PathConstraint Class Reference

Path constraint, used to constrain the degrees of freedom between two bodies to a path. More...

#include <PathConstraint.h>

Inheritance diagram for PathConstraint:

Public Member Functions
JPH_OVERRIDE_NEW_DELETE	PathConstraint (Body &inBody1, Body &inBody2, const PathConstraintSettings &inSettings)
	Construct point constraint.
virtual EConstraintSubType	GetSubType () const override
	Get the sub type of a constraint.
virtual void	NotifyShapeChanged (const BodyID &inBodyID, Vec3Arg inDeltaCOM) override
virtual void	SetupVelocityConstraint (float inDeltaTime) override
virtual void	ResetWarmStart () override
virtual void	WarmStartVelocityConstraint (float inWarmStartImpulseRatio) override
virtual bool	SolveVelocityConstraint (float inDeltaTime) override
virtual bool	SolvePositionConstraint (float inDeltaTime, float inBaumgarte) override
virtual void	DrawConstraint (DebugRenderer *inRenderer) const override
virtual void	SaveState (StateRecorder &inStream) const override
	Saving state for replay.
virtual void	RestoreState (StateRecorder &inStream) override
	Restoring state for replay.
virtual bool	IsActive () const override
	Solver interface.
virtual Ref< ConstraintSettings >	GetConstraintSettings () const override
	Debug function to convert a constraint to its settings, note that this will not save to which bodies the constraint is connected to.
virtual Mat44	GetConstraintToBody1Matrix () const override
	Calculates the transform that transforms from constraint space to body 1 space. The first column of the matrix is the primary constraint axis (e.g. the hinge axis / slider direction), second column the secondary etc.
virtual Mat44	GetConstraintToBody2Matrix () const override
	Calculates the transform that transforms from constraint space to body 2 space. The first column of the matrix is the primary constraint axis (e.g. the hinge axis / slider direction), second column the secondary etc.
void	SetPath (const PathConstraintPath *inPath, float inPathFraction)
	Update the path for this constraint.
const PathConstraintPath *	GetPath () const
	Access to the current path.
float	GetPathFraction () const
	Access to the current fraction along the path e [0, GetPath()->GetMaxPathFraction()].
void	SetMaxFrictionForce (float inFrictionForce)
	Friction control.
float	GetMaxFrictionForce () const
MotorSettings &	GetPositionMotorSettings ()
	Position motor settings.
const MotorSettings &	GetPositionMotorSettings () const
void	SetPositionMotorState (EMotorState inState)
EMotorState	GetPositionMotorState () const
void	SetTargetVelocity (float inVelocity)
float	GetTargetVelocity () const
void	SetTargetPathFraction (float inFraction)
float	GetTargetPathFraction () const
Public Member Functions inherited from TwoBodyConstraint
JPH_OVERRIDE_NEW_DELETE	TwoBodyConstraint (Body &inBody1, Body &inBody2, const TwoBodyConstraintSettings &inSettings)
	Constructor.
virtual EConstraintType	GetType () const override
	Get the type of a constraint.
virtual void	DrawConstraintReferenceFrame (DebugRenderer *inRenderer) const override
Body *	GetBody1 () const
	Access to the connected bodies.
Body *	GetBody2 () const
virtual void	BuildIslands (uint32 inConstraintIndex, IslandBuilder &ioBuilder, BodyManager &inBodyManager) override
	Link bodies that are connected by this constraint in the island builder.
virtual uint	BuildIslandSplits (LargeIslandSplitter &ioSplitter) const override
	Link bodies that are connected by this constraint in the same split. Returns the split index.
Public Member Functions inherited from Constraint
JPH_OVERRIDE_NEW_DELETE	Constraint (const ConstraintSettings &inSettings)
	Constructor.
virtual	~Constraint ()=default
	Virtual destructor.
uint32	GetConstraintPriority () const
void	SetConstraintPriority (uint32 inPriority)
void	SetNumVelocityStepsOverride (uint inN)
	Used only when the constraint is active. Override for the number of solver velocity iterations to run, 0 means use the default in PhysicsSettings::mNumVelocitySteps. The number of iterations to use is the max of all contacts and constraints in the island.
uint	GetNumVelocityStepsOverride () const
void	SetNumPositionStepsOverride (uint inN)
	Used only when the constraint is active. Override for the number of solver position iterations to run, 0 means use the default in PhysicsSettings::mNumPositionSteps. The number of iterations to use is the max of all contacts and constraints in the island.
uint	GetNumPositionStepsOverride () const
void	SetEnabled (bool inEnabled)
bool	GetEnabled () const
	Test if a constraint is enabled.
uint64	GetUserData () const
	Access to the user data, can be used for anything by the application.
void	SetUserData (uint64 inUserData)
virtual void	DrawConstraintLimits (DebugRenderer *inRenderer) const
float	GetDrawConstraintSize () const
	Size of constraint when drawing it through the debug renderer.
void	SetDrawConstraintSize (float inSize)
Public Member Functions inherited from RefTarget< Constraint >
	RefTarget ()=default
	Constructor.
	RefTarget (const RefTarget &)
	~RefTarget ()
	assert no one is referencing us
void	SetEmbedded () const
RefTarget &	operator= (const RefTarget &)
	Assignment operator.
uint32	GetRefCount () const
	Get current refcount of this object.
void	AddRef () const
	Add or release a reference to this object.
void	Release () const
Public Member Functions inherited from NonCopyable
	NonCopyable ()=default
	NonCopyable (const NonCopyable &)=delete
void	operator= (const NonCopyable &)=delete

Get Lagrange multiplier from last physics update (the linear/angular impulse applied to satisfy the constraint)
Vector< 2 >	GetTotalLambdaPosition () const
float	GetTotalLambdaPositionLimits () const
float	GetTotalLambdaMotor () const
Vector< 2 >	GetTotalLambdaRotationHinge () const
Vec3	GetTotalLambdaRotation () const

Additional Inherited Members
Static Public Member Functions inherited from RefTarget< Constraint >
static int	sInternalGetRefCountOffset ()
	INTERNAL HELPER FUNCTION USED BY SERIALIZATION.
Protected Member Functions inherited from Constraint
void	ToConstraintSettings (ConstraintSettings &outSettings) const
	Helper function to copy settings back to constraint settings for this base class.
Protected Attributes inherited from TwoBodyConstraint
Body *	mBody1
	The two bodies involved.
Body *	mBody2
Protected Attributes inherited from Constraint
float	mDrawConstraintSize
	Size of constraint when drawing it through the debug renderer.
Protected Attributes inherited from RefTarget< Constraint >
atomic< uint32 >	mRefCount
	Current reference count.
Static Protected Attributes inherited from RefTarget< Constraint >
static constexpr uint32	cEmbedded
	A large value that gets added to the refcount to mark the object as embedded.

Detailed Description

Path constraint, used to constrain the degrees of freedom between two bodies to a path.

Constructor & Destructor Documentation

PathConstraint()

PathConstraint::PathConstraint	(	Body &	inBody1,
		Body &	inBody2,
		const PathConstraintSettings &	inSettings )

Construct point constraint.

Member Function Documentation

DrawConstraint()

void PathConstraint::DrawConstraint ( DebugRenderer * inRenderer ) const

overridevirtual

Implements Constraint.

GetConstraintSettings()

Ref< ConstraintSettings > PathConstraint::GetConstraintSettings ( ) const

overridevirtual

Debug function to convert a constraint to its settings, note that this will not save to which bodies the constraint is connected to.

Implements Constraint.

GetConstraintToBody1Matrix()

virtual Mat44 PathConstraint::GetConstraintToBody1Matrix ( ) const

inlineoverridevirtual

Calculates the transform that transforms from constraint space to body 1 space. The first column of the matrix is the primary constraint axis (e.g. the hinge axis / slider direction), second column the secondary etc.

Implements TwoBodyConstraint.

GetConstraintToBody2Matrix()

virtual Mat44 PathConstraint::GetConstraintToBody2Matrix ( ) const

inlineoverridevirtual

Calculates the transform that transforms from constraint space to body 2 space. The first column of the matrix is the primary constraint axis (e.g. the hinge axis / slider direction), second column the secondary etc.

Implements TwoBodyConstraint.

GetMaxFrictionForce()

float PathConstraint::GetMaxFrictionForce ( ) const

inline

GetPath()

const PathConstraintPath * PathConstraint::GetPath ( ) const

inline

Access to the current path.

GetPathFraction()

float PathConstraint::GetPathFraction ( ) const

inline

Access to the current fraction along the path e [0, GetPath()->GetMaxPathFraction()].

GetPositionMotorSettings() [1/2]

MotorSettings & PathConstraint::GetPositionMotorSettings ( )

inline

Position motor settings.

GetPositionMotorSettings() [2/2]

const MotorSettings & PathConstraint::GetPositionMotorSettings ( ) const

inline

GetPositionMotorState()

EMotorState PathConstraint::GetPositionMotorState ( ) const

inline

GetSubType()

virtual EConstraintSubType PathConstraint::GetSubType ( ) const

inlineoverridevirtual

Get the sub type of a constraint.

Implements Constraint.

GetTargetPathFraction()

float PathConstraint::GetTargetPathFraction ( ) const

inline

GetTargetVelocity()

float PathConstraint::GetTargetVelocity ( ) const

inline

GetTotalLambdaMotor()

float PathConstraint::GetTotalLambdaMotor ( ) const

inline

GetTotalLambdaPosition()

Vector< 2 > PathConstraint::GetTotalLambdaPosition ( ) const

inline

GetTotalLambdaPositionLimits()

float PathConstraint::GetTotalLambdaPositionLimits ( ) const

inline

GetTotalLambdaRotation()

Vec3 PathConstraint::GetTotalLambdaRotation ( ) const

inline

GetTotalLambdaRotationHinge()

Vector< 2 > PathConstraint::GetTotalLambdaRotationHinge ( ) const

inline

IsActive()

virtual bool PathConstraint::IsActive ( ) const

inlineoverridevirtual

Solver interface.

Reimplemented from TwoBodyConstraint.

NotifyShapeChanged()

void PathConstraint::NotifyShapeChanged ( const BodyID & inBodyID, Vec3Arg inDeltaCOM )

overridevirtual

Notify the constraint that the shape of a body has changed and that its center of mass has moved by inDeltaCOM. Bodies don't know which constraints are connected to them so the user is responsible for notifying the relevant constraints when a body changes.

Parameters

inBodyID	ID of the body that has changed
inDeltaCOM	The delta of the center of mass of the body (shape->GetCenterOfMass() - shape_before_change->GetCenterOfMass())

Implements Constraint.

ResetWarmStart()

void PathConstraint::ResetWarmStart ( )

overridevirtual

Notify the system that the configuration of the bodies and/or constraint has changed enough so that the warm start impulses should not be applied the next frame. You can use this function for example when repositioning a ragdoll through Ragdoll::SetPose in such a way that the orientation of the bodies completely changes so that the previous frame impulses are no longer a good approximation of what the impulses will be in the next frame. Calling this function when there are no big changes will result in the constraints being much 'softer' than usual so they are more easily violated (e.g. a long chain of bodies might sag a bit if you call this every frame).

Implements Constraint.

RestoreState()

void PathConstraint::RestoreState ( StateRecorder & inStream )

overridevirtual

Restoring state for replay.

Reimplemented from Constraint.

SaveState()

void PathConstraint::SaveState ( StateRecorder & inStream ) const

overridevirtual

Saving state for replay.

Reimplemented from Constraint.

SetMaxFrictionForce()

void PathConstraint::SetMaxFrictionForce ( float inFrictionForce )

inline

Friction control.

SetPath()

void PathConstraint::SetPath	(	const PathConstraintPath *	inPath,
		float	inPathFraction )

Update the path for this constraint.

SetPositionMotorState()

void PathConstraint::SetPositionMotorState ( EMotorState inState )

inline

SetTargetPathFraction()

void PathConstraint::SetTargetPathFraction ( float inFraction )

inline

SetTargetVelocity()

void PathConstraint::SetTargetVelocity ( float inVelocity )

inline

SetupVelocityConstraint()

void PathConstraint::SetupVelocityConstraint ( float inDeltaTime )

overridevirtual

Implements Constraint.

SolvePositionConstraint()

bool PathConstraint::SolvePositionConstraint ( float inDeltaTime, float inBaumgarte )

overridevirtual

Implements Constraint.

SolveVelocityConstraint()

bool PathConstraint::SolveVelocityConstraint ( float inDeltaTime )

overridevirtual

Implements Constraint.

WarmStartVelocityConstraint()

void PathConstraint::WarmStartVelocityConstraint ( float inWarmStartImpulseRatio )

overridevirtual

Implements Constraint.

---

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

• Jolt/Physics/Constraints/PathConstraint.h
• Jolt/Physics/Constraints/PathConstraint.cpp