OTOY Forums

What does the 'Sample position displacement' option do in the Random Walk node and how is it used?

I can’t make much sense from the documentation: “allows a texture to control a volume's sample position displacement.” Does this mean it ONLY works on a vdb volume and not regular geometry?

Random walk is also volumetric, so whenever the engine needs to sample a particular point somewhere below the surface, the "sample position displacement" potentially modifies the actual point that is sampled.
This would usually be a procedural texture returning (3D) displacement vectors for any input point. The engine will then add the displacement to the original position it initially wanted and sample there instead. For volumes this can be used to add noise or even distort the volume shape. For subsurface scattering it's probably just for adding noise.