thanks for the comments people! I'm currently working on a method of making the lighting follow the contour of the brushstrokes so that the shading will seem painted rather than smooth. Here's what I've got so far:





I'm mapping the paint texture (which is grayscale) at a bright setting as the color gain of the ramp, and a nearly black version of the texture as the color offset. I'm also sticking it in the diffuse channel of the shading ref preveously mentioned, which is the main component of this technique.