I wanted to share this as it took me a really long time to figure this out.
My objective was to animate a complex particle hair groom via something other than a single curve. With the current set tools, you have kind of 2 obvious routes:
Throw on lattices and get the particles to deform by deforming the lattice
Use a curve force with the limitation that you can only use 1 curve to deform and it’s destructive to a generated groom
I went down a rabbit hole of geo nodes and looking into hacking .bphys files to hijack the solver cache and just pop in my own animated curves. These were not good solutions, however I realized that Ellie in the new short had animated hair, grabbed her rig and sure enough, particle hair. The trick w/ Ellie is it’s glued together through a script that updates the key curves on frame change or dep graph update. Not terribly awesome, but it works.
You have to have a mesh bake down of the groom curves and a set hierarchy defined in the script, also for whatever reason the curves that bake down from the “convert to mesh” button are not the same vert count, so I had to rebuild them via geo nodes. But once I got them up and running I was off to the races.
Hope that helps future hair animators, enjoy!