Constraints

Constraint definitions and utilities.

Constraint sets for conditioning motion generation (root 2D, full body, end-effectors).

kimodo.constraints.create_pairs(tensor_A, tensor_B)

Form all (a, b) pairs from two 1D tensors; output shape (len(A)*len(B), 2).

kimodo.constraints.compute_global_heading(global_joints_positions, skeleton)

Compute global root heading (cos, sin) from global joint positions using skeleton.

class kimodo.constraints.Root2DConstraintSet(

skeleton,

frame_indices,

smooth_root_2d,

to_crop=False,

global_root_heading=None,

)

Bases: object

Constraint set fixing root (x, z) trajectory and optionally global heading on given frames.

name = 'root2d'

__init__(

skeleton,

frame_indices,

smooth_root_2d,

to_crop=False,

global_root_heading=None,

)

update_constraints(data_dict, index_dict)

Append this constraint’s smooth_root_2d (and optional global_root_heading) to data/index dicts.

crop_move(start, end)

Return a new constraint set for the cropped frame range [start, end).

get_save_info()

Return a dict suitable for JSON serialization (frame_indices, smooth_root_2d, optional global_root_heading).

to(device=None, dtype=None)

classmethod from_dict(skeleton, dico)

Build a Root2DConstraintSet from a dict (e.g. loaded from JSON).

class kimodo.constraints.FullBodyConstraintSet(

skeleton,

frame_indices,

global_joints_positions,

global_joints_rots,

smooth_root_2d=None,

to_crop=False,

)

Bases: object

Constraint set fixing full-body global positions and rotations on given keyframes.

name = 'fullbody'

__init__(

skeleton,

frame_indices,

global_joints_positions,

global_joints_rots,

smooth_root_2d=None,

to_crop=False,

)

update_constraints(data_dict, index_dict)

Append global positions, smooth root 2D, root y, and global heading to data/index dicts.

crop_move(start, end)

Return a new FullBodyConstraintSet for the cropped frame range [start, end).

get_save_info()

Return a dict for JSON save: type, frame_indices, local_joints_rot, root_positions, smooth_root_2d.

to(device=None, dtype=None)

classmethod from_dict(skeleton, dico)

Build a FullBodyConstraintSet from a dict (e.g. loaded from JSON).

class kimodo.constraints.EndEffectorConstraintSet(

skeleton,

frame_indices,

global_joints_positions,

global_joints_rots,

smooth_root_2d,

*,

joint_names,

to_crop=False,

)

Bases: object

Constraint set fixing selected end-effector positions and rotations on given frames.

name = 'end-effector'

__init__(

skeleton,

frame_indices,

global_joints_positions,

global_joints_rots,

smooth_root_2d,

*,

joint_names,

to_crop=False,

)

update_constraints(data_dict, index_dict)

Append constrained joint positions/rots, smooth root 2D, root y, and heading to data/index dicts.

crop_move(start, end)

Return a new EndEffectorConstraintSet for the cropped frame range [start, end).

get_save_info()

Return a dict for JSON save: type, frame_indices, local_joints_rot, root_positions, smooth_root_2d, joint_names.

to(device=None, dtype=None)

classmethod from_dict(skeleton, dico)

Build an EndEffectorConstraintSet from a dict (e.g. loaded from JSON).

class kimodo.constraints.LeftHandConstraintSet(*args, **kwargs)

Bases: EndEffectorConstraintSet

End-effector constraint for the left hand only.

name = 'left-hand'

joint_names = ['LeftHand']

__init__(*args, **kwargs)

class kimodo.constraints.RightHandConstraintSet(*args, **kwargs)

Bases: EndEffectorConstraintSet

End-effector constraint for the right hand only.

name = 'right-hand'

joint_names = ['RightHand']

__init__(*args, **kwargs)

class kimodo.constraints.LeftFootConstraintSet(*args, **kwargs)

Bases: EndEffectorConstraintSet

End-effector constraint for the left foot only.

name = 'left-foot'

joint_names = ['LeftFoot']

__init__(*args, **kwargs)

class kimodo.constraints.RightFootConstraintSet(*args, **kwargs)

Bases: EndEffectorConstraintSet

End-effector constraint for the right foot only.

name = 'right-foot'

joint_names = ['RightFoot']

__init__(*args, **kwargs)

kimodo.constraints.load_constraints_lst(path_or_data, skeleton, device=None, dtype=None)

Load a list of constraints from JSON path or list of dicts.

Parameters:

• path_or_data – Path to constraints.json or list of constraint dicts.

• skeleton – Skeleton instance (used for from_dict).

• device – If set, move all constraint tensors and skeleton to this device.

• dtype – If set, cast constraint tensors to this dtype.

kimodo.constraints.save_constraints_lst(path, constraints_lst)

Save a list of constraint sets to a JSON file.

Returns None if list is empty.