[Bug Report] Collision is making unexpected movement for parallel env

[exaFLOPs26]

If you are submitting a bug report, please fill in the following details and use the tag [bug].

Describe the bug

When a robot arm starts contacting with an asset, the asset blows like the video. It happens when using in parallel environment.

Steps to reproduce

The code can't be released. But can share the usd is needed to reproduce.

System Info

Describe the characteristic of your environment:

• Commit: [e.g. 8f3b9ca]
• Isaac Sim Version: 4.5
• OS: Ubuntu 22.04
• GPU: L40S
• CUDA: 12.5
• GPU Driver: 535.129.03

Additional context

Add any other context about the problem here.

Checklist

• I have checked that there is no similar issue in the repo (required)
• I have checked that the issue is not in running Isaac Sim itself and is related to the repo
• I have checked that the water bottle asset is 0.4369 mass.
• I have checked that the collision is well set.
• I have checked that in single env, no blowing up occur.
• Starting from env num 4 starts to show this kind of behavior.
• Tried with and without replicated physics.

Acceptance Criteria

Add the criteria for which this task is considered done. If not known at issue creation time, you can add this once the issue is assigned.

• Criteria 1
• Criteria 2

Screen.Recording.2025-11-03.at.7.50.56.PM.mov

Screen.Recording.2025-11-03.at.7.57.51.PM.mov

[garylvov]

Try increasing the mass/inertial tensors/friction of the bottle

[exaFLOPs26]

But isn't weird that for single env, nothing happens the bottle is grasp well. Only when if gets parall env, this happens.

Then why is it related to mass or inertia? I don't get it.

[exaFLOPs26]

For single env, it is like this.

trim.82B0F47E-39B4-4E0A-B7DE-26C415F45EAF.MOV

[PeterL-NV]

what's your replicate_physics setting for parall env? Can you change it to see if that makes any diff?

[exaFLOPs26]

Alreadly checked with and without it and no difference.

[PeterL-NV]

Improper mass and inertia tensor settings for either the robot hand or the bottle can exaggerate force reactions at contact points. Please also check your settings for those as @garylvov already mentioned.

[exaFLOPs26]

I don't fully understand why improper mass and inertia tensor setting can be the reason for occurring only for parallel environment?

Does Isaac works as if improper mass and inertia tensor is setted for only 1-3 env it auto detects and fix but number of env above don't?

By the way, the mass is 0.469 kg for a water bottle.

[PeterL-NV]

Can you try to update to Isaac Sim 5.1.0 and see if the issue still exists there?