Distort noise to follow geometry flow?

Neon Junkyard · June 22, 2017

I'm trying to figure out how to distort noise so it follows the curvature and flow of the geometry. I attached an example of what I am trying to do, from the Nike Flyknit spot.

It is pretty well documented on how to do this using volumes and advecting points to create curl noise streamers, and I want to achieve a similar effect but using procedural textural noise. I am especially interested in the elongated striping shown in the example where it is not regularly broken up like turbulent noise does but is stretched along the flow direction.

The basic setup for doing this in volumes would be to take the double cross product of the volume gradient and an up vector, add noise, create a velocity field, advect points through it and create lines

So I have the same setup using the normals instead of volume gradient output to velocity and the vectors flow around the geo correctly. However from there I am not sure how to apply that to noise to have it distort the way I would like. If I output that to the input of the noise It sort of works but really just looks like adding noise to the normals. The part that I think I am missing is advecting the noise through a velocity field at a given time step to create the streaking. My guess you would do this like gridless advection where you multiply the velocity by a noise in a for loop and add it to back to the noise coordinates but so far haven't been able to figure it out

I also thought about doing a volume sample from the velocity field, or doing something with modulus or ramps but everything ended up streaky and full of artifacts

I attached a simple file I was messing with but didnt get too far. Any help on this would be very appreciated