I'm working on a scene where the fog changes from bright to dark over time and I would like to composite the fog if possible by rendering the volumetric and component as render elements. But I have not found a better way to composite the fog than having the layer additive. the volumetric doesn't seem to have an alpha. How can I composite the volumetric and get it looking exactly the same as in the beauty pass no matter what color the fog has? Any tips?