Lighting problem (Quake 3)

Post by **scythe** » Tue Nov 22, 2005 10:36 pm

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

Post by **Fjoggs** » Tue Nov 22, 2005 10:49 pm

Are the patch and bevels completely aligned? There's a slim chance they're a few units off grid.

Post by **scythe** » Tue Nov 22, 2005 11:23 pm

Nope, they're perfectly aligned as far as I can see (zoomed all the way in, in Radiant) Thanks for the idea though.

Post by **Hipshot** » Tue Nov 22, 2005 11:40 pm

Did you caulk behind?

Post by **scythe** » Tue Nov 22, 2005 11:52 pm

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.

Post by **Lenard** » Tue Nov 22, 2005 11:55 pm

I think people should have to specify when it's a q4 thread, not a q3 thread.

Post by **Hipshot** » Wed Nov 23, 2005 12:27 am

Yea, think so too.

Post by **o'dium** » Wed Nov 23, 2005 12:39 am

Even though the screenshot shows Q3 stuff.

Post by **scythe** » Wed Nov 23, 2005 12:47 am

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.

Post by **^misantropia^** » Wed Nov 23, 2005 1:09 am

What's the exact command line you used for that screenshot, scythe?

Post by **Oeloe** » Wed Nov 23, 2005 1:41 am

You're suggesting they're JPEG artifacts?

Post by **^misantropia^** » Wed Nov 23, 2005 8:04 am

Err... q3map2 command line.

Post by **obsidian** » Wed Nov 23, 2005 5:13 pm

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?

Post by **rgoer** » Wed Nov 23, 2005 7:33 pm

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.

Post by **scythe** » Wed Nov 23, 2005 9:00 pm

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:

Post by **rgoer** » Wed Nov 23, 2005 9:58 pm

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]

Post by **Fjoggs** » Wed Nov 23, 2005 10:02 pm

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.

Post by **scythe** » Wed Nov 23, 2005 10:08 pm

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.

Post by **scythe** » Fri Nov 25, 2005 6:48 pm

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

Post by **Foo** » Fri Nov 25, 2005 7:22 pm

I'm a bit late, but you might consider creating those curves like this instead:

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.

Post by **scythe** » Fri Nov 25, 2005 10:23 pm

I'll keep that in mind in the future, thanks Foo.