NPR Paint Shading


I have been experimenting with non-physical-rendering trying to get a impressionism painting look. Most of it was rubbish post processing, it looked bad whenever something moved. The only technique I liked was using a lit sphere - a sphere texture image that worked as a look up for shading using the view space normal, but the problem with that was that the lit sphere texture is view dependant. If the camera moved the light would rotate with it. Bummer.
So I had this idea to use an actual sphere with the (diffuse) light/shading baked into its texture, the sphere model would be rendered in an offscreen buffer and the output of that buffer would be used as a lit-sphere texture. The model-sphere just needs to rotate with the camera.
I’m not sure if that’s a very good idea, but check out the video, screen and run the demo - I think it looks kind of cool.
Download demo: (233.5 KB)