URDF Import in Isaac Sim 5.0 Shows Only Base Cube

[bnina.ayoub]

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 5050
• Driver Version: Latest Studio Driver

Topic Description

URDF Import in Isaac Sim 5.0 Shows Only Base Cube – Meshes Missing

Detailed Description

I’m trying to import a URDF into Isaac Sim 5.0 on Windows. The robot prim is created successfully, but only a small white cube appears (the base_footprint visual). All other visual meshes are missing.

I expected the full robot with all its visual meshes to appear, as happens in Isaac Sim 4.5 and in online URDF visualizers.

The import logs show warnings about missing mass and failed mesh paths, which suggest that Isaac is failing to resolve ROS package:// URIs and Linux-style relative paths, or is unable to convert some STL meshes to USD. The base_footprint contains a tiny box and no inertial data, which triggers additional inertia/placeholder warnings.

Steps to Reproduce

1. Open Isaac Sim 5.0 on Windows.
2. Import a URDF that uses ROS package:// URIs and Linux-style relative paths.
3. Observe that only the base_footprint cube appears; all other visual meshes are missing.
4. Check the import logs for warnings about missing mass and failed mesh conversions.

Error Messages

No mass specified for link base_footprint
getAttributeCount called on non-existent path /robodog/base_footprint/visuals/mesh_0

Screenshot

Additional Information

What I’ve Tried

• Verified that the URDF works correctly in Isaac Sim 4.5 and online visualizers.
• Checked the console for “Failed to convert” errors to identify missing meshes.
• Considered pre-converting STL meshes to USD or pointing to Windows absolute file:///c:/... URIs.
• Thought about adding inertial data or removing the tiny base_footprint box.
• Verified importer settings: Mesh Directory, Import Visuals, and Scale.

Additional Context

• This seems specific to Isaac Sim 5.0 on Windows, likely due to path resolution and mesh conversion differences from Isaac Sim 4.5.
• Any advice on ensuring all visuals appear correctly would be greatly appreciated.

[VickNV]

Thank you for sharing the issue. To help diagnose the problem, could you please provide the following:

The full URDF file you are using for import.

All mesh files referenced in the URDF (e.g., STL, DAE) and the directory structure as they are organized on your system.

Any additional resources (such as textures or material files) that your robot model uses.

Having access to these files will help reproduce the issue and pinpoint whether it’s related to mesh file paths, missing assets, or compatibility with Isaac Sim 5.0. This information will make it easier to identify and resolve the “base cube only” import problem.

Thank you!

[bnina.ayoub]

Hi @VickNV

As requested, here are the resources related to my issue:

1. Full URDF file, Mesh files, and directory structure
   robodogv1.zip (2.9 MB)

Meshes are inside the meshes folder in STL format

2. Additional resources

No external textures or material files beyond what’s defined in the URDF.

3. Screenshots

[bnina.ayoub]

Hello @VickNV,

Is there any update regarding my Issue? Or am I missing something? Because I am still new to Isaac Sim.

Thank you!

[Simplychenable]

@bnina.ayoub i am just another user, and i was able to reproduce the issue. however, after digging into it a bit further, i believe the URDF itself could be the cause. below is the result after making some adjustment to the URDF that subsequently allowed for a successful (i think) import:

and below is the snippet i added after the base footprint was defined (Ln17-21):

i’ll defer to the mods to confirm whether this is the right approach to resolve your issue. in the meantime, i would double check to see if the conventions in the robodog URDF conforms to that required by Isaac Sim for compatibility purposes.

[bnina.ayoub]

I added this snippet, and it worked perfectly. So it was the missing part of the base joint. Missed it, thank you!