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Dumb light question

Posted: Sat Jan 21, 2006 10:11 am
by Foo
I'm trying to cast light upwards from these holes, but all I get is the round green blob you see near the floor. The light sources are pretty deep in the holes, and if I look up to the ceiling there's a bright green blob where the light is reaching waaaaay up there.

Any idea why it's not casting along the wall? I've tried regular point lights and giving them target_positions. Have I R done something wots stupid?

Image

Posted: Sat Jan 21, 2006 11:21 am
by Fjoggs
How do you angle your info_null entities? they shouldn't go straight up, but slightly towards the wall.

Posted: Sat Jan 21, 2006 4:07 pm
by Foo
Yeah tried tilting them.

Though I don't get why it won't work as a simple point light, either. It's like it's disregarding the brushes between the 3 lights and lumping them together.

Posted: Sat Jan 21, 2006 4:29 pm
by Fjoggs
Quake3 sucks ass when it comes to creating shadows from brushes. You need a really high light value, or a shader_light value, to create an overall lighteffect.

Posted: Sat Jan 21, 2006 4:34 pm
by Foo
I may just fuck with the lightmap directly in photoshop if I can't get it looking right in-game.

It's something I'll look at down the line, I was just curious as to why it's not immediately working.

Posted: Sun Jan 22, 2006 2:08 am
by obsidian
Few other things to try:

* Increase the lightmap resolution of the wall by creating a func_group and then set _lightmapscale key with a floating point value (0.5 to double lightmap resolution).

* Check your construction techniques. Make sure you caulk behind those holes where the floor grate meets the wall. Use separate brushes for the wall. (Hope that made sense).

That should do it, but failing that, try the following hacks:

* Create a non-drawing lightmap projection shader similar to those stained glass window effects that people use, utilizing surfaceparm lightfilter.

* Use a _decal entity to project an image onto the wall to fake lightmap detail.

Posted: Sun Jan 22, 2006 2:23 am
by Foo
Setting a lightmap scale on func_group made it start performing a bit like expected. It looks like crap but at least I know the cause of the problem now.

Thanks sir. That's easily one of the neatest little lighting hacks I've encountered, and I'll prolly abuse it from now on :)

Image

Posted: Sun Jan 22, 2006 3:05 am
by obsidian
One bit of warning, increasing lightmap scale means you are using more lightmap images, therefore more texture memory is used and longer compile times. Use in small localised areas such as this is great or in places where you need sharper shadows. Just don't over do it. You can even use it lower the resolution in places that the player will not likely see, therefore increasing performance.

Other ways to change lightmap resolution, in worldspawn (same method) or via a shader using q3map_lightmapSampleSize N (default 16 which means a 1x1 luxel for every 16x16 game units).

Posted: Sun Jan 22, 2006 12:41 pm
by Fjoggs
Oh, I thought you had tried lightmapscale already. Surely, every mapper should know this awesome feature by now. :p

Posted: Sun Jan 22, 2006 5:11 pm
by Hipshot
I though so too :(