title: Cinema 4D .obj files do not import correctly
body: <p>I have a parser written in ActionScript for importing .obj files.  I then render them in Molehill, which is awesome.  So far, I can import what I think are standard .obj files with vertices in the x, y, z order or the z, x, y order.  However, any .obj file exported from Cinema 4D just fails.<br>
  A tetrahedron, for example, doesn't even render a z component (the .obj file has indices with proper z-depth!).  A simple cube is missing half of the triangle faces.  I heard that Cinema 4D exports in the x, z, y order and so I tried to account for that as well, but no luck.  And really, the vertex order shouldn't result in missing polygons anyway.</p>
  
  <p>Has anyone imported Cinema 4D meshes from .obj files?  Is there some special trick?  Does Cinema 4D just ingnore the Wavefront .obj standards?  Thanks in advance for any help.</p>
  
  <p>Update:
  I believe the culprit is that the index data for the polygons is in a set of 4 instead of 3.  For example, I want this: 1/1 2/2 3/3 but not this: 1/1 2/2 3/3 4/4.  The Cinema 4D exports .obj files as the latter.  Anyway to address this problem on either the parsing end or the Cinema 4D exporting end?</p>
  
  <p>Update2:
  Now the index data is the way I want it, but still I cannot render properly.  The following is for a regular tetrahedron.  When I attempt to render it, only two of the four faces appear:</p>
  
  <pre><code># WaveFront *.obj file (generated by CINEMA 4D)
  g __
  v -70.571068 -100 122.232675
  v 141.142136 -100 0
  v 0 100 0
  v -70.571068 -100 -122.232675
  vt 0.666667 0 0
  vt 0.5 0.5 0
  vt 0 0 0
  vt 1 0 0
  vt 0 0.5 0
  vt 0.333333 1 0
  vt 1 1 0
  vt 0.666667 1 0
  vt 0.333333 0 0
  vt 0.75 0.933013 0
  f 4/10 2/5 1/2 
  f 1/1 3/8 4/9 
  f 2/4 3/7 1/1 
  f 4/9 3/6 2/3 
  </code></pre>
  
  <p>Is there anything odd about the above conent?  (It would help if I had an .obj file exported from another standard 3D software of the same tetrahedron)</p>