Today I added support for visualizing molecular surfaces to chemkit. You can see the commit here. The new class is called GraphicsMolecularSurfaceItem and it was added to the chemkit-graphics library.
The rendering is fast due to the underlying O(n log n) alpha-shape based surface algorithm. There is still room for improvement but the new code works well.
Here is a screenshot of the new molecular surface item on top of a guanine molecule:
So far only Van Der Waals and solvent accessible surfaces are supported. Solvent excluded surfaces are coming soon. Stay tuned.