iMSTK: imstk::PbdModelConfig Class Reference

Gives parameters for PBD simulation. More...

#include <imstkPbdModelConfig.h>

Public Types
enum	ConstraintGenType { Custom, Distance, FemTet, Volume, Area, Bend, Dihedral, ConstantDensity }
	Gives the set of standard pbd constraint generation schemes/functors provided by iMSTK. Note, these do not correspond to constraint types as there may be multiple schemes for one constraint or even multiple constraints per scheme.

Public Member Functions
void	enableConstraint (ConstraintGenType type, const double stiffness, const int bodyId=2)
	Enables a constraint of type defined by ConstraintGenType with given stiffness. If constraint of that type already exists, sets the stiffness on it. More...

void	enableDistanceConstraint (const double stiffness, const double stretch, const int bodyId)
	Enables a Distance constraint on the body Will remove an existing distance constraint on the same body. More...

void	enableBendConstraint (const double stiffness, const int stride, const bool restLength0=true, const int bodyId=2)
	Enables a bend constraint with given stiffness, stride, and flag for 0 rest length You may enable multiple with differing strides If constraint with same stride already exists, updates the stiffness and restLength0 on it. More...

void	enableConstantDensityConstraint (const double stiffness, const double particleRadius, const double restDensity=6378.0, const int bodyId=2)
	Enables constant density constraint given the stiffness and particleSize. More...

void	enableFemConstraint (PbdFemConstraint::MaterialType material, const int bodyId=2)
	Enable a Fem constraint with the material provided. More...

void	enableFemConstraint (PbdFemConstraint::MaterialType material, double youngsModulus, double poissonRatio, const int bodyId)
	Enable a Fem constraint with the material provided and parameters. More...

void	computeElasticConstants ()
	If lame parameters (mu+lambda) are given in femParams, then youngs modulus and poissons ratio are computed Conversely if youngs and poissons are given, lame parameters are computed.

void	addPbdConstraintFunctor (std::shared_ptr< PbdConstraintFunctor > functor)
	Adds a functor to generate constraints. More...

void	addPbdConstraintFunctor (std::function< void(PbdConstraintContainer &)> functor)

std::unordered_map< ConstraintGenType, std::vector< std::shared_ptr< PbdConstraintFunctor > > > &	getFunctors ()

void	setBodyDamping (const int bodyId, const double linearDampCoeff, const double angularDampCoeff=0.01)
	Set damping for a specific body 1.0 is fully damped/all velocity removed, 0.0 is no damping. More...


double	getLinearDamping (const int bodyId)
	Returns global and per body damping multiplied together for a body 1.0 is fully damped/all velocity removed, 0.0 is no damping. More...

double	getAngularDamping (const int bodyId)

Public Attributes
double	m_linearDampingCoeff = 0.01
	Damping coefficient applied to linear velocity [0, 1].

double	m_angularDampingCoeff = 0.01
	Damping coefficient applied to angular velcoity [0, 1].

unsigned int	m_iterations = 10
	Internal constraints pbd solver iterations.

double	m_dt = 0.01
	Time step size.

bool	m_doPartitioning = true
	Does graph coloring to solve in parallel.

Vec3d	m_gravity = Vec3d(0.0, -9.81, 0.0)
	Gravity acceleration.

std::shared_ptr< PbdFemConstraintConfig >	m_femParams

PbdConstraint::SolverType	m_solverType = PbdConstraint::SolverType::xPBD

std::unordered_map< int, double >	m_bodyLinearDampingCoeff
	Per body linear damping, Body id -> linear damping for given body [0, 1].

std::unordered_map< int, double >	m_bodyAngularDampingCoeff
	Per body angular damping, Body id -> angular damping for given body [0, 1].

std::shared_ptr< DataTracker >	m_dataTracker

Protected Attributes
std::unordered_map< ConstraintGenType, std::vector< std::shared_ptr< PbdConstraintFunctor > > >	m_functors

Friends
class	PbdModel

Detailed Description

Gives parameters for PBD simulation.

Definition at line 24 of file imstkPbdModelConfig.h.

Member Function Documentation

◆ addPbdConstraintFunctor()

void imstk::PbdModelConfig::addPbdConstraintFunctor ( std::shared_ptr< PbdConstraintFunctor > functor )

inline

Adds a functor to generate constraints.

Template Parameters

Must	contain operator(PbdConstraintContainer&), could be a PbdConstraintFunctor or std::function<void(PbdConstraintContainer&)>

Definition at line 110 of file imstkPbdModelConfig.h.

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◆ enableBendConstraint()

void imstk::PbdModelConfig::enableBendConstraint	(	const double	stiffness,
		const int	stride,
		const bool	restLength0 = `true`,
		const int	bodyId = `2`
	)

Enables a bend constraint with given stiffness, stride, and flag for 0 rest length You may enable multiple with differing strides If constraint with same stride already exists, updates the stiffness and restLength0 on it.

Parameters

stiffness	How much constraint is enforced
stride	Distance between vertex connections
restLength0	When true rest length (and angle) are constrained to 0, useful when mesh initial/resting state is not 0 angled
bodyId	Body to add the constraint throughout, -1 applies to all bodies

Definition at line 129 of file imstkPbdModelConfig.cpp.

◆ enableConstantDensityConstraint()

void imstk::PbdModelConfig::enableConstantDensityConstraint	(	const double	stiffness,
		const double	particleRadius,
		const double	restDensity = `6378.0`,
		const int	bodyId = `2`
	)

Enables constant density constraint given the stiffness and particleSize.

Parameters

stiffness	how much constraint is enforced
particleRadius,radius	of particle
bodyId	Body to add the constraint throughout, -1 applies to all bodies

Definition at line 153 of file imstkPbdModelConfig.cpp.

◆ enableConstraint()

void imstk::PbdModelConfig::enableConstraint	(	ConstraintGenType	type,
		const double	stiffness,
		const int	bodyId = `2`
	)

Enables a constraint of type defined by ConstraintGenType with given stiffness. If constraint of that type already exists, sets the stiffness on it.

Parameters

type	Generation scheme type
stiffness	How much constraint is enforced
bodyId	Body to add the constraint throughout, -1 applies to all bodies

Definition at line 59 of file imstkPbdModelConfig.cpp.

◆ enableDistanceConstraint()

void imstk::PbdModelConfig::enableDistanceConstraint	(	const double	stiffness,
		const double	stretch,
		const int	bodyId
	)

Enables a Distance constraint on the body Will remove an existing distance constraint on the same body.

Parameters

stiffness	How much constraint is enforced
stretch	Allows to stretch or relax the material, the constraint restlength is multiplied by the strech factor
bodyId	Body to add the constraint

Definition at line 115 of file imstkPbdModelConfig.cpp.

◆ enableFemConstraint() [1/2]

void imstk::PbdModelConfig::enableFemConstraint	(	PbdFemConstraint::MaterialType	material,
		const int	bodyId = `2`
	)

Enable a Fem constraint with the material provided.

Parameters

material	FEM model type
bodyId	Body to add the constraint throughout, -1 applies to all bodies This function uses the global deformable parameter object, its only provided for backwards compatibility, don't use it

Definition at line 172 of file imstkPbdModelConfig.cpp.

◆ enableFemConstraint() [2/2]

void imstk::PbdModelConfig::enableFemConstraint	(	PbdFemConstraint::MaterialType	material,
		double	youngsModulus,
		double	poissonRatio,
		const int	bodyId
	)

Enable a Fem constraint with the material provided and parameters.

Parameters

material	FEM model type
youngsModulus	the youngs modulus of the material
poissonRatio	the Poisson ration of the material
bodyId	Body to add the constraint throughout

Definition at line 189 of file imstkPbdModelConfig.cpp.

◆ getLinearDamping()

double imstk::PbdModelConfig::getLinearDamping ( const int bodyId )

Returns global and per body damping multiplied together for a body 1.0 is fully damped/all velocity removed, 0.0 is no damping.

Parameters

bodyId Body that is damped

Definition at line 217 of file imstkPbdModelConfig.cpp.

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◆ setBodyDamping()

void imstk::PbdModelConfig::setBodyDamping	(	const int	bodyId,
		const double	linearDampCoeff,
		const double	angularDampCoeff = `0.01`
	)

Set damping for a specific body 1.0 is fully damped/all velocity removed, 0.0 is no damping.

Parameters

bodyId	Body to damp
How	much to damp linear velocity
How	much to damp angular velocity

Definition at line 209 of file imstkPbdModelConfig.cpp.

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Member Data Documentation

◆ m_femParams

std::shared_ptr<PbdFemConstraintConfig> imstk::PbdModelConfig::m_femParams

Initial value:

=
        std::make_shared<PbdFemConstraintConfig>(PbdFemConstraintConfig
        {
            0.0,                
            0.0,                
            1000.0,             
            0.2                 
            })

Definition at line 153 of file imstkPbdModelConfig.h.

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

Source/DynamicalModels/ObjectModels/imstkPbdModelConfig.h
Source/DynamicalModels/ObjectModels/imstkPbdModelConfig.cpp

Public Types

Public Member Functions

Public Attributes

Protected Attributes

Friends

Detailed Description

Member Function Documentation

◆ addPbdConstraintFunctor()

◆ enableBendConstraint()

◆ enableConstantDensityConstraint()

◆ enableConstraint()

◆ enableDistanceConstraint()

◆ enableFemConstraint() [1/2]

◆ enableFemConstraint() [2/2]

◆ getLinearDamping()

◆ setBodyDamping()

Member Data Documentation

◆ m_femParams