I'm trying to create an object to knock out part of my scene. Escenitally what I want is a useBackground shader that looks at an image sequence to define it's border and not the whole object.
I've tried assigning the maps to the Matte Opacity, but that doesn't do it. I've tried setting the Matte Opacity mode to black hole, solid matte, and opacity gain, but to no avail.
Anyone know how to do this?