Setting linear velocity of non-root articulation links is not supported

I’m using Isaac Sim 2023.1.1. My goal is to record robotic applications in Isaac Sim in a generalizable manner, to “bake” this movement into a USD file, so that i can later visualize it in AR. For this, the current workflow that I’m applying is the same as for this specific example.

  • I load an extension example (Like the follow target Franka example or the UR10 palletizing example).
  • I save the File as a USD to save a copy of the current scene and its objects.
  • I open the stage recorder extension, select my world, select overwrite files, and save in a new file this TimeSampled USD.
  • I then record for around 30 seconds. I stop recording and check that the TimeSampled USD is saved. I can see in this USD file, that the USD tree structure is there, but there are only xforms, all the meshes and joints are lost, so nothing displays on screen. The xforms have timesampled keyframes in some of their translation and orientation attributes.
  • I then open the first USD I saved, that contained the stage. I add as a new layer, this time sampled USD. I set it to Authoring Layer.
  • When I hit play, I get a short animation of around 1 second, but then it stops prematurely and I get the following set of errors on the console:

2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Transformation change on non-root links is not supported. Link: /World/Franka/panda_link6
2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Transformation change on non-root links is not supported. Link: /World/Franka/panda_link7
2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Transformation change on non-root links is not supported. Link: /World/Franka/panda_link3
2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Transformation change on non-root links is not supported. Link: /World/Franka/panda_link5
2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Transformation change on non-root links is not supported. Link: /World/Franka/panda_link2
2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Transformation change on non-root links is not supported. Link: /World/Franka/panda_link1
2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Transformation change on non-root links is not supported. Link: /World/Franka/panda_link4
2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Transformation change on non-root links is not supported. Link: /World/Franka/panda_leftfinger
2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Transformation change on non-root links is not supported. Link: /World/Franka/panda_rightfinger
2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Transformation change on non-root links is not supported. Link: /World/Franka/panda_link8
2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Transformation change on non-root links is not supported. Link: /World/Franka/panda_hand
2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Setting linear velocity of non-root articulation links is not supported. Link: /World/Franka/panda_link7
2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Setting linear velocity of non-root articulation links is not supported. Link: /World/Franka/panda_link8
2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Setting linear velocity of non-root articulation links is not supported. Link: /World/Franka/panda_link6
2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Setting linear velocity of non-root articulation links is not supported. Link: /World/Franka/panda_link5
2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Setting linear velocity of non-root articulation links is not supported. Link: /World/Franka/panda_rightfinger
2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Setting linear velocity of non-root articulation links is not supported. Link: /World/Franka/panda_link4
2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Setting linear velocity of non-root articulation links is not supported. Link: /World/Franka/panda_link3
2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Setting linear velocity of non-root articulation links is not supported. Link: /World/Franka/panda_leftfinger
2024-01-24 09:35:23 [2,171,572ms] [Error] [omni.physx.plugin] Setting linear velocity of non-root articulation links is not supported. Link: /World/Franka/panda_hand

I saw similar issue here:

Although I understand the issue regarding non-root link not being able to change during simulation, I don’t understand how I can achieve what I want. I’m also aware that some extensions have the option to log data and they play it back, but I don’t want that, since I want to embed the animation in the USD file.

Finally, just wanted to mention that in a previous version of Isaac Sim I used, 2022.2.1, I used an extension called omni.kit.recorder that was very basic but allowed me to do what I want now, without half of the complexity.

Thanks for the help!