Subject: Unable to Set Physical Material on Cylinder After URDF Import

Operating System:
Linux
Windows

Kit Version:
105 (Launcher)
106 (Kit App Template)
107 (Kit App Template)

Kit Template:
USD Composer
USD Explorer
USD Viewer
Custom

GPU Hardware:
A series (Blackwell)
A series (ADA)
A series
50 series
40 series
30 series

GPU Driver:
Latest
Recommended (573.xx)
Other


Work Flow:
Import URDF → Save Selected → Re-load → Try to assign physical material to collision geometry (cylinder)

Main Issue:
Unable to assign physical material to a cylinder collider under a wheel after importing URDF using Referenced Model and saving the robot with Save Selected.

Reproduction Steps:

  1. Import a robot URDF using Referenced Model option.
  2. Right-click the robot and choose Save Selected to export as USD.
  3. Open the saved USD — attempt to set physical material to /collisions/mesh_0/cylinder.
  4. Material assignment is not allowed; fields are grayed out.
  5. Re-importing using Create in Stage allows editing, but saving and reloading the robot leads to broken behavior.

Error Code:
(None shown, but physical material property is locked/uneditable.)

1 Like

@pprcr777 i am just another user, but a few things that stood out from the post for me that could use some clarification:

  • kit version - if you are still using the OV Launcher, it’s likely the composer version from launcher is quite out of date. the latest kit is 107.3.0 and can be found on github. you’d want to build the kit-app-template on your end to benefit from the latest updates. and as another reminder, OV Launcher will be deprecated by Oct 1st, so it would be to your benefit to start making the transition to building your own kit-app. you can checkout this playlist from NVIDIA that walks you through how to do so - https://www.youtube.com/playlist?list=PL3jK4xNnlCVcR4mkKPIUbvdJH7thO_LOJ
  • kit template - you’ve marked composer here but sounds like you are doing URDF import inside composer, is that correct? have you tried using Issac Sim at all? the reason i am asking is because Isaac Sim is another kit app that is tailored for simulation with real world physics. Composer should be able to do the same, but some of the physics extensions may need to be enabled/installed manually first in order to have correct behavior.
  • repro steps - could you clarify if you are setting the physical materials programmatically or via GUI?
  • workaround - you mentioned Create in Stage as a potential workaround given that it does break the robot on reload, can you be a bit more specific on what exactly is broken?
1 Like

Thank you @Simplychenable Yes I agree with your comments. @pprcr777 if you are still using anything on Launcher and especially anything based on kit 105, you are very much behind and using a really old version.

Launcher is now officially depreciated. Please uninstall all apps, and the launcher and move to our new workflow at GitHub - NVIDIA-Omniverse/kit-app-template: Omniverse Kit App Template

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