Lighting in my mod is part of the model's textures. The lighting is pre-rendered using mental ray and scanline renderers and applied as modulate layer on a duplicate of the mesh.
In other words it is equal to drawing accurate shadows on the texture, except they aren't drawn but computed.
It is not just a single model that does something, every model has its own unique shadow map or multiple ones if it is intended to be facing different directions or be in different light conditions.