Question on closed four bar link structure.

[KaixinZhan]

Hi everyone.

I have a robot which contains several closed link structures. I set a mjcf file which has a correct dynamic results in Mujoco. However, if I directly import this mjcf into the Isaac Sim, the closed loops vanish. Is there a way to automatically get closed loops in IsaacSim, or must I do it manually according to the documentation? Thanks a lot.

[vick-yu]

Thank you for your question. In order to better understand and help troubleshoot the issue you're experiencing with closed-loop structures in Isaac Sim, could you please provide your MJCF file (or ideally, a minimal example that reproduces the problem)? This will allow us to inspect how the closed loops and constraints are defined and help identify what might be going wrong with the import process. If possible, highlight or describe the specific joint or constraint that fails to import as expected.

Looking forward to your file so we can assist further.