Background: I have a projection on a plane that's been tracked with mocha in a comp (#2) which I Quad Warp to fill the screen. This is then used on another comp (#1) as the basis for another plane (using same tracking data) to clone over something in that scene at a different location, but following the same camera that produced the original Projected section.
Think: using something like Clone Stamp, but from any plane in a scene to any other plane in a scene, with a moving camera.
To feather the edges, I want to use a Mask on that projected plane in comp (#2), but it appears Masks are done before Effects, so I can't mask the Quad Warped image. I can mask the original projection before the Quad Warp, but it's a lot smaller and fiddlier (it's a section of distant ground in this instance) but the mask that then appears on the Quad Warped version is egg shaped, rather than round, due to perspective; and I certainly can't do any free form masking accurately.
So, to get the Mask I wanted on everything after it had been flattened, I dropped a Grade Layer on top of everything and applied the Mask to that. But nothing happened. At all.
Just to check, I put a Brightness and Contrast Effect on the Grade Layer and turned up the brightness. There was a hole in the brightness where the mask had cut it out - but the original image was still there in the hole.
Why isn't the Grade Layer flattening everything below it and why can't I mask the image itself, but can mask the Effects?
I even dropped the Clone Stamp Effect on the Grade Layer and managed to get that to work within the Quad Warped Image, just as if it was a normal flat plane (which it effectively is), but not the Mask.
I then tried just grabbing the whole lot and making it a composite (even though it already is) so I'd just be left with the single Quad Warped flat image as a one layer composite and try applying the mask to that, but it wouldn't let me! When I selected everything and Right Clicked, the Make Composite Shot option was not available, so I'm a bit stumped.
If Grade Layers don't flatten everything below them(!) and I can't make everything into a Composite to really(?) flatten it, what are my options?