HdCoordSys doesn't get dirtied when the target xform prim changes

[marktucker]

Description of Issue

When hydra creates an HdCoordSys, it points to an xformable prim. If that xformable prim is animated or is edited, I would expect the HdCoordSys to receive a Sync call so that it can update its internal representation of the xform. But this does not happen. Unfortunately as far as I am aware, no standard render delegates support HdCoordSys, so it is only the upcoming release of Karma (which supports coordsys through MaterialX) which can clearly demonstrate this failure (though setting breakpoints in a debugger with any render delegate should make this problem clear).

Steps to Reproduce

1. Open the attached file into usdview, and set the renderer to karma:
   coordsys_test.zip
2. Move to another frame. The image re-renders, but is unchanged.
3. Switch to another render delegate and back to karma. See the effect of the changed coordsys.

Package Versions

USD 22.05, error may only be visible with Houdini 19.5.

[spiffmon]

Hey @marktucker , I believe we added coordsys support specifically to get our HdPrman renders of internal Pixar assets working, and it looks like we support it??
Which is not to say invalidation and tracking is working properly... just speaking to your "lack of support" statement?

[jilliene]

Filed as internal issue #USD-7409

[marktucker]

Oh, cool. Very happy to be wrong on that point, especially if it means someone can validate that this does or doesn't work with hdprman.

[tcauchois]

Fixed by 1b74956