Based around the video here: youtube.com/watch?v=9HI8FerKr6Q and youtube.com/watch?v=6LVtqrv_QfA
Done in Houdini with a sop solver, some vdb nodes (to maintain a uniform detail) and a velocity field. I have a few more in the works, with different shapes / shaders.
Shoutout to Eetu on odforce as well, for giving a basic explanation of it which helped me figure it out.
Hip File for those interested. It's basically measure curvature, use as mask to displace/advect along gradient and vel field. Pretty simple for how neat it looks! It, for whatever reason is a bit crashy. Something with the sop solver and vdbs seems to make Houdini crash more often, usually when interactively hitting esc to stop the sim.