I have a mesh with some texture maps and then a light map, but I'd like to add another texture with parallax mapping on top of this for things like cracks and other details (so it's not just repetitive and flat). Is there an easy way to do this, outside of modifying the engine? I'm really not interested in making big changes to the engine until some time in the future because the engine is changing so rapidly (a good thing).
Thanks.
EDIT: If there's not a simple way I'm probably just going to write a shader to do this for me; is that the right way to go about it?