title: Indices issue in Blender->three.js exporting
body: <p>I'm trying to export my 3d model from blender to three.js using the json extension. However, I bet there is a problem with the exporting script: it looks like the indices are messed up, thus webgl can't read them and displays no geometry.
  To be specific, here's the indices for a simple cube:</p>
  
  <pre><code>[41,0,1,2,3,0,1,2,3,0,1,2,3,41,4,7,6,5,4,5,6,7,4,5,6,7,41,0,4,5,1,0,4,7,8,0,4,7,1,41,1,5,6,2,1,9,6,2,1,7,6,2,41,2,6,7,3,2,6,5,3,2,6,5,3,41,4,0,3,7,4,0,3,5,4,0,3,5]
  </code></pre>
  
  <p>The numbers are obviously exceeding the real index count, which ranges in 0-7.</p>
  
  <p>Just in case, here's the code used for parsing:</p>
  
  <pre><code>function loadTeapot() {
      var request = new XMLHttpRequest();
      request.open("GET", "teapotprova.json");
      request.onreadystatechange = function () {
          if (request.readyState == 4) {
              handleLoadedTeapot(JSON.parse(request.responseText));
          }
      }
      request.send();
  }
  </code></pre>
  
  <p>Everyone else having the same issue?</p>
  
  <p>*edit: the script i'm using for json exporting is <a href="https://github.com/mrdoob/three.js/tree/master/utils/exporters/blender" rel="nofollow">threejs blender export</a></p>