The following screenshots are of two different places in the same map with identical geometry. The first one is the problem, and the second picture is how the first one should look.

Wrong:Right:These were both taken at the same time. The red lights are the only source of light. Any ideas on why one side isn't being lit?

How are the faces cut?

They're both cut down the same line. The areas sit opposite of each other, but it's the same cut through.

hmm
Only thing i can think of is re-making the brushes a different way and re-compiling

I found using zhlt lightflags like (opaque blocks light)causes some damn weird light glitches like this. Have you used and lightflags anywhere around there?

I've also found using "texture light style" on func_walls to make texture lights blink, pulse or what have you, will also sometimes cause lighting glitches all across the map. If you have any of these in your map try deleting them.

Last thing i can think of is make sure they are either both world brushes or both brushed entities, as obviously world brushes will react differently to light than entity brushes.

Last last thing i can think of is if you have a light_environment in the map. maybe it's lighting that area more than the other fsr... you could try disabling the light_environment to test.

I found using zhlt lightflags like (opaque blocks light)causes some damn weird light glitches like this. Have you used and lightflags anywhere around there

This might have fixed it. I had one func_wall blocking light for a mirror, nowhere near the screenshots above, mind you, but letting light pass through seems to have fixed it (as well as some other areas too).

Yeah, the ZHLT lightflags seem to fail totally imo.

I had this hallway where the floor was not reflecting light at all--completely black--, no matter how high i turned the lights up. This pissed me off for hours because i couldn't fathom what was happening. Turns out the door in front of the hallway set to "opaque, block light" was causing the problem for some ungodly reason.. I never even try to use the zhlt lightflags anymore.

Is this for your rooms map?

)

Thanks for the tip.

Aye, it is; and it's really close to being done. Didn't get a chance at all to work on it Thursday or Friday, but I'm running a semi-final compile as I post this.