Crambin rendering performance improvement

[AndrewRadev]

Rendering crambin is way too slow. Atomic blender is faster at rendering them, possibly because of this note in their documentation:

Thanks to the Blender specific method called instancing vertices structure, which is used to build an atomic structure, the speed of the loading and the general handling of an atomic structure inside the Blender 3D View is quite fast. Atomic structures with 1000 atoms and much more can be easily handled.

We should take a look at this "instancing" and see if it can speed things up.

[AndrewRadev]

Closed by #36