I have been working on a more flexible cel-shading toon shader for Blender. I have come up with a solution I feel is intuitive and good for live [GLSL] adjusting. I will eventually learn how to use drivers to make this even MORE efficient for production–that way you do not have to go to another window to adjust things. This is a simple 2-toned shader with optional specular highlight. The material requires only 1 sun-lamp to function
properly, although works well with other lights just the same. I simply use a white light with power of 1. It is easy to setup another light if you want finer control of the specular, but this seems generally adequate.
Here is the Suzanne:
Rendertime: 5.08s @ 1024x1024px
The .blend of the node setup here: Suzanne_Toon_FS
And here is a RANDOM Blendswap file:
Credit: Christian– http://www.blendswap.com/3D-models/weapons/sci-fi-granade-launcher/
This file had a very simple texture applied for which I had to adjust some things in the material nodes. The Toon_Freestyle .blend here: Grenade Launcher
Rendertime: 3.86s @ 720x512px
Same CC0 by me, credit the model if you use it.