-blocksize 0 0 0
Compiler wll only create vis portals where a structural brush creates one.
You can also use higher block sizes if you still want exterior portals. Default block size is 1024. I think you can get radient to show these blocks on the grid. I know Netradient does.
Also, if you are surrounding your map with a skybox and it has a lot of areas that you can’t get too, I try to fill those areas in with Caulk Brushes so the game doesn’t draw portals in areas that players can’t even go to.




