what is the VIS-project doing? Because if you have a large map and you are running the BSP-project and you are at the 2e black window than it’s during 2 hours or something.
If have discovered that if you click the 2 black window away (X) than he skip the 2e window and go to the 3e. And if i run the map he works fine.
So why shall i not click away the 2e window. Wy VIS ?
Please do a search first… It’s been explained many times before.
Anway, in short, VIS is used to optimize FPS. It will work out what parts of the map should be drawn and what parts should not be drawn.
For example, if you are in fueldump at the first allied spawn, the fuel depot at the end of the map is miles away and cannot be seen, and thus is not drawn. But that only works if you ran a VIS compile. If you didn’t run the VIS compile the game will draw the whole map all the time, meaning you get very bad performance.
Judging by the compile time I’d say it already got bad performance but yeah read up on the subject on how to optimise your maps and you be cutting the compile time soon enough and boosting performance immensely.
The vis stage (visibility) creates the portals. If you have lots of structural brushes in your map, then there will be lots of portals (= takes longer time to compile).
I suggest that you search this forum and Google the net for information about: a) the three stages of compiling, bsp, vis and light, b) the two types of brushes (detailed and structural). This will aid you in your mapping.
Whenever you createa brush, it will be structural by default. I think you have to turn a lot of your brushes into detailed ones, to reduce the compiling time for stage 2 (vis).
Not entirely right, I believe.
As far as I know, portals are generated when you do a BSP -meta compile. After this stage, you can use the Portal view plug-in. (A good way to see where you have a lot of BSP splits.) Structural brushes create portals, like you said.
The VIS stage then takes all these portals and calculates what other portals can be seen when you are in one certain portal, and it does this for every portal.
anyway, try to make as much as possible brushes to detail. (but careful! still use structural as the base of the stuff.). that incredibly shortened my compile time.
My idea is to make the whole map… everything… by default DETAILED… than when you have it allready… you do the VIS-blocking which would be adding structural brushes… and makeing big rooms
(someone said somewhere… “even tho you think that goldrush is a nice open map… it is actually a few rooms connected to eachother…”)
Than if still needed add Hint Brushes 
This way you get decent performance and good Compile time… espetially for testing (while building the map) this is really SUGGESTED, cause it cuts the VIS compilation to one simple room (you tho should make it - a big STRUCTURAL room) around the whole map.
ChearZ, aburn
I usually use make main visible wall brushes structural for vis instead of an extra shell of structural brushes.
Nib made a really great tutorial about detail/structural/hint brushes a long time ago… http://nibsworld.com/rtcw/tutorial_detail_and_hint_brushes_part1.shtml