ok I just fixed a ton of things with my levels that helped frame rate go up dramaticly and I thought I would share the info for those have low frame rate problems.
follow thses rules and you will be happy.
SEP = Static ent proxy
SM= Static mesh
BSP = level geometry.
1. Never never "Clone" or copy static meshes or static meash entities. I just learned this lesson and now wish I never had the ability to do it in RFedit. Cloning these brushes cuase some kind of bug that will cus the engine to use tons of resources trying to decide what to draw. It will not only slow things down but can even destroy your level.
2. Balance your work. Use SEPs and SM and BSP where each is best used. For high poly models that cover large areas use SMs they work well just make sure you keep the edges off you BSP walls. Use SEP for anything small or if you need to have moving. BSP use only for basic structure. The reason I say this is BSP is the least versitile but works best for clipping. Also pay attention to you visability settings in you SM properties dialog. I have found that these settings make a big difference.
3, be carefull with traperent objects. I use alot of them. I use them for light cones and smoke and dust and even railing for stairs and fences.
Used wrong they will iether not appere or will disapere or kill your frame rate OR all three. (BTW wrong is relative term when talking about RF you could be doing ecything right but still it wont work.) ) SEP I have had ok luck with traperency but the best luck I have have with SM with the Zsort flage set to True. If you monkey aroung all the options long enough you will probably get it to work. Dont give up though just keep at it. If your SEPs dont work try SMs. If they still dont work try swaping them one by one. If that doesn't work try converting some of you larg poly SM and SEPs to BSP. (Yes I know its a nice woman to do that but you can do it. Its like going through the shreded documents and like the penguine says a little patience and a lot of tape.)
4. Go for detail in you textures that work with your level. If you have a texture of a wall set up your lights and shadows on the texture at 1024 1024 and place it on your BSP or SM faces to work in the scene. Its time consuming but make a huge difference. (for best results I find modeling out your whole level in a 3d prog first helps. Then map it there too, then rebuild bit by bit in RFeditpro using BSP as much as possible then using SM and SEP to fill in spots too detailed or that have to be smoothed. I dont recomend usibg RFs level shadows for anything. Stencle shadows work great for moving objects all static lighting can be done by painting your textures. Also I would aviod using repeatable textures. It make your level download size crazy huge vut if you use a unique 1024 bitmap for all walls and floors it looks alot better.)
5. Size does matter. I found that a scale decrease can dramaticly improve performance. Scale down your player and build at .3 for wide areas.
I have a 3600 poly out door area that now runs at 60-120 fps thanks to learning these tricks.