Retargeting

Convert GRAIL 4D HOI reconstructions (the output of grail.pipelines.recon_4dhoi) into G1 robot motion trajectories consumable by the task-general tracking stack under imports/SONIC/.

The retargeting pipeline is a standalone subpackage: grail/retargeting/. All steps run as plain CLI tools.

Install

1. Initialize the GMR submodule:

   git submodule update --init imports/GMR
   

2. In the published Docker image, activate the preinstalled environment:

   conda activate sonic
   

   For a source installation, run the one-shot installer from the GRAIL root:

   bash scripts/setup/install_env_sonic.sh
   

   This creates the sonic environment and installs Isaac Sim, Isaac Lab, public GMR, GRAIL, and the remaining retargeting/training dependencies. GRAIL-specific GMR behavior is applied at runtime by grail.adapters.gmr; the public GMR submodule is not modified. The script is idempotent.

   Override the env name via GRAIL_SONIC_ENV=<name>:

   GRAIL_SONIC_ENV=my_sonic_env bash scripts/setup/install_env_sonic.sh
   

Running the pipeline

End-to-end (recommended)

The first argument must point to your own successful 4D-HOI reconstruction output inside the current checkout or container. Replace <your_results_dir> with the value passed to reconstruction’s --results_dir, which defaults to results. The default SMPL-X reconstruction config writes validated results to generation/4dhoi_recon_smplx_valid/. This directory must contain at least one nested hoi_data/hoi_data.pkl; the second argument only chooses the new folder name under data/motion_lib/. Use the validated root to process every dataset, or append a dataset subdirectory to process only that dataset.

conda activate sonic
export DISPLAY=:1                    # GMR uses mujoco viewer, needs a display

RECON_DIR="<your_results_dir>/generation/4dhoi_recon_smplx_valid"
OUTPUT_FOLDER="<your_output_folder>"

# This must print at least one file before retargeting.
find "$RECON_DIR" -type f -path '*/hoi_data/hoi_data.pkl' -print -quit

bash grail/retargeting/scripts/retarget_pipeline.sh \
    "$RECON_DIR" \
    "$OUTPUT_FOLDER"

If the find command prints nothing, correct RECON_DIR or verify that the reconstruction stage produced valid results before continuing.

Outputs under data/motion_lib/<your_output_folder>/:

Directory	Contents
robot/	G1 joint trajectories (one pkl per motion)
objects/	Object 6-DOF trajectories
object_usd/	IsaacLab-ready USD assets
meta/	Scene metadata (table pose, object name, …)

Plus a preprocessed twin at data/motion_lib/<your_output_folder>_ha/:

Directory	Contents
robot/	Robot motions with hand-action + table pose
objects/	Object motions, contact points filtered to ≥ lift frame
meta/	Per-motion meta (table pose/quat/size, object name)

And a BPS encoding at data/motion_lib/<your_output_folder>/bps/ (multi-object datasets only).

Individual stages

Each stage is a plain Python CLI and can run in isolation.

RECON_DIR="<your_results_dir>/generation/4dhoi_recon_smplx_valid"
OUTPUT_BASE="data/motion_lib/<your_output_folder>"

# Stage 1 — retarget SMPL-X → G1
python -m grail.retargeting.retarget \
    --data_dir "$RECON_DIR" \
    --all --robot unitree_g1 --no_viewer \
    --output_dir "$OUTPUT_BASE"

# Stage 2 — hand-action + table-geometry processing
python -m grail.retargeting.process \
    --input  "$OUTPUT_BASE" \
    --output "${OUTPUT_BASE}_ha" \
    --meta_pkl data/g1_smplx/g1_skeleton_meta.pkl \
    --include_contact_points --grasp_from_lift \
    --lift_threshold 0.02 --grasp_anticipation_frames 10 \
    --skip_no_lift --per_object

# Add --treat_hands_equally to preserve both arms and derive left/right
# hand actions symmetrically from each hand's contacts.

# Stage 3 — BPS shape encoding (multi-object datasets only)
python -m grail.retargeting.compute_bps \
    --object_usd_dir "$OUTPUT_BASE/object_usd" \
    --output_dir     "$OUTPUT_BASE/bps"

The shell wrappers under grail/retargeting/scripts/ (retarget.sh, process.sh, compute_bps.sh) are thin convenience layers on top of these CLIs — read them if you want to know the exact defaults.

Terrain / sitting data

Terrain (curbs, slopes, stairs) and sitting data involve whole-body interaction with large environmental objects, not hand-held manipulation. Use --zero_out_wrist to skip hand IK:

TERRAIN_RECON_DIR="<your_results_dir>/generation/4dhoi_recon_smplx_valid"
TERRAIN_OUTPUT_FOLDER="<your_terrain_output_folder>"

bash grail/retargeting/scripts/retarget.sh \
    "$TERRAIN_RECON_DIR" \
    "$TERRAIN_OUTPUT_FOLDER" \
    --zero_out_wrist

Then skip the process.sh step — terrain data does not need hand-action preprocessing.

How the pipeline works

1. GMR (General Motion Retargeting) — SMPL-X body model → Unitree G1 MJCF via inverse kinematics. The retarget engine is the public YanjieZe/GMR submodule; GRAIL-specific compatibility behavior is applied at runtime by grail.adapters.gmr.

2. Object mesh → USD — convert_mesh.py runs IsaacLab’s MeshConverter headlessly to produce simulation-ready USD assets with convex-hull collision.

3. Hand-action + table geometry — process.py derives hand open/close commands from object lift/contact timing and applies table geometry fixes. By default, the legacy right-hand pickup path zeroes the left arm and keeps hand_action_left open. Use --treat_hands_equally to preserve both arms and derive each hand action from that hand’s contact timing.

4. BPS encoding — compute_bps.py samples surface points from each object USD and projects them onto a fixed basis-point set, producing a 10-D object shape embedding used as a policy observation in pnp_table.

Troubleshooting

Symptom	Likely cause / fix
ModuleNotFoundError: general_motion_retargeting	Rerun bash scripts/setup/install_env_sonic.sh — it installs GMR editable in the active env.
ModuleNotFoundError: pxr	pip install usd-core (standalone PXR; Isaac Sim-vendored pxr is only importable inside kit apps).
Black mujoco viewer / glfwInit failed	export DISPLAY=:1 before activating conda (it is an env var, not a conda setting).
FileNotFoundError: .../robot during processing	Retargeting found no inputs. Update the first pipeline argument to your reconstruction directory and confirm find "$RECON_DIR" -type f -path '*/hoi_data/hoi_data.pkl' returns files.
Retarget skips motions as “no lift”	process.py rejects motions where the object never rises 2 cm. Override with --lift_threshold 0.01.
imports/GMR is empty	Run git submodule update --init imports/GMR, then rerun the installer for a source installation.