that is a very nice looking rendering. Do I understand correctly that it was done in MoI? At least you show it in the MoI viewport.
Unfortunately I don't understand the following:
Here's a little shader test, using no lights.
- Point incidence gradient to create the cell diffuse look
- camera incidence gradient for the rim light (self illumination)
- multiply by an occlusion as self-illumination.
Sorry for the confusion, it's actually a 'fake' screen.
It's rendered in Modo, using easy (fast) computing method : only gradients and an ambient occlusion. (no raytrace shadow, no GI, etc)