I have a rectangle in photoshop that is transparent with a black outline, and I'd like to make a frame-by-frame animation of the rectangle filling with red. I know there are a few ways to do this but right now I'm doing it by creating a clipping mask and slowly bringing the clipping mask upwards, saving every time, and then playing the images back quickly.
However, I have a bit of an issue that stems from the fact that the rectangle has a transparent background.
and the issue is that, even though the red rectangle has a solid red background, the only part of the black rectangle that I'm moving the clipping mask over that gets filled is the black border.
I'd like something like this instead: https://imgur.com/a/ULHqcbX
but I can only achieve this effect when I actually fill in the background of the shape.
Any help here would be appreciated.