so it's not a generally problem of my gpu, and there is no console output.</p>