kangaroo_mujoco

MuJoCo simulation package for the Kangaroo robot. Provides pregenerated MJCF model variants and the launch infrastructure to run them under mujoco_ros2_control.

Contents

models/                        Pregenerated MJCF model variants
  assets/
    full/                      Shared visual mesh pool (all .obj files live here)
  mjcf_data_<variant>/
    mujoco_description_formatted.xml   Runtime MJCF (loaded by the launch file)
    mujoco_description.xml             Intermediate MJCF (not loaded at runtime)
    robot_description_formatted.urdf   Source URDF
    assets/
      full -> ../../assets/full        Symlink to the shared mesh pool
      decomposed/                      Per-variant convex-collision meshes
scripts/
  publish_mjcf.py              Latched ROS 2 publisher for a pregenerated MJCF
  consolidate_model_assets.py  Tool to deduplicate visual meshes across variants
test/
  test_model_assets.py         Regression tests for the consolidated asset layout

Model variants

Each variant is named mjcf_data_{arm_type}_{end_effector_right}_{end_effector_left}_{feet_type}_{world_type}. Currently pregenerated variants:

Consolidated asset layout

All visual .obj meshes live in a single shared pool at models/assets/full/. Each variant’s assets/full is a symlink pointing at that pool:

models/
  assets/
    full/               <-- one copy of every visual mesh
      d435/d435.obj
      torso_link/torso_link.obj
      arm1_link/arm1_link.obj
      ...
  mjcf_data_5dof_RH8D_RH8D/
    assets/
      full -> ../../assets/full   <-- symlink (no per-variant copy)
      decomposed/                 <-- real dir, collision meshes only
  mjcf_data_4dof_fake-forearm_fake-forearm/
    assets/
      full -> ../../assets/full
      decomposed/
  ...

This avoids triplicating ~55 MB of identical mesh data. The decomposed/ convex-collision sets are intentionally kept per-variant because the number of collision pieces differs across variants.

After regenerating a model variant

The upstream generator (mujoco_ros2_control’s robot_description_to_mjcf.sh) writes a fresh per-variant assets/full/ directory, replacing the symlink. After regeneration, restore the shared layout by running the consolidation script (see below).

Consolidating model assets

What the script does

scripts/consolidate_model_assets.py performs four idempotent steps:

1. Verify — MD5-scans all assets/full/ trees, reports duplicated files and aborts if any same-named file has different content across variants (conflict guard).
2. Build shared pool — merges all variant assets/full/ trees into models/assets/full/ (no-clobber, lossless union).
3. Install symlinks — replaces each variant’s assets/full/ directory with a symlink ../../assets/full.
4. Fix stale paths — patches any <compiler meshdir="/tmp/..."> in mujoco_description.xml files back to the correct relative assets/.

Usage

```bash

Report duplicates and conflicts only (read-only):

python3 scripts/consolidate_model_assets.py –verify

Preview what would change without touching anything:

python3 scripts/consolidate_model_assets.py –dry-run

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Changelog for package kangaroo_mujoco

2.5.0 (2026-06-26)

• Merge branch 'improve/ankle_fusion' into 'humble-devel' Improve ankle inertia fusion See merge request robots/kangaroo_simulation!20
• Add collision exclude between knee and ankle link
• Add fixed base mujoco simulation
• Remove duplicate density setting
• Refine the collision capsules for the new covers
• Add the capsules for the new feet with covers
• Update to new ankle configuration data
• Merge branch 'add/fixation_type/folder_naming' into 'humble-devel' Add fixation type to the folder naming See merge request robots/kangaroo_simulation!19
• Add fixation type to the folder naming
• Contributors: Sai Kishor Kothakota

2.4.0 (2026-06-23)

• Merge branch 'add/stairs' into 'humble-devel' Stairs world for lower body with detachable feet See merge request robots/kangaroo_simulation!18
• Stairs world for lower body with detachable feet
• Merge branch 'refine/models' into 'humble-devel' Refine models + Add lower body with detached foot See merge request robots/kangaroo_simulation!17
• Add lower body with detached foot precompiled simulation
• Remove pal_mujoco_scenes dependency
• Set --no-fuse for only fixed fixation type
• Set density to zero for the foot capsules
• Merge branch 'add/readme' into 'humble-devel' Add README to the package See merge request robots/kangaroo_simulation!16
• rename the script
• fix the generate decomposed pregenerated mjcf script
• Update README
• Merge branch 'add/worlds' into 'humble-devel' Adding world argument See merge request robots/kangaroo_simulation!15
• Adding world argument World suffix + launch option. Only works with pregenerated models. Will fallback gracefully to generating with empty if a given world name doesn't exist
• Merge branch 'add/cached_models_with_feet_type' into 'humble-devel' Add feet type to the cached models folder naming See merge request robots/kangaroo_simulation!14
• Add feet type to the cached models folder naming
• Merge branch 'add/density/foot_capsules' into 'humble-devel' Set foot capsules density set to zero See merge request robots/kangaroo_simulation!13
• Set foot capsules density set to zero
• Adding 5dof with RH8D pregenerated
• Contributors: Sai Kishor Kothakota, oscarmartinez, Óscar Martínez

2.3.0 (2026-06-21)

• Merge branch 'add/imu_args' into 'humble-devel' Add IMU args to the mujoco simulator See merge request robots/kangaroo_simulation!11
• Add IMU args to the mujoco simulator
• Contributors: Sai Kishor Kothakota

2.2.1 (2026-06-09)

• Merge branch 'fix/ankle_ft_missing_args' into 'humble-devel' Add missing ankle ft sensor arguments See merge request robots/kangaroo_simulation!10
• Add conditioning to pal_mujoco_scenes dependency
• Add missing ankle ft sensor arguments
• Contributors: Sai Kishor Kothakota

2.2.0 (2026-06-09)

• Merge branch 'update/models' into 'humble-devel' Update kangaroo models of 4DoF and lower body to local frozen mjcfs See merge request robots/kangaroo_simulation!9
• Add a script to publish the mujoco description if it is already generated
• Remove the bodies of the torso cameras
• Use capsules for the foot contact
• Add --cache-dir arg to reuse the generated mjcfs
• make meshdir, texturedir and assetdir relative paths
• Add the robot with configuration of lower body only
• rename the cached folder to mjcf_data_4dof_fake-forearm_fake-forearm
• Remove leg_type argument assuming is always leg
• Add new arguments as end_effector_<side> and feet_type
• Contributors: Aina, Sai Kishor Kothakota

2.1.1 (2026-04-23)

• Add missing dependency mujoco_ros2_control
• Contributors: Noel Jimenez

2.1.0 (2026-02-25)

• apply format
• removed unnecessary imports
• updated model
• set motor actuator default
• Enable topic publishing and also add emulate_tty for better noticing of logs
• Set back to 2kHz
• added test model and config to rl inference

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