Is there a way to create a mask of an object limited to the camera view ONLY. As an example ... lets say you have a box with an object placed in it. The object sticks out the top of the open box, it could be a board or what ever. If I render out alpha channels for both objects the masks are of the complete object. Can I also create a alpha of only what the camera sees sticking out of the box and not include what is hidden inside the box.