You're right cal823, I don't know how it is done, but I've seen it in maps I've played.
The trigger may be useful yet Herio, for buildings people make... Also, anybody know why changing the game constant "Building Facing Angle (Degrees)" doesn't do anything? I changed it from 270 to 225, and new buildings I place, old ones I placed, and new ones I custom made all place the way they used to. Opening/closing the map didn't do anything either.