Tangential Collisions¶

class ipctk.TangentialCollisions¶

Bases: pybind11_object

Public Data Attributes:

`vv_collisions`
`ev_collisions`
`ee_collisions`
`fv_collisions`

Public Methods:

`__init__`(self)
`build`(args, *kwargs)	Overloaded function.
`__len__`(self)	Get the number of friction collisions.
`empty`(self)	Get if the friction collisions are empty.
`clear`(self)	Clear the friction collisions.
`__getitem__`(self, i)	Get a reference to collision at index i.
`default_blend_mu`(mu0, mu1)

Inherited from pybind11_object

__annotations__ = {}¶

__getitem__(self, i: int) → ipctk.TangentialCollision¶

Get a reference to collision at index i.

Parameters:¶

i: int¶: The index of the collision.

Returns:¶

A reference to the collision.

__init__(self)¶

__len__(self) → int¶: Get the number of friction collisions.

__module__ = 'ipctk'¶

build(*args, **kwargs)¶

Overloaded function.

build(self: ipctk.TangentialCollisions, mesh: ipc::CollisionMesh, vertices: numpy.ndarray[numpy.float64[m, n]], collisions: ipctk.NormalCollisions, normal_potential: ipc::NormalPotential, normal_stiffness: float, mu: float) -> None
build(self: ipctk.TangentialCollisions, mesh: ipc::CollisionMesh, vertices: numpy.ndarray[numpy.float64[m, n]], collisions: ipctk.NormalCollisions, normal_potential: ipc::NormalPotential, normal_stiffness: float, mus: numpy.ndarray[numpy.float64[m, 1]]) -> None
build(self: ipctk.TangentialCollisions, mesh: ipc::CollisionMesh, vertices: numpy.ndarray[numpy.float64[m, n]], collisions: ipctk.NormalCollisions, normal_potential: ipc::NormalPotential, normal_stiffness: float, mus: numpy.ndarray[numpy.float64[m, 1]], blend_mu: Callable[[float, float], float]) -> None

clear(self) → None¶: Clear the friction collisions.

static default_blend_mu(mu0: float, mu1: float) → float¶

property ee_collisions : list[ipc::EdgeEdgeTangentialCollision]¶

empty(self) → bool¶: Get if the friction collisions are empty.

property ev_collisions : list[ipc::EdgeVertexTangentialCollision]¶

property fv_collisions : list[ipc::FaceVertexTangentialCollision]¶

property vv_collisions : list[ipc::VertexVertexTangentialCollision]¶

Tangential Collision¶

class ipctk.TangentialCollision¶

Bases: CollisionStencil

Public Data Attributes:

`dim`	Get the dimension of the collision.
`ndof`	Get the number of degrees of freedom for the collision.
`normal_force_magnitude`	Normal force magnitude
`mu`	Ratio between normal and tangential forces (e.g., friction coefficient)
`weight`	Weight
`weight_gradient`	Gradient of weight with respect to all DOF
`closest_point`	Barycentric coordinates of the closest point(s)
`tangent_basis`	Tangent basis of the collision (max size 3×2)

Public Methods:

`__init__`(args, *kwargs)
`compute_tangent_basis`(self, positions)	Compute the tangent basis of the collision.
`compute_tangent_basis_jacobian`(self, positions)	Compute the Jacobian of the tangent basis of the collision.
`compute_closest_point`(self, positions)	Compute the barycentric coordinates of the closest point.
`compute_closest_point_jacobian`(self, positions)	Compute the Jacobian of the barycentric coordinates of the closest point.
`relative_velocity`(self, velocities)	Compute the relative velocity of the collision.
`relative_velocity_matrix`(args, *kwargs)	Overloaded function.
`relative_velocity_matrix_jacobian`(self, ...)	Construct the Jacobian of the relative velocity premultiplier wrt the closest points.

Inherited from CollisionStencil

`__init__`(args, *kwargs)
`num_vertices`(self)	Get the number of vertices in the collision stencil.
`dim`(self, ndof)	Get the dimension of the collision stencil.
`vertex_ids`(self, edges, faces)	Get the vertex IDs of the collision stencil.
`vertices`(self, vertices, edges, faces)	Get the vertex attributes of the collision stencil.
`dof`(self, X, edges, faces)	Select this stencil's DOF from the full matrix of DOF.
`compute_distance`(self, positions)	Compute the distance of the stencil.
`compute_distance_gradient`(self, positions)	Compute the distance gradient of the stencil w.r.t.
`compute_distance_hessian`(self, positions)	Compute the distance Hessian of the stencil w.r.t.

Inherited from pybind11_object

__annotations__ = {}¶

__init__(*args, **kwargs)¶

__module__ = 'ipctk'¶

property closest_point : numpy.ndarray[numpy.float64[m, 1]]¶: Barycentric coordinates of the closest point(s)

compute_closest_point(self, positions: numpy.ndarray[numpy.float64[m, 1]]) → numpy.ndarray[numpy.float64[m, 1]]¶

Compute the barycentric coordinates of the closest point.

Parameters:¶

positions: numpy.ndarray[numpy.float64[m, 1]]¶: Collision stencil’s vertex positions.

Returns:¶

Barycentric coordinates of the closest point.

compute_closest_point_jacobian(self, positions: numpy.ndarray[numpy.float64[m, 1]]) → numpy.ndarray[numpy.float64[m, n]]¶

Compute the Jacobian of the barycentric coordinates of the closest point.

Parameters:¶

positions: numpy.ndarray[numpy.float64[m, 1]]¶: Collision stencil’s vertex positions.

Returns:¶

Jacobian of the barycentric coordinates of the closest point.

compute_tangent_basis(self, positions: numpy.ndarray[numpy.float64[m, 1]]) → numpy.ndarray[numpy.float64[m, n]]¶

Compute the tangent basis of the collision.

Parameters:¶

positions: numpy.ndarray[numpy.float64[m, 1]]¶: Collision stencil’s vertex positions.

Returns:¶

Tangent basis of the collision.

compute_tangent_basis_jacobian(self, positions: numpy.ndarray[numpy.float64[m, 1]]) → numpy.ndarray[numpy.float64[m, n]]¶

Compute the Jacobian of the tangent basis of the collision.

Parameters:¶

positions: numpy.ndarray[numpy.float64[m, 1]]¶: Collision stencil’s vertex positions.

Returns:¶

Jacobian of the tangent basis of the collision.

property dim : int¶: Get the dimension of the collision.

property mu : float¶: Ratio between normal and tangential forces (e.g., friction coefficient)

property ndof : int¶: Get the number of degrees of freedom for the collision.

property normal_force_magnitude : float¶: Normal force magnitude

relative_velocity(self, velocities: numpy.ndarray[numpy.float64[m, 1]]) → numpy.ndarray[numpy.float64[m, 1]]¶

Compute the relative velocity of the collision.

Parameters:¶

velocities: numpy.ndarray[numpy.float64[m, 1]]¶: Collision stencil’s vertex velocities.

Returns:¶

Relative velocity of the collision.

relative_velocity_matrix(*args, **kwargs)¶

Overloaded function.

relative_velocity_matrix(self: ipctk.TangentialCollision) -> numpy.ndarray[numpy.float64[m, n]]

Construct the premultiplier matrix for the relative velocity.

Note:
Uses the cached closest point.

Returns:
A matrix M such that relative_velocity = M * velocities.
relative_velocity_matrix(self: ipctk.TangentialCollision, closest_point: numpy.ndarray[numpy.float64[m, 1]]) -> numpy.ndarray[numpy.float64[m, n]]

Construct the premultiplier matrix for the relative velocity.

Parameters:
closest_point: Barycentric coordinates of the closest point.

Returns:
A matrix M such that relative_velocity = M * velocities.

relative_velocity_matrix_jacobian(self, closest_point: numpy.ndarray[numpy.float64[m, 1]]) → numpy.ndarray[numpy.float64[m, n]]¶

Construct the Jacobian of the relative velocity premultiplier wrt the closest points.

Parameters:¶

closest_point: numpy.ndarray[numpy.float64[m, 1]]¶: Barycentric coordinates of the closest point.

Returns:¶

Jacobian of the relative velocity premultiplier wrt the closest points.

property tangent_basis : numpy.ndarray[numpy.float64[m, n]]¶: Tangent basis of the collision (max size 3×2)

property weight : float¶: Weight

property weight_gradient : scipy.sparse.csc_matrix[numpy.float64]¶: Gradient of weight with respect to all DOF

Vertex-Vertex Tangential Collision¶

class ipctk.VertexVertexTangentialCollision¶

Bases: VertexVertexCandidate, TangentialCollision

Public Data Attributes:

Inherited from VertexVertexCandidate

`vertex0_id`	ID of the first vertex
`vertex1_id`	ID of the second vertex

Inherited from TangentialCollision

`dim`	Get the dimension of the collision.
`ndof`	Get the number of degrees of freedom for the collision.
`normal_force_magnitude`	Normal force magnitude
`mu`	Ratio between normal and tangential forces (e.g., friction coefficient)
`weight`	Weight
`weight_gradient`	Gradient of weight with respect to all DOF
`closest_point`	Barycentric coordinates of the closest point(s)
`tangent_basis`	Tangent basis of the collision (max size 3×2)

Public Methods:

`__init__`(args, *kwargs)	Overloaded function.

Inherited from VertexVertexCandidate

`__init__`(self, vertex0_id, vertex1_id)
`__str__`(self)
`__repr__`(self)
`__eq__`(self, other)
`__ne__`(self, other)
`__lt__`(self, other)	Compare EdgeVertexCandidates for sorting.

Inherited from TangentialCollision

`__init__`(args, *kwargs)
`compute_tangent_basis`(self, positions)	Compute the tangent basis of the collision.
`compute_tangent_basis_jacobian`(self, positions)	Compute the Jacobian of the tangent basis of the collision.
`compute_closest_point`(self, positions)	Compute the barycentric coordinates of the closest point.
`compute_closest_point_jacobian`(self, positions)	Compute the Jacobian of the barycentric coordinates of the closest point.
`relative_velocity`(self, velocities)	Compute the relative velocity of the collision.
`relative_velocity_matrix`(args, *kwargs)	Overloaded function.
`relative_velocity_matrix_jacobian`(self, ...)	Construct the Jacobian of the relative velocity premultiplier wrt the closest points.

Inherited from CollisionStencil

`__init__`(args, *kwargs)
`num_vertices`(self)	Get the number of vertices in the collision stencil.
`dim`(self, ndof)	Get the dimension of the collision stencil.
`vertex_ids`(self, edges, faces)	Get the vertex IDs of the collision stencil.
`vertices`(self, vertices, edges, faces)	Get the vertex attributes of the collision stencil.
`dof`(self, X, edges, faces)	Select this stencil's DOF from the full matrix of DOF.
`compute_distance`(self, positions)	Compute the distance of the stencil.
`compute_distance_gradient`(self, positions)	Compute the distance gradient of the stencil w.r.t.
`compute_distance_hessian`(self, positions)	Compute the distance Hessian of the stencil w.r.t.

Inherited from ContinuousCollisionCandidate

`__init__`(args, *kwargs)
`ccd`(self, vertices_t0, 1]], vertices_t1, ...)	Perform narrow-phase CCD on the candidate.
`print_ccd_query`(self, vertices_t0, vertices_t1)	Print the CCD query to cout.

Inherited from pybind11_object

__annotations__ = {}¶

__init__(*args, **kwargs)¶

Overloaded function.

__init__(self: ipctk.VertexVertexTangentialCollision, collision: ipctk.VertexVertexNormalCollision) -> None
__init__(self: ipctk.VertexVertexTangentialCollision, collision: ipctk.VertexVertexNormalCollision, positions: numpy.ndarray[numpy.float64[m, 1]], normal_potential: ipc::NormalPotential, normal_stiffness: float) -> None

__module__ = 'ipctk'¶

Edge-Vertex Tangential Collision¶

class ipctk.EdgeVertexTangentialCollision¶

Bases: EdgeVertexCandidate, TangentialCollision

Public Data Attributes:

Inherited from EdgeVertexCandidate

`edge_id`	ID of the edge
`vertex_id`	ID of the vertex

Inherited from TangentialCollision

`dim`	Get the dimension of the collision.
`ndof`	Get the number of degrees of freedom for the collision.
`normal_force_magnitude`	Normal force magnitude
`mu`	Ratio between normal and tangential forces (e.g., friction coefficient)
`weight`	Weight
`weight_gradient`	Gradient of weight with respect to all DOF
`closest_point`	Barycentric coordinates of the closest point(s)
`tangent_basis`	Tangent basis of the collision (max size 3×2)

Public Methods:

`__init__`(args, *kwargs)	Overloaded function.

Inherited from EdgeVertexCandidate

`__init__`(self, edge_id, vertex_id)
`known_dtype`(self)
`__str__`(self)
`__repr__`(self)
`__eq__`(self, other)
`__ne__`(self, other)
`__lt__`(self, other)	Compare EdgeVertexCandidates for sorting.

Inherited from TangentialCollision

`__init__`(args, *kwargs)
`compute_tangent_basis`(self, positions)	Compute the tangent basis of the collision.
`compute_tangent_basis_jacobian`(self, positions)	Compute the Jacobian of the tangent basis of the collision.
`compute_closest_point`(self, positions)	Compute the barycentric coordinates of the closest point.
`compute_closest_point_jacobian`(self, positions)	Compute the Jacobian of the barycentric coordinates of the closest point.
`relative_velocity`(self, velocities)	Compute the relative velocity of the collision.
`relative_velocity_matrix`(args, *kwargs)	Overloaded function.
`relative_velocity_matrix_jacobian`(self, ...)	Construct the Jacobian of the relative velocity premultiplier wrt the closest points.

Inherited from CollisionStencil

`__init__`(args, *kwargs)
`num_vertices`(self)	Get the number of vertices in the collision stencil.
`dim`(self, ndof)	Get the dimension of the collision stencil.
`vertex_ids`(self, edges, faces)	Get the vertex IDs of the collision stencil.
`vertices`(self, vertices, edges, faces)	Get the vertex attributes of the collision stencil.
`dof`(self, X, edges, faces)	Select this stencil's DOF from the full matrix of DOF.
`compute_distance`(self, positions)	Compute the distance of the stencil.
`compute_distance_gradient`(self, positions)	Compute the distance gradient of the stencil w.r.t.
`compute_distance_hessian`(self, positions)	Compute the distance Hessian of the stencil w.r.t.

Inherited from ContinuousCollisionCandidate

`__init__`(args, *kwargs)
`ccd`(self, vertices_t0, 1]], vertices_t1, ...)	Perform narrow-phase CCD on the candidate.
`print_ccd_query`(self, vertices_t0, vertices_t1)	Print the CCD query to cout.

Inherited from pybind11_object

__annotations__ = {}¶

__init__(*args, **kwargs)¶

Overloaded function.

__init__(self: ipctk.EdgeVertexTangentialCollision, collision: ipctk.EdgeVertexNormalCollision) -> None
__init__(self: ipctk.EdgeVertexTangentialCollision, collision: ipctk.EdgeVertexNormalCollision, positions: numpy.ndarray[numpy.float64[m, 1]], normal_potential: ipc::NormalPotential, normal_stiffness: float) -> None

__module__ = 'ipctk'¶

Edge-Edge Tangential Collision¶

class ipctk.EdgeEdgeTangentialCollision¶

Bases: EdgeEdgeCandidate, TangentialCollision

Public Data Attributes:

Inherited from EdgeEdgeCandidate

`edge0_id`	ID of the first edge.
`edge1_id`	ID of the second edge.

Inherited from TangentialCollision

`dim`	Get the dimension of the collision.
`ndof`	Get the number of degrees of freedom for the collision.
`normal_force_magnitude`	Normal force magnitude
`mu`	Ratio between normal and tangential forces (e.g., friction coefficient)
`weight`	Weight
`weight_gradient`	Gradient of weight with respect to all DOF
`closest_point`	Barycentric coordinates of the closest point(s)
`tangent_basis`	Tangent basis of the collision (max size 3×2)

Public Methods:

`__init__`(args, *kwargs)	Overloaded function.

Inherited from EdgeEdgeCandidate

`__init__`(self, edge0_id, edge1_id)
`known_dtype`(self)
`__str__`(self)
`__repr__`(self)
`__eq__`(self, other)
`__ne__`(self, other)
`__lt__`(self, other)	Compare EdgeEdgeCandidates for sorting.

Inherited from TangentialCollision

`__init__`(args, *kwargs)
`compute_tangent_basis`(self, positions)	Compute the tangent basis of the collision.
`compute_tangent_basis_jacobian`(self, positions)	Compute the Jacobian of the tangent basis of the collision.
`compute_closest_point`(self, positions)	Compute the barycentric coordinates of the closest point.
`compute_closest_point_jacobian`(self, positions)	Compute the Jacobian of the barycentric coordinates of the closest point.
`relative_velocity`(self, velocities)	Compute the relative velocity of the collision.
`relative_velocity_matrix`(args, *kwargs)	Overloaded function.
`relative_velocity_matrix_jacobian`(self, ...)	Construct the Jacobian of the relative velocity premultiplier wrt the closest points.

Inherited from CollisionStencil

`__init__`(args, *kwargs)
`num_vertices`(self)	Get the number of vertices in the collision stencil.
`dim`(self, ndof)	Get the dimension of the collision stencil.
`vertex_ids`(self, edges, faces)	Get the vertex IDs of the collision stencil.
`vertices`(self, vertices, edges, faces)	Get the vertex attributes of the collision stencil.
`dof`(self, X, edges, faces)	Select this stencil's DOF from the full matrix of DOF.
`compute_distance`(self, positions)	Compute the distance of the stencil.
`compute_distance_gradient`(self, positions)	Compute the distance gradient of the stencil w.r.t.
`compute_distance_hessian`(self, positions)	Compute the distance Hessian of the stencil w.r.t.

Inherited from ContinuousCollisionCandidate

`__init__`(args, *kwargs)
`ccd`(self, vertices_t0, 1]], vertices_t1, ...)	Perform narrow-phase CCD on the candidate.
`print_ccd_query`(self, vertices_t0, vertices_t1)	Print the CCD query to cout.

Inherited from pybind11_object

__annotations__ = {}¶

__init__(*args, **kwargs)¶

Overloaded function.

__init__(self: ipctk.EdgeEdgeTangentialCollision, collision: ipctk.EdgeEdgeNormalCollision) -> None
__init__(self: ipctk.EdgeEdgeTangentialCollision, collision: ipctk.EdgeEdgeNormalCollision, positions: numpy.ndarray[numpy.float64[m, 1]], normal_potential: ipc::NormalPotential, normal_stiffness: float) -> None

__module__ = 'ipctk'¶

Face-Vertex Tangential Collision¶

class ipctk.FaceVertexTangentialCollision¶

Bases: FaceVertexCandidate, TangentialCollision

Public Data Attributes:

Inherited from FaceVertexCandidate

`face_id`	ID of the face
`vertex_id`	ID of the vertex

Inherited from TangentialCollision

`dim`	Get the dimension of the collision.
`ndof`	Get the number of degrees of freedom for the collision.
`normal_force_magnitude`	Normal force magnitude
`mu`	Ratio between normal and tangential forces (e.g., friction coefficient)
`weight`	Weight
`weight_gradient`	Gradient of weight with respect to all DOF
`closest_point`	Barycentric coordinates of the closest point(s)
`tangent_basis`	Tangent basis of the collision (max size 3×2)

Public Methods:

`__init__`(args, *kwargs)	Overloaded function.

Inherited from FaceVertexCandidate

`__init__`(self, face_id, vertex_id)
`known_dtype`(self)
`__str__`(self)
`__repr__`(self)
`__eq__`(self, other)
`__ne__`(self, other)
`__lt__`(self, other)	Compare FaceVertexCandidate for sorting.

Inherited from TangentialCollision

`__init__`(args, *kwargs)
`compute_tangent_basis`(self, positions)	Compute the tangent basis of the collision.
`compute_tangent_basis_jacobian`(self, positions)	Compute the Jacobian of the tangent basis of the collision.
`compute_closest_point`(self, positions)	Compute the barycentric coordinates of the closest point.
`compute_closest_point_jacobian`(self, positions)	Compute the Jacobian of the barycentric coordinates of the closest point.
`relative_velocity`(self, velocities)	Compute the relative velocity of the collision.
`relative_velocity_matrix`(args, *kwargs)	Overloaded function.
`relative_velocity_matrix_jacobian`(self, ...)	Construct the Jacobian of the relative velocity premultiplier wrt the closest points.

Inherited from CollisionStencil

`__init__`(args, *kwargs)
`num_vertices`(self)	Get the number of vertices in the collision stencil.
`dim`(self, ndof)	Get the dimension of the collision stencil.
`vertex_ids`(self, edges, faces)	Get the vertex IDs of the collision stencil.
`vertices`(self, vertices, edges, faces)	Get the vertex attributes of the collision stencil.
`dof`(self, X, edges, faces)	Select this stencil's DOF from the full matrix of DOF.
`compute_distance`(self, positions)	Compute the distance of the stencil.
`compute_distance_gradient`(self, positions)	Compute the distance gradient of the stencil w.r.t.
`compute_distance_hessian`(self, positions)	Compute the distance Hessian of the stencil w.r.t.

Inherited from ContinuousCollisionCandidate

`__init__`(args, *kwargs)
`ccd`(self, vertices_t0, 1]], vertices_t1, ...)	Perform narrow-phase CCD on the candidate.
`print_ccd_query`(self, vertices_t0, vertices_t1)	Print the CCD query to cout.

Inherited from pybind11_object

__annotations__ = {}¶

__init__(*args, **kwargs)¶

Overloaded function.

__init__(self: ipctk.FaceVertexTangentialCollision, collision: ipctk.FaceVertexNormalCollision) -> None
__init__(self: ipctk.FaceVertexTangentialCollision, collision: ipctk.FaceVertexNormalCollision, positions: numpy.ndarray[numpy.float64[m, 1]], normal_potential: ipc::NormalPotential, normal_stiffness: float) -> None

__module__ = 'ipctk'¶

Last update: Nov 16, 2024