Flattening scene index

I am investigating the Hydra 2.0 scene index chain and have a question regarding the flattening scene index. I did some test changing the transform of an xform prim and I thought that with a chain scene index containing the flattening scene index that modifying a transform will call PrimDirtied on all child. But I still get only one _PrimDirtied on the prim I changed. After investigation it seems that the root cause is _PrimLevelWrappingDataSource in the function
bool _PrimLevelWrappingDataSource::PrimDirtied( const _DataSourceLocatorSetVector& relativeDirtyLocators)
when doing the

HdDataSourceBaseAtomicHandle& dsAtomicHandle = computedDataSources[i]; HdDataSourceBaseHandle const ds = HdDataSourceBase::AtomicLoad(dsAtomicHandle); if (!ds) { continue; }
the datasourcehandle is empty and we break the loop.
Is this normal behaviour or am I missing something ? Maybe I am doing something wrong…
Any thought ?


I finally found out my mistake. As I’m trying to trick hydra, I was never calling the XFormSchema. Doing so fixes my issue (which is finally a mistake). Hope it can helps other if anyone is struggling with this in the future.