Adds environment for lifting a deformable cube

[masoudmoghani]

Description

Add soft cube RL env.

Type of change

• New feature (non-breaking change which adds functionality)

Checklist

• [ ] I have run the pre-commit checks with ./isaaclab.sh --format
• [ ] I have made corresponding changes to the documentation
• [ ] My changes generate no new warnings
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] I have updated the changelog and the corresponding version in the extension's config/extension.toml file
• [ ] I have added my name to the CONTRIBUTORS.md or my name already exists there

[Mayankm96]

Does the training work properly for all the workflows? Can you share the training plots and videos of how it looks like? Also need to update the environment table:

https://github.com/isaac-sim/IsaacLab/blob/main/docs/source/features/environments.rst

[LeiHanyue]

I've tried this example. After the object is picked up by the gripper, it seems to slip out of its jaws. Why is that happening? Does it mean that the gripper cannot securely clamp the object once it's been picked up, or is this slipping uncontrollable? @masoudmoghani

[masoudmoghani]

@LeiHanyue thanks for running the example. We have yet to assign the cube's soft body/material properties properly. On the task cfg, the effort limit on the franka hand is lowered to make it not crush the soft cube with current prop but this is not finalized yet.

[Mayankm96]

@masoudmoghani We'd like this environment in our coming release (due early next week). Can you please address the concerns above?

Or should we have someone take over this MR if you have limited availability right now?

[masoudmoghani]

@Mayankm96 I was planning to get back to this before the end of this month, but if this is required for next week release, it would be great if someone can run training evals and finish up this MR. I'd be happy to meet or answer questions offline.