QUOTE
(CLIP), used to block player movement. A brush covered in CLIP does not stop grenades or gunfire, it is invisible, and it does not block VIS. There isn't any way to add more nodes or clipnodes to the bsp's (its already maxed out). However, at least clipnodes can be reduced with a bit of work.
When the maps are compiled all the 3d 'space' a player can get to is broken up into convex regions just like brushes are required to be, alot of them are extremely small or too small for a player, and if you put a CLIP brush over them they don't become clipnodes at all (well really there are still a few intersecting the brush on its surfaces, but the brush can be excluding dozens or hundreds of them at a time).
When the maps are compiled all the 3d 'space' a player can get to is broken up into convex regions just like brushes are required to be, alot of them are extremely small or too small for a player, and if you put a CLIP brush over them they don't become clipnodes at all (well really there are still a few intersecting the brush on its surfaces, but the brush can be excluding dozens or hundreds of them at a time).
There is a several ways to reduce the clipnodes. One of the ways is to make the objects in your map func_wall. However this is not very good, because you have to use more entities. The other way is to make not so complicated a.k.a simple walls, ground and building. The best and efficient way is to use the CLIP texture. http://er4o.org/gallery/c69581e38422c1449100764b054a94ba.gif (you can find it in ZHLT.wad)
So how to reduce the clipnodes in my map?
1. Open your map and search for places where the player can't reach like higher windows, doors etc. http://er4o.org/gallery/7a9c7ddefc337fec3f90c3d2aa8c5529.JPG Now select the CLIP texture and fill the empty space in front of the window. http://er4o.org/gallery/c2312655056a5bd5794475f80c41c42c.JPG You can cover handrails too. http://er4o.org/gallery/d3279a121eaef4b38fc487fbe98acb0e.JPG http://er4o.org/gallery/503682ff0640f6c254982c3173254a1c.JPG ( do this with every window, door, hole etc.)
2. The second way is when you create a fence, pylon, vent, ladder or any other textures with blue background on which the name starts with this sign {. http://er4o.org/gallery/6e0fccb7bb8a4b7c20918c9532b54a0b.JPG Such textures are better to be created with func_illusionary and then covered with CLIP textures. http://er4o.org/gallery/41eba228b59bb008dcbc2787b8a2a0b8.JPG
3. Another way to reduce the clipnodes is to add a clip texture on top of building, mountains etc. http://er4o.org/gallery/23a0d91370111dfbe64e529ab2cfba95.JPG http://er4o.org/gallery/8e8ee78a05dae329563d52b949c5a792.JPG
4. If you had built a mountains with triangle method http://er4o.org/gallery/1642b2aafff5af702910b48539de65dc.JPG it is good to copy the mountains, then select the CLIP texture and hit the replace button. Now place the CLIP textures over the original mountains. http://er4o.org/gallery/c0c3218b66b6e3f4107680176e8f477b.JPG