Possible, sure, and reasonably easy too. The hard part comes from optimizing such a process. I'm not sure how efficient engine triggers are (my guess is not very efficient), but to come up with a way to remove the zones from redundant bricks. Examples of redundant bricks are bricks under an overhang, in a wall, underwater, brick that look like they should cover a certain amount of area but actually don't, irregularly shaped objects (pine trees), and things of a similar nature