Attribute Paint has a "Recache Stroke" feature that can record the stroke I applied and re-applied them in the case the upstream topology is changed. That's cool.

But

1. Why don't other brush tools (Sculpt, Comb, etc) support this?

2. Without Recache Stroke, how can I re-apply my Sculpt when the upstream topology is changed? I can probably keep the old geometry network, and Ray my new geometry to it... but this way I need to keep the whole old geometry (and potentially a lot of old nodes). Is it possible to "bake" the difference between old and new geometry into a new Edit or Scult node?

Attribute Paint SOP is much newer and takes advantage of the stroke based workflow
While Sculpt, Edit, Comb, old Paint, ... Directly modify the geometry delta that gets applied on top of incoming geo and is dependent on element indices
So instead of reaching you'd need to transfer the modifications by another way yourself whether matching by UVs or capture by old geo +deform or reproject or any way you can think of, ...

(Technically it's not about older/newer since guidegroom went from being able to recache to not being able, mostly because of the complexity of some operations which makes them nonrecacheable, especially the vellum brushes)

raincole
Is it possible to "bake" the difference between old and new geometry into a new Edit or Scult node?

Yes, there is a sopcreateedit [www.sidefx.com] Hscript command you can use in Textport to generate Edit Sop by comparing 2 sops with the same topo

tamte
Yes, there is a sopcreateedit Hscript command you can use in Textport to generate Edit Sop by comparing 2 sops with the same topo

Thank you! That's very handy.

That being said, I feel SideFX should make a more generic way to do this... for example, what's the equivalent of sopcreateedit for normal...?

Edit: Hmm Edit SOP can rotate normals, so sopcreatedit should be able to handle normals too? I haven't tested it.