Help with disappearing brushes Created 13 years ago2010-10-23 18:13:57 UTC by JJ_Grant

Hey guys I'm hoping someone can help out with a problem I'm having on a map I'm working on. When you look at certain geometry from certain angles and certain distances they disappear.

To demonstrate I made a short video below showing what I'm talking about. Does anyone know what could cause something like this?

http://www.youtube.com/watch?v=5FeJhdhCKLU

Have you tried compiling with full vis and extra rad?

Yes. VVIS compiles fine and there are no errors or leaks. It's compiled in HDR and cubemaps are built. I have a func_viscluster over the entire area because it's so big and open but that shouldn't cause that should it?

Is there a skybox brush between the player's location and the disappearing geometry? Is it tied to an entity of any sort? Do you have any far-z clip settings set in your fog controller? And do you receive any console errors about 'too many vertex format changes' or anything similar which indicates too much geometry is being rendered?

@RabidMonkey - Thanks for the reply. There is no skybox in between those areas. Those buildings are just tied to func_detail. I do receive a ton of "too many vertex format changes" errors. Is that why they don't render at certain angles? What's the best remedy for that? I those areas enclosed in func_visclusters.

I'm starting to realize that source doesn't like big open areas too much.

That's your problem; the error means that your scene has too much 'stuff' and some of it isn't being rendered as a result. That's why it happens only when you look at things at certain angles; because those particular views are causing the game to draw too much than it can handle.

You want to make sure you're not running vvis with the -fast parameter; as doing so will bypass the vis process and can result in this error happening (even if your level is lit correctly and compiles without error, if you ran with -fast it's not optimized visibility-wise).

If you did indeed perform a full compile, the only remedy is to optimize your map somehow and reduce the amount of things being drawn. Perhaps you have some areas with unnecessary or excessive brushwork that you could reduce? If you have a lot of complicated structures made from brushes, you could convert them to static or physics props with Propper, but this will mostly just free up brushes and not vertices, which doesn't help with your problem. Occluders and areaportals can help, depending on how your map is laid out. Setting/style permitting, you could also try using fog to obscure distant parts of your scene that are far away from the player.

Source should be able to handle outdoor maps just fine provided it's not rendering too much in a single scene. Most of the big-huge Valve maps (hl2 coast levels) utilize fog as a visibility control with the FarZ clip value; this just culls/hides anything beyond the FarZ clip value from the player, while the fog masks the fact that the distant objects are disappearing.

[m]EDIT[/m]: If you're using func_viscluster this could be contributing to the error, as well - if multiple func_visclusters with lots of models, brushes, etc can see each other, than the game will think they're all visible at once, even when they might not be, so use them sparingly, if at all!

@RabidMonkey - Thanks for the great reply. Sorry it took me so long to get back to you. I will try some things out per your advice and see what happens.