Sorry, I was a bit in a hurry…
Let’s say that in the first pass I have a building and a camera moving around - simple fly-trough animation. For the second pass I have a car, stopping in front of the building. I matte all other objects except the car. After that I bring the two beauty passes in Fusion and combine them. As you can guess, that way I won’t have the car’s reflection in the glass facade of the building. Is there a way to compose them ontop of the existing ones that were already there in the first beauty pass?
I know that I can achieve that if I make the car invisible to camera in the first pass but lets say that I didn’t know that there would be a car in the composite in the first place. Or I want the cars to be something that I would like to mess with later on when I know how they will look like.