I think this is a good explanation of ventilator. But then how do engines solve this problem like the ones from id software, or the JupiterX Engine (F.E.A.R.) or the one from the game "Chronicles of Riddick" or even the Lawmaker Engine? They all support CSG objects for big indoor worlds with shaders on level geometry.

But I really hope that the new render kernel will have a similar solution to support modern gpu's.