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Underground Ambient Light
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 Re: Underground Ambient Light
Posted by DocBadwrench on Tue Jan 18th at 5:44pm 2005

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.




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 Re: Underground Ambient Light
Posted by Static88 on Tue Jan 18th at 6:01pm 2005

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. [addsig]



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 Re: Underground Ambient Light
Posted by DocBadwrench on Tue Jan 18th at 6:07pm 2005

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. I look forward to investigating it.



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 Re: Underground Ambient Light
Posted by ReNo on Tue Jan 18th at 7:11pm 2005

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.
[addsig]



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 Re: Underground Ambient Light
Posted by Rof on Tue Jan 18th at 7:25pm 2005

? quote:
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.
[addsig]



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 Re: Underground Ambient Light
Posted by ReNo on Tue Jan 18th at 7:28pm 2005

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.
[addsig]



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 Re: Underground Ambient Light
Posted by Orkin on Tue Jan 18th at 7:41pm 2005

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...





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 Re: Underground Ambient Light
Posted by Rof on Tue Jan 18th at 7:43pm 2005

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).
[addsig]



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 Re: Underground Ambient Light
Posted by DocBadwrench on Tue Jan 18th at 9:44pm 2005

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. As always, thanks to you all for your help.




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 Re: Underground Ambient Light
Posted by ReNo on Tue Jan 18th at 10:54pm 2005

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.
[addsig]



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 Re: Underground Ambient Light
Posted by DocBadwrench on Tue Jan 18th at 11:23pm 2005

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.




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 Re: Underground Ambient Light
Posted by Rof on Wed Jan 19th at 2:40am 2005

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.
[addsig]




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