I tested bumps and displacement in the principled shader core.
hip:https://drive.google.com/file/d/1UmrMuPRPJjgUy3og1iO4IUKRWFW_cAT-/view?usp=sharing
I referenced several HP. It's big help for me.
https://www.sidefx.com/forum/topic/49305/?page=1#thumbs-up
https://www.sidefx.com/forum/topic/15611/?page=1#post-73669
