I know that Looki created a circular mask shader (which is awesome btw), but I was wondering if there's a rectangular mask shader floating around somewhere. If a circular mask can be done I would assume that a rectangular mask could be created in a similar manner. I might try to create one myself if there isn't one out there already, but I have very limited programming experience and no experience with HLSL. Idk, I'm thinking it'd probably just have an input variable for the upper-left coordinate and one for the lower-right coordinate of the mask. Definitely gonna have to look into this more if one doesn't already exist.