canassa/three.js — comment on commit ace704d5681f491c82c477ab1ccb71f726e9eb8a
File:  line 0
By canassa:

But Three.js has supports for only normal maps, am I right? The JSON loader wasn't doing anything with the old "mapBump" material property but was looking for a "mapNormal" which was never found. Since the loader doesn't loads bump maps maybe its safe to assume that every map is a normal map.