VRayScatterVolume on GPU/RTX

[HowardDay]

Is this still on the roadmap? I heard some estimates for by the end of last year, but nothing since.
Thanks!

[nikoleta.garkova]

Hi Howie,

Yes, it is still on the roadmap - I've bumped its priority additionally, will let you know when there is any movement on it.

[HowardDay]

Any movement on this one?
Also, I'm wondering if this is equivalent to the volume shaders in Corona? I'm really looking for a way to do planetary clouds and volumetric effects that don't require VDBs or volumegrids.
Thanks!

[Muhammed_Hamed]

Any movement on this one?

Hey HowardDay

This request has been fulfilled, the new translucency modes (SSS/Volumetric) are based on the volumetric random walk, originally developed for the VrayScatterVolume material, and slightly more advanced
The new modes perform actual multibounce volumetric light scattering, hence they require closed objects and GI with minimum of 16 bounces(brute force or light cache).
There is also thin-walled mode, which is also supported in update 2

Volumetric mode might be useful in your use case, it is used together with Refraction Color to scatter light inside an object as you want to avoid VDBs

Best,
Muhammed

[HowardDay]

Do these shaders work on the GPU/RTX mode?

[Muhammed_Hamed]

Yes, in update 2

[super gnu]

but, they do not support 3d procedural/volumetric texturing in any of their slots, so you can forget modulating density or colour within the volume. this is the case on both cpu and gpu.

[Muhammed_Hamed]

Thanks for the feedback super gnu
Which parameters would you want to map? Could you please explain more about your workflow?
we had one request about SSS amount, which is a slider in 3Ds Max and not mappable

Best,
Muhammed

[super gnu]

well ive already discussed this in a couple of other threads, but the ability to map the density or colour throughout the volume would be very nice. as it is, the density map slot on scattervolume (a volumetric property on a volumetric shader) only affects the density on the surface.. which, given the scattervolume isnt even used for surfaces, is nonsensical.

an example... planetary atmosphere. distance tex to reduce density the further we get from earth. does not work.

doing clouds using a piece of geometry to define volume, then procedural maps to break up interior... nope..

ice, with clear sections and cloudy sections.... nope!

marble, with coloured and translucent veins ruinning through it...nope.

in fact as it stands, only totally homogenous materials can be simulated. and the map slots are essentially useless for volumetric work.

the only tool (apart from volumegrid) that has proper volumetric texture sampling is vray environment fog, and that lacks all the other sss controls and is very slooow.

[Muhammed_Hamed]

ice, with clear sections and cloudy sections.... nope!

marble, with coloured and translucent veins ruinning through it...nope.

Could use some distorted geometry inside the volume for these 2 examples, it gets the job done with the current SSS models
I will talk to the developers about your request and see what is possible. Which rendering engines did you use for the examples above?

[super gnu]

Could use some distorted geometry inside the volume for these 2 examples, it gets the job done with the current SSS models
I will talk to the developers about your request and see what is possible. Which rendering engines did you use for the examples above?

i didnt produce these examples.. i merely wish the texture slots for volumetric properties of volumetric materials sampled volumetric textures, volumetrically... i would consider map slots which only affect the surface of a shader specifically not designed to shade surfaces, a bug.

[Muhammed_Hamed]

Thanks for explaining that, I will talk with devs and see what is possible

Best,
Muhammed

[ViperCGI]

Could use some distorted geometry inside the volume for these 2 examples, it gets the job done with the current SSS models
I will talk to the developers about your request and see what is possible. Which rendering engines did you use for the examples above?

Sorry, I know this is an old thread, but these issues remain to this day. Specifically for planet atmospheres, which is something that comes up a lot, Vray still can't properly do it. What we need is a way to alter the density of the medium based on distance to a reference object. Ideally with a customizable curve so the density can decrease in a non linear way.

Corona can do it fairly well cause both its volume material and the distance node work in three dimensions. But I don't want to have to pay for two different renderers, and Corona has its own set of issues (No GPU, no proper UDIM support, no ACES, etc)

I should also say, the fact that vray doesn't have a true volumetric shader is weird to me. There's no way to model the shape of a cloud and use a shader for its material if I need to. The only way to do it is by simulating or importing a VDB. If we had such a shader, then at least we could use OSL to solve the atmosphere and clouds on planets (Which are also an issue. At the moment I could get by with fastSSS but it's not the correct solution)

[piotrus3333]

Sorry, I know this is an old thread, but these issues remain to this day. Specifically for planet atmospheres, which is something that comes up a lot, Vray still can't properly do it. What we need is a way to alter the density of the medium based on distance to a reference object. Ideally with a customizable curve so the density can decrease in a non linear way.

Corona can do it fairly well cause both its volume material and the distance node work in three dimensions. But I don't want to have to pay for two different renderers, and Corona has its own set of issues (No GPU, no proper UDIM support, no ACES, etc)

I should also say, the fact that vray doesn't have a true volumetric shader is weird to me. There's no way to model the shape of a cloud and use a shader for its material if I need to. The only way to do it is by simulating or importing a VDB. If we had such a shader, then at least we could use OSL to solve the atmosphere and clouds on planets (Which are also an issue. At the moment I could get by with fastSSS but it's not the correct solution)

distance map does work with volume grids.
https://forums.chaos.com/forum/v-ray...10#post1156110

[ViperCGI]

distance map does work with volume grids.
https://forums.chaos.com/forum/v-ray...10#post1156110

I'm not sure how that's supposed to help. The amount of voxels I'd need to use to get a good resolution shadows would be prohibitive I think. This should all be possible using shaders in spheres. Again, Corona can do it. I don't understand why we are so limited in Vray