/proc/create_all_lighting_overlays()
	for(var/zlevel = 1 to world.maxz)
		create_lighting_overlays_zlevel(zlevel)

/proc/create_lighting_overlays_zlevel(var/zlevel)
	ASSERT(zlevel)

	for(var/turf/T in block(locate(1, 1, zlevel), locate(world.maxx, world.maxy, zlevel)))
		if(T.dynamic_lighting)
			T.lighting_build_overlay()