Volumetric Clouds

[Sosna 0]

In Arma right now there isn't much variation in sky appearance, at times it's a real atmosphere killer.

I was thinking, what if a system of realistic 3D clouds were implemented?

Here's an example of such a system: http://simul.co.uk/cloudwright/gallery

The main drawback is system resource usage. I don't know how much more resources would be used compared to the current layered skybox.

However there are many benefits:

- Realistic shape, no paper thin clouds (particularly nice for high altitude flight)

- Realistic ground shading from clouds

- Unlimited randomized variation, no "familiar" clouds

- No need for pre-drawn sky boxes and cloud graphics

- Perfectly smooth weather transitions (instead of skybox switching)

It could be done with particles, or perhaps voxels. I'm not sure of the costs vs benefits...

Anyways, just something to consider.

[SaBrE_UK 0]

Nice idea. As games move further technology wise, more and more of these things will be implemented. As it becomes possible and there is spare time and graphics memory then these things will be standard in most games. Crysis style graphics will be in every game in under 5 years.

[ryankaplan 1]

sounds nice, but i'd personally rather have my cpu working towards that battalion vs battalion fight.

[Scoo 0]

sounds nice, but i'd personally rather have my cpu working towards that battalion vs battalion fight.

Still nothing wrong with having optional fancy clouds right? :) Might benefit the machinima community too, or generally for "calm" missions or when there is a lull in the fighting. A nice implemention would be to scale what performance they consume, freeing more CPU power for combat.

[LtCmdrBoon 0]

FSX does it nice, however seen as it doesn't have much else to draw, might be unrealistic expectation. Would be nice though.

[mrj-fin 0]

There is nothing impossible its only how hard developer will waant game to support such of issues. I am quite sure that BIS will not put this to high importance in their list.

[hoot 0]

You may want to read what 'volumetric cloud rendering' is based on and how complex 'volumetric rendering' generally (dealing with fluid dynamics and marker and cells, generating iso-contours and so on) can be. Guess time is running short for such implementations and a release of ArmAII in 2008

[CarlGustaffa 4]

I'm not too concerned with volumetric clouds per se, but nicer 3D looking clouds is always welcome. However, the weather system in general is quite a limitation. I know Arma2 now supports ground fog, and it looks extremely cool. To the foot soldier, this might be the one that has greatest impact combat wise.

But it would be nice to setup 4 or 5 different "layers" of clouds:

Low altitude cumulus (can rain as showers)

Low altitude stratus (can rain as steady precipitation)

Medium altitude cumulus (no rain usually)

Medium altitude stratus (no rain usually)

Cirrus of random type, just define coverage

Stratus clouds are "sheet clouds", that cover a widespread area, indicating a stable airmass. Rain from these are called rain or precipitation and is considered quite stable. These are relatively easy to create in a game just using a few "layered sheets" of textures (with alpha transparency)

Cirrus are the easiest to create for a game; just mix in some textures and paint a sky with it, unreachable for all aircraft.

Cumulus are those cauliflower looking clouds, lumps of clearly defined white lumps of cloud appearing to be very local. These clouds will be by far the most challenging to make from a programmers standpoint, I have really no idea how to make these efficient AND good looking. If these rain, it is called showers and can go on and off quite rapidly. Showers are often an indication of unstable air masses, and thunderstorms may be frequent. Only thunderstorm clouds (cumulunimbus) can produce hail, and these are developed cumulus clouds that has gone through the towering cumulus stage.

A quick sidenote; flying in cumulus clouds is more bumpy than flying in stratus clounds. Thunderstorms are extremely nasty and usually avoided if possible. Maybe this should be reflected in aircraft handling? For easiness, reduce effect near ground to avoid crashes.

That's a little of the background in weather.

In ArmA2, I'd like to see seasonal changes. That is, date determines texture mix; snow/dry surface and snow altitude. Collecting snow might be bit too much though

Another ArmA2 specific thing I'd like to see is temperature; too high and it affects your endurance/stamina. Too low and it affect your aiming shake. Proper outfitting should reduce these effects. Pretty simple.

Now, in the editor, have a timeline where you can set how long the timeline is (in minutes), with a random factor at the end of the scale. Create "weather keyframes" here.

Under this there are the following graphs, and a governing random factor for each, on the right:

Fog density; 0-1 (how dense the groundfog is)

Fog altitude; 0-1 in thousands of feet.

Fog halfheight; 0-1 (in thoughsands of feet, how thick it is).

Haze density; 0-1 (this is todays style of fog, affects distance only)

Haze altitude; 0-1 in thousands of feet. Lower remains same.

Haze halfheight; 0-1 (in thoughsands of feet, how thick it is).

Low altitude cumulus, 0-1, 0.7-0.8=TCU, and 0.8-1=CB

Low altitude stratus, 0-1

Medium altitude cumulus, 0-1

Medium altitude stratus, 0-1

Cirrus of random type; 0,1

Cumulus precipitation amount; 0-1

Cumulus precipitation type; temp based or rain, snow, (hail only if CB)

Stratus precipitation amount; 0-1

Stratus precipitation type; temp based or rain, snow, drizzle (nearly fog).

Temperature 0 feet MSL: -40°C to +40°C

Temperature 1000 feel MSL: -40°C to +40°C

Temperature 2000 feel MSL: -40°C to +40°C

There might be a temperature inversion going on allowing increasing temperatures with altitude.

These are just my ideas about how an extremely good weather system might be in Arma2.

Hey, it's my dream, don't ruin it