Error
Failed binding material.
Warning
Can only append a property 'material:binding:collection:spheres' to a prim path (/)
Warning
Cannot create relationship at invalid path </.material:binding:collection:spheres>
If I put in the prim that contains the collection used for the prim pattern I get a warning, and it still does not bind, however the usda looks like it might correct.
Warning
Cannot set metadata. Failed to create spec </collections.material:binding:collection> in layer @anon:0x7efd6bf24c00@
Using an explicit prim list instead of a collection with collection based assignment only works if the collection prim already exists, and is an ancester prim of that which is being assigned. The node will not create a new prim to contain the collection. If an existing collections prim is used, the binding is created but does not work. Even in the case of an ancester prim being used for the collection and it working in the viewer, I am still seeing a warning:
Warning
Cannot set metadata. Failed to create spec </shapes.material:binding:collection> in layer @anon:0x7fcdf4424d80@
Am I right to assume that collection based assignments only work when located in ancestor prims of those in the collection?
This would make the /collections and %foocollection workflow kind of useless for material assignments, as collections would always need to be localized.
I've attached example output from when I used an existing collection created by the collection lop for the collection based assignment and /collections is used as the collection path.
Edit:
/collections based collections and %foo syntax do work when used as the prim pattern for collection based assignments, but only when the destination prim for the collection is an ancestor of the collected prims. This creates a collection that ‘includes’ the /collections.foo collection instead of redundantly duplicating it which is nice. I still see the warning as above though. I think the help should be more clear that only ancestor prim collections will by considered by hydra and that a blank path for the target collection is never valid.