Fog in T3D w Skybox vs Scatter Sky - fogBandHeight

#1 I am of the understanding that ScatterSky is built with fancy shaders and the sort - you'd then have to have fog populate into those shaders.

Skybox is an object to display a cubemap.

#2 ok.... i get that.

My biggest complaint about the fog is that it is being used as a setting. The LevelInfo seems to ignore the skys and just effect the land and both the Skys fog settings effect.... well the skys themselves.

Would it be possible to make a Fog Object that combines settings from Precipitation, LevelInfo and the Skys and use that so that it effects BOTH the land and sky. Im just curious at this point. it seems like an interesting thing to add.

#3 Precipitation might be a great start - use a particle based volumetric fog, or some sort of "fog band" polygons (I'm thinking like they used in Freelancer for the junk fields, but less obviously painted on geometry).

#4 Thanks Richard....

due to your suggestion i was able to create ...imo.... a reasonable zone wide fog and was even able to contain it to an area like a lake or a forest.

#5 Glad I could pass on the idea and that it was useful! So ... screenshots?

#6 [IMG]http://img813.imageshack.us/img813/3641/ffog.th.png[/IMG]

#7 wow, that really looks good,
care to explain what you did?

#8 That is sweeeeeeeeet! Precipitation? Big fog "drops" and slow fall rate? Or a particle emitter? However you did it, it looks great.

#9 That could make a great resource, hint hint

#10 looks very cool for a dense fog but what happens when you look up Paul ? do the billboards get funky and you have a clear view of the sky ?

#11 @Richard and others - Ill be posting some stuff on "how to" in the next day or 2.

@Andy - Ill do another pic when i get home tonight, but as far as i *remember* it looks fine even looking up.

the one issue that i DID notice is that using it as a lake fog means that the bottom of the lake became visible. i think thats a setting that i left on for the "normal" fog though. Im still working out that. I had to get the rest of the dynamic weather/cloud/moon system out over the weekend so that fog took a back seat for a day or 2.

#12
This is the view looking up.

#13 There was a z-sorting issue with water and other alpha-blended materials a while back where trees, for instance, would lose their transparent parts when viewed from under water. This water fog thing might be a similar issue.

#14 Bit of a bump, but played around with the idea myself, and it has some very cool uses, can fake a localized volumetric fog if subtle enough, and with a very small amount of turbulence movement can give a very spooky effect too.

Few pics from a quick test


could very easily be used to create a localized fog over a lake, or in amongst a wooded area

#15 beautiful pics.

that was about what i had gotten the more i played with the idea. what was your FPS hit?

#16 nothing noticable to be honest although i havent checked, that one theres only a 100x100x20 precipitaiton box with 500 billboards thrown together quick, ill have a little look later today to see what the fps is like with and without it but didnt notice anything slowing down when near it to make me bother checking metrics lol

btw Paul, in your second picture where youre looking up, I noticed a line across the middle, the image file your using for the billboards, try using a big circle faded out to nothing so theres no 'edge' as such to the image, gives a much smoother blended effect even on the edge of the precipitation area

#17 ok just loaded it back up to check the fps on that example.

Around 85-90 while running around that map without the fog in view, when approaching the fog, at a long distance, some reason it drops down to around 70. but when closer to it and going through it, it goes back up to around 80.

#18 ill try the circle when we add that to the test environment - thanks for the suggestion! i had used the default rain and thats what caused the line you saw. Im willing to bet the faded circles may fix part of the issue that i had with the water also - or at least hopefully make it less noticable.

we are getting about the same performance. thats what i was hoping to see.

#19 any help on how this is done?

#20 This resource should help with fog and scatter skies.

This resource explains how to use precipitation for fog as shown here.

Thanks again, Paul - great stuff!