Hi,

I noticed that the Instancer lop creates a top level Flattened_Prototype_1 prim which is referenced by instances.
According my understand the prototype should be the prim under /instancer1/Prototypes.
I can't find the relation between Flattened_Prototype_1 and /instancer1/Prototypes/cube.
I want to know the reason for doing this?

Thanks!

Looks like you're inspecting the flattened stage rather than the active layer? When USD flattens a stage, all implicit instance prototypes become "explicit" and show up on the stage as regular prims. In the scene graph tree you can turn on the display of implicit instance prototypes and you'll see this same /Flattened_Prototye_1 prim appear. I'm not sure exactly why flattening a stage saves out these implicit prototypes, but I'm sure there's a good reason for it.