pymomentum.skel_state

pymomentum.skel_state.blend(skel_states: Tensor, weights: Tensor | None = None) → Tensor

Blend k skeleton states with the passed-in weights.

Parameters:

• skel_states (torch.Tensor) – The skeleton states to blend.

• weights – The weights to use, if not provided, weights are assumed to be all 1s

Returns:

The blended skeleton state.

pymomentum.skel_state.check(skel_state: Tensor) → None

Check if the skeleton state has the correct shape.

Parameters:

skel_state (torch.Tensor) – The skeleton state to check.

Raises:

ValueError – If the skeleton state does not have the correct shape.

pymomentum.skel_state.from_matrix(matrices: Tensor) → Tensor

Convert 4x4 matrices to skeleton states. Assumes that the scale is uniform.

Args:

matrices (torch.Tensor): A tensor of 4x4 matrices.

Returns:

torch.Tensor: The corresponding skeleton states.

pymomentum.skel_state.from_quaternion(rotation: Tensor) → Tensor

Create a skeleton state from rotation.

Parameters:

rotation (torch.Tensor) – The rotation component.

Returns:

The skeleton state.

Return type:

torch.Tensor

pymomentum.skel_state.from_scale(scale: Tensor) → Tensor

Create a skeleton state from scale.

Parameters:

scale (torch.Tensor) – The scale component.

Returns:

The skeleton state.

Return type:

torch.Tensor

pymomentum.skel_state.from_translation(translation: Tensor) → Tensor

Create a skeleton state from translation.

Parameters:

translation (torch.Tensor) – The translation component.

Returns:

The skeleton state.

Return type:

torch.Tensor

pymomentum.skel_state.identity(size: Sequence[int] | None = None, device: device | None = None) → Tensor

Returns a skeleton state representing the identity transform.

Parameters:

• sizes (list[int], optional) – The size of each dimension in the output tensor. Defaults to None, which means the output will be a 1D tensor with 8 elements.

• device (torch.device, optional) – The device on which to create the tensor. Defaults to None, which means the tensor will be created on the default device.

Returns:

The identity skeleton state.

Return type:

torch.Tensor

pymomentum.skel_state.inverse(skeleton_states: Tensor) → Tensor

Compute the inverse of a skeleton state.

Parameters:

skeleton_states (torch.Tensor) – The skeleton state to invert.

Returns:

The inverted skeleton state.

Return type:

torch.Tensor

pymomentum.skel_state.match_leading_dimensions(t_left: Tensor, t_right: Tensor) → Tensor

Match the leading dimensions of two tensors.

Parameters:

• t_left (torch.Tensor) – The first tensor.

• t_right (torch.Tensor) – The second tensor.

Returns:

The first tensor with its leading dimensions matched to the second tensor.

Return type:

torch.Tensor

pymomentum.skel_state.multiply(s1: Tensor, s2: Tensor) → Tensor

Multiply two skeleton states.

Parameters:

• s1 (torch.Tensor) – The first skeleton state.

• s2 (torch.Tensor) – The second skeleton state.

Returns:

The product of the two skeleton states.

Return type:

torch.Tensor

pymomentum.skel_state.split(skel_state: Tensor) → tuple[Tensor, Tensor, Tensor]

Split a skeleton state into translation, rotation, and scale components.

Parameters:

skel_state (torch.Tensor) – The skeleton state to split.

Returns:

A tuple of tensors (translation, rotation, scale).

Return type:

tuple[torch.Tensor, torch.Tensor, torch.Tensor]

pymomentum.skel_state.to_matrix(skeleton_state: Tensor) → Tensor

Convert skeleton state to a tensor of 4x4 matrices. The matrix represents the transform from a local joint space to the world space.

Parameters:

skeleton_state (torch.Tensor) – The skeleton state to convert.

Returns:

A tensor containing 4x4 matrix transforms.

Return type:

torch.Tensor

pymomentum.skel_state.transform_points(skel_state: Tensor, points: Tensor) → Tensor

Transform 3d points by the transform represented by the skeleton state.

Parameters:

• skel_state (torch.Tensor) – The skeleton state to use for transformation.

• points (torch.Tensor) – The points to transform.

Returns:

The transformed points.

Return type:

torch.Tensor