Which of these is a viable approach for mapping or grouping compound types from other data sources to OpenUSD?

OpenUSD does not have a native "struct" data type. The established convention for grouping related data components, such as from a compound type in another source, is to use namespace-prefixed attributes. A common prefix is used for all attributes that belong to the group, creating a logical association. For example, a complex primvar might be represented by primvars:myVar:values and primvars:myVar:indices. This approach is fundamental to how schemas like UsdGeomPrimvars organize complex data on primitives.

A. arrays are a value type for a single attribute, not a mechanism for grouping multiple distinct attributes together into a compound structure.

C. structs are a concept from other languages or systems; OpenUSD uses namespace-prefixed attributes to achieve a similar grouping, rather than having a native struct type.

1. Pixar, "USD Glossary - Namespace". OpenUSD Documentation. Accessed Oct 2023. (Describes the use of colons as namespace delimiters in identifiers).

2. Pixar, "UsdGeomPrimvars: UsdGeomPrimvar". OpenUSD Documentation. Accessed Oct 2023. (Provides concrete examples of namespace-prefixed attributes like primvars:displayColor and primvars:myindexedprimvar:indices).

3. Pixar, "Coding Standard: Schemas". OpenUSD Documentation. Accessed Oct 2023. (Section on "Attribute Names" discusses the namespacing convention for schema attributes).