Do a quick read on how visportals work and/or how to use the hint brush texture. Glass shouldn’t cause many problems unless your brushes are either A) Concave, all brushes MUST be convex. Use multiple brushes to create a concave shape. Or B) You have two verticies on a horziontal line between two corners, as in ±--------±--------+
Weld the third vertex to form a single line ±--------------+
It might not hurt to turn your glass into func_detail entities, if they aren’t already to see if that allieviates some problems.
Vertex manipulation in Hammer can be a cruel mistress at times. In most cases I generally just layer brushes up to make the shape I want rather than carving and vertex editing a single brush. The end result SHOULD be the same, but sometimes might result in strange brush cutting.
