#include <FEMMass.h>

Computes and stores the mass matrix for a finite element model. More...

Inheritance diagram for sofa::component::mass::FEMMass< TDataTypes, TElementType >:

Detailed Description

template<class TDataTypes, class TElementType>
class sofa::component::mass::FEMMass< TDataTypes, TElementType >

Computes and stores the mass matrix for a finite element model.

This class calculates the mass matrix for a given set of finite elements based on a nodal mass density field. The mass matrix is computed using numerical integration (quadrature) over the element domain. The mass density is interpolated from the nodes using the element's shape functions.

Mathematically, the mass matrix M is defined as: $M_{ij} = \int_{\Omega} \rho(\mathbf{x}) N_i(\mathbf{x}) N_j(\mathbf{x}) d\Omega$ where $\rho(\mathbf{x})$ is the mass density and $N_i(\mathbf{x})$ are the shape functions.

The resulting matrix is a block-diagonal-like matrix where each block is a scalar multiple of the identity, representing the contribution to each degree of freedom. This allows for efficient storage and computation.

Template Parameters

TDataTypes	The data types used for positions, velocities, etc. (e.g., Vec3Types).
TElementType	The type of finite element (e.g., sofa::geometry::Tetrahedron).

Public Attributes
sofa::SingleLink< FEMMass, NodalMassDensity, sofa::BaseLink::FLAG_STOREPATH\|sofa::BaseLink::FLAG_STRONGLINK >	l_nodalMassDensity
	Link to the nodal mass density component. More...

Public Attributes inherited from sofa::core::behavior::BaseForceField
Data< SReal >	rayleighStiffness
	Rayleigh Damping stiffness matrix coefficient. More...

Public Attributes inherited from sofa::core::objectmodel::BaseComponent
Data< bool >	f_listening
	if true, handle the events, otherwise ignore the events More...

Public Attributes inherited from sofa::core::objectmodel::Base
std::vector< lifecycle::DeprecatedData * >	m_oldAttributes

Data< int >	d_messageLogCount

Data< std::string >	name
	Name of the object. More...

Data< bool >	f_printLog
	if true, emits extra messages at runtime. More...

Data< sofa::core::objectmodel::TagSet >	f_tags
	list of the subsets the object belongs to More...

Data< sofa::type::BoundingBox >	f_bbox
	this object bounding box More...

Data< sofa::core::objectmodel::ComponentState >	d_componentState
	The state of the component among (Dirty, Valid, Undefined, Loading, Invalid). More...

std::string	m_definitionSourceFileName {""}

int	m_definitionSourceFilePos {-1}

std::string	m_instanciationSourceFileName {""}

int	m_instanciationSourceFilePos {-1}

Public Attributes inherited from sofa::core::behavior::BaseMass
Data< bool >	m_separateGravity

Data< SReal >	rayleighMass
	Rayleigh Damping mass matrix coefficient. More...

Public Attributes inherited from sofa::core::behavior::TopologyAccessor
sofa::SingleLink< TopologyAccessor, sofa::core::topology::BaseMeshTopology, sofa::BaseLink::FLAG_STOREPATH\|sofa::BaseLink::FLAG_STRONGLINK >	l_topology

Protected Attributes
GlobalMassMatrixType	m_globalMassMatrix
	Represents the global mass matrix of the system. More...

Protected Attributes inherited from sofa::core::behavior::Mass< TDataTypes >
std::unique_ptr< std::ofstream >	m_gnuplotFileEnergy
	stream to export Kinematic, Potential and Mechanical Energy to gnuplot files More...

Protected Attributes inherited from sofa::core::behavior::StateAccessor
MultiLink< StateAccessor, BaseMechanicalState, BaseLink::FLAG_DUPLICATE >	l_mechanicalStates

Protected Attributes inherited from sofa::core::objectmodel::BaseComponent
SingleLink< BaseComponent, BaseContext, BaseLink::FLAG_DOUBLELINK >	l_context

LinkSlaves	l_slaves

SingleLink< BaseComponent, BaseComponent, BaseLink::FLAG_DOUBLELINK >	l_master

Protected Attributes inherited from sofa::core::objectmodel::Base
std::map< std::string, sofa::core::DataTrackerCallback >	m_internalEngine

VecData	m_vecData
	List of fields (Data instances) More...

MapData	m_aliasData
	name -> Data multi-map (includes names and aliases) More...

VecLink	m_vecLink
	List of links. More...

MapLink	m_aliasLink
	name -> Link multi-map (includes names and aliases) More...

Protected Attributes inherited from sofa::core::behavior::SingleStateAccessor< TDataTypes >
SingleLink< SingleStateAccessor< TDataTypes >, MechanicalState< TDataTypes >, BaseLink::FLAG_STRONGLINK >	mstate

Static Protected Attributes
static constexpr sofa::Size	spatial_dimensions = DataTypes::spatial_dimensions

static constexpr sofa::Size	NumberOfNodesInElement = ElementType::NumberOfNodes

static constexpr sofa::Size	NumberOfDofsInElement = NumberOfNodesInElement * spatial_dimensions

static constexpr sofa::Size	TopologicalDimension = FiniteElement::TopologicalDimension

Public Member Functions
	SOFA_CLASS2 (SOFA_TEMPLATE2(FEMMass, DataTypes, ElementType), core::behavior::Mass< TDataTypes >, sofa::core::behavior::TopologyAccessor)

void	init () final
	Initializes the component. More...

bool	isDiagonal () const override
	Indicates whether the mass matrix is diagonal. More...

void	addForce (const core::MechanicalParams *mparams, sofa::DataVecDeriv_t< DataTypes > &f, const sofa::DataVecCoord_t< DataTypes > &x, const sofa::DataVecDeriv_t< DataTypes > &v) override
	Adds the gravity force (f = M * g) to the force vector. More...

void	buildMassMatrix (sofa::core::behavior::MassMatrixAccumulator *matrices) override
	Accumulates the mass matrix into a global matrix accumulator. More...

void	addMDx (const core::MechanicalParams *mparams, DataVecDeriv_t< DataTypes > &f, const DataVecDeriv_t< DataTypes > &dx, SReal factor) override
	Adds the product of the mass matrix and a vector to another vector (f += M * dx * factor). More...

void	accFromF (const core::MechanicalParams *mparams, DataVecDeriv_t< DataTypes > &a, const DataVecDeriv_t< DataTypes > &f) override
	Supposed to compute $ a = M^{-1} f $, but triggers an error in this implementation. More...

SReal	getKineticEnergy (const core::MechanicalParams *mparams, const DataVecDeriv_t< DataTypes > &v) const override
	Computes the total kinetic energy of the system. More...

SReal	getPotentialEnergy (const core::MechanicalParams *mparams, const DataVecCoord_t< DataTypes > &x) const override
	Computes the total gravitational potential energy of the system. More...

Public Member Functions inherited from sofa::core::behavior::Mass< TDataTypes >
	SOFA_CLASS2 (SOFA_TEMPLATE(Mass, TDataTypes), SOFA_TEMPLATE(ForceField, TDataTypes), BaseMass)

void	initGnuplot (const std::string path) override
	initialization to export kinetic and potential energy to gnuplot files format More...

void	exportGnuplot (const MechanicalParams *mparams, SReal time) override
	export kinetic and potential energy state at "time" to a gnuplot file More...

void	addGravityToV (const MechanicalParams *mparams, MultiVecDerivId) override
	perform v += dt*g operation. Used if mass wants to added G separately from the other forces to v. More...

virtual void	addGravityToV (const MechanicalParams *, DataVecDeriv &)

SReal	getElementMass (sofa::Index) const override
	recover the mass of an element More...

void	getElementMass (sofa::Index index, linearalgebra::BaseMatrix *m) const override
	Get the matrix relative to the DOF at index. More...

bool	insertInNode (objectmodel::BaseNode *node) override

bool	removeInNode (objectmodel::BaseNode *node) override

void	addMDx (const MechanicalParams *mparams, MultiVecDerivId fid, SReal factor) override
	f += factor M dx More...

virtual void	addMDx (const MechanicalParams *mparams, DataVecDeriv &f, const DataVecDeriv &dx, SReal factor)

void	accFromF (const MechanicalParams *mparams, MultiVecDerivId aid) override

virtual void	accFromF (const MechanicalParams *mparams, DataVecDeriv &a, const DataVecDeriv &f)

void	addDForce (const MechanicalParams *, DataVecDeriv &, const DataVecDeriv &) override
	Mass forces (gravity) often have null derivative. More...

void	addMBKdx (const MechanicalParams *mparams, MultiVecDerivId dfId) override

SReal	getKineticEnergy (const MechanicalParams *mparams) const override

virtual SReal	getKineticEnergy (const MechanicalParams *mparams, const DataVecDeriv &v) const

SReal	getPotentialEnergy (const MechanicalParams *mparams) const override

SReal	getPotentialEnergy (const MechanicalParams *mparams, const DataVecCoord &x) const override

type::Vec6	getMomentum (const MechanicalParams *mparams) const override

virtual type::Vec6	getMomentum (const MechanicalParams *, const DataVecCoord &, const DataVecDeriv &) const

void	addKToMatrix (sofa::linearalgebra::BaseMatrix *, SReal, unsigned int &) override

void	addBToMatrix (sofa::linearalgebra::BaseMatrix *, SReal, unsigned int &) override

void	addMToMatrix (const MechanicalParams mparams, const sofa::core::behavior::MultiMatrixAccessor matrix) override
	Add Mass contribution to global Matrix assembling. More...

virtual void	addMToMatrix (sofa::linearalgebra::BaseMatrix *matrix, SReal mFact, unsigned int &offset)

void	addMBKToMatrix (const MechanicalParams mparams, const sofa::core::behavior::MultiMatrixAccessor matrix) override

Public Member Functions inherited from sofa::core::behavior::ForceField< TDataTypes >
	SOFA_CLASS2 (SOFA_TEMPLATE(ForceField, TDataTypes), BaseForceField, SOFA_TEMPLATE(SingleStateAccessor, TDataTypes))

void	addForce (const MechanicalParams *mparams, MultiVecDerivId fId) override

virtual void	addForce (const MechanicalParams *, DataVecDeriv &f, const DataVecCoord &x, const DataVecDeriv &v)=0

void	addDForce (const MechanicalParams *mparams, MultiVecDerivId dfId) override

void	addKToMatrix (const MechanicalParams mparams, const sofa::core::behavior::MultiMatrixAccessor matrix) override
	Compute the system matrix corresponding to . More...

void	addBToMatrix (const MechanicalParams mparams, const sofa::core::behavior::MultiMatrixAccessor matrix) override
	Compute the system matrix corresponding to . More...

template<class IndexArray , class ElementMat >
void	addToMatrix (sofa::linearalgebra::BaseMatrix *bm, unsigned offset, const IndexArray &nodeIndex, const ElementMat &em, SReal scale)

Public Member Functions inherited from sofa::core::behavior::BaseForceField
	SOFA_ABSTRACT_CLASS (BaseForceField, StateAccessor)

virtual void	buildStiffnessMatrix (StiffnessMatrix *matrix)

virtual void	buildDampingMatrix (DampingMatrix *matrix)

Public Member Functions inherited from sofa::core::behavior::StateAccessor
	SOFA_ABSTRACT_CLASS (StateAccessor, objectmodel::BaseComponent)

virtual const MultiLink< StateAccessor, BaseMechanicalState, BaseLink::FLAG_DUPLICATE >::Container &	getMechanicalStates () const
	Return a list of mechanical states to which this component is associated. More...

void	computeBBox (const core::ExecParams *params, bool onlyVisible=false) override

Public Member Functions inherited from sofa::core::objectmodel::BaseComponent
	SOFA_CLASS (BaseComponent, Base)

virtual void	draw (const core::visual::VisualParams *)
	Render internal data of this object, for debugging purposes. More...

void	setSrc (const std::string &v, std::vector< std::string > *attributeList=nullptr)
	Sets a source Object and parses it to collect dependent Data. More...

void	setSrc (const std::string &v, const BaseComponent loader, std::vector< std::string > attributeList=nullptr)

Base *	findLinkDestClass (const BaseClass destType, const std::string &path, const BaseLink link) override

virtual std::string	getPathName () const override
	Return the full path name of this object. More...

SReal	getTime () const
	Current time. More...

const BaseContext *	getContext () const

BaseContext *	getContext ()

const BaseComponent *	getMaster () const

BaseComponent *	getMaster ()

const VecSlaves &	getSlaves () const

BaseComponent *	getSlave (const std::string &name) const

virtual void	addSlave (BaseComponent::SPtr s)

virtual void	removeSlave (BaseComponent::SPtr s)

virtual void	handleEvent (Event *)
	Handle an event. More...

virtual void	handleTopologyChange ()

virtual void	handleTopologyChange (core::topology::Topology *t)

void	parse (BaseObjectDescription *arg) override
	Parse the given description to assign values to this object's fields and potentially other parameters. More...

virtual void	bwdInit ()
	Initialization method called at graph creation and modification, during bottom-up traversal. More...

virtual void	reinit ()
	Update method called when variables used in precomputation are modified. More...

void	updateInternal ()
	Update method called when variables (used to compute other internal variables) are modified. More...

virtual void	storeResetState ()
	Save the initial state for later uses in reset() More...

virtual void	reset ()
	Reset to initial state. More...

virtual void	cleanup ()

Public Member Functions inherited from sofa::core::objectmodel::Base
virtual const BaseClass *	getClass () const

void	addDeprecatedAttribute (lifecycle::DeprecatedData *attribute)

void	addUpdateCallback (const std::string &name, std::initializer_list< BaseData * > inputs, std::function< sofa::core::objectmodel::ComponentState(const DataTracker &)> function, std::initializer_list< BaseData * > outputs)

void	addOutputsToCallback (const std::string &name, std::initializer_list< BaseData * > outputs)

const std::string &	getName () const
	Accessor to the object name. More...

void	setName (const std::string &n)
	Set the name of this object. More...

void	setName (const std::string &n, int counter)
	Set the name of this object, adding an integer counter. More...

std::string	getTypeName () const
	Get the type name of this object (i.e. class and template types) More...

virtual std::string	getClassName () const
	Get the class name of this object. More...

virtual std::string	getTemplateName () const final
	Get the template type names (if any) used to instantiate this object. More...

std::string	getNameSpaceName () const
	Get the template type names (if any) used to instantiate this object. More...

void	setDefinitionSourceFileName (const std::string &sourceFileName)
	Set the source filename (where the component is implemented) More...

const std::string &	getDefinitionSourceFileName () const
	Get the source filename (where the component is implemented) More...

void	setDefinitionSourceFilePos (const int)
	Set the source location (where the component is implemented) More...

int	getDefinitionSourceFilePos () const
	Get the source location (where the component is implemented) More...

void	setInstanciationSourceFileName (const std::string &sourceFileName)

const std::string &	getInstanciationSourceFileName () const

void	setInstanciationSourceFilePos (const int)

int	getInstanciationSourceFilePos () const

void	addMessage (const sofa::helper::logging::Message &m) const

size_t	countLoggedMessages (sofa::helper::logging::Message::TypeSet t=sofa::helper::logging::Message::AnyTypes) const

const std::deque< sofa::helper::logging::Message > &	getLoggedMessages () const

const std::string	getLoggedMessagesAsString (sofa::helper::logging::Message::TypeSet t=sofa::helper::logging::Message::AnyTypes) const

void	clearLoggedMessages () const

bool	notMuted () const

const sofa::core::objectmodel::TagSet &	getTags () const
	Represents the subsets the object belongs to. More...

bool	hasTag (Tag t) const
	Return true if the object belong to the given subset. More...

void	addTag (Tag t)
	Add a subset qualification to the object. More...

void	removeTag (Tag t)
	Remove a subset qualification to the object. More...

ComponentState	getComponentState () const

bool	isComponentStateValid () const

bool	isComponentStateInvalid () const

	SOFA_ATTRIBUTE_DEPRECATED__TOBASECONSTRAINT () virtual const behavior

	SOFA_ATTRIBUTE_DEPRECATED__TOBASEOBJECT () virtual const objectmodel

virtual bool	parseField (const std::string &attribute, const std::string &value)
	Assign one field value (Data or Link) More...

virtual bool	hasField (const std::string &attribute) const
	Check if a given Data field or Link exists. More...

void	parseFields (const std::list< std::string > &str)
	Assign the field values stored in the given list of name + value pairs of strings. More...

virtual void	parseFields (const std::map< std::string, std::string * > &str)
	Assign the field values stored in the given map of name -> value pairs. More...

void	writeDatas (std::ostream &out, const std::string &separator=" ")

BaseData *	findData (const std::string &name) const

std::vector< BaseData * >	findGlobalField (const std::string &name) const
	Find data fields given a name: several can be found as we look into the alias map. More...

BaseLink *	findLink (const std::string &name) const

std::vector< BaseLink * >	findLinks (const std::string &name) const
	Find link fields given a name: several can be found as we look into the alias map. More...

virtual void	updateLinks (bool logErrors=true)
	Update pointers in case the pointed-to objects have appeared. More...

template<class T >
BaseData::BaseInitData	initData (::sofa::core::objectmodel::Data< T > field, const char n, const char *help, ::sofa::core::objectmodel::BaseData::DataFlags dataflags)
	Helper method used to initialize a data field containing a value of type T. More...

template<class T >
BaseData::BaseInitData	initData (Data< T > field, const char n, const char *help, bool isDisplayed=true, bool isReadOnly=false)
	Helper method used to initialize a data field containing a value of type T. More...

template<class T >
Data< T >::InitData	initData (Data< T > field, const T &value, const char n, const char *help, bool isDisplayed=true, bool isReadOnly=false)
	Helper method used to initialize a data field containing a value of type T. More...

void	addData (BaseData *f, const std::string &name)

void	addData (BaseData *f)

void	removeData (BaseData *f)
	Remove a data field. More...

void	addAlias (BaseData field, const char alias)
	Add an alias to a Data. More...

void	addLink (BaseLink *l)
	Add a link. More...

void	addAlias (BaseLink link, const char alias)
	Add an alias to a Link. More...

const VecData &	getDataFields () const
	Accessor to the vector containing all the fields of this object. More...

const MapData &	getDataAliases () const
	Accessor to the map containing all the aliases of this object. More...

const VecLink &	getLinks () const
	Accessor to the vector containing all the fields of this object. More...

const MapLink &	getLinkAliases () const
	Accessor to the map containing all the aliases of this object. More...

virtual bool	findDataLinkDest (BaseData &ptr, const std::string &path, const BaseLink link)

template<class T >
bool	findLinkDest (T &ptr, const std::string &path, const BaseLink link)

Public Member Functions inherited from sofa::core::behavior::SingleStateAccessor< TDataTypes >
	SOFA_ABSTRACT_CLASS (SOFA_TEMPLATE(SingleStateAccessor, TDataTypes), StateAccessor)

void	init () override
	Initialization method called at graph creation and modification, during top-down traversal. More...

MechanicalState< TDataTypes > *	getMState ()

const MechanicalState< TDataTypes > *	getMState () const

Public Member Functions inherited from sofa::core::behavior::BaseMass
	SOFA_ABSTRACT_CLASS (BaseMass, StateAccessor)

Public Member Functions inherited from sofa::core::behavior::TopologyAccessor
	SOFA_CLASS (TopologyAccessor, sofa::core::objectmodel::BaseComponent)

void	init () override
	Initialization method called at graph creation and modification, during top-down traversal. More...

Protected Member Functions
	FEMMass ()
	Default constructor. More...

void	elementFEMMass_init ()
	Performs the internal calculation and assembly of the mass matrix. More...

void	calculateElementMassMatrix (const auto &elements, sofa::type::vector< ElementMassMatrix > &elementMassMatrices)
	Computes the mass matrix for each finite element. More...

void	initializeGlobalMassMatrix (const auto &elements, const sofa::type::vector< ElementMassMatrix > &elementMassMatrices)
	Assembles the global mass matrix from individual element mass matrices. More...

void	validateNodalMassDensity ()
	Ensures that a valid NodalMassDensity component is linked. More...

Protected Member Functions inherited from sofa::core::behavior::Mass< TDataTypes >
	Mass (MechanicalState< TDataTypes > *mm=nullptr)

	~Mass () override

Protected Member Functions inherited from sofa::core::behavior::ForceField< TDataTypes >
	ForceField (MechanicalState< DataTypes > *mm=nullptr)

	~ForceField () override

Protected Member Functions inherited from sofa::core::behavior::BaseForceField
	BaseForceField ()

	~BaseForceField () override=default

Protected Member Functions inherited from sofa::core::behavior::StateAccessor
	StateAccessor ()

	~StateAccessor () override=default

Protected Member Functions inherited from sofa::core::objectmodel::BaseComponent
	BaseComponent ()

	~BaseComponent () override

virtual void	doUpdateInternal ()
	Implementation of the internal update. More...

void	changeContextLink (BaseContext before, BaseContext &after)

void	changeSlavesLink (BaseComponent::SPtr ptr, std::size_t, bool add)
	This method insures that slaves objects have master and context links set correctly. More...

void	trackInternalData (const BaseData &data)
	Method called to add the Data to the DataTracker (listing the Data to track) More...

void	cleanTracker ()

bool	hasDataChanged (const BaseData &data)
	Method called to know if a tracked Data has changed. More...

Protected Member Functions inherited from sofa::core::objectmodel::Base
	Base ()

virtual	~Base ()

void	initData0 (BaseData field, BaseData::BaseInitData &res, const char name, const char *help, bool isDisplayed=true, bool isReadOnly=false)
	Helper method used by initData() More...

void	initData0 (BaseData field, BaseData::BaseInitData &res, const char name, const char *help, BaseData::DataFlags dataFlags)
	Helper method used by initData() More...

template<class T >
void	initData0 (Data< T > field, typename Data< T >::InitData &res, const T &value, const char n, const char *help, bool isDisplayed=true, bool isReadOnly=false)
	Helper method used by initData() More...

Protected Member Functions inherited from sofa::core::IntrusiveObject
virtual	~IntrusiveObject ()=default

Protected Member Functions inherited from sofa::core::behavior::SingleStateAccessor< TDataTypes >
	SingleStateAccessor (MechanicalState< TDataTypes > *mm=nullptr)

	~SingleStateAccessor () override=default

Protected Member Functions inherited from sofa::core::behavior::BaseMass
	BaseMass ()

	~BaseMass () override=default

Protected Member Functions inherited from sofa::core::behavior::TopologyAccessor
	TopologyAccessor ()

void	validateTopology ()

Additional Inherited Members
Static Public Member Functions inherited from sofa::core::behavior::ForceField< TDataTypes >
template<class T >
static bool	canCreate (T &obj, objectmodel::BaseContext context, objectmodel::BaseObjectDescription *arg)

template<class T >
static std::string	shortName (const T ptr=nullptr, objectmodel::BaseObjectDescription arg=nullptr)

Static Public Member Functions inherited from sofa::core::objectmodel::BaseComponent
template<class T >
static bool	canCreate (T , BaseContext , BaseObjectDescription *)
	Pre-construction check method called by ObjectFactory. More...

template<class T >
static T::SPtr	create (T , BaseContext context, BaseObjectDescription *arg)
	Construction method called by ObjectFactory. More...

Static Public Member Functions inherited from sofa::core::objectmodel::Base
static const BaseClass *	GetClass ()

template<class T >
static std::string	shortName (const T ptr=nullptr, BaseObjectDescription =nullptr)

Attribute details

◆ l_nodalMassDensity

template<class TDataTypes , class TElementType >

sofa::SingleLink<FEMMass, NodalMassDensity, sofa::BaseLink::FLAG_STOREPATH | sofa::BaseLink::FLAG_STRONGLINK> sofa::component::mass::FEMMass< TDataTypes, TElementType >::l_nodalMassDensity

Link to the nodal mass density component.

This component provides the mass density at each node of the mesh. It must be present in the context for the mass to be calculated correctly.

◆ m_globalMassMatrix

template<class TDataTypes , class TElementType >

GlobalMassMatrixType sofa::component::mass::FEMMass< TDataTypes, TElementType >::m_globalMassMatrix

protected

Represents the global mass matrix of the system.

This matrix is stored in a compressed sparse row format. Since the mass contribution for each node is isotropic (affects all spatial dimensions identically), this matrix stores only the scalar scaling factor for each identity block of size spatial_dimensions * spatial_dimensions.

For example, in 3D, a node's mass contribution is a 3x3 diagonal matrix m * I. Only m is stored here.

◆ NumberOfDofsInElement

template<class TDataTypes , class TElementType >

constexpr sofa::Size sofa::component::mass::FEMMass< TDataTypes, TElementType >::NumberOfDofsInElement = NumberOfNodesInElement * spatial_dimensions

staticconstexprprotected

◆ NumberOfNodesInElement

template<class TDataTypes , class TElementType >

constexpr sofa::Size sofa::component::mass::FEMMass< TDataTypes, TElementType >::NumberOfNodesInElement = ElementType::NumberOfNodes

staticconstexprprotected

◆ spatial_dimensions

template<class TDataTypes , class TElementType >

constexpr sofa::Size sofa::component::mass::FEMMass< TDataTypes, TElementType >::spatial_dimensions = DataTypes::spatial_dimensions

staticconstexprprotected

◆ TopologicalDimension

template<class TDataTypes , class TElementType >

constexpr sofa::Size sofa::component::mass::FEMMass< TDataTypes, TElementType >::TopologicalDimension = FiniteElement::TopologicalDimension

staticconstexprprotected

Constructor details

◆ FEMMass()

template<class TDataTypes , class TElementType >

sofa::component::mass::FEMMass< TDataTypes, TElementType >::FEMMass

protected

Default constructor.

Function details

◆ accFromF()

template<class TDataTypes , class TElementType >

void sofa::component::mass::FEMMass< TDataTypes, TElementType >::accFromF	(	const core::MechanicalParams *	mparams,
		DataVecDeriv_t< DataTypes > &	a,
		const DataVecDeriv_t< DataTypes > &	f
	)

override

Supposed to compute $ a = M^{-1} f $, but triggers an error in this implementation.

Parameters

mparams	Mechanical parameters for the computation.
a	The result vector of $M^{-1} f$.
f	The vector to be multiplied by the inverse mass matrix.

◆ addForce()

template<class TDataTypes , class TElementType >

void sofa::component::mass::FEMMass< TDataTypes, TElementType >::addForce	(	const core::MechanicalParams *	mparams,
		sofa::DataVecDeriv_t< DataTypes > &	f,
		const sofa::DataVecCoord_t< DataTypes > &	x,
		const sofa::DataVecDeriv_t< DataTypes > &	v
	)

override

Adds the gravity force (f = M * g) to the force vector.

This method computes the product of the mass matrix and the gravity vector, adding the result to the force vector f.

Parameters

mparams	Mechanical parameters for the computation.
f	The force vector to which the gravity force will be added.
x	The current positions (unused in this implementation).
v	The current velocities (unused in this implementation).

◆ addMDx()

template<class TDataTypes , class TElementType >

void sofa::component::mass::FEMMass< TDataTypes, TElementType >::addMDx	(	const core::MechanicalParams *	mparams,
		DataVecDeriv_t< DataTypes > &	f,
		const DataVecDeriv_t< DataTypes > &	dx,
		SReal	factor
	)

override

Adds the product of the mass matrix and a vector to another vector (f += M * dx * factor).

This is used for computing accelerations or in iterative solvers.

Parameters

mparams	Mechanical parameters for the computation.
f	The result vector to which the product is added.
dx	The vector to be multiplied by the mass matrix.
factor	A scaling factor for the product.

◆ buildMassMatrix()

template<class TDataTypes , class TElementType >

void sofa::component::mass::FEMMass< TDataTypes, TElementType >::buildMassMatrix ( sofa::core::behavior::MassMatrixAccumulator * matrices )

overridevirtual

Accumulates the mass matrix into a global matrix accumulator.

This is used during the assembly of the system matrix for implicit solvers. It maps the stored sparse mass matrix into the global system matrix.

Parameters

matrices The accumulator used to build the global system matrix.

Reimplemented from sofa::core::behavior::BaseMass.

◆ calculateElementMassMatrix()

template<class TDataTypes , class TElementType >

void sofa::component::mass::FEMMass< TDataTypes, TElementType >::calculateElementMassMatrix	(	const auto &	elements,
		sofa::type::vector< ElementMassMatrix > &	elementMassMatrices
	)

protected

Computes the mass matrix for each finite element.

This method iterates over all elements provided by the topology and performs numerical integration (quadrature) to compute the local mass matrix for each element. The mass density is interpolated from the nodal values using the element's shape functions.

Parameters

	elements	The sequence of elements to process.
[out]	elementMassMatrices	A vector to be populated with the computed local mass matrices.

◆ elementFEMMass_init()

template<class TDataTypes , class TElementType >

void sofa::component::mass::FEMMass< TDataTypes, TElementType >::elementFEMMass_init

protected

Performs the internal calculation and assembly of the mass matrix.

This method iterates over all elements, performs numerical integration to find element-level mass matrices, and then assembles them into the global sparse matrix m_globalMassMatrix.

◆ getKineticEnergy()

template<class TDataTypes , class TElementType >

SReal sofa::component::mass::FEMMass< TDataTypes, TElementType >::getKineticEnergy	(	const core::MechanicalParams *	mparams,
		const DataVecDeriv_t< DataTypes > &	v
	)		const

override

Computes the total kinetic energy of the system.

The kinetic energy $T$ is computed as: $T = \frac{1}{2} \mathbf{v}^T \mathbf{M} \mathbf{v}$ where $\mathbf{M}$ is the global mass matrix and $\mathbf{v}$ is the velocity vector.

Parameters

mparams	Mechanical parameters for the computation.
v	The current velocity vector.

Returns: The computed kinetic energy.

◆ getPotentialEnergy()

template<class TDataTypes , class TElementType >

SReal sofa::component::mass::FEMMass< TDataTypes, TElementType >::getPotentialEnergy	(	const core::MechanicalParams *	mparams,
		const DataVecCoord_t< DataTypes > &	x
	)		const

override

Computes the total gravitational potential energy of the system.

The potential energy $V$ is computed as: $V = - \mathbf{x}^T \mathbf{M} \mathbf{g}$ where $\mathbf{M}$ is the global mass matrix, $\mathbf{x}$ is the position vector, and $\mathbf{g}$ is the gravity vector.

Parameters

mparams	Mechanical parameters for the computation.
x	The current position vector.

Returns: The computed gravitational potential energy.

◆ init()

template<class TDataTypes , class TElementType >

void sofa::component::mass::FEMMass< TDataTypes, TElementType >::init ( void )

finalvirtual

Initializes the component.

This method performs several initialization steps:

Initializes the topology accessor.
Initializes the base Mass class.
Validates that a valid nodal mass density is linked.
Computes and assembles the global mass matrix.

Reimplemented from sofa::core::objectmodel::BaseComponent.

◆ initializeGlobalMassMatrix()

template<class TDataTypes , class TElementType >

void sofa::component::mass::FEMMass< TDataTypes, TElementType >::initializeGlobalMassMatrix	(	const auto &	elements,
		const sofa::type::vector< ElementMassMatrix > &	elementMassMatrices
	)

protected

Assembles the global mass matrix from individual element mass matrices.

This method takes the precomputed local mass matrices and distributes their contributions into the global sparse mass matrix m_globalMassMatrix. It handles the mapping from local element node indices to global degree-of-freedom indices.

Parameters

elements	The sequence of elements corresponding to the provided mass matrices.
elementMassMatrices	The precomputed local mass matrices for each element.

◆ isDiagonal()

template<class TDataTypes , class TElementType >

bool sofa::component::mass::FEMMass< TDataTypes, TElementType >::isDiagonal ( ) const

inlineoverridevirtual

Indicates whether the mass matrix is diagonal.

Returns: Always returns false, as FEM mass matrices are generally not diagonal (unless lumped).

Implements sofa::core::behavior::BaseMass.

◆ SOFA_CLASS2()

template<class TDataTypes , class TElementType >

sofa::component::mass::FEMMass< TDataTypes, TElementType >::SOFA_CLASS2	(	SOFA_TEMPLATE2(FEMMass< TDataTypes, TElementType >, DataTypes, ElementType)	,
		core::behavior::Mass< TDataTypes >	,
		sofa::core::behavior::TopologyAccessor
	)

◆ validateNodalMassDensity()

template<class TDataTypes , class TElementType >

void sofa::component::mass::FEMMass< TDataTypes, TElementType >::validateNodalMassDensity

protected

Ensures that a valid NodalMassDensity component is linked.

If no link is set, it attempts to find a suitable component in the current context. If no component is found, it marks the component state as invalid.

Detailed Description

template<class TDataTypes, class TElementType> class sofa::component::mass::FEMMass< TDataTypes, TElementType >

Public Attributes

Protected Attributes

Static Protected Attributes

Public Member Functions

Protected Member Functions

Additional Inherited Members

Attribute details

◆ l_nodalMassDensity

◆ m_globalMassMatrix

◆ NumberOfDofsInElement

◆ NumberOfNodesInElement

◆ spatial_dimensions

◆ TopologicalDimension

Constructor details

◆ FEMMass()

Function details

◆ accFromF()

◆ addForce()

◆ addMDx()

◆ buildMassMatrix()

◆ calculateElementMassMatrix()

◆ elementFEMMass_init()

◆ getKineticEnergy()

◆ getPotentialEnergy()

◆ init()

◆ initializeGlobalMassMatrix()

◆ isDiagonal()

◆ SOFA_CLASS2()

◆ validateNodalMassDensity()

template<class TDataTypes, class TElementType>
class sofa::component::mass::FEMMass< TDataTypes, TElementType >