Where can I find volumetric textures of wood, marbles etc.?
Many thanks,
Yossi
You can generate them yourself with a little work, using POV-ray. The nice thing with POV is that it has a very powerful text-based shader language (describing volumetric parametric textures), and comes with pre-configured textures for wood, marble, granite, jade, etc.
Thus rendering a simple quad to file, set up in an animation loop that moves the texture transform a little bit every frame, will generate a number of texture bitmaps, which you can compose into a 3D texture with some more work.
Not “instant” but a fun project, and easier than writing your own from scratch 