Filed as internal issue #USD-7060

I've run into the same issue and fixed it in my clone of the repo. I had to fix two locations:

1. In HdxTaskController::_SetParameters
2. In HdxTaskController::_SetBuiltInLightingState

After fixing those two locations I ran into another issue. After the dome light has been created, changes to its transformation are ignored (unless the light is removed and then added back). I traced the bug to HdxTaskController::_SetBuiltInLightingState where in the loop over lights to check for updates the transformation is not extracted again and the transformation of the SPrim is not marked dirty.

https://github.com/PixarAnimationStudios/USD/blob/release/pxr/imaging/hdx/taskController.cpp#L794

I fixed it by inserting this at the top

_delegate.SetParameter(_lightIds[i], 
                       HdTokens->transform,
                       lights[i].GetTransform());

and then marking the transform dirty as well.

GetRenderIndex()->GetChangeTracker().MarkSprimDirty(
        _lightIds[i], HdLight::DirtyTransform | HdLight::DirtyParams);

I hope this helps fix two issues in one go.

Cheers, Florian

Hey Howdy Hey, @florianhecht ! We don't seem to have a CLA from Adobe yet, but if that can be surmounted, we'd love a PR of your work, here.

Happy Holidays!

Hi @spiffmon . I'll check with my folks on that, but nothing is most likely to happen before end of January, due to travels.

Have a great Holiday break.