No Draw Brush Created 16 years ago2008-05-25 17:33:50 UTC by Baron Samedi

so i decompiled this official tf2 map today, cp_Dustbowl. just so i could understand the entities and what textures are widely used.

and i came across a few randomly placed no_draw brushes. all of them had the no draw texture on all 6 sides of the brush and were placed seemingly randomly into the cliffside.

i know decompiling can cause brush errors, but i just wanted to make sure there is no greater purpose for doing this.

http://img182.imageshack.us/img182/1416/57266036lk0.jpg

Isnt that the same as a clip brush in HL1 ? Its like a invisible wall, so you dont get errors when the player walks over it on near it. Like wall bugs and stuff.

To me it looks like those Nodraw brushes are placed to seal off leaks, as displacement surfaces don't seal off the map.

Also, the nodraw and clip textures aren't the same, the HL1 equivalent is the Null texture, which is just an invisible solid brush. You can't shoot though it, but you can with clip brushes.

Muzz again has it right. They are used to seal off the map as displacements don't seal from leaks.

Although when I read your question I thought you meant literally blocks covered in nodraw in the middle of nowhere...

I've actually seen blocks like that and I wonder why Valve did it :S

maybe it's so people don't get stuck in little divots in the ground, or caught on the cliff displacements?

yeah i think muzzle is right. because under other displacement structures throughout the map there are nodraw brushes behind or under the displacements.

but that brings me to another question. does the sky box not qualify as something to seal leaks in source? or are there other types of leaks that come with displacements.

i just learned about displacements yesterday, thats why i am asking.

Yeah, the skybox does seal leaks. But it should only be used for the roof and upper walls of your map. If you use it under your map, or just box the map in with skybox, it's going to cause a lot of optimisation problems and lengthen your compile times.