Is it possible to put fog around a tunnel (underwater with glass windows)?

theoretically yes. In practice, no. Technically you could place several fog planes all surrounding the tunnel and pointing away from it. But in the sense you are asking, no you cant.

I tried making some fog planes that all face away from it, but then tool gives errors about it.

FOG LORD (my new self appointed title) to the rescue!

Well, kindof.

I believe this is possible, but, I'm not exactly sure how, haven't tried it yet, and, because I don't fully understand halo's fog mechanics yet myself, may be bad at explaining it.

My fog problems are very similar to yours, however. We both want fog in specific areas, but not in other areas at or below the same elevation.

For all I know about fog so far, see my latest post in this...
http://forum.halomaps.org/index.cfm%3Fpage=topic&topicID=21625

I think there could be 2 strategies for doing this, 1: setting the fog to use, if any, for the specific clusters in guerrilla, and 2: using the fog planes to define specific fog volumes.

1: Set up a portal for the area you want fog to be in. Have a fog plane above this portal. I don't know if it matters if it's inside of the portal or not, or if it expands horizontally beyond it or not. Once a fog plane is made in the level, and fog applied in sapien, it affects the entire bsp (By default). The hard part is leaving it in some parts of the bsp below a certain elevation, and not having it in others at or below that same elevation. As with sky, it may be possible to set the fog used in each individual cluster. You would set no fog for every cluster in the level except for that one cluster. See the above thread for all I currently know on that setting in guerrilla. (More info on this concept can be seen in another thread that dealt with defining which sky individual clusters use. But by now that thread must be past page 6. I don't have time to hunt it down now.)

2: The fog planes themselves must affect the fog somehow. Most fog planes are perfectly horizontal, and you never go to any areas in the same bsp below their level where there is no fog. (One exception is the first elevator shaft in c10 which goes below the level of the swamp fog outside the bunker, above the swamp water, but does not have it).
If fog was as simple as having only one type of fog in a level (Other then the atmospheric fog of the sky tag. We're not talking about that), below one elevation, then they would probably just have "Fog altitude (fog appears below this altitude in the bsp)" and "Fog type (The fog tag to use for this level)" settings in guerrilla in the bsp tag, and nothing (or those same settings) in sapien. But they don't.
This leads me to believe that the fog planes affect the fog in more ways then just defining its elevation.* They could be used to make a fog volume to be inside a specific area, and not in other around it. As the HEK tutorial says about the fog shader symbol, $, "Fog plane property. This flag or shader symbol when applied to a material that is applied to a face or surface makes the surface not be rendered. The faces acts as a fog plane that can be used to define a volumetric fog region." How? Who knows.


*So far, it's theoretically possible to have more then one type of fog available for clusters to use in a level (thus the fog pallet in sapien and fog settings for individual clusters), apply it to volumes not defines by perfectly horizontal planes, and only have it applied to specific clusters, or have different fog applied to different clusters.
NOTE: By "applied", I do not mean that there is necessarily fog visible in that cluster. I mean that the game engine checks and finds parts of that cluster that are below/within the fog region, (which is somehow defined by fog plane(s)), and if it finds any areas, it has fog below/ in those areas. A cluster can have fog applied and not display the fog if it is above the fog plane, and it can be below the fog plane and not display that fog, if that's how it's set.


I have not tried making a non- horizontal fog plane yet, or messing with the fog settings of specific clusters of a bsp. If there were a tilted fog plane, I don't know how tool/sapien/halo would react. It might decide that the fog level is the highest, lowest, or average height of the fog plane, or it might apply fog relative to the slant of the face and it's normal. I don't know how the shape of the fog plane affects the final result, since as far as I can tell, it automatically applies fog everywhere below a certain altitude in the entire level, no matter the extents of the fog plane) I don't know how multiple fog planes with different facing normals (not on the same spacial plane), work. But I am investigating and will reply with my findings. If you find anything, please reply in my fog thread listed above. Thank you!

One more thing, about water. You should read my fog thread above. Water levels (literally. The level of the water.) are defined by fog. You'll see in a fog tag, that the fog turns into water at a certain distance below the fogs surface. For instance, the fog used above the water in c10 is set to turn into water .4 world units below the fog plane. This matches up with the water you see, because the render only water plane that you see as the waters surface, (which has nothing to do with fog), is .4 world units below the fog plane. (The fog plane is .4 world units above the water plane. Form the fog plane to the water level, there is regular fog, but below the water level, there is water fog, which makes a splash noise when you enter/ exit it, is very dark and hard to see in, has underwater noises, and may be somehow connected to the bubbles you see when you fire human weapons under the water in c10. I'm still trying to figure out those bubbles...
Anyway, if you want to just have water fog below your water plane, you can add the fog plane symbol to the water plane, in addition to the !, making it a render only water/ fog plane, then changing the fog tag to become water 0.0 units below the surface. If you want to have alot of regular fog which does not become water, the oly way I know of to do it is tu just set the setting really high, so the fog becomes water like 100 units below the fog plane..

Here, China, you're wall back.
Edited by Vick Jr on Dec 26, 2008 at 10:01 PM
Edited by Vick Jr on Dec 26, 2008 at 10:03 PM