How to create a volumetric material (3D texture) in Substance Designer?

[Nikolay358978232bdj]

I'm trying to create a volumetric material like here:
https://www.artstation.com/marketplace/p/doBV0/3d-volumetric-wood-smart-material

https://www.artstation.com/marketplace/p/deVg/3d-volumetric-oak-wood

I probably need to use a 3D Texture SDF node.
I can't find any tutorials. Help me to understand.

[davescm]

Take a look at this that I made a while ago - the pixel processor does the heavy lifting and I've attached the sbs file so you can look at the function within it. It calculates where in 3D world space each point on a material surface is and uses that to map a pattern based on a volume through a cube.

It needs a baked position map from mesh in order to work and do that calculation.

Dave