How much brush cutting is worth the improvement of nodraw?

Armadillo of Doom

Group Founder, Lover of Pie
aa
Oct 25, 2007
949
1,228
Simple example, I have a brush against the skybox wall. Since nobody can see the back or bottom of said brush, it should be nodraw. What if however, I have 2 brushes next to the first, aligned on the side. One goes from the ground to the middle of the original, while the second goes from 3/4 of the original height to up past it. Since nobody can see the areas where brush number 1 touches the other two, in theory those parts should be nodraw. But that would involve cutting up your 3 brushes into 6. My crude picture;

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As opposed to;
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So which is better? In the first, you'll have textures being drawn that cannot be seen. While in the second, you have removed the excess textures in favor of chopping up the brushes like sushi. Provided the brushes line up (edges touching) the visleafs should be exactly the same. Which leads back to the original question, lol. How much of this is worth it for nodraw/hiding unseen textures?
 

Earl

L6: Sharp Member
Dec 21, 2007
284
38
If the big brush is skybox, there's no point in splitting it up. If I'm not mistaken, the entire 3D skybox is rendered before, and everything else is just rendered on top of it.

However, if it was a normal textured brush, it would be good to split it up, not only to slightly improve performance but to improve your lighting at the corners.
 

Big Lou

L3: Member
Mar 17, 2008
120
27
I just set my default texture to nodraw, build the geometry, and use the face edit tool to texture only what's visible.
 

Armadillo of Doom

Group Founder, Lover of Pie
aa
Oct 25, 2007
949
1,228
OpenBlade- yes they both work, but it's not a question of effort, it's about performance. And Earl, I was just using the skybox as an example backdrop. Though I wasn't aware that splitting brushes in such a fashion improves the light at corners.
 

Earl

L6: Sharp Member
Dec 21, 2007
284
38
Another thing: My second comment only applies if the smaller brushes are func_detail. If all brushes are world brushes, they are sliced up automatically, and the hidden part is removed/not rendered with no extra effort on your part.
 

Armadillo of Doom

Group Founder, Lover of Pie
aa
Oct 25, 2007
949
1,228
Another thing: My second comment only applies if the smaller brushes are func_detail. If all brushes are world brushes, they are sliced up automatically, and the hidden part is removed/not rendered with no extra effort on your part.

For reals? I did not know that. Thanks for the info m8 :D
 

Earl

L6: Sharp Member
Dec 21, 2007
284
38
Yeah, if you've ever noclipped through the walls in you map, you'll notice that superfluous faces are automatically clipped and removed from world brushes.