/vr/ - Retro Games

I wonder if GZDoom allows fragment shaders to access the color *behind* a sprite's pixel, so you can selectively choose a blend mode for a part of a sprite. If it can do that, it'd be possible to use a grayscale image (perhaps sprite rendered from 3D with a chrome surface like pic related) to make an invisible monster that displaces the pixels behind it like the invisibility effect in Predator.