Procedural clouds

[GregoryVFX]

Hey Vlado,

Are these clouds a 3D atmospheric effect, or a 2D plate projection effect ?
It seems they are always rendered as a background plate.
Maybe, they were never meant to be fully 3d volumetric, but... I can't help it but think that...

It would be utterly amazing if we could render objects in-between and behind those clouds.
It would take the environment fog and aerial perspective setups to a whole new level.

Any thoughts?

[vlado]

They are a 3D volumetric effect but are currently a part of the VRaySky texture and so are behind all else in the scene. This is done for performance reasons. They can be made into an atmospheric effect - perhaps as part of the aerial perspective - and that's something that we can consider for an update.

Best regards,
Vlado

[GregoryVFX]

They can be made into an atmospheric effect - perhaps as part of the aerial perspective - and that's something that we can consider for an update.

I think it's pretty clear how extremely beneficial that would be for cloudy and foggy environment scenes, considering the easy of use of the toolset, compared to the Environment Fog settings.

[Mr.Mxyzptlk]

I'm just going to add to this.
The artifacts reported are not present when disabling visibility in the domelight.

Good catch. I got the same result.

[rod_barr]

Just Tested the Procedural Clouds in VraySun, its amazing,
however is it possible to add like auto offset on clouds when using the Daylighting System in Max ?
for example the clouds move position when the sun is on a different position, or rather an auto offset multiplier to control the offset every movement,
its would be a gamechager if there was this feature, it would be really beneficial for short videos.

[anders]

not sure if bug or just how it is .. but if I add the DefaultVraySky to a domelight, it renders a LOT faster and cleaner, as expected, but it takes +10 seconds before it starts rendering, when I turn off the dome, it takes less than 1 second to start .. why the long pause?
(see attached video)

[vlado]

The pause is because the dome light needs to pre-sample the sky so that it can do importance sampling. We've already done some improvements there after the beta release; at some point we can move this to the GPU.

Best regards,
Vlado

[kosso_olli]

not sure if bug or just how it is .. but if I add the DefaultVraySky to a domelight, it renders a LOT faster and cleaner, as expected, but it takes +10 seconds before it starts rendering, when I turn off the dome, it takes less than 1 second to start .. why the long pause?
(see attached video)

Same here. Plugging the VraySky into a domelight creates a noticeable delay when changing values, whereas it is near instant when used as environment map.

Here is the first test. The speed and ease are great!
Apart from having a "storminess" value that was already requested, a kind of fuzziness value would be great. So the clouds can be made a little sharper and richer in detail. Right now they look a little blurred, almost painterly.

[Vizioen]

If you go low in values like 10 m for heighth you get these grid like patterns.

[Dave_Wortley]

Am I the only person who expected to find the cloud settings in the VraySky Material rather than the VRaySun?

[^Lele^]

Well, the vraySky map is used only when manually overriding the sun, otherwise all the sky parameters are on the Sun itself.
So it does make sense to have the clouds' settings in the sun as well.
Speaking of which, we'd need the settings duplicated in the sky map to ensure usability in case of non-V-Ray sun usage.

[Vizioen]

Am I the only person who expected to find the cloud settings in the VraySky Material rather than the VRaySun?

No that was the first place I was looking for it too.

[matanov]

New builds with some improvements - https://nightlies.chaos.com/main#/vr.../beta/20220610

• the sun disk now is properly hidden if behind clouds
• baking for V-Ray GPU is a little faster
• banding artifacts should be fixed

[racoonart]

Another issue for me right now is atmospherics. I've played around with this over the last couple of days but nothing really does it...
So far Aerial Perspective was kinda fine, except for godrays but with cloud shadows it all pretty much falls apart.

- godrays with env fog are hard... I rarely get something I like. Biggest issue is the lack of forward/backward scattering in the env fog, like the phase in ScatterVolumeMtl
- godrays with a box and a ScatterVolumeMtl are comparatively easy , but fall apart with reflections within the box. Also just discovered a bug with the Adaptive dome (bug report in issues following shortly)
- env fog + aerial perspective doesn't work together

So, long story short: What I wish for is an environment fog that can emulate aerial perspective AND has proper phase settings (or whatever is necessary to get more control over these types of effects, dust vs droplets and so on).
Clouds are super fun, but for big environment hero shots we need some improvement on atmospherics.

[vlado]

Yes, we do need some improvements to the environment fog and/or the aerial perspective and I've made a note to look into it. It is possible to get stuff like in the attached image but it is indeed quite fiddly without the phase function control and looks more like dust.

Best regards,
Vlado