USD exporter aborts on duplicate prim paths from identically named objects in collections

The short answer

This is expected behavior, not a bug you can toggle off. USD requires every prim path in a stage to be unique, and Blender's io_scene_usd exporter maps object names directly onto prim paths. When two objects would land on the same path (for example, both becoming /root/Cube), the exporter aborts rather than silently renaming one of them. Unlike the Alembic and FBX exporters, it has no automatic numeric-suffix disambiguation, so the collision has to be resolved before export — by you or by a script.

Why duplicates exist at all

Blender normally enforces unique object names inside a single .blend file by auto-appending .001, so genuine collisions usually come from one of these sources:

• Linked data: objects linked from different library files that happen to share a name.
• Instanced collections whose contents flatten to the same path as scene objects.
• Library overrides where the override and another object resolve to the same exported path.

That origin matters, because it determines which fix is available to you.

Fixes, in order of preference

1. Rename the conflicting objects

The direct fix: give every exported object a name that produces a unique prim path, then re-export. If the objects are linked from a library and cannot be renamed in place, rename them in the source file, or rename the parent collection/empty that scopes their path — changing the parent path disambiguates the children without touching the objects themselves.

2. Use instancing instead of duplicates

If the identically named objects are genuinely the same thing repeated, collection instances or Geometry Nodes instancing map naturally onto USD point instancers: one prototype prim plus instance transforms. This eliminates the path collision entirely and produces a much smaller file. It does require restructuring the scene, so it is a design decision, not a quick patch.

3. Pre-export rename script

For large scenes, a small Python pass before export can detect collisions under the same parent path, rename, and log what it changed:

import bpy

seen = {}
for obj in bpy.context.scene.objects:
    key = (obj.parent.name if obj.parent else "", obj.name)
    if key in seen:
        obj.name = f"{obj.name}_dup"
        print(f"renamed conflicting object -> {obj.name}")
    seen[key] = obj

Keep the log: downstream consumers (lookdev, layout, shading assignments) often treat prim paths as stable identifiers, and any rename you perform must be reconcilable.

Verify the fix

Re-export and open the resulting .usda in a text editor — search for the previously colliding path and confirm each prim appears exactly once. Also check the USD export options panel in your Blender version before scripting anything: exporter options are version-sensitive, and newer releases may add collision-handling or instancing settings that make a workaround unnecessary. Behavior described here reflects established exporter behavior as of recent Blender 3.x/4.x releases; confirm against the version you run.

On the open design questions

Auto-rename as a default would trade a hard failure for a silent identifier change — arguably worse for pipelines that key off prim paths. An opt-in rename option with a written mapping report is the safer middle ground. Automatic point-instancer generation is the most USD-native answer but only valid when duplicates are truly identical, which the exporter cannot safely infer. Until Blender settles this, explicit renaming plus instancing where applicable remains the reliable path.