Language

unilab.tasks.motion_tracking.common.motion_loader¶

Shared motion loading and sampling for motion-tracking tasks.

Functions

`compute_frame_blend`(times, duration, ...)	Compute frame indices and blend weights for interpolation.
`compute_motion_velocities`(base_poss, ...)	Numerically differentiate a trajectory into base/dof velocities.
`ensure_quat_continuity`(q)	Flip quaternion signs in a time sequence to keep adjacent dots positive.
`interpolate_motion`(base_poss_input, ...)	Resample a root+joint trajectory from `input_fps` to `output_fps`.
`quat_slerp`(q1, q2, t)	Spherical linear interpolation between two quaternions (wxyz format).

Classes

`InterpolatedMotion`	Root/joint trajectory resampled to the output frame rate.
`MotionData`	Container for motion data at specific frame(s).
`MotionLoader`	Loads and provides access to motion data from NPZ files.

class unilab.tasks.motion_tracking.common.motion_loader.MotionData[source]¶

Bases: object

Container for motion data at specific frame(s).

Parameters:

joint_pos (Tensor)
joint_vel (Tensor)
body_pos_w (Tensor)
body_quat_w (Tensor)
body_lin_vel_w (Tensor)
body_ang_vel_w (Tensor)

joint_pos: Tensor¶

joint_vel: Tensor¶

body_pos_w: Tensor¶

body_quat_w: Tensor¶

body_lin_vel_w: Tensor¶

body_ang_vel_w: Tensor¶

__init__(joint_pos, joint_vel, body_pos_w, body_quat_w, body_lin_vel_w, body_ang_vel_w)¶

Parameters:

joint_pos (Tensor)
joint_vel (Tensor)
body_pos_w (Tensor)
body_quat_w (Tensor)
body_lin_vel_w (Tensor)
body_ang_vel_w (Tensor)

unilab.tasks.motion_tracking.common.motion_loader.quat_slerp(q1, q2, t)[source]¶

Spherical linear interpolation between two quaternions (wxyz format).

The computation runs in the input dtype; pass float64 arrays for a float64 interpolation path.

Parameters:

q1 (ndarray)
q2 (ndarray)
t (float)

Return type:

ndarray

unilab.tasks.motion_tracking.common.motion_loader.ensure_quat_continuity(q)[source]¶

Flip quaternion signs in a time sequence to keep adjacent dots positive.

Parameters:: q (ndarray)
Return type:: ndarray

class unilab.tasks.motion_tracking.common.motion_loader.InterpolatedMotion[source]¶

Bases: object

Root/joint trajectory resampled to the output frame rate.

Parameters:

output_frames (int)
base_poss (ndarray)
base_rots (ndarray)
dof_poss (ndarray)
base_lin_vels (ndarray)
base_ang_vels (ndarray)
dof_vels (ndarray)

output_frames: int¶

base_poss: ndarray¶

base_rots: ndarray¶

dof_poss: ndarray¶

base_lin_vels: ndarray¶

base_ang_vels: ndarray¶

dof_vels: ndarray¶

__init__(output_frames, base_poss, base_rots, dof_poss, base_lin_vels, base_ang_vels, dof_vels)¶

Parameters:

output_frames (int)
base_poss (ndarray)
base_rots (ndarray)
dof_poss (ndarray)
base_lin_vels (ndarray)
base_ang_vels (ndarray)
dof_vels (ndarray)

unilab.tasks.motion_tracking.common.motion_loader.compute_motion_velocities(base_poss, base_rots, dof_poss, dt)[source]¶

Numerically differentiate a trajectory into base/dof velocities.

Parameters:

base_poss (ndarray)
base_rots (ndarray)
dof_poss (ndarray)
dt (float)

Return type:

tuple[ndarray, ndarray, ndarray]

unilab.tasks.motion_tracking.common.motion_loader.compute_frame_blend(times, duration, input_frames)[source]¶

Compute frame indices and blend weights for interpolation.

Parameters:

times (ndarray)
duration (float)
input_frames (int)

Return type:

tuple[ndarray, ndarray, ndarray]

unilab.tasks.motion_tracking.common.motion_loader.interpolate_motion(base_poss_input, base_rots_input, dof_poss_input, *, input_fps, output_fps)[source]¶

Resample a root+joint trajectory from input_fps to output_fps.

Positions and joint angles are linearly interpolated, root quaternions (wxyz) use slerp, and velocities are computed by numerical differentiation at the output rate.

Parameters:

base_poss_input (ndarray)
base_rots_input (ndarray)
dof_poss_input (ndarray)
input_fps (int)
output_fps (int)

Return type:

InterpolatedMotion

class unilab.tasks.motion_tracking.common.motion_loader.MotionLoader[source]¶

Bases: object

Loads and provides access to motion data from NPZ files.

Parameters:

motion_file (str | Sequence[str])
body_indices (Sequence[int] | None)

__init__(motion_file, body_indices=None)[source]¶

Initialize motion loader.

Parameters:

motion_file (str | Sequence[str]) – Path to one NPZ file, or a sequence of NPZ files
body_indices (Sequence[int] | None) – Optional indices into the NPZ body axis. The exported motion files currently keep MuJoCo body-id layout, so these indices are expected to follow that convention.

get_clip_indices(frame_idx)[source]¶

Map global frame indices to clip indices.

Parameters:: frame_idx (ndarray)
Return type:: ndarray

motion_features_torch(device)[source]¶

Return the immutable motion feature table on the requested device.

NPZ parsing and validation remain inside this cold-path leaf. Runtime consumers receive one contiguous float32 table with columns packed in the documented motion-feature order rather than mutable NumPy arrays.

Parameters:: device (str | device)
Return type:: Tensor

clip_offsets_torch(device)[source]¶

Return immutable clip start frames as a device-resident Torch table.

Parameters:: device (str | device)
Return type:: Tensor

clip_end_frames_torch(device)[source]¶

Return immutable clip end frames as a device-resident Torch table.

Parameters:: device (str | device)
Return type:: Tensor