[MuJoCo parser] Support parsing models from mujoco menagerie

[RussTedrake]

The MuJoCo XML parser loads and properly displays all of the models in the DeepMind Control Suite (or will after my upcoming set of PRs) except for dog.xml, which is an outlier with tendons and skin, etc. I've opened this issue to keep track of the (sad) state of our current MuJoCo parser in loading the menagerie assets.

All of the models are now parsed in detail_mujoco_parser_examples_test.cc, with a clear demarkation about any remaining errors that prevent the model from loading properly.

A number of models still fail to load properly load the visual textures.

To reproduce, run e.g.

from pydrake.all import ModelVisualizer, StartMeshcat, PackageMap

visualizer = ModelVisualizer(meshcat=meshcat)
visualizer.parser().package_map().AddRemote(
    package_name="mujoco_menagerie",
    params=PackageMap.RemoteParams(
        # This repository doesn't have up-to-date tags/releases; the scary
        # hash in the url is the most recent commit sha at the time of my
        # writing.
        urls=[
            f"https://github.com/google-deepmind/mujoco_menagerie/archive/bf110a75a56e5bd146c7ed76965737c71d48425d.tar.gz"
        ],
        sha256=("2562301c38ac82b593b31e523004b94c263b20952f99d2bcbb9939fa5c6bebd2"),
        strip_prefix="mujoco_menagerie-bf110a75a56e5bd146c7ed76965737c71d48425d/",
    ),
)
visualizer.AddModels(
    url="package://mujoco_menagerie/unitree_a1/a1.xml"
)
visualizer.Run(loop_once=True)

[RussTedrake]

See this (TRI internal) slack discussion for discussion about the extent to which we want to support "the legacy, non-standard, MuJoCo texture projection".

[RussTedrake]

#21666 resolves some errors. I've just done a complete sweep through the menagerie and made a detailed list of errors/warnings above.

[RussTedrake]

OK, I've addressed all of the small errors I know about. I've also create make_drake_compatible_model that will preprocess an xml (or urdf) to overcome all of the known errors.

A few more things on my list before I close out this issue:

• Advertise make_drake_compatible_model from the parser. Is it ok to advertise the manipulation repo version? Or is migrating this to drake a prerequisite?
• Escalate warnings for missing meshes to errors. It results in incorrect dynamics. And now that make_drake_compatible_model is in better shape, there is a reasonable work-around.
• Capture warnings about missing textures in the detail_mujoco_parser_examples_test; make sure they are representative of the experience in meshcat, at least.
• Resolve missing textures... possibly in make_drake_compatible_model, if's it's not currently viable in the parser. I think the immediate work-around is to generate an .mtl for the .obj that gets generated. (or gltf, if that is now to be preferred)

@jwnimmer-tri , @rpoyner-tri -- would appreciate any feedback you have on these.

[jwnimmer-tri]

Advertise make_drake_compatible_model from the parser.

One nice tactic for situations like this would be have the parser's message hyperlink to a (new) anchor on https://drake.mit.edu/troubleshooting.html and then have that documentation explain in more detail (and link to work-arounds like that tool). We don't want the parser message to be too brief (it should still be self-contained and directly explain the problem), but IMO explaining work-arounds is best left to the website.

Or alternatively, if there is a specific issue filed we can link to the issue instead of the troubleshooting, and the issue OP can contain an explanation of the workarounds, and people can subscribe to the issue to track progress.

[jwnimmer-tri]

... would appreciate any feedback you have on these.

Escalate warnings for missing meshes to errors. It results in incorrect dynamics.

SGTM

Capture warnings about missing textures in the detail_mujoco_parser_examples_test; ...

No opinion.

Resolve missing textures ...

I don't understand enough of the problem to offer an opinion.

[RussTedrake]

I've added mujoco texture support to make_drake_compatible_model in the manipulation repo. This example notebook loads all of the robot models from the menagerie and visualizes them in meshcat. Apart from a few missing textures on a few model elements, and a few funky normals/windings picked up during the mesh file conversions, everything model now works or has a specific Drake issue tracking it.