I've recently been toying with the Gooch et al. (1998) non-photorealistic lighting model. Unfortunately, the nature of the project does not permit me to post any of the "real" results quite yet, but some of the tests have a nice look to them all on their own.

My implementation takes a normal map and colour map, e.g.:

This is the result from those inputs:

For the first time since 2008, I have a new demo reel. This one finally has a quick breakdown of Blind Spot, and a lot of awesome shots from The Borgias.