Hi,

did a quick test with a USD file, which just contained a Mesh (rectangular, 3D) and a Nurbs cube (built with 6 NurbsPatches).
It seems that Houdini can push around the NurbsPatch(es) as packed prims after import, but as soon as you try to unpack a
NurbsPatch to a Polygon Mesh, it displays the error in the attached image ("Can't convert prim for unpack...Type=NurbsPatch").

As another test, I also created a SOP sphere and set its type to "NURBS" (Connectivity: Quads).
When I tried to add this to a stage (e.g. inside a SOP Create), it always gets converted to a "Mesh" PrimitiveType.
It can not be added as a NurbsPatch Type.

Did I overlook something or does Houdini not currently support unpacking NurbsPatches from imported / referenced USD ?
Also, does Houdini also not support writing NurbsPatches (from SOP Nurbs) to USD ?

In that case, is support for this planned to be added in the near future ?

Thanks

svenkr
Did I overlook something or does Houdini not currently support unpacking NurbsPatches from imported / referenced USD ?
Also, does Houdini also not support writing NurbsPatches (from SOP Nurbs) to USD ?

Nope, Houdini does not support writing NURBS surfaces to USD. I don't think it's planned any time soon either since it's not really supported in Hydra. Although it's possible to write a USD NURBS prim, when it goes to hydra, it's converted to polygons as if it were a catmull-rom subdivision surface--which will product distorted surfaces. Support needs to be improved on the Hydra side before it's worth Sidefx putting any time into it.