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Lighting problem (Quake 3)

Posted: Tue Nov 22, 2005 10:36 pm
by scythe
Hey all,
As you can hopefully see in the pic below, I'm having a problem with light from a sky shader "bleeding through" patch meshes which are close to the sky. (The problematic patches are the trim pieces near the sky in the shot) Does anyone have any idea what could be causing this and how I would go about fixing it? I'd appreciate any input.

Thanks.
Scythe
Image

Posted: Tue Nov 22, 2005 10:49 pm
by Fjoggs
Are the patch and bevels completely aligned? There's a slim chance they're a few units off grid.

Posted: Tue Nov 22, 2005 11:23 pm
by scythe
Nope, they're perfectly aligned as far as I can see (zoomed all the way in, in Radiant) Thanks for the idea though.

Posted: Tue Nov 22, 2005 11:40 pm
by Hipshot
Did you caulk behind?

Posted: Tue Nov 22, 2005 11:52 pm
by scythe
Yep, the map is built "caulk hull" style, very neat and precise. That's why I'm perplexed.

Btw, I only get the light bleed when I compile with radiosity (-bounce 4) enabled. I'm using GTK 1.4.0 with Q3map2 2.5.16.

Posted: Tue Nov 22, 2005 11:55 pm
by Lenard
I think people should have to specify when it's a q4 thread, not a q3 thread.

Posted: Wed Nov 23, 2005 12:27 am
by Hipshot
Yea, think so too.

Posted: Wed Nov 23, 2005 12:39 am
by o'dium
Even though the screenshot shows Q3 stuff.

Posted: Wed Nov 23, 2005 12:47 am
by scythe
Yeah, well I just wanted to clarify which game I was posting about (before they clicked the topic) for people since there have been a lot of Q4 threads lately.

Posted: Wed Nov 23, 2005 1:09 am
by ^misantropia^
What's the exact command line you used for that screenshot, scythe?

Posted: Wed Nov 23, 2005 1:41 am
by Oeloe
You're suggesting they're JPEG artifacts?

Posted: Wed Nov 23, 2005 8:04 am
by ^misantropia^
Err... q3map2 command line.

Posted: Wed Nov 23, 2005 5:13 pm
by obsidian
You're not using portal skies are you?

Also, try func_group'ing those patches together.

Can you show us an editor screenshot of where the patches meet the sky brushes?

Posted: Wed Nov 23, 2005 7:33 pm
by rgoer
Is your caulk hull mitred? I know this sounds silly, but sky lights can leak through un-mitred edges, if an un-mitred edge happens to line up on an axis that is shared by visible geometry.

Posted: Wed Nov 23, 2005 9:00 pm
by scythe
Obsidian, no they're not portal skies, just a normal sky shader.

Rgoer, yes the caulk hull is mitred.

Misantropia, I compiled with:

bsp -meta -samplesize 4

vis -saveprt

light -fast -gamma 1.3 -compensate 1.3 -patchshadows -samples 3 -bounce 4

Here's an editor shot, top-down. The "ceiling" of the area is the sky brush:

Image

Posted: Wed Nov 23, 2005 9:58 pm
by rgoer
one thing you might try is something like this, to give -light -patchshadows a helping hand:

[lvlshot]http://webpages.charter.net/rgoer/patch1.jpg[/lvlshot]

[lvlshot]http://webpages.charter.net/rgoer/patch2.jpg[/lvlshot]

Posted: Wed Nov 23, 2005 10:02 pm
by Fjoggs
Not that it makes any difference, but you miter where it's not needed. Hard to explain, but the two lower left brushes doesnt need to be mitered on the bottom and far most to the left. The same goes for every other brush like that.

Posted: Wed Nov 23, 2005 10:08 pm
by scythe
rgoer, thanks, I'll give that a try tonight.

Fjoggs, I understand what you're saying, I just tend to miter corners out of habit.

Posted: Fri Nov 25, 2005 6:48 pm
by scythe
Thanks for the help guys. I ended up fixing the problem with a combination of "capping" the bevels like rgoer suggested, clipping the sky brush to approximate the curve of the bevel, and filling in the top corners with caulk brushes.

-Scythe

Posted: Fri Nov 25, 2005 7:22 pm
by Foo
I'm a bit late, but you might consider creating those curves like this instead:
Image

by making the undersides from caps and 2 brushes, you save some tris, and as a side benefit light wont leak down through the patch (because the caulked brushes are in its way.

Posted: Fri Nov 25, 2005 10:23 pm
by scythe
I'll keep that in mind in the future, thanks Foo.