Using procedural noise to drive volume density

[DanCaldwell3D]

Hi everyone, happy 2020!

I was looking at the post regarding the 2020.1 beta release, and I saw an image there which seems to show a volumetric cube with a wispy cloud type effect driven by a procedural texture (its under the native C4D noise support section)

I want to know how I can set this up.. Is it something that can be done in the current release?

Thanks,
Dan

[aoktar]

Connect ant 3d procedural with 3d projection to scattering pin of mediums and tweak absorption,scattering, density values. Also scale and parameters of procedurals and done!

[DanCaldwell3D]

Thanks I'll give it a try!

Cheers

[DanCaldwell3D]

Thanks for your advice, aoktar. I finally got around to trying it out and.. it doesn't work

I have linked a ridged fractal procedural to the scattering input of a volume medium, which is linked to the medium input of a specular material which has transmission set to 1 and IOR set to 1 as well. Roughness and reflection are set to 0. I have the material applied to a plain ol' box.

When I wire the ridged fractal texture into transmission, I can see the texture is projecting in 3d space as expected, however when I wire it to scattering the result is just a uniform grey cube, the same as if I just set scattering to 1. I feel like this is something that should work, but doesn't for some reason.

I am trying this on Octane 2019.1.4 in Modo. I have tried the same thing in Octane Standalone (also 2019.1.4) and it doesn't work there either.

Any input on how to solve this issue would be appreciated

Cheers

[bepeg4d]

Hi,
It is a good idea to always post some screenshots, to better explain your issue.
In your original post you asked about volume density and textures, but with Specular material you should need to use a Scattering Medium node, not a Volume Medium node, and you need v2020 with Random Walk, to be able to use a texture with Scattering Medium.

ciao Beppe

[DanCaldwell3D]

Ohhh i see.. Thanks Beppe, I didn't know random walk SSS was required for the effect! I'll include screenshots next time.

So if I understand correctly, does this mean that scattering and absorption can only be a single colour for Octane materials pre 2020 builds?

Thanks

[bepeg4d]

Yes correct, for materials with Scattering Medium pre 2020, you need to use the texture in Transmission, possibly with higher Power, to give more energy to the light to come in.
For Volumes, you can use a texture in Absorption and Scattering of a Volume Medium node from 2019.1.

Happy GPU Rendering,
ciao Beppe