Detailed Description

template<typename T>
class drake::multibody::DeformableModel< T >

DeformableModel implements the interface in PhysicalModel and provides the functionalities to specify deformable bodies.

Unlike rigid bodies, the shape of deformable bodies can change in a simulation. Each deformable body is modeled as a volumetric mesh with persisting topology, changing vertex positions, and an approximated signed distance field. A finite element model is built for each registered deformable body that is used to evaluate the dynamics of the body.

Warning: This feature is considered to be experimental and may change or be removed at any time, without any deprecation notice ahead of time.

Template Parameters

T	The scalar type, which must be `double`.

#include <drake/multibody/tree/multibody_element.h>

Public Member Functions
	DeformableModel (MultibodyPlant< T > *plant)
	(Internal only) Constructs a DeformableModel to be owned by the given MultibodyPlant. More...

	~DeformableModel () final

int	num_bodies () const
	Returns the number of deformable bodies registered with this DeformableModel. More...

DeformableBodyId	RegisterDeformableBody (std::unique_ptr< geometry::GeometryInstance > geometry_instance, ModelInstanceIndex model_instance, const fem::DeformableBodyConfig< T > &config, double resolution_hint)
	Registers a deformable body in `this` DeformableModel with the given GeometryInstance. More...

DeformableBodyId	RegisterDeformableBody (std::unique_ptr< geometry::GeometryInstance > geometry_instance, const fem::DeformableBodyConfig< T > &config, double resolution_hint)
	Registers a deformable body in `this` DeformableModel with the default model instance. More...

void	SetWallBoundaryCondition (DeformableBodyId id, const Vector3< T > &p_WQ, const Vector3< T > &n_W)
	Sets wall boundary conditions for the body with the given `id`. More...

MultibodyConstraintId	AddFixedConstraint (DeformableBodyId body_A_id, const RigidBody< T > &body_B, const math::RigidTransform< double > &X_BA, const geometry::Shape &shape_G, const math::RigidTransform< double > &X_BG)
	Defines a fixed constraint between a deformable body A and a rigid body B. More...

systems::DiscreteStateIndex	GetDiscreteStateIndex (DeformableBodyId id) const
	Returns the discrete state index of the deformable body identified by the given `id`. More...

void	SetPositions (systems::Context< T > *context, DeformableBodyId id, const Eigen::Ref< const Matrix3X< T >> &q) const
	Sets the vertex positions of the deformable body with the given `id` in the provided `context`. More...

void	SetVelocities (systems::Context< T > *context, DeformableBodyId id, const Eigen::Ref< const Matrix3X< T >> &v) const
	Sets the vertex velocities of the deformable body with the given `id` in the provided `context`. More...

void	SetPositionsAndVelocities (systems::Context< T > *context, DeformableBodyId id, const Eigen::Ref< const Matrix3X< T >> &q, const Eigen::Ref< const Matrix3X< T >> &v) const
	Sets the vertex positions and velocities of the deformable body with the given `id` in the provided `context`. More...

Matrix3X< T >	GetPositions (const systems::Context< T > &context, DeformableBodyId id) const
	Returns the matrix of vertex positions for the deformable body with the given `id` in the provided `context`. More...

Matrix3X< T >	GetVelocities (const systems::Context< T > &context, DeformableBodyId id) const
	Returns the matrix of vertex velocities for the deformable body with the given `id` in the provided `context`. More...

Matrix3X< T >	GetPositionsAndVelocities (const systems::Context< T > &context, DeformableBodyId id) const
	Returns the matrix of vertex positions and velocities for the deformable body with the given `id` in the provided `context`. More...

void	AddExternalForce (std::unique_ptr< ForceDensityFieldBase< T >> external_force)
	Registers an external force density field that applies external force to all deformable bodies. More...

const std::vector< const ForceDensityFieldBase< T > * > &	GetExternalForces (DeformableBodyId id) const
	Returns the force density fields acting on the deformable body with the given `id`. More...

void	Disable (DeformableBodyId id, systems::Context< T > *context) const
	Disables the deformable body with the given `id` in the given context. More...

void	Enable (DeformableBodyId id, systems::Context< T > *context) const
	Enables the deformable body with the given `id` in the given context. More...

bool	is_enabled (DeformableBodyId id, const systems::Context< T > &context) const

const fem::FemModel< T > &	GetFemModel (DeformableBodyId id) const
	Returns the FemModel for the body with `id`. More...

const VectorX< double > &	GetReferencePositions (DeformableBodyId id) const
	Returns the reference positions of the vertices of the deformable body identified by the given `id`. More...

DeformableBodyId	GetBodyId (DeformableBodyIndex index) const
	Returns the DeformableBodyId of the body with the given body index. More...

DeformableBodyId	GetBodyId (geometry::GeometryId geometry_id) const
	Returns the DeformableBodyId associated with the given `geometry_id`. More...

const DeformableBody< T > &	GetBody (DeformableBodyId id) const
	Returns the deformable body with the given `id`. More...

const DeformableBody< T > &	GetBody (DeformableBodyIndex index) const
	Returns the deformable body with the given `index`. More...

DeformableBody< T > &	GetMutableBody (DeformableBodyId id)
	Returns a mutable reference to the deformable body with the given `id`. More...

bool	HasBodyNamed (const std::string &name) const
	Returns true if and only if a deformable body with the given `name` has been registered with this model. More...

bool	HasBodyNamed (const std::string &name, ModelInstanceIndex model_instance) const
	Returns true if and only if a deformable body with the given `name` has been registered with this model under the given `model_instance`. More...

const DeformableBody< T > &	GetBodyByName (const std::string &name) const
	Returns the DeformableBody with the given name. More...

const DeformableBody< T > &	GetBodyByName (const std::string &name, ModelInstanceIndex model_instance) const
	Returns the DeformableBody with the given name from the given model instance. More...

std::vector< DeformableBodyId >	GetBodyIds (ModelInstanceIndex model_instance) const
	Returns the DeformableIds of the bodies that belong to the given model instance. More...

DeformableBodyIndex	GetBodyIndex (DeformableBodyId id) const
	Returns the DeformableBodyIndex of the body with the given id. More...

geometry::GeometryId	GetGeometryId (DeformableBodyId id) const
	Returns the GeometryId of the geometry associated with the body with the given `id`. More...

bool	HasConstraint (DeformableBodyId id) const
	Returns the true if the deformable body with the given `id` has constraints associated with it. More...

const multibody::fem::internal::DiscreteTimeIntegrator< T > &	integrator () const
	(Internal use only) Returns the time integrator used to for all FemModels in this model. More...

systems::OutputPortIndex	configuration_output_port_index () const
	(Internal use only) Returns the output port index of the vertex positions port for all registered deformable bodies. More...

bool	is_empty () const
	Returns true if there's no deformable body or external force registered to `this` DeformableModel. More...

bool	is_cloneable_to_double () const final

bool	is_cloneable_to_autodiff () const final
	Returns true if and only if this DeformableModel is empty. More...

bool	is_cloneable_to_symbolic () const final
	Returns true if and only if this DeformableModel is empty. More...

void	SetParallelism (Parallelism parallelism)
	(Internal use only) Configures the parallelism that `this` DeformableModel uses when opportunities for parallel computation arises. More...

Parallelism	parallelism () const
	(Internal use only) Returns the parallelism that `this` DeformableModel uses when opportunities for parallel computation arises. More...

void	SetDefaultState (const systems::Context< T > &context, systems::State< T > *state) const
	(Internal use only) Sets the default state for the deformable model. More...

Does not allow copy, move, or assignment
	DeformableModel (const DeformableModel &)=delete

DeformableModel &	operator= (const DeformableModel &)=delete

	DeformableModel (DeformableModel &&)=delete

DeformableModel &	operator= (DeformableModel &&)=delete

Public Member Functions inherited from PhysicalModel< T >
	PhysicalModel (MultibodyPlant< T > *owning_plant)
	Constructs a PhysicalModel owned by the given `owning_plant`. More...

	~PhysicalModel () override

template<typename ScalarType >
std::unique_ptr< PhysicalModel< ScalarType > >	CloneToScalar (MultibodyPlant< ScalarType > *plant) const
	(Internal only) Creates a clone of `this` concrete PhysicalModel object with the scalar type `ScalarType` to be owned by the given `plant`. More...

bool	is_cloneable_to_double () const override
	Defaults to false. More...

bool	is_cloneable_to_autodiff () const override
	Defaults to false. More...

bool	is_cloneable_to_symbolic () const override
	Defaults to false. More...

void	DeclareSystemResources ()
	(Internal only) MultibodyPlant calls this from within Finalize() to declare additional system resources. More...

void	DeclareSceneGraphPorts ()
	(Internal only) Declares zero or more output ports in the owning MultibodyPlant to communicate with a SceneGraph. More...

PhysicalModelPointerVariant< T >	ToPhysicalModelPointerVariant () const
	Returns (a const pointer to) the specific model variant of `this` PhysicalModel. More...

const MultibodyPlant< T > &	plant () const

	PhysicalModel (const PhysicalModel &)=delete

PhysicalModel &	operator= (const PhysicalModel &)=delete

	PhysicalModel (PhysicalModel &&)=delete

PhysicalModel &	operator= (PhysicalModel &&)=delete

Friends
template<typename U >
class	DeformableModel

Additional Inherited Members
Protected Member Functions inherited from PhysicalModel< T >
MultibodyPlant< T > *	mutable_plant ()

const internal::MultibodyTree< T > &	internal_tree () const

void	ThrowIfSystemResourcesDeclared (const char *function_name) const

void	ThrowIfSystemResourcesNotDeclared (const char *function_name) const

geometry::SceneGraph< T > &	mutable_scene_graph ()

systems::DiscreteStateIndex	DeclareDiscreteState (const VectorX< T > &model_value)

systems::AbstractParameterIndex	DeclareAbstractParameter (const AbstractValue &model_value)

systems::LeafOutputPort< T > &	DeclareAbstractOutputPort (std::string name, typename systems::LeafOutputPort< T >::AllocCallback alloc_function, typename systems::LeafOutputPort< T >::CalcCallback calc_function, std::set< systems::DependencyTicket > prerequisites_of_calc={ systems::System< T >::all_sources_ticket()})

systems::LeafOutputPort< T > &	DeclareVectorOutputPort (std::string name, const systems::BasicVector< T > &model_vector, typename systems::LeafOutputPort< T >::CalcVectorCallback vector_calc_function, std::set< systems::DependencyTicket > prerequisites_of_calc={ systems::System< T >::all_sources_ticket()})

Constructor & Destructor Documentation

◆ DeformableModel() [1/3]

DeformableModel ( const DeformableModel< T > & )

delete

◆ DeformableModel() [2/3]

DeformableModel ( DeformableModel< T > && )

delete

◆ DeformableModel() [3/3]

DeformableModel ( MultibodyPlant< T > * plant )

explicit

(Internal only) Constructs a DeformableModel to be owned by the given MultibodyPlant.

This constructor is only intended to be called internally by MultibodyPlant.

Precondition: plant != nullptr.; Finalize() has not been called on plant.

◆ ~DeformableModel()

~DeformableModel ( )

final

Member Function Documentation

◆ AddExternalForce()

void AddExternalForce ( std::unique_ptr< ForceDensityFieldBase< T >> external_force )

Registers an external force density field that applies external force to all deformable bodies.

Exceptions

std::exception	if `this` DeformableModel is not of scalar type double.
std::exception	if `this` DeformableModel belongs to a continuous MultibodyPlant.
std::exception	if Finalize() has been called on the multibody plant owning this deformable model.

◆ AddFixedConstraint()

MultibodyConstraintId AddFixedConstraint	(	DeformableBodyId	body_A_id,
		const RigidBody< T > &	body_B,
		const math::RigidTransform< double > &	X_BA,
		const geometry::Shape &	shape_G,
		const math::RigidTransform< double > &	X_BG
	)

Defines a fixed constraint between a deformable body A and a rigid body B.

Such a fixed constraint is modeled as distance holonomic constraints:

p_PᵢQᵢ(q) = 0 for each constrained vertex Pᵢ

where Pᵢ is the i-th vertex of the deformable body under constraint and Qᵢ is a point rigidly affixed to the rigid body B. To specify the constraint, we put the reference mesh M of the deformable body A in B's body frame with the given pose X_BA and prescribe a shape G with pose X_BG in B's body frame. All vertices Pᵢ in M that are inside (or on the surface of) G are subject to the fixed constraints with Qᵢ being coincident with Pᵢ when M is in pose X_BA. p_PᵢQᵢ(q) denotes the relative position of point Qᵢ with respect to point Pᵢ as a function of the configuration of the model q. Imposing this constraint forces Pᵢ and Qᵢ to be coincident for each vertex i of the deformable body specified to be under constraint.

Parameters

[in]	body_A_id	The unique id of the deformable body under the fixed constraint.
[in]	body_B	The rigid body under constraint.
[in]	X_BA	The pose of deformable body A's reference mesh in B's body frame
[in]	shape_G	The prescribed geometry shape, attached to rigid body B, used to determine which vertices of the deformable body A is under constraint.
[in]	X_BG	The fixed pose of the geometry frame of the given `shape` in body B's frame.

Returns: the unique id of the newly added constraint.

Exceptions

std::exception	if no deformable body with the given `body_A_id` has been registered.
std::exception	unless `body_B` is registered with the same multibody plant owning this deformable model.
std::exception	if Finalize() has been called on the multibody plant owning this deformable model.
std::exception	if `this` DeformableModel is not of scalar type double.
std::exception	if no constraint is added (i.e. no vertex of the deformable body is inside the given `shape` with the given poses).

◆ configuration_output_port_index()

systems::OutputPortIndex configuration_output_port_index ( ) const

(Internal use only) Returns the output port index of the vertex positions port for all registered deformable bodies.

Exceptions

std::exception if called before DeclareSceneGraphPorts() is called.

◆ Disable()

void Disable	(	DeformableBodyId	id,
		systems::Context< T > *	context
	)		const

Disables the deformable body with the given id in the given context.

Disabling a deformable body sets its vertex velocities and accelerations to zero and freezes its vertex positions. A disabled deformable body is not subject to any constraint (e.g. frictional contact constraint or fixed constraint); it does not move under the influence of external forces (e.g. gravity); and it does not necessarily satisfy the prescribed boundary condition (if any). On the flip side, a disabled deformable body does not affect the dynamics of other bodies, even if the collision between the disabled body's geometry and other geometries is not filtered. Effectively, the physics of the deformable body stop being computed. The deformable body can be enabled by calling Enable(). Calling Disable() on a body which is already disabled has no effect.

See also: Enable().

Exceptions

std::exception	if the passed in context isn't compatible with the MultibodyPlant associated with this DeformableModel.
std::exception	if a deformable body with the given id is not registered.
std::exception	if context is null.

◆ Enable()

void Enable	(	DeformableBodyId	id,
		systems::Context< T > *	context
	)		const

Enables the deformable body with the given id in the given context.

Calling Enable() on a body which is already enabled has no effect.

See also: Disable().

Exceptions

std::exception	if the passed in context isn't compatible with the MultibodyPlant associated with this DeformableModel.
std::exception	if a deformable body with the given id is not registered.
std::exception	if context is null.

◆ GetBody() [1/2]

const DeformableBody<T>& GetBody ( DeformableBodyId id ) const

Returns the deformable body with the given id.

Exceptions

std::exception if no deformable body with the given id has been registered in this model.

◆ GetBody() [2/2]

const DeformableBody<T>& GetBody ( DeformableBodyIndex index ) const

Returns the deformable body with the given index.

Exceptions

std::exception if no deformable body with the given index is registered in this model.

◆ GetBodyByName() [1/2]

const DeformableBody<T>& GetBodyByName ( const std::string & name ) const

Returns the DeformableBody with the given name.

Exceptions

std::exception if there's no body with the given name or if more than one model instance contains a deformable body with the given name.

◆ GetBodyByName() [2/2]

const DeformableBody<T>& GetBodyByName	(	const std::string &	name,
		ModelInstanceIndex	model_instance
	)		const

Returns the DeformableBody with the given name from the given model instance.

Exceptions

std::exception if there's no body with the given name that is registered with the given model instance.

◆ GetBodyId() [1/2]

DeformableBodyId GetBodyId ( DeformableBodyIndex index ) const

Returns the DeformableBodyId of the body with the given body index.

Exceptions

std::exception if no deformable body with the given index has been registered in this model.

◆ GetBodyId() [2/2]

DeformableBodyId GetBodyId ( geometry::GeometryId geometry_id ) const

Returns the DeformableBodyId associated with the given geometry_id.

Exceptions

std::exception if the given geometry_id does not correspond to a deformable body registered with this model.

◆ GetBodyIds()

std::vector<DeformableBodyId> GetBodyIds ( ModelInstanceIndex model_instance ) const

Returns the DeformableIds of the bodies that belong to the given model instance.

Returns the empty vector if no deformable bodies are registered with the given model instance.

◆ GetBodyIndex()

DeformableBodyIndex GetBodyIndex ( DeformableBodyId id ) const

Returns the DeformableBodyIndex of the body with the given id.

Exceptions

std::exception if no body with the given id has been registered.

◆ GetDiscreteStateIndex()

systems::DiscreteStateIndex GetDiscreteStateIndex ( DeformableBodyId id ) const

Returns the discrete state index of the deformable body identified by the given id.

Exceptions

std::exception if MultibodyPlant::Finalize() has not been called yet. or if no deformable body with the given id has been registered in this model.

◆ GetExternalForces()

const std::vector<const ForceDensityFieldBase<T>*>& GetExternalForces ( DeformableBodyId id ) const

Returns the force density fields acting on the deformable body with the given id.

Exceptions

std::exception if MultibodyPlant::Finalize() has not been called yet. or if no deformable body with the given id has been registered in this model.

◆ GetFemModel()

const fem::FemModel<T>& GetFemModel ( DeformableBodyId id ) const

Returns the FemModel for the body with id.

Exceptions

exception if no deformable body with id is registered with this DeformableModel.

◆ GetGeometryId()

geometry::GeometryId GetGeometryId ( DeformableBodyId id ) const

Returns the GeometryId of the geometry associated with the body with the given id.

Exceptions

std::exception if no body with the given id has been registered.

◆ GetMutableBody()

DeformableBody<T>& GetMutableBody ( DeformableBodyId id )

Returns a mutable reference to the deformable body with the given id.

Exceptions

std::exception if no deformable body with the given id has been registered in this model.

◆ GetPositions()

Matrix3X<T> GetPositions	(	const systems::Context< T > &	context,
		DeformableBodyId	id
	)		const

Returns the matrix of vertex positions for the deformable body with the given id in the provided context.

Parameters

[in]	context	The context associated with the MultibodyPlant that owns this DeformableModel.
[in]	id	The identifier of the deformable body whose positions are being queried.

Return values

q	A 3×N matrix containing the positions of all vertices of the body.

Exceptions

std::exception

if any of the following conditions are met:

context does not belong to the MultibodyPlant associated with this DeformableModel.
No body with the given id is registered.
Finalize() has not been called on the MultibodyPlant that owns this deformable model.

◆ GetPositionsAndVelocities()

Matrix3X<T> GetPositionsAndVelocities	(	const systems::Context< T > &	context,
		DeformableBodyId	id
	)		const

Returns the matrix of vertex positions and velocities for the deformable body with the given id in the provided context.

The first N columns are the positions and the next N columns are the velocities.

Parameters

[in]	context	The context associated with the MultibodyPlant that owns this DeformableModel.
[in]	id	The identifier of the deformable body whose state is being queried.

Returns: A 3x2N matrix containing the positions and velocities of all vertices of the body.

Exceptions

std::exception

if any of the following conditions are met:

context does not belong to the MultibodyPlant associated with this DeformableModel.
No body with the given id is registered.
Finalize() has not been called on the MultibodyPlant that owns this deformable model.

◆ GetReferencePositions()

const VectorX<double>& GetReferencePositions ( DeformableBodyId id ) const

Returns the reference positions of the vertices of the deformable body identified by the given id.

The reference positions are represented as a VectorX with 3N values where N is the number of vertices. The x-, y-, and z-positions (measured and expressed in the world frame) of the j-th vertex are 3j, 3j + 1, and 3j + 2 in the VectorX.

Exceptions

std::exception if no deformable body with the given id has been registered in this model.

◆ GetVelocities()

Matrix3X<T> GetVelocities	(	const systems::Context< T > &	context,
		DeformableBodyId	id
	)		const

Returns the matrix of vertex velocities for the deformable body with the given id in the provided context.

Parameters

[in]	context	The context associated with the MultibodyPlant that owns this DeformableModel.
[in]	id	The identifier of the deformable body whose velocities are being queried.

Return values

v	A 3×N matrix containing the velocities of all vertices of the body.

Exceptions

std::exception

if any of the following conditions are met:

context does not belong to the MultibodyPlant associated with this DeformableModel.
No body with the given id is registered.
Finalize() has not been called on the MultibodyPlant that owns this deformable model.

◆ HasBodyNamed() [1/2]

bool HasBodyNamed ( const std::string & name ) const

Returns true if and only if a deformable body with the given name has been registered with this model.

◆ HasBodyNamed() [2/2]

bool HasBodyNamed	(	const std::string &	name,
		ModelInstanceIndex	model_instance
	)		const

Returns true if and only if a deformable body with the given name has been registered with this model under the given model_instance.

◆ HasConstraint()

bool HasConstraint ( DeformableBodyId id ) const

Returns the true if the deformable body with the given id has constraints associated with it.

◆ integrator()

const multibody::fem::internal::DiscreteTimeIntegrator<T>& integrator ( ) const

(Internal use only) Returns the time integrator used to for all FemModels in this model.

Exceptions

std::exception if the integrator hasn't been set.

◆ is_cloneable_to_autodiff()

bool is_cloneable_to_autodiff ( ) const

final

Returns true if and only if this DeformableModel is empty.

◆ is_cloneable_to_double()

bool is_cloneable_to_double ( ) const

final

◆ is_cloneable_to_symbolic()

bool is_cloneable_to_symbolic ( ) const

final

Returns true if and only if this DeformableModel is empty.

◆ is_empty()

bool is_empty ( ) const

Returns true if there's no deformable body or external force registered to this DeformableModel.

◆ is_enabled()

bool is_enabled	(	DeformableBodyId	id,
		const systems::Context< T > &	context
	)		const

Returns: true if and only if the deformable body with the given id is enabled.

Exceptions

std::exception	if the passed in context isn't compatible with the MultibodyPlant associated with this DeformableModel.
std::exception	if a deformable body with the given id is not registered.

◆ num_bodies()

int num_bodies ( ) const

Returns the number of deformable bodies registered with this DeformableModel.

◆ operator=() [1/2]

DeformableModel& operator= ( DeformableModel< T > && )

delete

◆ operator=() [2/2]

DeformableModel& operator= ( const DeformableModel< T > & )

delete

◆ parallelism()

Parallelism parallelism ( ) const

(Internal use only) Returns the parallelism that this DeformableModel uses when opportunities for parallel computation arises.

◆ RegisterDeformableBody() [1/2]

DeformableBodyId RegisterDeformableBody	(	std::unique_ptr< geometry::GeometryInstance >	geometry_instance,
		ModelInstanceIndex	model_instance,
		const fem::DeformableBodyConfig< T > &	config,
		double	resolution_hint
	)

Registers a deformable body in this DeformableModel with the given GeometryInstance.

The body is represented in the world frame and simulated with FEM with linear elements and a first order quadrature rule that integrates linear functions exactly. See FemModel for details. Returns a unique identifier for the added geometry.

Parameters

[in]	geometry_instance	The geometry to be registered with the model.
[in]	config	The physical properties of deformable body.
[in]	model_instance	The model instance index which this body is part of.
[in]	resolution_hint	The parameter that guides the level of mesh refinement of the deformable geometry. It has length units (in meters) and roughly corresponds to a typical edge length in the resulting mesh for a primitive shape.

Precondition: resolution_hint > 0.

Exceptions

std::exception	if `this` DeformableModel is not of scalar type double.
std::exception	if `this` DeformableModel belongs to a continuous MultibodyPlant.
std::exception	if the model instance does not exist.
std::exception	if a deformable body with the same name has already been registered to the model instance.
std::exception	if Finalize() has been called on the multibody plant owning this deformable model.

◆ RegisterDeformableBody() [2/2]

DeformableBodyId RegisterDeformableBody	(	std::unique_ptr< geometry::GeometryInstance >	geometry_instance,
		const fem::DeformableBodyConfig< T > &	config,
		double	resolution_hint
	)

Registers a deformable body in this DeformableModel with the default model instance.

◆ SetDefaultState()

void SetDefaultState	(	const systems::Context< T > &	context,
		systems::State< T > *	state
	)		const

(Internal use only) Sets the default state for the deformable model.

This should only be called by MultibodyPlant as a part of MultibodyPlant::SetDefaultState().

◆ SetParallelism()

void SetParallelism ( Parallelism parallelism )

(Internal use only) Configures the parallelism that this DeformableModel uses when opportunities for parallel computation arises.

◆ SetPositions()

void SetPositions	(	systems::Context< T > *	context,
		DeformableBodyId	id,
		const Eigen::Ref< const Matrix3X< T >> &	q
	)		const

Sets the vertex positions of the deformable body with the given id in the provided context.

Parameters

[in,out]	context	The context associated with the MultibodyPlant that owns this DeformableModel.
[in]	id	The identifier of the deformable body whose positions are being set.
[in]	q	A 3×N matrix of vertex positions.

Exceptions

std::exception

if any of the following conditions are met:

context is nullptr.
context does not belong to the MultibodyPlant associated with this DeformableModel.
No body with the given id is registered.
The number of columns of q does not match the number of vertices of the body.
q contains non-finite values.
Finalize() has not been called on the MultibodyPlant that owns this deformable model.

◆ SetPositionsAndVelocities()

void SetPositionsAndVelocities	(	systems::Context< T > *	context,
		DeformableBodyId	id,
		const Eigen::Ref< const Matrix3X< T >> &	q,
		const Eigen::Ref< const Matrix3X< T >> &	v
	)		const

Sets the vertex positions and velocities of the deformable body with the given id in the provided context.

Parameters

[in,out]	context	The context associated with the MultibodyPlant that owns this DeformableModel.
[in]	id	The identifier of the deformable body whose positions and velocities are being set.
[in]	q	A 3×N matrix of vertex positions.
[in]	v	A 3×N matrix of vertex velocities.

Exceptions

std::exception

if any of the following conditions are met:

context is nullptr.
context does not belong to the MultibodyPlant associated with this DeformableModel.
No body with the given id is registered.
The number of columns of q or v does not match the number of vertices of the body.
q or v contains non-finite values.
Finalize() has not been called on the MultibodyPlant that owns this deformable model.

◆ SetVelocities()

void SetVelocities	(	systems::Context< T > *	context,
		DeformableBodyId	id,
		const Eigen::Ref< const Matrix3X< T >> &	v
	)		const

Sets the vertex velocities of the deformable body with the given id in the provided context.

Parameters

[in,out]	context	The context associated with the MultibodyPlant that owns this DeformableModel.
[in]	id	The identifier of the deformable body whose velocities are being set.
[in]	v	A 3×N matrix of vertex velocities.

Exceptions

std::exception

if any of the following conditions are met:

context is nullptr.
context does not belong to the MultibodyPlant associated with this DeformableModel.
No body with the given id is registered.
The number of columns of v does not match the number of vertices of the body.
v contains non-finite values.
Finalize() has not been called on the MultibodyPlant that owns this deformable model.

◆ SetWallBoundaryCondition()

void SetWallBoundaryCondition	(	DeformableBodyId	id,
		const Vector3< T > &	p_WQ,
		const Vector3< T > &	n_W
	)

Sets wall boundary conditions for the body with the given id.

All vertices of the mesh of the deformable body whose reference positions are inside the prescribed open half space are put under zero displacement boundary conditions. The open half space is defined by a plane with outward normal n_W. A vertex V is considered to be subject to the boundary condition if n̂ ⋅ p_QV < 0 where Q is a point on the plane and n̂ is normalized n_W.

Parameters

[in]	id	The body to be put under boundary condition.
[in]	p_WQ	The position of a point Q on the plane in the world frame.
[in]	n_W	Outward normal to the half space expressed in the world frame.

Precondition: n_W.norm() > 1e-10.

Warning: Be aware of round-off errors in floating computations when placing a vertex very close to the plane defining the half space.

Exceptions

std::exception if no deformable body with the given id has been registered in this model.

Friends And Related Function Documentation

◆ DeformableModel

friend class DeformableModel

friend

The documentation for this class was generated from the following file:

drake/multibody/plant/deformable_model.h

Detailed Description

template<typename T> class drake::multibody::DeformableModel< T >

Public Member Functions

Friends

Additional Inherited Members

Constructor & Destructor Documentation

◆ DeformableModel() [1/3]

◆ DeformableModel() [2/3]

◆ DeformableModel() [3/3]

◆ ~DeformableModel()

Member Function Documentation

◆ AddExternalForce()

◆ AddFixedConstraint()

◆ configuration_output_port_index()

◆ Disable()

◆ Enable()

◆ GetBody() [1/2]

◆ GetBody() [2/2]

◆ GetBodyByName() [1/2]

◆ GetBodyByName() [2/2]

◆ GetBodyId() [1/2]

◆ GetBodyId() [2/2]

◆ GetBodyIds()

◆ GetBodyIndex()

◆ GetDiscreteStateIndex()

◆ GetExternalForces()

◆ GetFemModel()

◆ GetGeometryId()

◆ GetMutableBody()

◆ GetPositions()

◆ GetPositionsAndVelocities()

◆ GetReferencePositions()

◆ GetVelocities()

◆ HasBodyNamed() [1/2]

◆ HasBodyNamed() [2/2]

◆ HasConstraint()

◆ integrator()

◆ is_cloneable_to_autodiff()

◆ is_cloneable_to_double()

◆ is_cloneable_to_symbolic()

◆ is_empty()

◆ is_enabled()

◆ num_bodies()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ parallelism()

◆ RegisterDeformableBody() [1/2]

◆ RegisterDeformableBody() [2/2]

◆ SetDefaultState()

◆ SetParallelism()

◆ SetPositions()

◆ SetPositionsAndVelocities()

◆ SetVelocities()

◆ SetWallBoundaryCondition()

Friends And Related Function Documentation

◆ DeformableModel

template<typename T>
class drake::multibody::DeformableModel< T >