title: Three.js: show index number of each vertex in .obj file
body: <p>is there some helper method in THREE.js that allows one to see the number assigned to each vertex in a mesh loaded from an obj file? [<a href="http://paulbourke.net/dataformats/obj/box.obj" rel="nofollow noreferrer">minimal obj file</a>]</p>
  
  <p>I'm trying to rig up some bones inside a mesh, and want to position those bones between particular vertices, but don't know the vertex numbers yet. A little tool like this could be super helpful for this purpose.</p>
  
  <p>If there's no such method in THREE.js, I'll likely build a tool to this effect, but I wanted to save the time if I can. Any suggestions on where to look in THREE.js for this functionality would be greatly appreciated!</p>