Took a detour from my turn-based system to play with some more programmable brush stuff. My goal was to give the walls the illusion of depth.
Turns out, there are a few different schemes for this, but I settled on one that is the easiest, I think. It only requires 16 unique tiles, while some require 32 or more.
Of course, the art is the very definition of 'gray boxing', but that can be improved later.