Stage requires 1 default, root primitive

[Jose.C]

Hey a newbie question here!

I am trying to create a pipeline from OV assets to houdini and export them back to OV as a shattered version using RBD.

For doing that I sop import the model with the usdimporter, assign it the rbdmaterialfracture and import it from the lop context with a SOP Import. Then I validate the process with a omni validator that gives me the " Stage requires 1 default, root primitive" error.
If I export it with that error OV is unable to load the model saying it has no default primitive. But is Houdini I have created it with the restructurescenegraph1node. ( see hierarchy image).

How Can I fix it?

Thx

[Richard3D]

Wow this is VERY advanced stuff. Impressive. Let me get someone to help. Thanks.

[dloginowski]

Hello. You can (and should) specify a default prim path in the output rop before exporting back to omniverse. When going back and forth between lop and sop contexts, things like default prim definitions do not get preserved (without additional steps).

[Jose.C]

HI @dloginowski , can you enlighten me how to proceed?
ave created an Attribute Wrangle setting the usdprimpath ( see image ) but omni validator is still warning me about the missing root primitive

[dloginowski]

Hi you don’t need a wrangle, just click on the “usd_rop2” node and there is a default primitive field.

[dloginowski]

you can also use a configure layer lop.

[dloginowski]

I actually went into my houdini configs and made the output ROPs have /World as my default so that it throws an error when I try to export a scene that isn’t setup properly. /World is the recommended name per our standards but the most important thing is just to always have a default prim defined at all times.

[Jose.C]

@dloginowski. Much appreciated.
It works!