Yup, another question that likely has little or no actual effect on things. Is there any reason to use hollow boxes with mitered corners instead of solid blocks, assuming that when the map is compiled you'll only see the outside faces anyways? I've noticed that people seem to do a lot of things with 8 or 16 thick walls around empty space, whereas my tendency is to create a bunch of solid brushes that I arrange as needed and then clip if it seems necessary. My understanding is that anything you can never see will get thrown away, so the only incidences where mitered corners will really come into play would be displacements. But as I understand displacements, you only need a common edge to sew two pieces together, making mitered corners more or less superfluous. At the same time I'm looking at my map and getting the sneaking feeling that I've gone and screwed up again, and will be replacing a lot of brushes.