I have a scene with some glass windows that show through to the World background. For now, the world is just a flat color. But in post, a different background will be photoshopped in. So I need the world to be alpha.
However, the world is also a light source in the scene. I want it to be able to light the scene with its color (thus tinting the scene overall), but that causes it to tint the glass of the windows too much. This will look wrong when the real background image is added in post.
I want the windows to let the light in, and to pick up highlights and reflections from lights and objects in the room, but not to get colored by the world lighting. I'm guessing there's some combination of light path settings used on the glass or world to do this, but I can't figure it out.
Is this possible?