Hi,
when something like UpdateForTime is called in the imaging adapter is there a way to change prim that this adapter is being called on and store some data on it?
UsdImaging is a read-only client of the stage; writing to the scene would probably cause serious stability issues.
Hydra itself is scene-agnostic, and referring to USD prims would break encapsulation.
If you want to make stage edits on time update, I’d recommend doing that in your application code instead. If you want to transform data as it goes to the renderer, I’d recommend the hydra scene index plugin system.