The base class for a constraint. More...

#include <Constraint.h>

Inheritance diagram for agx::Constraint:

Public Types
enum	SolveType { DIRECT = 1 , ITERATIVE = (1<<2) , DIRECT_AND_ITERATIVE = (DIRECT \| ITERATIVE) }
	Specifies in what solvers the constraint will be solved. More...

Public Member Functions
agx::Bool	addElementaryConstraint (const agx::Name &name, agx::ElementaryConstraint *elementaryConstraint)
	Add elementary constraint (like Spherical, Dot1, Dot2 etc) given name.

agx::Bool	addSecondaryConstraint (const agx::Name &name, agx::ElementaryConstraint *secondaryConstraint)
	Add secondary constraint (like motor, range and/or lock etc) given name.

	AGXSTREAM_DECLARE_ABSTRACT_SERIALIZABLE (agx::Constraint)

template<typename T >
T *	as ()
	Try to do dynamic_cast on the constraint and return a pointer to the casted constraint.

template<typename T >
const T *	as () const
	Try to do dynamic_cast on the constraint and return a pointer to the casted constraint.

RealVector	calculateCurrentViolation () const
	Calculates the current violation of the ordinary degrees of freedom of this constraint, e.g., three translational and two rotational (total 5 elements) of a hinge, i.e., controllers DOF are not included.

agx::UInt	calculateNumActiveRows () const
	Calculates the current number of active rows, including both elementary and secondary constraints.

template<typename T >
ref_ptr< T >	createFromBody (Vec3 bodyPoint, Vec3 bodyAxis, RigidBody rb1, RigidBody rb2)

template<typename T >
ref_ptr< T >	createFromWorld (Vec3 worldPoint, Vec3 worldAxis, RigidBody rb1, RigidBody rb2)

agx::Attachment *	getAttachment (agx::UInt i) const

agx::RigidBodyAttachment *	getAttachment (const agx::RigidBody *rb) const

agx::AttachmentPair *	getAttachmentPair () const

agx::RigidBody *	getBodyAt (agx::UInt i)

const agx::RigidBody *	getBodyAt (agx::UInt i) const

virtual agx::Real	getCompliance (agx::UInt dof) const
	Get the compliance for DOF i.

agx::Real	getCurrentForce (agx::UInt dof) const
	Consider using `getLastForce` instead.

virtual Real	getDamping (agx::UInt dof) const
	Get the damping for DOF `dof`.

virtual agx::Real	getElasticity (agx::UInt dof) const
	Get the elasticity for DOF i.

agx::ElementaryConstraint *	getElementaryConstraint (const agx::UInt index) const

agx::ElementaryConstraint *	getElementaryConstraintGivenName (const agx::Name &name) const
	Find elementary constraint given name.

agx::Bool	getEnable () const

agx::Bool	getEnableComputeForces () const

bool	getEnableDebugRendering () const

bool	getEnableLinearization () const

agx::UInt32	getEntityId () const

agx::RangeReal	getForceRange (agx::UInt dof=0) const
	Get the force range for DOF `dof`.

agx::Bool	getLastForce (agx::UInt bodyIndex, agx::Vec3 &retForce, agx::Vec3 &retTorque, agx::Bool giveForceAtCm=false) const
	If 'compute forces' is enabled, returns the last force and torque applied by this constraint on the body with `bodyIndex`.

agx::Bool	getLastForce (const agx::RigidBody *rb, agx::Vec3 &retForce, agx::Vec3 &retTorque, agx::Bool giveForceAtCm=false) const
	If 'compute forces' is enabled, returns the last force and torque applied by this constraint on the body `rb`.

agx::Bool	getLastLocalForce (agx::UInt bodyIndex, agx::Vec3 &retForce, agx::Vec3 &retTorque, agx::Bool giveForceAtCm=false) const
	If 'compute forces' is enabled, returns the last force and torque applied by this constraint on the body with `bodyIndex`.

agx::Bool	getLastLocalForce (const agx::RigidBody *rb, agx::Vec3 &retForce, agx::Vec3 &retTorque, agx::Bool giveForceAtCm=false) const
	If 'compute forces' is enabled, returns the last force and torque applied by this constraint on the body `rb`.

agx::UInt	getNumBodies () const
	returns the number of bodies involved

virtual int	getNumDOF () const =0

agx::UInt	getNumElementaryConstraints () const

agx::UInt	getNumSecondaryConstraints () const

virtual agx::RegularizationParameters *	getRegularizationParameters (agx::UInt i)

virtual const agx::RegularizationParameters *	getRegularizationParameters (agx::UInt i) const

agx::ConstraintImplementation *	getRep ()

const agx::ConstraintImplementation *	getRep () const

agx::ElementaryConstraint *	getSecondaryConstraint (const agx::UInt index) const

agx::ElementaryConstraint *	getSecondaryConstraintGivenName (const agx::Name &name) const
	Find secondary constraint given name.

agx::Constraint::SolveType	getSolveType () const

agx::Bool	getValid () const

agx::Bool	isEnabled () const

virtual agx::Bool	rebind ()
	Rebind this constraint, i.e., use current state as the initial configuration.

agx::Bool	removeElementaryConstraint (agx::ElementaryConstraint *elementaryConstraint)
	Remove elementary constraint.

agx::Bool	removeElementaryConstraint (const agx::Name &name)
	Remove elementary constraint.

agx::Bool	removeSecondaryConstraint (agx::ElementaryConstraint *secondaryConstraint)
	Remove secondary constraint.

agx::Bool	removeSecondaryConstraint (const agx::Name &name)
	Remove secondary constraint.

virtual void	render (class agxRender::RenderManager *mgr, float scale) const =0
	Inherited method of how to render this constraint into DebugRenderer.

void	restore (agxStream::InputArchive &in) override

virtual void	restoreLightData (agxStream::StorageStream &str) override

void	setCompliance (agx::Real compliance)
	Set the compliance of this constraint for all DOFs.

virtual void	setCompliance (agx::Real compliance, agx::Int dof)
	Set the compliance of this constraint for the i:th DOF.

void	setDamping (agx::Real damping)
	Set the damping of this constraint for all DOFs.

virtual void	setDamping (agx::Real damping, agx::Int dof)
	Set the damping of this constraint for the i:th DOF.

virtual void	setElasticity (agx::Real elasticity)
	Set the elasticity of this constraint for all DOFs.

virtual void	setElasticity (agx::Real elasticity, agx::Int dof)
	Set the elasticity of this constraint for the i:th DOF.

virtual void	setEnable (agx::Bool enable)
	Enable/disable a constraint.

void	setEnableComputeForces (agx::Bool enable)
	Enable (or disable) computation of the forces applied to the dynamic bodies in this constraint.

void	setEnableDebugRendering (agx::Bool enable)
	Enable/disable debug rendering of this constraint.

void	setEnableLinearization (bool enable)
	Pass `true` to enable linearization of constraint compliance.

void	setForceRange (agx::RangeReal forceRange)
	Assign force range for all DOF of the elementary constraints.

void	setForceRange (agx::RangeReal forceRange, agx::Int dof)
	Assign force range, of an elementary constraint, for a given DOF.

void	setForceRange (agx::Real lower, agx::Real upper, agx::Int dof)
	Assign force range, of an elementary constraint, for a given DOF.

void	setSolveType (agx::Constraint::SolveType solveType)
	Specify the solve type for this constraint.

void	store (agxStream::OutputArchive &out) const override

virtual void	storeLightData (agxStream::StorageStream &str) const override

Public Member Functions inherited from agx::Interaction
	Interaction ()
	Default constructor.

	AGXSTREAM_DECLARE_SERIALIZABLE_BASE (agx::Interaction)

const agx::Name &	getName () const

agx::PropertyContainer *	getPropertyContainer ()

const agx::PropertyContainer *	getPropertyContainer () const

agxSDK::SimulationProxy *	getSimulationProxy () const

agx::Bool	hasPropertyContainer () const

virtual void	postSystemCallback (agx::DynamicsSystem *)
	Called after all post step events, after solve.

virtual void	preSystemCallback (agx::DynamicsSystem *)
	Called after all pre step events, before solve.

void	setName (const agx::Name &name)
	Name this interaction.

void	setPropertyContainer (agx::PropertyContainer *propertyContainer)
	Assign a new property container.

virtual void	updateForce (agx::DynamicsSystem *dynamicsSystem)
	This virtual method is implemented so that it computes the interaction forces on all the physical bodies implicated.

Public Member Functions inherited from agx::Referenced
	Referenced ()
	Default constructor.

	Referenced (const Referenced &)

template<typename T >
T *	as ()
	Subclass casting.

template<typename T >
const T *	as () const

template<typename T >
T *	asSafe ()
	Safe subclass casting, return nullptr if template type does not match.

template<typename T >
const T *	asSafe () const

int	getReferenceCount () const

template<typename T >
bool	is () const
	Subclass test.

Referenced &	operator= (const Referenced &)
	Assignment operator. Will increment the number of references to the referenced object.

void	reference (void *ptr=nullptr) const
	Explicitly increment the reference count by one, indicating that this object has another pointer which is referencing it.

void	unreference (void *ptr=nullptr) const
	Decrement the reference count by one, indicating that a pointer to this object is referencing it.

void	unreference_nodelete () const
	Decrement the reference count by one, indicating that a pointer to this object is referencing it.

Public Member Functions inherited from agxStream::Serializable
virtual	~Serializable ()
	Destructor for normal C++ use but hidden from SWIG bindings.

virtual const char *	getClassName () const

bool	getEnableSerialization () const

bool	getEnableUuidGeneration ()

agx::UInt32	getIndex () const
	This index is given at creation of this object.

virtual StorageAgent *	getStorageAgent () const =0

agx::Uuid	getUuid () const

bool	isFinished () const

void	setEnableSerialization (bool flag)
	Set to false to disable serialization of this object.

void	setFinished ()
	Tells this class that it is restored correctly and should not be deleted during destruction of an Archive.

void	setUuid (const agx::Uuid &uuid)
	Explicitly set a Uuid on a serializable object.

Static Public Member Functions
static agx::Bool	calculateFramesFromBody (agx::Vec3 bodyPoint, agx::Vec3 bodyAxis, agx::Vec3 secondBodyAxis, const agx::RigidBody body, agx::Frame bodyFrame, const agx::RigidBody otherBody, agx::Frame otherFrame)
	Calculates the constraint attachment frames given point and axes in body coordinates of `body`.

static agx::Bool	calculateFramesFromBody (agx::Vec3 bodyPoint, agx::Vec3 bodyAxis, const agx::RigidBody body, agx::Frame bodyFrame, const agx::RigidBody otherBody, agx::Frame otherFrame)
	Calculates the constraint attachment frames given point and axis in body coordinates of `body`.

static agx::Bool	calculateFramesFromWorld (agx::Vec3 worldPoint, agx::Vec3 worldAxis, agx::Vec3 secondWorldAxis, const agx::RigidBody rb1, agx::Frame rb1Frame, const agx::RigidBody rb2, agx::Frame rb2Frame)
	Given a point and two axes in world, this function calculates each local attachment frame for one or two bodies.

static agx::Bool	calculateFramesFromWorld (agx::Vec3 worldPoint, agx::Vec3 worldAxis, const agx::RigidBody rb1, agx::Frame rb1Frame, const agx::RigidBody rb2, agx::Frame rb2Frame)
	Given a point and an axis in world, this function calculates each local attachment frame for one or two bodies.

template<typename T >
static agx::ref_ptr< T >	createFromBody (agx::Vec3 bodyPoint, agx::Vec3 bodyAxis, agx::RigidBody rb1, agx::RigidBody rb2=nullptr)
	Creates a constraint given a point and an axis in `rb1` model frame.

template<typename T >
static agx::ref_ptr< T >	createFromWorld (agx::Vec3 worldPoint, agx::Vec3 worldAxis, agx::RigidBody rb1, agx::RigidBody rb2=nullptr)
	Creates a constraint given a point and an axis in world frame.

Static Public Member Functions inherited from agx::Interaction
static agxStream::Serializable *	create (agxStream::InputArchive &)

Static Public Member Functions inherited from agx::Referenced
template<typename T >
static bool	ValidateCast (const Referenced *object)

Static Public Member Functions inherited from agxStream::Serializable
static void	setEnableUuidGeneration (bool flag)
	Specify if there should be UUID:s generated for each new Serializable object. By default it is enabled.

Protected Member Functions
	Constraint ()

virtual	~Constraint ()

virtual void	addNotification () override
	Called when added to a simulation.

virtual void	postSystemCallback (agx::DynamicsSystem *dynamicsSystem) override
	Called after all post step events, after solve.

virtual void	preSystemCallback (agx::DynamicsSystem *dynamicsSystem) override
	Called after all pre step events, before solve.

virtual void	removeNotification () override
	Called when removed from a simulation.

void	setRep (agx::ConstraintImplementation *_rep)

virtual void	setSimulation (agxSDK::Simulation *simulation) override
	Assign simulation.

virtual void	setSystem (agx::DynamicsSystem *)

Protected Member Functions inherited from agx::Interaction
virtual	~Interaction ()
	Reference counted object, protected destructor.

virtual void	addNotification ()
	Called when added to a simulation.

virtual void	removeNotification ()
	Called when removed from a simulation.

virtual void	setSimulation (agxSDK::Simulation *simulation)
	Assign simulation.

Protected Member Functions inherited from agx::Referenced
virtual	~Referenced ()
	Destructor.

void	allocateObserverVector () const

void	deleteUsingDeleteHandler () const

Protected Member Functions inherited from agxStream::Serializable
	Serializable ()
	Default constructor.

	Serializable (const Serializable &other)
	Copy constructor.

void	generateUuid ()

Protected Attributes
agx::ConstraintImplementation *	m_implementation

Protected Attributes inherited from agx::Referenced
Mutex	m_mutex

ObserverContainer	m_observers

AtomicValue	m_refCount

Additional Inherited Members
Static Protected Member Functions inherited from agx::Referenced
static DeleteHandler *	getDeleteHandler ()

static void	setDeleteHandler (DeleteHandler *handler)
	Internal: Set a DeleteHandler to which deletion of all referenced counted objects will be delegated to.

Detailed Description

The base class for a constraint.

This is an interface class for all constraints. The virtual functions are place holders for the computation of Jacobians and constraint value. In addition, there are interfaces defined here to setup the interacting bodies.

Consider the case of two constrained rigid bodies. Before the constraint is applied, the relative motion is the manifold \(R^3\times SO(3)\). If the constraint is a prismatic joint, the remaining manifold of relative motion is just \(R\), the Real line. We put a chart on that manifold so we can put a value on the extension of the prismatic joint. On the resulting joint coordinate, we might then enforce a secondary constraint such as joint limits, a position lock, or a driver that imposes a velocity.

The constraint processing consists of the following stages: -perform necessary geometric computation from rigid bodies' kinematic data -evaluate the constraint value and basic Jacobians -configure dynamical parameters (compliance and damping) -compute joint angles according to manifold chart if needed -if there are secondary constraints:

compute the value of the constraint
compute the secondary Jacobian by collapsing recursion
add rows to the constraint Jacobian
configure dynamics parameters (compliance and damping) -if there are effort constraints
for simple limits, add these to parameters
for additional limits, register these with corresponding Jacobians

Definition at line 88 of file Constraint.h.

Member Enumeration Documentation

◆ SolveType

enum agx::Constraint::SolveType

Specifies in what solvers the constraint will be solved.

Enumerator
DIRECT	Solved only in the DIRECT solver.
ITERATIVE	Solved only in the ITERATIVE solver.
DIRECT_AND_ITERATIVE	Solved both in the ITERATIVE and the DIRECT solver.

Definition at line 92 of file Constraint.h.

Constructor & Destructor Documentation

◆ Constraint()

agx::Constraint::Constraint ( )

protected

◆ ~Constraint()

virtual agx::Constraint::~Constraint ( )

protectedvirtual

Member Function Documentation

◆ addElementaryConstraint()

agx::Bool agx::Constraint::addElementaryConstraint	(	const agx::Name &	name,
		agx::ElementaryConstraint *	elementaryConstraint
	)

Add elementary constraint (like Spherical, Dot1, Dot2 etc) given name.

General for elementary constraints is that their input is based on body relative data (far from general).

Returns: true if this constraint supports the elementary constraint and the elementary constraint will be used - otherwise false

◆ addNotification()

virtual void agx::Constraint::addNotification ( )

overrideprotectedvirtual

Called when added to a simulation.

Reimplemented from agx::Interaction.

Reimplemented in agx::IGenericConstraint, and agxDriveTrain::VelocityConstraint.

◆ addSecondaryConstraint()

agx::Bool agx::Constraint::addSecondaryConstraint	(	const agx::Name &	name,
		agx::ElementaryConstraint *	secondaryConstraint
	)

Add secondary constraint (like motor, range and/or lock etc) given name.

General for secondary constraints is that their input is based on the current constraint angle.

Returns: true if this constraint supports the secondary constraint and the secondary constraint will be used - otherwise false

◆ AGXSTREAM_DECLARE_ABSTRACT_SERIALIZABLE()

agx::Constraint::AGXSTREAM_DECLARE_ABSTRACT_SERIALIZABLE ( agx::Constraint )

◆ as() [1/2]

template<typename T >

T * agx::Constraint::as

Try to do dynamic_cast on the constraint and return a pointer to the casted constraint.

Definition at line 940 of file Constraint.h.

◆ as() [2/2]

template<typename T >

const T * agx::Constraint::as

Try to do dynamic_cast on the constraint and return a pointer to the casted constraint.

Definition at line 947 of file Constraint.h.

◆ calculateCurrentViolation()

RealVector agx::Constraint::calculateCurrentViolation ( ) const

Calculates the current violation of the ordinary degrees of freedom of this constraint, e.g., three translational and two rotational (total 5 elements) of a hinge, i.e., controllers DOF are not included.

Returns: violation vector of size getNumDOF()

◆ calculateFramesFromBody() [1/2]

static agx::Bool agx::Constraint::calculateFramesFromBody	(	agx::Vec3	bodyPoint,
		agx::Vec3	bodyAxis,
		agx::Vec3	secondBodyAxis,
		const agx::RigidBody *	body,
		agx::Frame *	bodyFrame,
		const agx::RigidBody *	otherBody,
		agx::Frame *	otherFrame
	)

static

Calculates the constraint attachment frames given point and axes in body coordinates of body.

The frames' z-axis will be aligned with the bodyAxis and its y-axis will be normal to the bodyAxis-secondBodyAxis plane.

Parameters

bodyPoint	- point in body coordinates of reference rigid body "body"
bodyAxis	- axis in body coordinates of reference rigid body "body"
secondBodyAxis	- non-parallel axis to bodyAxis in body coordinates of reference rigid body "body"
body	- reference body, invalid if null
bodyFrame	- reference body attachment frame, invalid if null
otherBody	- other rigid body, if null otherFrame will be calculated in world frame
otherFrame	- other frame, invalid if null

Returns: true if the calculations succeeded - otherwise false

◆ calculateFramesFromBody() [2/2]

static agx::Bool agx::Constraint::calculateFramesFromBody	(	agx::Vec3	bodyPoint,
		agx::Vec3	bodyAxis,
		const agx::RigidBody *	body,
		agx::Frame *	bodyFrame,
		const agx::RigidBody *	otherBody,
		agx::Frame *	otherFrame
	)

static

Calculates the constraint attachment frames given point and axis in body coordinates of body.

Parameters

bodyPoint	- point in body coordinates of reference rigid body "body"
bodyAxis	- axis in body coordinates of reference rigid body "body"
body	- reference body, invalid if null
bodyFrame	- reference body attachment frame, invalid if null
otherBody	- other rigid body, if null otherFrame will be calculated in world frame
otherFrame	- other frame, invalid if null

Returns: true if the calculations succeeded - otherwise false

◆ calculateFramesFromWorld() [1/2]

static agx::Bool agx::Constraint::calculateFramesFromWorld	(	agx::Vec3	worldPoint,
		agx::Vec3	worldAxis,
		agx::Vec3	secondWorldAxis,
		const agx::RigidBody *	rb1,
		agx::Frame *	rb1Frame,
		const agx::RigidBody *	rb2,
		agx::Frame *	rb2Frame
	)

static

Given a point and two axes in world, this function calculates each local attachment frame for one or two bodies.

The frames' z-axis will be aligned with the worldAxis and its y-axis will be normal to the worldAxis-secondWorldAxis plane. The first body, rb1, has to be valid. If the second body, rb2, is zero the second frame, rb2Frame, will be given in world frame.

Parameters

worldPoint	- point in world
worldAxis	- axis in world (for example prismatic- or hinge axis)
secondWorldAxis	- axis in world (must be non-parallel to worldAxis)
rb1	- first rigid body, invalid if null
rb1Frame	- frame to calculate for rb1, invalid if null
rb2	- second rigid body, if null rb2Frame will be given in world
rb2Frame	- frame to calculate for rb2, invalid if null

Returns: true if the calculations succeeded - otherwise false (if false, rb1Frame and rb2Frame are not touched)

◆ calculateFramesFromWorld() [2/2]

static agx::Bool agx::Constraint::calculateFramesFromWorld	(	agx::Vec3	worldPoint,
		agx::Vec3	worldAxis,
		const agx::RigidBody *	rb1,
		agx::Frame *	rb1Frame,
		const agx::RigidBody *	rb2,
		agx::Frame *	rb2Frame
	)

static

Given a point and an axis in world, this function calculates each local attachment frame for one or two bodies.

The first body, rb1, has to be valid. If the second body, rb2, is zero the second frame, rb2Frame, will be given in world frame.

Parameters

worldPoint	- point in world
worldAxis	- axis in world (for example prismatic- or hinge axis)
rb1	- first rigid body, invalid if null
rb1Frame	- frame to calculate for rb1, invalid if null
rb2	- second rigid body, if null rb2Frame will be given in world
rb2Frame	- frame to calculate for rb2, invalid if null

Returns: true if the calculations succeeded - otherwise false (if false, rb1Frame and rb2Frame are not touched)

◆ calculateNumActiveRows()

agx::UInt agx::Constraint::calculateNumActiveRows ( ) const

Calculates the current number of active rows, including both elementary and secondary constraints.

The result can be used to allocate temporary buffers for additional calls to solver related methods, e.g., getViolation.

Returns: the (current) total number of active rows in this constraint

◆ createFromBody() [1/2]

template<typename T >

static agx::ref_ptr< T > agx::Constraint::createFromBody	(	agx::Vec3	bodyPoint,
		agx::Vec3	bodyAxis,
		agx::RigidBody *	rb1,
		agx::RigidBody *	rb2 = `nullptr`
	)

static

Creates a constraint given a point and an axis in rb1 model frame.

Seen from body one frame - both relative attachment frames will coincide at the given point with their z-axes pointing in the axis direction.

Parameters

bodyPoint	- constraint center point given in first body's frame
bodyAxis	- constraint axis given in first body's frame
rb1	- first rigid body (not defined if null)
rb2	- second rigid body, if null, `rb1` will be attached in world

Returns: the constraint of type T

◆ createFromBody() [2/2]

template<typename T >

ref_ptr< T > agx::Constraint::createFromBody	(	Vec3	bodyPoint,
		Vec3	bodyAxis,
		RigidBody *	rb1,
		RigidBody *	rb2
	)

Definition at line 929 of file Constraint.h.

◆ createFromWorld() [1/2]

template<typename T >

static agx::ref_ptr< T > agx::Constraint::createFromWorld	(	agx::Vec3	worldPoint,
		agx::Vec3	worldAxis,
		agx::RigidBody *	rb1,
		agx::RigidBody *	rb2 = `nullptr`
	)

static

Creates a constraint given a point and an axis in world frame.

Both relative attachment frames will coincide at the given world point with their z-axes pointing in the given world axis direction.

Parameters

worldPoint	- constraint center point given in the world frame
worldAxis	- constraint axis given in world frame
rb1	- first rigid body (not defined if null)
rb2	- second rigid body, if null, `rb1` will be attached in world

Returns: the constraint of type T

◆ createFromWorld() [2/2]

template<typename T >

ref_ptr< T > agx::Constraint::createFromWorld	(	Vec3	worldPoint,
		Vec3	worldAxis,
		RigidBody *	rb1,
		RigidBody *	rb2
	)

Definition at line 919 of file Constraint.h.

◆ getAttachment() [1/2]

agx::Attachment * agx::Constraint::getAttachment ( agx::UInt i ) const

Returns: the attachment frame for body with index i (call equal to constraint->getAttachment( constraint->getBodyAt( i ) ))

◆ getAttachment() [2/2]

agx::RigidBodyAttachment * agx::Constraint::getAttachment ( const agx::RigidBody * rb ) const

Returns: the attachment frame for rb if present - otherwise 0

◆ getAttachmentPair()

agx::AttachmentPair * agx::Constraint::getAttachmentPair ( ) const

Returns: the attachment pair if this constraint supports it - otherwise 0

◆ getBodyAt() [1/2]

agx::RigidBody * agx::Constraint::getBodyAt ( agx::UInt i )

Returns: rigid body at index i (the bodies are ordered as they were added)

◆ getBodyAt() [2/2]

const agx::RigidBody * agx::Constraint::getBodyAt ( agx::UInt i ) const

Returns: rigid body at index i (the bodies are ordered as they were added)

◆ getCompliance()

virtual agx::Real agx::Constraint::getCompliance ( agx::UInt dof ) const

virtual

Get the compliance for DOF i.

Note that indices > number of DOF for this constraint is not defined, so compliance of index 0 will be returned.

Parameters

dof	- index of the requested DOF

Returns: compliance for the given DOF

Reimplemented in agx::DistanceJoint, agx::SingleControllerConstraint1DOF, and agxWire::EyeNodeArea.

◆ getCurrentForce()

agx::Real agx::Constraint::getCurrentForce ( agx::UInt dof ) const

Consider using getLastForce instead.

This method returns the magnitude of the force in a given degree of freedom (DOF). Enabled controllers in the given DOF will NOT be included, agx::ElementaryConstraint::getCurrentForce has to be used for that.

Returns: the current force magnitude (i.e., the force magnitude last time step) in given DOF >= 0 && <= NUM_DOFS

See also: setEnableComputeForces and getLastForce

◆ getDamping()

virtual Real agx::Constraint::getDamping ( agx::UInt dof ) const

virtual

Get the damping for DOF dof.

Note that indices > number of DOF for this constraint is not defined, so damping of index 0 will be returned.

Parameters

dof	- index of the requested DOF

Returns: damping for the given DOF

Reimplemented in agx::DistanceJoint, agx::SingleControllerConstraint1DOF, and agxWire::EyeNodeArea.

◆ getElasticity()

virtual agx::Real agx::Constraint::getElasticity ( agx::UInt dof ) const

virtual

Get the elasticity for DOF i.

Note that indices > number of DOF for this constraint is not defined, so elasticity of index 0 will be returned.

Parameters

dof	- index of the requested DOF

Returns: elasticity for the given DOF

◆ getElementaryConstraint()

agx::ElementaryConstraint * agx::Constraint::getElementaryConstraint ( const agx::UInt index ) const

Parameters

index - index of the elementary constraint

Returns: elementary constraint given index

◆ getElementaryConstraintGivenName()

agx::ElementaryConstraint * agx::Constraint::getElementaryConstraintGivenName ( const agx::Name & name ) const

Find elementary constraint given name.

Parameters

name	- name of the elementary constraint

Returns: elementary constraint given name

◆ getEnable()

agx::Bool agx::Constraint::getEnable ( ) const

Returns: true if the constraint is enabled.

◆ getEnableComputeForces()

agx::Bool agx::Constraint::getEnableComputeForces ( ) const

Returns: true if this constraint has been enabled to compute the forces applied to its bodies - otherwise false

◆ getEnableDebugRendering()

bool agx::Constraint::getEnableDebugRendering ( ) const

Returns: true if this constraints debug rendering is enabled - otherwise false

◆ getEnableLinearization()

bool agx::Constraint::getEnableLinearization ( ) const

Returns: true if constraint compliance linearization is enabled for this constraint. False otherwise.

◆ getEntityId()

agx::UInt32 agx::Constraint::getEntityId ( ) const

Returns: the entity id of the constraint

◆ getForceRange()

agx::RangeReal agx::Constraint::getForceRange ( agx::UInt dof = 0 ) const

Get the force range for DOF dof.

Note: Indices > number of DOF for this constraint is not defined, an infinite force range will be returned.; For controllers (secondary constraints), use their specific method, e.g., constraint->getMotor1D()->getForceRange().

Parameters

dof	- index of the requested DOF

◆ getLastForce() [1/2]

agx::Bool agx::Constraint::getLastForce	(	agx::UInt	bodyIndex,
		agx::Vec3 &	retForce,
		agx::Vec3 &	retTorque,
		agx::Bool	giveForceAtCm = `false`
	)		const

If 'compute forces' is enabled, returns the last force and torque applied by this constraint on the body with bodyIndex.

The force is given in world coordinates and is the one applied at the anchor position of this constraint.

The result includes force and torque from this constraint including all enabled controllers (e.g., motors, locks, ranges).

See also: setEnableComputeForces

Parameters

bodyIndex	- index of body, if number of bodies = 1 and bodyIndex = 1, the force and torque applied to "the world body" is returned
retForce	- the force applied by this constraint on body at `bodyIndex` last solve
retTorque	- the torque applied by this constraint on body at `bodyIndex` last solve
giveForceAtCm	- this parameter affects the resulting torque. The default behavior (giveForceAtCm = false) calculates the force applied by this constraint at the anchor position. Letting giveForceAtCm = true, the force will be applied at center of mass, affecting the torque as \( T_{new} = T - r \times F \) where r is the vector from the anchor point to the center of mass of the body.

Returns: true if resulting force and torque was written to retForce and retTorque - otherwise false

◆ getLastForce() [2/2]

agx::Bool agx::Constraint::getLastForce	(	const agx::RigidBody *	rb,
		agx::Vec3 &	retForce,
		agx::Vec3 &	retTorque,
		agx::Bool	giveForceAtCm = `false`
	)		const

If 'compute forces' is enabled, returns the last force and torque applied by this constraint on the body rb.

The force is given in world coordinates and is the one applied at the anchor position of this constraint.

The result includes force and torque from this constraint including all enabled controllers (e.g., motors, locks, ranges).

See also: setEnableComputeForces

Parameters

rb	- body in this constraint. If this constraint is attached in world, nullptr can be used.
retForce	- the force applied by this constraint on body `rb` at the last solve
retTorque	- the torque applied by this constraint on body `rb` at the last solve
giveForceAtCm	- this parameter affects the resulting torque. The default behavior (giveForceAtCm = false) calculates the force applied by this constraint at the anchor position. Letting giveForceAtCm = true, the force will be applied at center of mass, affecting the torque as \(T_{new} = T - r \times F\) where r is the vector from the anchor point to the center of mass of the body.

Returns: true if resulting force and torque was written to retForce and retTorque - otherwise false

◆ getLastLocalForce() [1/2]

agx::Bool agx::Constraint::getLastLocalForce	(	agx::UInt	bodyIndex,
		agx::Vec3 &	retForce,
		agx::Vec3 &	retTorque,
		agx::Bool	giveForceAtCm = `false`
	)		const

If 'compute forces' is enabled, returns the last force and torque applied by this constraint on the body with bodyIndex.

The force is given in the frame of the constraint.

The result includes force and torque from this constraint including all enabled controllers (e.g., motors, locks, ranges).

See also: setEnableComputeForces

Parameters

bodyIndex	- index of body, if number of bodies = 1 and bodyIndex = 1, the force and torque applied to "the world body" is returned
retForce	- the force applied by this constraint on body at `bodyIndex` last solve
retTorque	- the torque applied by this constraint on body at `bodyIndex` last solve
giveForceAtCm	- this parameter affects the resulting torque. The default behavior (giveForceAtCm = false) calculates the force applied by this constraint at the anchor position. Letting giveForceAtCm = true, the force will be applied at center of mass, affecting the torque as \(T_{new} = T - r \times F\) where r is the vector from the anchor point to the center of mass of the body.

Returns: true if resulting force and torque was written to retForce and retTorque - otherwise false

◆ getLastLocalForce() [2/2]

agx::Bool agx::Constraint::getLastLocalForce	(	const agx::RigidBody *	rb,
		agx::Vec3 &	retForce,
		agx::Vec3 &	retTorque,
		agx::Bool	giveForceAtCm = `false`
	)		const

If 'compute forces' is enabled, returns the last force and torque applied by this constraint on the body rb.

The force is given in the frame of the constraint.

The result includes force and torque from this constraint including all enabled controllers (e.g., motors, locks, ranges).

See also: setEnableComputeForces

Parameters

rb	- body in this constraint. If this constraint is attached in world, nullptr can be used.
retForce	- the force applied by this constraint on body `rb` at the last solve
retTorque	- the torque applied by this constraint on body `rb` at the last solve
giveForceAtCm	- this parameter affects the resulting torque. The default behavior (giveForceAtCm = false) calculates the force applied by this constraint at the anchor position. Letting giveForceAtCm = true, the force will be applied at center of mass, affecting the torque as \(T_{new} = T - r \times F\) where r is the vector from the anchor point to the center of mass of the body.

Returns: true if resulting force and torque was written to retForce and retTorque - otherwise false

◆ getNumBodies()

agx::UInt agx::Constraint::getNumBodies ( ) const

returns the number of bodies involved

◆ getNumDOF()

virtual int agx::Constraint::getNumDOF ( ) const

pure virtual

Returns: the number of DOF for this constraint, not including secondary constraints. -1 if num DOF is undefined for the constraint.

Implemented in agx::AngularLockJoint, agx::BallJoint, agx::CylindricalJoint, agx::DistanceJoint, agx::Dot1Joint, agx::GenericConstraint, agx::Hinge, agx::IGenericConstraint, agx::LockJoint, agx::PlaneJoint, agx::Prismatic, agx::PrismaticUniversalJoint, agx::SingleControllerConstraint1DOF, agx::SlackCylindricalJoint, agx::SlackHingeJoint, agx::SlackLockJoint, agx::SlackPrismaticJoint, agx::SplineJoint, agx::SwingTwistLock, agx::UniversalJoint, agxDriveTrain::ElectricMotorConstraint, agxDriveTrain::VelocityConstraint, agxUtil::ConstraintHolder, agxVehicle::Steering, agxVehicle::Ackermann, agxVehicle::WheelJoint, agxWire::EyeNodeArea, and agx::AngularJointBase.

◆ getNumElementaryConstraints()

agx::UInt agx::Constraint::getNumElementaryConstraints ( ) const

Returns: the number of elementary constraints

◆ getNumSecondaryConstraints()

agx::UInt agx::Constraint::getNumSecondaryConstraints ( ) const

Returns: the number of secondary constraints

◆ getRegularizationParameters() [1/2]

virtual agx::RegularizationParameters * agx::Constraint::getRegularizationParameters ( agx::UInt i )

virtual

Returns: a pointer to the regularization parameter object of this constraint for the i:th DOF

Reimplemented in agx::DistanceJoint, and agx::SingleControllerConstraint1DOF.

◆ getRegularizationParameters() [2/2]

virtual const agx::RegularizationParameters * agx::Constraint::getRegularizationParameters ( agx::UInt i ) const

virtual

Returns: a pointer to the regularization parameter object of this constraint for the i:th DOF

Reimplemented in agx::DistanceJoint, and agx::SingleControllerConstraint1DOF.

◆ getRep() [1/2]

ConstraintImplementation * agx::Constraint::getRep ( )

inline

Returns: a pointer to the internal constraint implementation

Definition at line 908 of file Constraint.h.

Referenced by agxSDK::MergeSplitHandler::getProperties().

◆ getRep() [2/2]

const ConstraintImplementation * agx::Constraint::getRep ( ) const

inline

Returns: a pointer to the internal constraint implementation

Definition at line 913 of file Constraint.h.

◆ getSecondaryConstraint()

agx::ElementaryConstraint * agx::Constraint::getSecondaryConstraint ( const agx::UInt index ) const

Parameters

index - index of the secondary constraint

Returns: secondary constraint given index

◆ getSecondaryConstraintGivenName()

agx::ElementaryConstraint * agx::Constraint::getSecondaryConstraintGivenName ( const agx::Name & name ) const

Find secondary constraint given name.

Parameters

name	- name of the elementary constraint

Returns: elementary constraint given name

◆ getSolveType()

agx::Constraint::SolveType agx::Constraint::getSolveType ( ) const

Returns: the current solve type for this constraint

Note: Solve type is ignored by iterative solvers.

◆ getValid()

agx::Bool agx::Constraint::getValid ( ) const

Returns: true if this constraints is valid It is possible for a constraint to declare itself invalid during a simulation. This may happen if for example a body that is included in this constraint is removed from the simulation.

◆ isEnabled()

agx::Bool agx::Constraint::isEnabled ( ) const

Returns: true if the constraint is enabled.

◆ postSystemCallback()

virtual void agx::Constraint::postSystemCallback ( agx::DynamicsSystem * )

overrideprotectedvirtual

Called after all post step events, after solve.

Reimplemented from agx::Interaction.

◆ preSystemCallback()

virtual void agx::Constraint::preSystemCallback ( agx::DynamicsSystem * )

overrideprotectedvirtual

Called after all pre step events, before solve.

Reimplemented from agx::Interaction.

◆ rebind()

virtual agx::Bool agx::Constraint::rebind ( )

virtual

Rebind this constraint, i.e., use current state as the initial configuration.

Returns: true if the rebinding is successful - false otherwise

◆ removeElementaryConstraint() [1/2]

agx::Bool agx::Constraint::removeElementaryConstraint ( agx::ElementaryConstraint * elementaryConstraint )

Remove elementary constraint.

Parameters

elementaryConstraint - elementary constraint to remove

Returns: true if removed

◆ removeElementaryConstraint() [2/2]

agx::Bool agx::Constraint::removeElementaryConstraint ( const agx::Name & name )

Remove elementary constraint.

Parameters

name	- name of the elementary constraint to remove

Returns: true if removed

◆ removeNotification()

virtual void agx::Constraint::removeNotification ( )

overrideprotectedvirtual

Called when removed from a simulation.

Reimplemented from agx::Interaction.

Reimplemented in agx::IGenericConstraint.

◆ removeSecondaryConstraint() [1/2]

agx::Bool agx::Constraint::removeSecondaryConstraint ( agx::ElementaryConstraint * secondaryConstraint )

Remove secondary constraint.

Parameters

secondaryConstraint - secondary constraint to remove

Returns: true if removed

◆ removeSecondaryConstraint() [2/2]

agx::Bool agx::Constraint::removeSecondaryConstraint ( const agx::Name & name )

Remove secondary constraint.

Parameters

name	- name of the secondary constraint to remove

Returns: true if removed

◆ render()

virtual void agx::Constraint::render	(	class agxRender::RenderManager *	mgr,
		float	scale
	)		const

pure virtual

Inherited method of how to render this constraint into DebugRenderer.

Implemented in agxDriveTrain::ElectricMotorConstraint, agxDriveTrain::VelocityConstraint, agx::AngularJointBase, agx::BallJoint, agx::CylindricalJoint, agx::DistanceJoint, agx::Dot1Joint, agx::LockJoint, agx::Prismatic, agx::SingleControllerConstraint1DOF, agx::SlackCylindricalJoint, agx::SlackLockJoint, agx::SlackPrismaticJoint, agx::SwingTwistLock, agxWire::EyeNodeArea, agx::AngularLockJoint, agx::PlaneJoint, agxUtil::ConstraintHolder, agx::GenericConstraint, agx::IGenericConstraint, agx::Hinge, agx::SlackHingeJoint, agxVehicle::Steering, agxVehicle::WheelJoint, and agx::SplineJoint.

◆ restore()

void agx::Constraint::restore ( agxStream::InputArchive & in )

override

◆ restoreLightData()

virtual void agx::Constraint::restoreLightData ( agxStream::StorageStream & str )

overridevirtual

◆ setCompliance() [1/2]

void agx::Constraint::setCompliance ( agx::Real compliance )

Set the compliance of this constraint for all DOFs.

Parameters

compliance - value of compliance

◆ setCompliance() [2/2]

virtual void agx::Constraint::setCompliance	(	agx::Real	compliance,
		agx::Int	dof
	)

virtual

Set the compliance of this constraint for the i:th DOF.

Parameters

compliance	- value of compliance
dof	- index of the requested DOF (-1 indicates all)

Reimplemented in agxWire::EyeNodeArea, agx::DistanceJoint, and agx::SingleControllerConstraint1DOF.

Referenced by agxModel::BeamStiffnessDamping::apply().

◆ setDamping() [1/2]

void agx::Constraint::setDamping ( agx::Real damping )

Set the damping of this constraint for all DOFs.

Parameters

damping - value of damping

◆ setDamping() [2/2]

virtual void agx::Constraint::setDamping	(	agx::Real	damping,
		agx::Int	dof
	)

virtual

Set the damping of this constraint for the i:th DOF.

Parameters

damping	- value of damping
dof	- index of the requested DOF (-1 indicates all).

Reimplemented in agxWire::EyeNodeArea, agx::DistanceJoint, and agx::SingleControllerConstraint1DOF.

Referenced by agxModel::BeamStiffnessDamping::apply().

◆ setElasticity() [1/2]

virtual void agx::Constraint::setElasticity ( agx::Real elasticity )

virtual

Set the elasticity of this constraint for all DOFs.

Parameters

elasticity - value of elasticity

◆ setElasticity() [2/2]

virtual void agx::Constraint::setElasticity	(	agx::Real	elasticity,
		agx::Int	dof
	)

virtual

Set the elasticity of this constraint for the i:th DOF.

Elasticity is 1 / compliance.

Parameters

elasticity	- value of elasticity
dof	- index of the requested DOF (-1 indicates all)

◆ setEnable()

virtual void agx::Constraint::setEnable ( agx::Bool enable )

virtual

Enable/disable a constraint.

Parameters

enable - If true the constraint will be enabled.

◆ setEnableComputeForces()

void agx::Constraint::setEnableComputeForces ( agx::Bool enable )

Enable (or disable) computation of the forces applied to the dynamic bodies in this constraint.

Matrix-vector operation to compute the forces after solve.

See also: getLastForce

Parameters

enable - true to enable, false to disable

Referenced by agxSDK::ConstraintLogListener::addConstraint().

◆ setEnableDebugRendering()

void agx::Constraint::setEnableDebugRendering ( agx::Bool enable )

Enable/disable debug rendering of this constraint.

◆ setEnableLinearization()

void agx::Constraint::setEnableLinearization ( bool enable )

Pass true to enable linearization of constraint compliance.

This makes constraint violation a linear function of the force or torque used to violate the constraint also for the elementary constraint types for which this isn't already the case, such as QuatLock. The effect of this is that the parameters sent to the solver by the constraint are tweaked to make the constrain more closely follow Hook's law.

Setting this to true has no effect on most constraints. It does have an effect on the rotational part of AngularLockJoint, LockJoint, and Prismatic.

When false, the default, the resulting violation of any QuatLock in the constraint is linear in quaternion space instead of degrees and radians.

◆ setForceRange() [1/3]

void agx::Constraint::setForceRange ( agx::RangeReal forceRange )

Assign force range for all DOF of the elementary constraints.

Note: Using this method will NOT change the force range of the controllers (secondary constraints), if present. Use their specific methods instead, e.g., constraint->getMotor1D()->setForceRange( fRange ).

Parameters

forceRange - value of force range for all elementary DOFs

◆ setForceRange() [2/3]

void agx::Constraint::setForceRange	(	agx::RangeReal	forceRange,
		agx::Int	dof
	)

Assign force range, of an elementary constraint, for a given DOF.

Note: For controllers (secondary constraints), use their specific methods, e.g., constraint->getMotor1D()->setForceRange( fRange ).

Parameters

forceRange	- value of force range for the given DOF
dof	- index of the DOF (-1 indicates all)

◆ setForceRange() [3/3]

void agx::Constraint::setForceRange	(	agx::Real	lower,
		agx::Real	upper,
		agx::Int	dof
	)

Assign force range, of an elementary constraint, for a given DOF.

Note: For controllers (secondary constraints), use their specific methods, e.g., constraint->getMotor1D()->setForceRange( fLower, fUpper ).

Parameters

lower	- lower value of force range for the given DOF
upper	- lower value of force range for the given DOF
dof	- index of the DOF (-1 indicates all)

◆ setRep()

void agx::Constraint::setRep ( agx::ConstraintImplementation * _rep )

protected

◆ setSimulation()

virtual void agx::Constraint::setSimulation ( agxSDK::Simulation * simulation )

overrideprotectedvirtual

Assign simulation.

Be careful.

Reimplemented from agx::Interaction.

◆ setSolveType()

void agx::Constraint::setSolveType ( agx::Constraint::SolveType solveType )

Specify the solve type for this constraint.

Valid is DIRECT (default for non-iterative solvers), ITERATIVE or DIRECT_AND_ITERATIVE where DIRECT_AND_ITERATIVE means that this constraint will be solved both direct and iterative.

Parameters

solveType - new solve type for this constraint

Note: Solve type is ignored by iterative solvers.

◆ setSystem()

virtual void agx::Constraint::setSystem ( agx::DynamicsSystem * )

inlineprotectedvirtual

Definition at line 658 of file Constraint.h.

◆ store()

void agx::Constraint::store ( agxStream::OutputArchive & out ) const

override

◆ storeLightData()

virtual void agx::Constraint::storeLightData ( agxStream::StorageStream & str ) const

overridevirtual

Member Data Documentation

◆ m_implementation

agx::ConstraintImplementation* agx::Constraint::m_implementation

protected

Definition at line 677 of file Constraint.h.

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

Constraint.h

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ SolveType

Constructor & Destructor Documentation

◆ Constraint()

◆ ~Constraint()

Member Function Documentation

◆ addElementaryConstraint()

◆ addNotification()

◆ addSecondaryConstraint()

◆ AGXSTREAM_DECLARE_ABSTRACT_SERIALIZABLE()

◆ as() [1/2]

◆ as() [2/2]

◆ calculateCurrentViolation()

◆ calculateFramesFromBody() [1/2]

◆ calculateFramesFromBody() [2/2]

◆ calculateFramesFromWorld() [1/2]

◆ calculateFramesFromWorld() [2/2]

◆ calculateNumActiveRows()

◆ createFromBody() [1/2]

◆ createFromBody() [2/2]

◆ createFromWorld() [1/2]

◆ createFromWorld() [2/2]

◆ getAttachment() [1/2]

◆ getAttachment() [2/2]

◆ getAttachmentPair()

◆ getBodyAt() [1/2]

◆ getBodyAt() [2/2]

◆ getCompliance()

◆ getCurrentForce()

◆ getDamping()

◆ getElasticity()

◆ getElementaryConstraint()

◆ getElementaryConstraintGivenName()

◆ getEnable()

◆ getEnableComputeForces()

◆ getEnableDebugRendering()

◆ getEnableLinearization()

◆ getEntityId()

◆ getForceRange()

◆ getLastForce() [1/2]

◆ getLastForce() [2/2]

◆ getLastLocalForce() [1/2]

◆ getLastLocalForce() [2/2]

◆ getNumBodies()

◆ getNumDOF()

◆ getNumElementaryConstraints()

◆ getNumSecondaryConstraints()

◆ getRegularizationParameters() [1/2]

◆ getRegularizationParameters() [2/2]

◆ getRep() [1/2]

◆ getRep() [2/2]

◆ getSecondaryConstraint()

◆ getSecondaryConstraintGivenName()

◆ getSolveType()

◆ getValid()

◆ isEnabled()

◆ postSystemCallback()

◆ preSystemCallback()

◆ rebind()

◆ removeElementaryConstraint() [1/2]

◆ removeElementaryConstraint() [2/2]

◆ removeNotification()

◆ removeSecondaryConstraint() [1/2]

◆ removeSecondaryConstraint() [2/2]

◆ render()

◆ restore()

◆ restoreLightData()

◆ setCompliance() [1/2]

◆ setCompliance() [2/2]

◆ setDamping() [1/2]

◆ setDamping() [2/2]

◆ setElasticity() [1/2]

◆ setElasticity() [2/2]