Export problem when converting USD format to .STL( .FBX, .OBJ)

Omniverse Isaac Sim
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1

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Isaac Sim Version

5.0.0
4.5.0
4.2.0
4.1.0
4.0.0
4.5.0
2023.1.1
2023.1.0-hotfix.1
Other (please specify):

Operating System

Ubuntu 22.04
Ubuntu 20.04
Windows 11
Windows 10
Other (please specify):

GPU Information

  • Model: RTX A4000
  • Driver Version: 572.83

Topic Description

Detailed Description

(Describe the issue in detail, including what you were trying to do, what you expected to happen, and what actually happened)

I’m having an issue where when I try to export a .usd file created in Omniverse Isaac Sim to .stl (or .fbx, .obj) via the Export feature in the file tab, only a material file folder in .png format is created and no mesh data is created.

Steps to Reproduce

  1. Just do as described in the description above to reproduce.

(Add more steps as needed)

Error Messages

(If applicable, copy and paste any error messages you received)

2025-09-29 01:50:59 [1,016,594ms] [Info] [omni.kit.asset_converter.impl.omni_client_wrapper] Copying from http://omniverse-content-production.s3-us-west-2.amazonaws.com/Assets/Isaac/4.1/Isaac/Environments/Modular_Warehouse/Props/Source/textures/t_firebutton_a01_albedo.png to c:/Users/6414868/Desktop/warehouse_for_AMIO_STL/materials/textures/t_firebutton_a01_albedo.png…
2025-09-29 01:50:59 [1,016,604ms] [Info] [omni.kit.asset_converter.impl.omni_client_wrapper] Copying from http://omniverse-content-production.s3-us-west-2.amazonaws.com/Assets/Isaac/4.1/Isaac/Environments/Modular_Warehouse/Props/Source/textures/t_firebutton_a01_albedo.png to c:/Users/6414868/Desktop/warehouse_for_AMIO_STL/materials/textures/t_firebutton_a01_albedo.png done…
2025-09-29 01:50:59 [1,016,612ms] [Info] [omni.kit.asset_converter.impl.omni_client_wrapper] Copying from http://omniverse-content-production.s3-us-west-2.amazonaws.com/Assets/Isaac/4.1/Isaac/Environments/Modular_Warehouse/Props/Source/textures/t_firebutton_a01_opacity.png to c:/Users/6414868/Desktop/warehouse_for_AMIO_STL/materials/textures/t_firebutton_a01_opacity.png…
2025-09-29 01:50:59 [1,016,620ms] [Info] [omni.kit.asset_converter.impl.omni_client_wrapper] Copying from http://omniverse-content-production.s3-us-west-2.amazonaws.com/Assets/Isaac/4.1/Isaac/Environments/Modular_Warehouse/Props/Source/textures/t_firebutton_a01_opacity.png to c:/Users/6414868/Desktop/warehouse_for_AMIO_STL/materials/textures/t_firebutton_a01_opacity.png done…
2025-09-29 01:50:59 [1,016,629ms] [Info] [omni.kit.asset_converter.impl.omni_client_wrapper] Copying from http://omniverse-content-production.s3-us-west-2.amazonaws.com/Assets/Isaac/4.1/Isaac/Environments/Modular_Warehouse/Props/Source/textures/t_panelcontrol_b01_decal_albedo.png to c:/Users/6414868/Desktop/warehouse_for_AMIO_STL/materials/textures/t_panelcontrol_b01_decal_albedo.png…
2025-09-29 01:50:59 [1,016,638ms] [Info] [omni.kit.asset_converter.impl.omni_client_wrapper] Copying from http://omniverse-content-production.s3-us-west-2.amazonaws.com/Assets/Isaac/4.1/Isaac/Environments/Modular_Warehouse/Props/Source/textures/t_panelcontrol_b01_decal_albedo.png to c:/Users/6414868/Desktop/warehouse_for_AMIO_STL/materials/textures/t_panelcontrol_b01_decal_albedo.png done…
2025-09-29 01:50:59 [1,016,646ms] [Info] [omni.kit.asset_converter.impl.omni_client_wrapper] Copying from http://omniverse-content-production.s3-us-west-2.amazonaws.com/Assets/Isaac/4.1/Isaac/Environments/Modular_Warehouse/Props/Source/textures/t_panelcontrol_b01_decal_opacity.png to c:/Users/6414868/Desktop/warehouse_for_AMIO_STL/materials/textures/t_panelcontrol_b01_decal_opacity.png…
2025-09-29 01:50:59 [1,016,655ms] [Info] [omni.kit.asset_converter.impl.omni_client_wrapper] Copying from http://omniverse-content-production.s3-us-west-2.amazonaws.com/Assets/Isaac/4.1/Isaac/Environments/Modular_Warehouse/Props/Source/textures/t_panelcontrol_b01_decal_opacity.png to c:/Users/6414868/Desktop/warehouse_for_AMIO_STL/materials/textures/t_panelcontrol_b01_decal_opacity.png done…
2025-09-29 01:50:59 [1,016,664ms] [Info] [omni.kit.asset_converter.impl.omni_client_wrapper] Copying from http://omniverse-content-production.s3-us-west-2.amazonaws.com/Assets/Isaac/4.1/Isaac/Environments/Modular_Warehouse/Props/Source/textures/t_panelcontrol_b01_decal_orm.png to c:/Users/6414868/Desktop/warehouse_for_AMIO_STL/materials/textures/t_panelcontrol_b01_decal_orm.png…
2025-09-29 01:50:59 [1,016,675ms] [Info] [omni.kit.asset_converter.impl.omni_client_wrapper] Copying from http://omniverse-content-production.s3-us-west-2.amazonaws.com/Assets/Isaac/4.1/Isaac/Environments/Modular_Warehouse/Props/Source/textures/t_panelcontrol_b01_decal_orm.png to c:/Users/6414868/Desktop/warehouse_for_AMIO_STL/materials/textures/t_panelcontrol_b01_decal_orm.png done…
2025-09-29 01:51:52 [1,069,416ms] [Info] [omni.kit.asset_converter.impl.task_manager] Info, T35272: Removed 6897 nodes and 0 animation channels (2283 output nodes)

2025-09-29 01:51:52 [1,069,464ms] [Info] [omni.kit.asset_converter.impl.task_manager] Info, T35272: Kept 0 lights and 0 cameras.

2025-09-29 01:51:52 [1,069,464ms] [Info] [omni.kit.asset_converter.impl.task_manager] Info, T35272: Moved 5581 meshes to WCS (number of output meshes: 2282)

2025-09-29 01:51:52 [1,069,521ms] [Info] [omni.kit.asset_converter.impl.task_manager] Warn, T35272: Skip a ear, due to its angle is near 0 or 180.

2025-09-29 01:51:53 [1,070,688ms] [Info] [omni.kit.asset_converter.impl.task_manager] Error, T35272: Failed to triangulate polygon (no ear found). Probably not a simple polygon?

2025-09-29 01:51:54 [1,071,474ms] [Info] [omni.kit.asset_converter.impl.task_manager] Warn, T35272: Skip a ear, due to its angle is near 0 or 180.

2025-09-29 01:51:56 [1,073,463ms] [Info] [omni.kit.asset_converter.impl.task_manager] Error, T35272: Failed to triangulate polygon (no ear found). Probably not a simple polygon?

2025-09-29 01:51:56 [1,073,613ms] [Info] [omni.kit.asset_converter.impl.task_manager] Warn, T35272: Skip a ear, due to its angle is near 0 or 180.

2025-09-29 01:52:00 [1,077,346ms] [Info] [omni.kit.asset_converter.impl.task_manager] Info, T35272: TriangulateProcess finished. All polygons have been triangulated.

2025-09-29 01:54:06 [1,203,461ms] [Info] [omni.kit.asset_converter.impl.task_manager] Costs 189s for exporter to export asset.
2025-09-29 01:54:12 [1,209,374ms] [Error] [omni.kit.asset_converter.impl.task_manager] Couldn’t Import Asset: 9269320, code: OmniConverterStatus.UNSUPPORTED_EXPORT_FORMAT, error: Failed to export unsupported format with assimp: c:/Users/6414868/Desktop/warehouse_for_AMIO_STL/warehouse_for_AMIO_4.stl
2025-09-29 02:37:09 [3,786,285ms] [Info] [carb.omniclient.plugin] Tick: provider_nucleus: Refreshing authorization token for omniverse://localhost
2025-09-29 03:37:09 [7,386,951ms] [Info] [carb.omniclient.plugin] Tick: provider_nucleus: Refreshing authorization token for omniverse://localhost

Screenshots or Videos

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Additional Information

What I’ve Tried

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Related Issues

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Additional Context

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2

@Ryuichi_Sakamoto i am just another user but have a few inquiries:

  • what’s your target software you plan to import the .STL to? i am asking because i am getting mixed result when importing an exported .STL from Isaac Sim. one says not a valid .STL; but another imports it just fine. and i have no issue exporting the mesh with .FBX or .OBJ format.
  • how big is the export in terms of both the number of prims? if you are trying to export many pieces in bulk, try to test on a scene with only one or two prims and see if you are getting the same behavior.
  • is the asset sourced from NVIDIA’s asset? looking at the report generated, you may have been trying to export prop assets from the modular warehouse scene.
  • have you tried exporting other assets and are able to confirm the same issue persists?
3

Hi @Ryuichi_Sakamoto,

The UNSUPPORTED_EXPORT_FORMAT error for STL is a limitation of the asset converter version (v2.8.3) shipped with Isaac Sim 4.5. STL export support was added and fixed in later versions of the converter:

  • v5.0.19 — STL export error handling and mesh skipping logic
  • v5.0.20 — Fix crash when STL export fails due to non-triangular meshes
  • v5.0.22 — Fix crash when USD file contains no materials

Isaac Sim 5.1 ships asset converter v5.0.17 and Isaac Sim 6.0 ships v5.1.1 (which includes all the above fixes).

If you need to stay on 4.5, here are workarounds:

  1. Export to OBJ or FBX (these are supported in 4.5), then convert to STL externally using Blender or MeshLab.
  2. Flatten references before export — since the warehouse uses many referenced sub-assets, use File > Export All to ensure all referenced content is included in the output.
  3. The triangulation warnings (Failed to triangulate polygon - not a simple polygon) suggest some mesh geometry in the warehouse has degenerate polygons, which may cause issues in any export format. Try exporting a subset of the scene first.

Closing this out. If you upgrade to 5.1 or 6.0 and still encounter STL export issues, feel free to open a new topic with the updated version info and link back to this one.