iMSTK: imstk::PbdContactConstraint Class Reference

A constraint on a rigid body that defines rotationl correction through dx applied at a local position r on the body. More...

#include <imstkPbdContactConstraint.h>

Inheritance diagram for imstk::PbdContactConstraint:

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Collaboration diagram for imstk::PbdContactConstraint:

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Public Member Functions
void	projectConstraint (PbdState &bodies, const double dt, const SolverType &type) override
	Update positions by projecting constraints.

virtual Vec3d	computeRelativeVelocity (PbdState &imstkNotUsed(bodies))

const Vec3d &	getR (const int i) const
	Get the support point r/the difference to the contact point.

void	correctVelocity (PbdState &bodies, const double dt) override
	Solve the velocities given to the constraint. More...

Vec3d	getVelocityOnRigidBody (PbdState &bodies, const int bodyId, const Vec3d &pt)
	Returns the velocity at the given point on body Either body in collision could be rigid body.

double	getTorque (const double dt, const int i)
	Get torque magnitude after solve.

Public Member Functions inherited from imstk::PbdConstraint
virtual const std::string	getTypeName () const =0

virtual bool	computeValueAndGradient (PbdState &bodies, double &c, std::vector< Vec3d > &dcdx)=0
	Compute value and gradient of the constraint. More...

std::vector< PbdParticleId > &	getParticles ()
	Get the vertex indices of the constraint.

bool	getCorrectVelocity () const
	Get/Set whether velocity should be corrected for this constraint.

void	setCorrectVelocity (const bool correctVelocity)

const Vec3d &	getGradient (const int i) const
	Get gradient given the particle index in constraint.

double	getForce (const double dt) const
	Get the force magnitude, valid after solving lambda Only valid with xpbd.

double	getConstraintC () const
	Get constraint value C (how much the constraint is violated)

double	getLambda () const
	Get constraint value C (how much the constraint is violated)

virtual double	getRestValue () const
	Get reference constraint value. This value will have different context depending on the constraint being used.

void	zeroOutLambda ()
	Zero's out the lagrange multplier before integration only used for xpbd, must be called before solving.

double	computeGeneralizedInvMass (const PbdState &bodies, const size_t particleIndex) const
	Compute generalized inverse mass of the particle. Note perf sensitive function. It has been intentionally inlined. More...

double	computeGeneralizedInvMass (const PbdState &bodies, const size_t particleIndex, const Vec3d &r) const
	Compute generalized inverse mass of the particle. More...

double	getRestitution () const
	Get/Set restitution.

void	setRestitution (const double restitution)

double	getFriction () const
	Get/Set friction.

void	setFriction (const double friction)

double	getStiffness () const
	Get/Set the stiffness.

void	setStiffness (const double stiffness)

double	getCompliance () const
	Get/Set the compliance This function is also provided in case users need 0 compliance.

void	setCompliance (const double compliance)

Protected Member Functions
	PbdContactConstraint (const int numParticles)

Protected Member Functions inherited from imstk::PbdConstraint
	PbdConstraint (const size_t numParticles)

Protected Attributes
std::vector< Vec3d >	m_r

std::vector< double >	m_weights

Protected Attributes inherited from imstk::PbdConstraint
std::vector< PbdParticleId >	m_particles
	body, particle index

std::vector< Vec3d >	m_dcdx
	Normalized constraint gradients (per particle)

double	m_stiffness = 1.0
	used in PBD, [0, 1]

double	m_compliance = 1e-7
	used in xPBD, inverse of Stiffness

double	m_lambda = 0.0
	Lagrange multiplier.

double	m_C = 0.0
	Constraint Value.

double	m_friction = 0.0

double	m_restitution = 0.0

bool	m_correctVelocity = false