mrdoob/three.js — pull request #4422 by pehrlich (2014-02-12 00:48:38+00:00)
Title: Add error for invalid skinIndices or skinWeights import data lengths. Fixes #4421

I use `geometry.bones.length > 0` to determine whether the mesh is intended to be skinned or not. Perhaps there should instead be a field in the json itself, allowing this line in the javascript to be scrapped: `material.skinning = true`.

But that is outside the scope of this PR.