The_Caretaker writes...

I am also getting the MAX MAP NODES error.

I wanted to clear up what you said because I am still learning too. If detail brushes help cut down problems and increase FPS, then what's the point of having any structural brushes? Whats the difference if i just made everything detail?

Are structural cells ONLY to be used on outside brushes to seal in the portal cells inside?

The error usually means your map contains too much stuff...

There is an optimum.. too much detailed brushes will in actually reduce FPS..

If you make your whole map detailed, it will basically turn into one big cell, because every cell can see the other. Which means the engine will have to fully draw the entire map every time, thus lowering FPS. Structural brushes make it so the portals are blocked from eachothers view, thus make it so the engine doesn't have to draw everything.

And yes.. think of a house.. only leave the roof, outer walls and floor structural, but make everything inside detail (stairs, inner walls etc). When you then portal all the windows and doors you've made one big cell. When you're inside that cell, the cells you can't see from inside won't be drawn by the engine.