bump mapping with baked light

Question

I'm creating an opengl-es 2.0 app of a car/garage scene. The textures have the lighting baked right in. I'm now ready to try a little bump/normal mapping for some added details, however the shaders I've come across all work with light direction and light vectors. Is it possible to do the bump mapping with lighting baked in?

Answer 1

From Wikipedia:

Bump mapping is a technique in computer graphics for simulating bumps and wrinkles on the surface of an object. This is achieved by perturbing the surface normals of the object and using the perturbed normal during lighting calculations. The result is an apparently bumpy surface rather than a smooth surface although the surface of the underlying object is not actually changed.

I'm pretty new to computer graphics, but I would think that vector-based lighting would be necessary for bump mapping. With baked lighting (as I understand it) there would be no lighting calculations to perturb.

You could also check out this thread on the Unity forums. The gist of it is that you might be able to use a combination of baked lighting and vector-based lighting to achieve what you want.