Smoke is not animated actually; though the game moves/switches it around (from density 2 to 3) and the final effect is decent.. I think. Frankly smoke wasn't "scheduled" for modification, I had to do it because otherwise the swarm alien would have been invisible in vanilla smoke. Layered density is still partly visible but, yeah, the final look of it is not as heavy as vanilla's (though vanilla smoke wasn't meant to be layered, IIRC it was flat like explosions.