I am thinking about making some children's educational games, and one effect I'd like to achieve is for each frame to look like a 2D drawing in a comic or colloring book. I've been playing around with various settings and textures, and so far I get the closest to my goal if I use only ambient lighting and texture a black "outline" on the edge of each component (for example around the waist and ankles of a pair of pants). The main problem is somehow drawing an outline around the visible edges of each object. I'm thinking I could duplicate each object and texture one completely black and scale it up a tad, then use a pseudo-billboarding effect to always have it behind to other object. I thought I'd see if anyone here has some additional ideas I could try to improve the effect I'm after.