Inelastic Rope Simulation in Brax

[jc-bao]

Hello Brax team,

I'm interested in simulating an inelastic rope within Brax, similar to this example. When the rope transitions from a loose to taut state, it seems to mimic an inelastic collision. Given Brax's capabilities, I believe this might be feasible. Could you provide any insights or guidance on this?

[btaba]

Hi @jc-bao , it looks like the example you linked to is using tendons in MuJoCo, so I would take a look at the implementation here https://github.com/google-deepmind/mujoco. I'm not very familiar with the implementation but hope that helps

[jc-bao]

Yeah, a system with a tendon is a hybrid system, which shares a lot of similarities with the contact model. Issac also supports tendon now. It would be great if Brax could support it.

[btaba]

Check out our recent announcement: #409

tendons will more easily be supported through MJX, and subsequently a MJX brax backend

[jc-bao]

I believe my concern has now been alleviated. A big thank you to the Brax team for integrating Mujoco with the powerful Jax! 👏🙌