USD exporter aborts on duplicate prim paths from identically named objects in collections
0 reputation · 01 Jan 2021, 16:28 UTC
Duplicate prim path failure during USD export
Blender's built-in USD exporter (io_scene_usd) halts with a "Duplicate prim path detected" error when a collection contains multiple objects that share the same name. USD stages require unique prim paths, so the exporter treats identically named objects as conflicts and aborts the entire export rather than continuing.
Unresolved handling strategy
Unlike the Alembic and FBX exporters, which automatically append numeric suffixes (e.g., Cube, Cube_001) to resolve name collisions, the USD exporter currently offers no automatic disambiguation. Developer discussions indicate three unresolved directions: strict failure (current), optional auto-rename with user notification, or delegation to external pipeline tools. Auto-rename risks breaking downstream workflows that depend on stable prim paths as identifiers, while point instancer–based instancing—though capable of representing duplicates as instances of a single prototype—requires manual Geometry Nodes or Collection Instance setup.
Open design questions
- Should automatic suffix-based renaming be implemented as a default, an opt-in option, or left entirely to pipeline scripts?
- Would generating point instancers for duplicate objects automatically provide a more USD-native alternative to renaming?
- How should the exporter communicate any disambiguation it performs so downstream consumers can reconcile modified prim paths?
