View Full Version : CSG merge??

10-24-2003, 04:11 PM
OK, I have read in the past not to use CSG Substract, but I have never seen or heard anything on CSG merge.... What exactly does this do, is it something to avoid like CSG substract, and (if any) what kind of problems can it create?? If it doesnt cause problems, will it help improve or decrease FPS??

10-24-2003, 04:25 PM
CSG merge allows you to merge 2 adjacent brushes that are concave. It's a useful tool if you want to make a complex brush out of smaller pieces and then merge them all together, just tidies up really. Calling it CSG merge was a a bad idea as it gives people the impression it's as cursed as CSG subtract when all it does is merge brushes that could have been made out of one brush to start.

You know what's better though? Mesh split and mesh merge, my god they help sooo much!

10-24-2003, 04:35 PM
ah, ok... so if I have like a giant pillar that is made up of 10 pieces, I can select all those pieces and csg merge them to make one piece?? By doing this, do you know if it gives any gain to the frame rate on the map??

10-24-2003, 05:14 PM
dont think it would affect the fps at all.

it only works however for convex brushes.

10-24-2003, 05:23 PM
Ah, ok... so much for gaining a few frames per second... LOL

I was just messing with it a little bit, I also noticed that it will change the texture of the two items as well when they are merged

OK... thanks for the info

10-24-2003, 09:27 PM
When you merge brushes, you'll get some faces that turn into a single face...and you can only have one texture per face. So even if the two brushes are exactly in line, if you want them to have different textures...they stay two brushes.

In SOME cases this can affect FPS. But if you use -meta in the BSP phase of a q3map2 compile, then the compiler will automatically merge adjacent coplanar tris.

CSG subract isn't all bad, really...you jsut have to avoid using it by, say, cutting a long skinny hole out of an x-wing prefab. Brushes all over the place...ick!

10-24-2003, 09:42 PM
I always get concave and convex confused when I'm drunk, stupid stupid stupid! I mean come on, a cave is a hole, it goes in....it's eeeeeeeeeeeeeasy to remember, ARGH!

10-25-2003, 04:05 PM
Yeah, i never have had any problems with subtract, and when i get tons of tiny burshes, i just remake the whole brush to fit the area.