title: Obj renderer nlack with Three.js (on some laptop)
body: <p>I'm using Three.js to build a watch in 3D (with all the parts separately).
  Most of the parts are built from a SLT file, two of them (strap ans case) are built from a OBJ file converted by using Blender.</p>
  
  <p>All the part render perfectly on my laptop (on chrome Version 42.0.2311.135 m).
  But on a other laptop (same browsers same version), the case and the strap are diplayed without the texture (UV mapping). I've tried to juste set color but these elements still stay black.</p>
  
  <p>By the way, the same problem happends on mobile.</p>
  
  <p>Test color:
  var color = new THREE.Color(0xff0000);
  mesh.material.color = color;</p>
  
  <p>image on this link:
  <a href="https://github.com/mrdoob/three.js/issues/6526" rel="nofollow">https://github.com/mrdoob/three.js/issues/6526</a></p>
  
  <p>Ty :)</p>