WorldCode Exported JSON Field Specification
The following specification is based on the actual outputs produced by the export script, as well as the example file worldcode_HS-2-1420125020208_2025-10-21-14-50-09_3_s0_vlta_reorg_sample_1-2.json.
Top-level Fields
| Field | Description |
|---|---|
worldcode_name | Name of the current sample, typically also the filename of the exported JSON. |
dataset_path | Absolute path to the original worldcode directory. |
task_description | Description of the task. |
status | Overall status of the current worldcode, e.g., success. |
subtasks | List of subtasks describing key action intervals. |
num_frames | Total number of frames. |
camera_calibration | Calibration parameters for each camera. |
frames | Per-frame data. |
_validation_warnings | Optional field; appears only when missing files are detected during validation. |
subtasks
Each subtask contains:
| Field | Description |
|---|---|
subtask_index | Subtask number. |
subtask_description | Description of the subtask. |
status | Status of the subtask. |
timestamp_range | Timestamp range corresponding to the subtask. |
frame_index_range | Frame index range corresponding to the subtask. |
camera_calibration
Organized by camera name, for example lf_chest_fisheye, ldr_hand_fisheye.
Each camera contains:
| Field | Description |
|---|---|
intrinsic | 3x3 camera intrinsic matrix. |
distortion | Distortion parameters. |
width | Image width. |
height | Image height. |
camera_model | Camera model, e.g., fisheye. |
frames
Each frame contains:
| Field | Description |
|---|---|
frame_index | Frame index. |
timestamp | Timestamp of the current frame. |
images | Relative paths to images from each camera. |
wrist_poses | Placeholder zero poses for the left and right end-effectors. |
chest_poses | Poses of the left and right end-effectors in the current frame's chest coordinate system. |
ego_poses | Pose of each camera relative to its own frame 0. |
chest_0_poses | Pose of each camera in the chest coordinate system. |
hand_states | Hand pose data; only populated when end_effector_type == "hand". |
Pose Fields
wrist_poses
- Meaning: Zero poses of
left_eefandright_eef. - Values:
position: [0, 0, 0],quaternion: [0, 0, 0, 1]. - Physical meaning: Placeholder field representing the zero pose of the robotic arm end-effector (wrist).
chest_poses
- Meaning: Pose of
left_eefandright_eefrelative to thechestframe at the current timestep. - Computation:
chest_inv @ eef_pose_in_chest. - Reference frame: Current frame's
chest. - Physical meaning: Pose of the robotic arm end-effector in the current local
chestcoordinate system.
ego_poses
- Meaning: Pose of each camera relative to its own frame 0.
- Computation:
base_inv @ curr_pose. - Reference frame: Each camera's own frame 0.
- Physical meaning: Self-motion trajectory of the camera.
chest_0_poses
- Meaning: Pose of each camera in the
chestframe at frame 0. - Computation: Read directly from
pose_in_chestin the HDF5 file. - Reference frame:
chest. - Physical meaning: Transform of the camera relative to the
chest.
Additional Field Notes
images
- Keys are camera names, values are relative paths to images.
- Paths are relative to the current worldcode root directory, e.g.,
camera/lf_chest_fisheye/xxx.jpg.
hand_states
- Used when
end_effector_type == "hand". - Contains
left_handandright_hand. - Each value is the hand state vector for the current frame, taken directly from the data path specified in the configuration.