In one of my maps I have some areas surrounded by water canals. The brushes where players fight on land are 400 units tall from the map's floor. The main play area is 1000 x 1000 units and the 4 other areas are half that or smaller (and various sizes) but all are 400 units high and solid brushes right now. Everything is working out great geometry wise but I'm not sure if I should leave these huge brushes solid, make them hallow boxes with brushes, or make them hallow boxes with flat displacements. Or is there another option I could take here? 4 out of 5 of them have the appearance of dock shores at industrial loading docks so it's important I keep them square and flat on the sides to maintain that look. Later I do plan to clip the bottoms that can't be seen looking above into the water and raising the map's floor to match. Players cannot go into these canals so they won't see the bottom after I put in the water.