-
getting masks to work together.
So, here’s the deal. I’m masking out this door in order to show a different room in the BG. My only issue is that I need to mask both above and below his arm. I was going to use two mask and just key frame them as I go.

However, eventually he removes his arm from the frame and the top and bottom masks need to merge or overlap. My only problem is that I can’t get these masks to overlap without excluding some other part of the alternate mask. I’ve tried different layer modes, inverting the mask.
What am I missing here? I know it’s got to be some simple setting.
Thanks.