DarkPlaces [...] doesn't do the swirl effect. [...] tends to make water look a bit like a solid wall.. I think the warping will help counteract this

Exactly. In Retroquad it looks great because the texture swirls while the lighting doesn't. 

Yeah, I compiled e1m2 with lit water and noticed the "solid wall" effect too, but this was even with the turbulent effect.

Another thing I noticed is that the lightmapping tends to make translucent water less noticeable; it's actually more difficult to fine-tune a good value of r_wateralpha that works well.

The thing about fullbright translucent water surfaces is that they actually blend with the lighting on the solid surfaces below them. This comes back to the statement I made earlier on about translucent surfaces probably not needing to be lit at all, but yeah, it's something that people are only ever going to be able to evaluate once they see it.

Having a cvar to enable/disable options is useless IMO if the cvar isn't exposed to the player somehow. Because most players won't even be aware that it exists. That's a total cop-out; people don't read readmes so you need to pick sensible defaults and unfortunately I suspect that while community judgement on lit water is going to be "it looks crap", people are so drunk on the kool-aid that we're going to end up with a set of defaults that in a years time nobody will want. 

To me the value of lit water is that even if it is a tradeoff of sorts and can have undesirable effects (I still haven't really managed to see it in action aside from screenshots, so I can't say if it makes water look like a solid surface or not), it's still better than having water that glows in the dark.

That's really what it's about for me - letting mappers use water in dark areas without it looking awful and out of place. The way it is right now looks fine in places like this, but not so much in places like this. You can make it more subtle by increasing wateralpha (it's 0.6 in these screenshots), but then you lose some of that murkiness and uncertainty from the water that a mapper might want. And it doesn't solve the problem completely anyway.

By the way @ericw, thanks for the hint about the _shadow key, worked a charm. Too bad my fence textures are too finely detailed and barely let any light through :( 

mh: Having a cvar to enable/disable options is useless IMO if the cvar isn't exposed to the player somehow.

That's why I'm used to implementing menu options for this kind of thing. And such menu options needs cvars.

Lots of engines have options to toggle colored lighting, wateralpha and so on. It's really hard to believe you haven't thought of this possibility.

Anyway, even if nobody else implements it in their engines, even if nobody else compiles it in their maps, I'll just keep doing my own thing. Even if everybody else thinks it looks bad. 

I think Retroquad looks great but i also think it should be a criminal offense that I can't play it ;-; 

Let's say I have a lot of fiddly little clip brushes used to smooth over some terrain (turning the collision into steps basically, not slopes). Should the clip brushes be made func_detail, like the terrain, or should clip always be world / func_group, regardless of how detailed it is? 

But in Source clip brushes don't cut visibility. 

I used to place small brushes in func_wall, but for vising sake it would be func_detail. 

I'm pretty sure it's fine to put them in func_detail, they will behave the same as if they are in worldspawn or func_group.

(Clip brushes are only included in hull1/2, and func_detail is specific to hull0, so the features shouldn't have any interaction) 

Thanks very much, that all makes sense. 

1) If I want to upgrade to the latest tyrutils-ericw (v0.15.9) on Linux 64 bit, can I just download the Linux64.zip archive, extract it and immediately use it? That's what I tried, and qbsp seems to work ok, but light gives me the error message
error while loading shared libraries: libembree.so.2: cannot open shared object file: No such file or directory.
There is a file called "libembree.so.2" in "tyrutils-ericw-v0.15.9-Linux/bin/", though, so I'm confused.

2) When using running light, does it matter in which order I type in the command-line options? E.g. is there a difference between
light -bounce -extra4 -dirt
and
light -dirt -bounce -extra4?
Are they both correct? Or both wrong? Do I need to give "bounce" a value? (I've tried various variations, but I find it hard to know when/if I'm doing things correctly, as I'm not sure what the in-game results are supposed to be).

3) This is not a huge problem (yet), but one brush face in a map I've been working on suddenly stopped being lit, both when running light normally and with "-dirtdebug" (which should light all faces evenly, right? That's what it's always done before when I used it). Is there a known reason for this kind of thing? Is there anything one can do to avoid it, or is it one of those mysterious things that just sometimes happens?

This is using tyrutils-ericw 0.15.8 and an outdated version of TB2 beta (the reason being that when I last tried to upgrade TB2, I seemingly had to first upgrade my then freshly installed OS, or fiddle around with repository settings to get the necessary dependencies updated to the versions required for updating TB2 -- and I didn't have the time or patience to do so. At some point I will update both). I just mention this in case this might be an issue related to the editor rather than the light tool (in which case I'll just have to live with it until I update my OS and editor). Oh, and my engine is QuakeSpasm 0.92.0. 

1. Looks like I messed up packaging the linux binary.
If you don't mind running light manually from the terminal, try "cd"-ing into the "bin" directory and run:
LD_LIBRARY_PATH=$(pwd) ./light {options here}
Otherwise, I'll fix it in the next release.

2. Order doesn't matter, except the map has to come last. There is no parameter for -bounce (there are separate flags like -bouncescale X though). Only a few commands take optional parameters (-soft can take a number like "-soft 2"). The tool should be strict if there are mistakes in the command line options, and refuse to run. For now the manual is the best reference: here, or the website front page.

3. It would just be a bug in "light". Things that have caused black faces in the past:
- bmodels (func_wall, etc.) that intersect the world
- regular world faces with an obstruction near the center of the face, within 1 unit of the surface.
I *think* I fixed all of these for the next version, I should put up a beta or release soon. Feel free to send me your map/bsp if you want me to check it out though. 

1. I didn't know there was an alternative to running it manually from terminal; that's what I always do. :) Anyway, I tested typing that arcane string of characters and it works, thanks! That'll tide me over till the next release.

2. Order doesn't matter
Thanks for clearing that up! :)

There is no parameter for -bounce
the manual is the best reference
I had already read through the manual and the stuff on the front page a few times, but was still a little confused.

The example of the front page is
-bounce -bouncescale 2
which made me think that it doesn't take any parameters.

But the manual made it seem to me as if do need to specify a value ("n"):

bounce n

Enables 1 bounce, 0=disable even if set in worldspawn. Available as a worldspawn key.

I guess I'm misinterpreting something?

3. Thanks for all of this info. The brush with the unlit face is just a regular unobstructed worldbrush, but it's good to know these things for future reference.

Thank you very much for offering to look at the map. If the problem persists, I might take you up on the offer, but a lot is bound to change in the map, so the problem might resolve itself in the mean time. Plus, the file is a huge mess of provisional brushwork, newbie mistakes, textures that have not been properly aligned yet, etc., and though I know no-one but me cares, I'm still too embarrassed to share it in its current state. 

Hi,
I noticed that color lights have different intensity than the neutral ones. https://flic.kr/p/SQKPAU In the picture all the lights have the "light" key of 150, but the attenuation and the intensity is very different.
If that's "a feature", what can I do to make them look more uniform? 

That looks like a custom engine screw-up. What engine are you using? 

When you change the color, it reduces the intensity of the colors that you don't want. If a white light has RGB color of 1, 1, 1 and you make it pure blue, the color becomes 0, 0, 1.

You could reduce the brightness 1/2 by making the color 0.5, 0.5, 0.5

I don't think the light program compensates for this and maybe it's what you are seeing. 

That's not the problem at all here. Look at the image - that's an engine thing. The light program just can't blow the lightmap brightness up like that. 

Okay, you're probably right. The picture was so dark I couldn't really see anything other than the white and blue blobs, and I was too lazy to turn the gamma up. 

White and colored lights shouldn't have vastly different intensity / falloff, and if anything white will be brighter than colored as Rick was saying.. so something is wrong here.

Is the "_color" key set on the white lights (the dim ones on the right)?

The engine's brightness/contrast controls are blowing out the colors so it's hard to tell what's going on. Also assuming that is Darkplaces, you can view the lightmap only by entering "gl_lightmaps 1" in the console. 

It's clearly amplifying the light instead of reducing.

Somehow, it seems to be adding the color to the light instead of multiplying. 

It's Darkplaces. Only the color lights have "_color" key. I'm at work right now but AFAIR I didn't use any "_deviance".

If anyone wants to check it, I could take more screenshots with higher brightness or should I mess with any other parameters?

I'll check the same settings in FitzQuake and will let you know. 

Use floats, ie values between 0 and 1.
Values greater than 1 will either oversaturate or be divided by 255, depending on implementation (welcome to the wild west).

The lighting in that screenshot actually has nothing to do with tyrlight[-ericw], because the engine you're using is basically ignoring its output and making up its own thing based on the map entities.
set r_shadow_realtime_world 0 to get it to behave properly. This'll also boost framerates significantly, so a double win...


ericw, how about a feature to ignore/strip certain lights so you can more easily set up rtlights without damaging static lights? maybe 

Loathe as I am to suggest continually adding fudges to support all the different implementations custom engines expect - on the compile side, would it make sense to always normalise 0-255 values into 0-1 values when saved to the bsp? 

I've updated my FGD file for version v0.15.9 of Ericw tools so you can now set phong on brush models and projected textures on lights.

https://dl.dropboxusercontent.com/u/33279452/quake4ericwTools.fgd

Tested with J.A.C.K steam release 

Spike, ah, rtlights explains it. Hmm maybe a key to omit an entity from the bsp could be handy, although in this case the mapper could just use colors values in 0-1.

I kind of hate to add hacks like scaling the "_color" values in the bsp to 0-1, although I suppose it improves compatibility with darkplaces "auto-rtlights" and should be pretty safe.