TL DR : I want to create an alembic file containing an empty group with a custom attribute that's readable in Katana
I have a question that has been driving me crazy today.
When exporting alembics from Houdini and using them in Katana, let's say I have a geometry in Houdini with this path primitive attribute : fx_grp/fx/fxShape
From there I can easily add any attribute I want to the shape, but what about adding attributes to the transform ? and to the parent group ? fx_grp and fx_grp/fx have no real existence in Houdini so I would have to create an empty primitive with a path fx_grp and then add my attributes to this primitive. The problem is, if I create a primitive in Houdini for this group with
addprim(0, 'poly', 0);
addprim(0, 'AlembicRef', 0);
The only thing that's doing half of the work is creating a geometry node named fx_grp and exporting that with an alembic render node with Root Object set to /obj/ and Objects set to fx_grp. This gives an empty group with right name in Katana but I don't think it's possible to add attributes at the Object level.
Thanks !