Makings of a good filter. First impressions:
– Illumination currently makes it look like it is over- or unevenly inflated. Something between this and the render in Gmic for animation - #13 by David_Tschumperle might be an improvement.
– The sharp edges and their illumination break the illusion of 3d-ness.
Source: Wikipedia
Source: My Little Day
When this is done, could we have I chocolate filter? 
Source: Wikipedia
(This might be a joke. Secretly, I am hoping for the illumination of not just empty shapes but ones with relief as well, like the ridges on the chocolate piece.)