One of the goals of the Divine Consultants short film project has been to try and achieve a non-photorealistic look with our 3D assets. Something along the line of Telltale's Walking Dead, Wolf Among us, Borderlands and other stylized video games. A look inspired by realtime graphics that's pushed a little bit further with offline rendering and heavy compositing. Generally this means having line art in the character textures but also rendering some kind of cartoony outlines.
So far the most efficient way to do this is to use the normal pass; blurring the normal pass a slight amount and then comparing the difference to the original image generates lines where there's details. This black and white image can then be further adjusted and multiplied on top of the original image.
Here's how the passes look like:
Character's beauty pass |
Normal pass |
Generated outlines |