Optimal Embodiment

Finding the best possible embodiment to imitate humans.

Research framework for discovering robot morphologies that best enable imitation of human motion. Uses morphological randomization from XHugWBC (Unitree G1 base) and motion retargeting via GMR.

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Setup

git clone <URL>
cd OptimalEmbodiment
git submodule update --init --recursive
conda create -n optimal-embodiment python=3.10 -y
conda activate optimal-embodiment
pip install -e .

Data: Download AMASS and body models (SMPL+H, DMPLs) per BlenderProc guide. Place under data/AMASS/ and data/body_models/.

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Scripts

scripts/retargeting.py

Retargets AMASS/SMPLH motion (.npz) to randomized humanoid robots. Generates XML + IK config per robot and saves retargeted motion as .pkl.

python scripts/retargeting.py --motion-npz data/AMASS/ACCAD/.../motion.npz

# With options:
python scripts/retargeting.py --motion-npz path/to/motion.npz \
  --body-models-dir data \
  --output-dir outputs/retargeting \
  --num-robots 3 \
  --visualize \
  --record-video

Flag	Description
--motion-npz	Path to .npz (AMASS/ACCAD stageii)
--body-models-dir	Directory with body_models/ (default: data)
--template-xml	Base XML for randomization (default: assets/g1_29dof/g1_29dof.xml)
--output-dir	Output directory (default: outputs/retargeting)
--num-robots	Number of randomized robots
--visualize	Open MuJoCo viewer during retargeting
--record-video	Record .mp4 per robot
--generate-only	Only generate XML+IK, no retargeting

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scripts/visualize.py

Visualizes retargeted motions (.pkl) together with robot.xml in MuJoCo.

# Single robot folder:
python scripts/visualize.py outputs/retargeting/robot_000

# Parent folder (plays all robot_XXX sequentially):
python scripts/visualize.py outputs/retargeting

# With options:
python scripts/visualize.py outputs/retargeting --loop --record-video

Flag	Description
--loop	Loop each clip indefinitely
--record-video	Save .mp4 next to the .pkl
--no-camera-follow	Disable camera follow
--cam-distance	Camera distance (default: 2.5)
--cam-elevation	Camera elevation angle (default: -10)

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Related Work

• GMR: YanjieZe/GMR — real-time retargeting.
• XHugWBC: Xue et al., arXiv:2602.05791 — cross-embodiment control; we use its morphological randomization.
• AMASS: amass.is.tue.mpg.de

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MIT License.