Composition (what @cinevva/usdjs supports)

OpenUSD composition (Pcp) is deep. @cinevva/usdjs implements a practical subset that targets common real-world assets and keeps the API small.

Supported (today)

• Sublayers (subLayers)
• References (common authoring patterns)
• Payloads (supported in the arc expansion path)
• Variants
• Inherits (class opinions)
• Internal references (</PrimPath> style) used for instancing-like patterns in some assets

Not supported (yet)

• Full Pcp prim indexing / caching parity
• Specializes
• Relocates
• Clips

Design intent

• Prefer deterministic behavior and “works on real assets” over implementing every edge case up front.
• Preserve unknown metadata/fields so downstream tools can round-trip without losing information.