I'm looking to add collisions to a surface which simulate the rough surface of a wall. Since subdividing for a displacement modifier would be a little too taxing on my computer, I was wondering if there was a way to program collision vector modifiers directly into an applied texture, similar to the texture force field but without adding energy to the particles. I want them to bounce off in slightly changed courses depending on the shading of the texture as if it was a rough surface. I know this seems a little extreme but its essential that we're able to do this.
If its not possible, then is there a way to randomize the direction of a particle upon collision based on an equation (Cosine distribution of particles)?