Hi,
I am a bit confused about how the rest position node affects the displace VOP when I am using it in a bump displacement setting.
As you see in the pictures I have a basic set up linking a surface color with proper uv data node to the value of a displacement node. Just for the record, the displacement node is set to bump displacement.

And the set up works great without the rest position being feeded into the P input of the displacement node. It actually works great even after FEM deformations (I tryed it, no problem with deformations).

Nonetheless for the sake of being prudent i decided to feed the rest pos and then this happens ( see picture 2 ).

I don't quite understand why this happens. Why the rest position will have any effect at all on a non-deformed geometry. And I also wonder if it matters at all when using UV maps to give rest position data to the displace VOP.

I know that there is some basic concept here I am not understanding so any help will be appreciated.

I recreated the problem in the attached hip file. you can see the result when plugin or un-plugin the rest position node.