Move materials to instances, so we can change them on a per-instance basis instead of globally for every instance of a given object.
Global overrides can still be done by placing the "materials" array/object at the root of the object instead of in each instance.
Also merge in the incomplete glTF stuff so I can work on it in master directly.
Move materials to instances, so we can change them on a per-instance basis instead of globally for every instance of a given object. Global overrides can still be done by placing the "materials" array/object at the root of the object instead of in each instance. Also merge in the incomplete glTF stuff so I can work on it in master directly.