Underground Ambient Light

Though light_env is a great
solution for those of us with a skybox, I'd like to know if there are
any ways to properly adjust the base light level of a map that is
completely enclosed.

Once light_env is enabled on my
map, regardless of the brightness or what not, the results are always
the same: blackness. Though I want to use actual light sources as
illumination, I'd rather not start from a baseline of "pitch dark" if I
can help it.

A question that just arose as of my writing this: Should I create a
Skybox with the light_env entity enabled? Will it still matter
that my actual map is a set of completely enclosed tunnels?

Thanks in advance.

If I were you, i'd check my map and make sure that you have no leaks at all. Your light_env should illuminate your map, providing your light levels aren't set to pitch black. Otherwise, i'll leave this question to someone who knows more than me. :razz:

I'll check my map. At worst, I can create a huge honkin' cube,
hollow it out and build my map in there. At least then I can
verify that the damned entity's working (and fix leaks once I've done
that).

I'm still very new to the process. How big/how many leaks are
libel to give me problems. I'm unaware that I have any leaks at the
moment, but that must not be the case given your response. :smile: I
look forward to investigating it.

A light_env just makes the skybox emit light in the given direction
with the given brightness. If a face does not fall in sight of the
skybox according to the light_env settings then it won't get lit,
therefore there is no reason for you to bother with a light_env if your
map has no view of the sky.

If you want to have all the map be at least a certain value of
brightness, then you would specify the ambient light level for RAD to
use during compile. I haven't used that command in HL2, so I can't tell
you exactly how to use it, but it should be easy to figure out.

A light_env just makes the skybox emit light in the given direction
with the given brightness. If a face does not fall in sight of the
skybox according to the light_env settings then it won't get lit,
therefore there is no reason for you to bother with a light_env if your
map has no view of the sky.

Are you sure, Reno? I though the "brightness" property of the light_env
sets the light emitted by the skybox, but the "ambient" property allows
you to set a base light level for everywhere, even if an area can't see
the skybox (or you have no skybox at all).

I'll admit that I haven't actually explicitly tried this, though, but it sounds logical.

I did read a post by Jeff Lane (Valve guy) on the VERC forums that said
that you shouldn't need ambient lighting, because you should put in
enough standard light entities (light, light_spot) that bounces from
them should fill in the dark areas. But he may have been talking more
about aesthetics than technical limitation.

Hmm, you might be right with the ambient property, though I think HL1
had a compile option that allowed you to set the indirect lighting from
the sky (anything that could see the skybox got that value of lighting,
even if it didnt fall under the light_environment direction) and I
sorta assumed that the ambient property did the same thing. Test it and
see is the only suggestion I can make on that really.

I'm pretty sure the ambient property on light_env is only for indirect lighting from the sky box faces (not the light_env entity itself). The reason I say this is because last time I added a new building to my outdoor/indoor map, and didn't put light sources in, it was pitch black inside, but outside areas still had ambient lighting.

And Jeff Lane is right, with the lightmaps being computed using radiosity, there really shouldn't be much need for an ambient light level. Ambient light is basically a hack used to simulate the effect of light bouncing off several objects before reaching our eyes before computers were fast enough to do it for real. Radiosity removes the hack and does it the right way.

As for a solution to DocBadwrench's question...I really don't know...

Actually, that sounds very plausable, Reno. I'm probably wrong, but I'll try it and find out.

I found the thread with Jeff Lane talking about this

at VERC. Looks like he say's it's not possible. Perhaps with a
compile option, like you say (though I'm wondering if that was only
present on Zoner's version of RAD, for HL1).

Actually, using Light objects
would be fantastic for me. My main concern was that by putting in
so many "light" objects I might create a situation where clients have a
hard time rendering it all. I'd personally love to have things
pitch black and then "lighten" things up with honest-to-god light
sources. Again, I am mainly concerned that I'll lag things hard.

Since I don't have a thorough enough background of experience with
HAMMER, I'm sort of figuring/guessing as I go. :smile: As always, thanks to
you all for your help.

I wouldn't worry about having too many lights - provided they are
static (ie. just normal light / light spot entities, NOT light_dynamic
or lights with effects) you can pretty much have as many as you like.
Source, like HL1, uses lightmaps. These are generated during compile
time, and so while more lights will mean compiles take longer, they
won't have any effect on FPS during gameplay.

Thanks for the tip, Reno. That makes me feel much better about the
project I'm working on! I've heard from enough people that
dynamic lights are memory hogs and don't necessarily function
realistically in some circumstances, so I decided against using them.

Yep, I tested this and Reno is right. The ambient property of light_env
controls the omnidirectional light emitted by the skybox. (As opposed
to the unidirectional light emitted from the skybox due to the
"brightness" field). You can use it to fill in the shadows a little in
outside locations, but it doesn't do any lighting of enclosed areas at
all.