Review the following code for creating 1000 sphere instances.

The authored prims do not produce scenegraph-instancing efficiencies because the code authors local prim hierarchies directly under each /test_i prim rather than composing shared content through references, payloads, inherits, specializes, or variant arcs. NVIDIA’s Learn OpenUSD scenegraph instancing guidance states that “Instancing is driven by your composition arcs” and explains that if there are no composition arcs on the instanceable prims, there is nothing from which OpenUSD can generate shared prototypes. ( docs.nvidia.com )

Option A is correct because instanceable = true alone is not sufficient. OpenUSD scenegraph instancing works by sharing composed subgraphs brought in through composition arcs; in this code, every sphere is authored as a unique local child in the same layer stack. NVIDIA’s Omniverse instancing guide states that if no composition arcs are directly authored on an instanceable prim, the prim behaves as if instanceable were false. ( docs.omniverse.nvidia.com )

Option B is incorrect because instance roots may vary by transform, primvars, and other root-level data while still sharing prototypes. Option C is incorrect because the child sphere is not the instance root; marking it instanceable would still not create shared prototypes without composition arcs. This aligns with Content Aggregation → Asset Modularity and Instancing → Scenegraph Instancing, Composition Arcs, Instance Roots, and Implicit Prototypes .