Back in a college graphics class I had a lot of fun, and some lucky success, with roughly simulating watercolors with GL shaders. I kept several textures that r

Back in a college graphics class I had a lot of fun, and some lucky success, with roughly simulating watercolors with GL shaders. I kept several textures that represented the paper, it's wetness, and the paint. The shader would calculate new states for each based on the previous state, time and user input. The cool thing was that you could watch the paint disperse in real time and could add things like gravity to cause it to drip down the page. It wasn't physically that accurate, but it looked pretty good and was super fun to hack on. If only I could find the source :(