my map is taking shape quite nicely and has a nice feel to it now all the routes are opened up but by creating the rooms I seem to have killed the fps :S and as most of the buildings are still undetailed place holders, I am worried that the map will be totally unplayable when I make them look like buildings :(
I've read a few tutorials about using hints/occluders/portals but they don't offer much hope or advice for open, outdoor maps.

I think I am going to have to use fog to limit the visibility but although I can get the fps up to a respectable level, I am having real problems getting it to look right

suggestions please

gl (http://www.student.kun.nl/rvanhoorn/Optimization.htm)

On an outdoor map I'm making, I used a combination of fog (starting at around 3500 units, ending at 4500, Z clip at 4600) and making models fading out within that range.

Of course the rest was pretty much displacements and the odd house here and there. I get 60fps at a bare minimum looking over the most concentrated area which is probably a good 500m+ area in view.

Is the terrain very complex? Is it made from displacement surfaces or created manually?

thanks for the replies
most of the terrain is displacements although so far it is only so I can paint alphas on them, and as it is an open rural map, a lot will have painted geometry as well.

I think I might have found some areas where I can remove the terrain and put it in the skybox but I don't know if that will actually help or not, will just have to try it and see.

will try those settings for the fog and hopefully I can get the fps back up.

thanks again :)

well you're lucky in a way, displacements are actually very good, I believe it's in the way their lod fades so if its a lot of terrain and very little world brushes you shouldn't have too much of a problem getting decent performance from your map.

thnx Travis
I was thinking that I would have to get rid of some of the displacements but if they are lighter on the fps load than brushes then I can leave them :D