Is there any description of the .map format used as input to q3map2? I'm somewhat confused by the fact that the 6 square surfaces of a box seem to be described by only 6 triangles -- shouldn't 6 square surfaces give 12 triangles?

I only had a glance at the .map format, but I don't think theyre triangles, every 3 vectors define the planes that make up a polygon.

Which is why objects in a map have to be convex: they are described as the intersection of four or more half-spaces (a half-space is the part of the space on one side of a plane).

This representation makes it BTW quite simple to decide if a point is inside or outside a brush.