SPOT LIGHT AS MASK

[tylor.larson]

I'm looking for a way to make a mask out of the area the light hits and object or objects it hits. The best I can do is a diffuse pass of the light compositing it with a shadow pass. I'm just trying to think of a better way of doing this. here is roughly what my scene looks like.

[Stephen.Blair]

You can separate out the light contribution with a light group AOV. Maybe you can make that into a mask?

[lee_griggs]

If it had UVs you could also try to bake it.