I have two layers - layer A on top of layer B. I want to cut a hole through layer A on certain areas to see through to layer B. I have already done this by placing a distinctly colored sprite/object where I want the cutout(s), draw the layer to a surface, and then apply a shader that removes all pixels with that distinct color. Spoiler: Illustration However, I would like to achieve the same effect without using a surface. What I'm thinking is a shader that works sort of like a magic wand, that will select my distinct area(s) and then remove everything within that area but only on that layer. But I'm not even completely sure if this can be done with shaders? And if so, any idea where to start?