How to specify commit or tag for Menagerie models?

[kevinzakka]

Hi Stéphane,

In Menagerie, we continually update models to improve them. This can sometimes bump up the minimum required MuJoCo version for that model. If a user does not want to upgrade and would rather stick to an older version, what is the recommended way to specify a commit or tag for Menagerie models in robot_descriptions without having to downgrade robot_descriptions itself?

[stephane-caron]

Sure thing: loaders in robot-descriptions have a commit keyword argument to pin the version of any robot description. For instance, to load a UR5e from a specific commit of MuJoCo Menagerie:

from robot_descriptions.loaders.mujoco import load_robot_description

model = load_robot_description(
    "ur5e_mj_description",
    commit="cc3868ec21bae324e6dd3b01ea185b6e6f0fa172",
)

I just pushed this example in specific_commit.py.

[kevinzakka]

Sometimes I don't want to get an MjModel object, for instance when I want to load the model with dm_control's PyMJCF. We should probably look into returning the MJCF_PATH if requested by the user.

[kevinzakka]

I should have looked at the code more closely 🤦‍♂️ I have only been using the "imported module" API and forgot this was possible. Thanks @stephane-caron!

[stephane-caron]

No worries 👌 Reopening the discussion as the question is relevant and can be useful to others discovering the library. (Contrary to issues, closing discussions is mainly when they are not relevant or duplicate.)