I have a fairly large(obviously if I'm receiving this error) map that I recently have almost completed. It used to compile fine, but then I started having some wierd errors so I made my own wad for the textures(I was using like 14 before and I heard that's bad). After that I added some more to the level, altered the sky a bit and compiled, and now I'm getting the max clipnode error.

So my question is this:
Would it be more efficient for me to tighten the skybox itself or to simply add a bunch of clip brushes in areas where people will most likely not be able to reach?

I mean, I could tighten the skybox, but that might mess up bullet trajectories in some areas because there is a secton of the level that is quite vertical and if I changed the box, when looking downward and forward it might be in the way of the bullets from this high place, and I've noticed that the skybox does absorb bullets. On the other hand, here's my problem with adding lots of clip brushes. Does adding lots of clipbrushes in fact make you use MORE clipnodes because you are carving the un-occupiable space into a more complex shape, or do they in fact eliminate clipnodes?

Also, do I need to clip areas that are within the sealed area of the map(inside the sky and ground) but are completely sealed off themselves from entry or sight, or are they automatically clipped during compile? (Can the compiler determine if a place is inaccessible or not?) If the answer to this question is yes, I do have to clip them, then this is most likely the problem with my map because I have quite a few areas like this.

If anyone can answer these questions I'd really appreciate it. In fact I'll even send you a copy of my saved (uncompiled) map if you think looking at it would help you answer better. Thanks :)

Ok firstly tighten the Skybox, the closer it is the less clipnodes made available to the compile program. Also I don't think the sky will affect your bullets at all they only affect grenades from what i understand.

Any area that you can't get to at needs to be clipped off, the compile program can't tell what those areas are from what I understand, also small areas that a player can't get into should be clipped off, same with the tops of roofs and other areas where you don't want people getting boosted etc etc.

If I'm wrong about this someone else can correct me but I'm sure thats sound enough advice :)

Cover complex brushes with clip brushes,
or use func_walls for complex brushes, will seriously reduce the clipnodes,
reduce the amount of visible faces (use 3D flat mode to see this)
and use clip brushes where the player can't go,
or/and use xp-cagey zhlt tools to extend max_clipnode limit.
Do a search in the forum and with any internet search engine to find more infos.