With a phys map everything just falls apart. On my map it breaks on ammount of damage like a crate in gmod.
The wall is lots of parts like a phys map but are conected like a breakable weld. They are house walls with a bunch of gibs fiting into the middle. When a rpg hits the wall the weld goes away and it will fall apart. When in game it is alot like bad company 2 and alot of fun to mess around with.
The map does not lag because only a small part of each wall breaks away. Just enouth room for a player to crouch threw. On certain places it all breaks but the edges and stufe. The map allso does not lag because it is noy very big or the map is split into multiple maps.
I can make it one big map with out lag but it would have to be sorta like a desert map with not that many buildings on it.
I made an example of what I mean.
If this is what you mean I can make maps with buildings that break sorta like in bad company 2.
I can easily do the same for the ground but that would only be possable in places I have made. It would only make explosion holes in the ground where I have placed them.