Base class for all physics constraints. A constraint removes one or more degrees of freedom for a rigid body. More...

#include <Constraint.h>

Inheritance diagram for Constraint:

Public Member Functions
JPH_OVERRIDE_NEW_DELETE	Constraint (const ConstraintSettings &inSettings)
	Constructor.

virtual	~Constraint ()=default
	Virtual destructor.

virtual EConstraintType	GetType () const
	Get the type of a constraint.

virtual EConstraintSubType	GetSubType () const =0
	Get the sub type of a constraint.

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	NotifyShapeChanged (const BodyID &inBodyID, Vec3Arg inDeltaCOM)=0

virtual void	ResetWarmStart ()=0

virtual void	BuildIslands (uint32 inConstraintIndex, IslandBuilder &ioBuilder, BodyManager &inBodyManager)=0
	Link bodies that are connected by this constraint in the island builder.

virtual uint	BuildIslandSplits (LargeIslandSplitter &ioSplitter) const =0
	Link bodies that are connected by this constraint in the same split. Returns the split index.

virtual void	DrawConstraint (DebugRenderer *inRenderer) const =0

virtual void	DrawConstraintLimits (DebugRenderer *inRenderer) const

virtual void	DrawConstraintReferenceFrame (DebugRenderer *inRenderer) const

float	GetDrawConstraintSize () const
	Size of constraint when drawing it through the debug renderer.

void	SetDrawConstraintSize (float inSize)

virtual void	SaveState (StateRecorder &inStream) const
	Saving state for replay.

virtual void	RestoreState (StateRecorder &inStream)
	Restoring state for replay.

virtual Ref< ConstraintSettings >	GetConstraintSettings () const =0
	Debug function to convert a constraint to its settings, note that this will not save to which bodies the constraint is connected to.

Solver interface
virtual bool	IsActive () const

virtual void	SetupVelocityConstraint (float inDeltaTime)=0

virtual void	WarmStartVelocityConstraint (float inWarmStartImpulseRatio)=0

virtual bool	SolveVelocityConstraint (float inDeltaTime)=0

virtual bool	SolvePositionConstraint (float inDeltaTime, float inBaumgarte)=0

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

Protected Member Functions
void	ToConstraintSettings (ConstraintSettings &outSettings) const
	Helper function to copy settings back to constraint settings for this base class.

Protected Attributes
float	mDrawConstraintSize
	Size of constraint when drawing it through the debug renderer.

Protected Attributes inherited from RefTarget< Constraint >
atomic< uint32 >	mRefCount
	Current reference count.

Friends
class	ConstraintManager

Additional Inherited Members
Static Public Member Functions inherited from RefTarget< Constraint >
static int	sInternalGetRefCountOffset ()
	INTERNAL HELPER FUNCTION USED BY SERIALIZATION.

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

Base class for all physics constraints. A constraint removes one or more degrees of freedom for a rigid body.

Constructor & Destructor Documentation

◆ Constraint()

JPH_OVERRIDE_NEW_DELETE Constraint::Constraint ( const ConstraintSettings & inSettings )

inlineexplicit

Constructor.

◆ ~Constraint()

virtual Constraint::~Constraint ( )

virtualdefault

Virtual destructor.

Member Function Documentation

◆ BuildIslands()

virtual void Constraint::BuildIslands	(	uint32	inConstraintIndex,
		IslandBuilder &	ioBuilder,
		BodyManager &	inBodyManager )

pure virtual

Link bodies that are connected by this constraint in the island builder.

Implemented in TwoBodyConstraint, and VehicleConstraint.

◆ BuildIslandSplits()

virtual uint Constraint::BuildIslandSplits ( LargeIslandSplitter & ioSplitter ) const

pure virtual

Link bodies that are connected by this constraint in the same split. Returns the split index.

Implemented in TwoBodyConstraint, and VehicleConstraint.

◆ DrawConstraint()

virtual void Constraint::DrawConstraint ( DebugRenderer * inRenderer ) const

pure virtual

Implemented in ConeConstraint, DistanceConstraint, FixedConstraint, GearConstraint, HingeConstraint, PathConstraint, PointConstraint, PulleyConstraint, RackAndPinionConstraint, SixDOFConstraint, SliderConstraint, SwingTwistConstraint, and VehicleConstraint.

◆ DrawConstraintLimits()

virtual void Constraint::DrawConstraintLimits ( DebugRenderer * inRenderer ) const

inlinevirtual

Reimplemented in ConeConstraint, HingeConstraint, SixDOFConstraint, SliderConstraint, SwingTwistConstraint, and VehicleConstraint.

◆ DrawConstraintReferenceFrame()

virtual void Constraint::DrawConstraintReferenceFrame ( DebugRenderer * inRenderer ) const

inlinevirtual

Reimplemented in TwoBodyConstraint.

◆ GetConstraintPriority()

uint32 Constraint::GetConstraintPriority ( ) const

inline

Priority of the constraint when solving. Higher numbers have are more likely to be solved correctly. Note that if you want a deterministic simulation and you cannot guarantee the order in which constraints are added/removed, you can make the priority for all constraints unique to get a deterministic ordering.

◆ GetConstraintSettings()

virtual Ref< ConstraintSettings > Constraint::GetConstraintSettings ( ) const

pure virtual

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

Implemented in ConeConstraint, DistanceConstraint, FixedConstraint, GearConstraint, HingeConstraint, PathConstraint, PointConstraint, PulleyConstraint, RackAndPinionConstraint, SixDOFConstraint, SliderConstraint, SwingTwistConstraint, and VehicleConstraint.

◆ GetDrawConstraintSize()

float Constraint::GetDrawConstraintSize ( ) const

inline

Size of constraint when drawing it through the debug renderer.

◆ GetEnabled()

bool Constraint::GetEnabled ( ) const

inline

Test if a constraint is enabled.

◆ GetNumPositionStepsOverride()

uint Constraint::GetNumPositionStepsOverride ( ) const

inline

◆ GetNumVelocityStepsOverride()

uint Constraint::GetNumVelocityStepsOverride ( ) const

inline

◆ GetSubType()

virtual EConstraintSubType Constraint::GetSubType ( ) const

pure virtual

Get the sub type of a constraint.

Implemented in ConeConstraint, DistanceConstraint, FixedConstraint, GearConstraint, HingeConstraint, PathConstraint, PointConstraint, PulleyConstraint, RackAndPinionConstraint, SixDOFConstraint, SliderConstraint, SwingTwistConstraint, and VehicleConstraint.

◆ GetType()

virtual EConstraintType Constraint::GetType ( ) const

inlinevirtual

Get the type of a constraint.

Reimplemented in TwoBodyConstraint.

◆ GetUserData()

uint64 Constraint::GetUserData ( ) const

inline

Access to the user data, can be used for anything by the application.

◆ IsActive()

virtual bool Constraint::IsActive ( ) const

inlinevirtual

Reimplemented in PathConstraint, TwoBodyConstraint, and VehicleConstraint.

◆ NotifyShapeChanged()

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

pure virtual

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())

Implemented in ConeConstraint, DistanceConstraint, FixedConstraint, GearConstraint, HingeConstraint, PathConstraint, PointConstraint, PulleyConstraint, RackAndPinionConstraint, SixDOFConstraint, SliderConstraint, SwingTwistConstraint, and VehicleConstraint.

◆ ResetWarmStart()

virtual void Constraint::ResetWarmStart ( )

pure virtual

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).

Implemented in ConeConstraint, DistanceConstraint, FixedConstraint, GearConstraint, HingeConstraint, PathConstraint, PointConstraint, PulleyConstraint, RackAndPinionConstraint, SixDOFConstraint, SliderConstraint, SwingTwistConstraint, and VehicleConstraint.

◆ RestoreState()

void Constraint::RestoreState ( StateRecorder & inStream )

virtual

Restoring state for replay.

Reimplemented in ConeConstraint, DistanceConstraint, FixedConstraint, GearConstraint, HingeConstraint, PathConstraint, PointConstraint, PulleyConstraint, RackAndPinionConstraint, SixDOFConstraint, SliderConstraint, SwingTwistConstraint, and VehicleConstraint.

◆ SaveState()

void Constraint::SaveState ( StateRecorder & inStream ) const

virtual

Saving state for replay.

Reimplemented in ConeConstraint, DistanceConstraint, FixedConstraint, GearConstraint, HingeConstraint, PathConstraint, PointConstraint, PulleyConstraint, RackAndPinionConstraint, SixDOFConstraint, SliderConstraint, SwingTwistConstraint, and VehicleConstraint.

◆ SetConstraintPriority()

void Constraint::SetConstraintPriority ( uint32 inPriority )

inline

◆ SetDrawConstraintSize()

void Constraint::SetDrawConstraintSize ( float inSize )

inline

◆ SetEnabled()

void Constraint::SetEnabled ( bool inEnabled )

inline

Enable / disable this constraint. This can e.g. be used to implement a breakable constraint by detecting that the constraint impulse (see e.g. PointConstraint::GetTotalLambdaPosition) went over a certain limit and then disabling the constraint. Note that although a disabled constraint will not affect the simulation in any way anymore, it does incur some processing overhead. Alternatively you can remove a constraint from the constraint manager (which may be more costly if you want to disable the constraint for a short while).

◆ SetNumPositionStepsOverride()

void Constraint::SetNumPositionStepsOverride ( uint inN )

inline

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.

◆ SetNumVelocityStepsOverride()

void Constraint::SetNumVelocityStepsOverride ( uint inN )

inline

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.

◆ SetupVelocityConstraint()

virtual void Constraint::SetupVelocityConstraint ( float inDeltaTime )

pure virtual

Implemented in ConeConstraint, DistanceConstraint, FixedConstraint, GearConstraint, HingeConstraint, PathConstraint, PointConstraint, PulleyConstraint, RackAndPinionConstraint, SixDOFConstraint, SliderConstraint, SwingTwistConstraint, and VehicleConstraint.

◆ SetUserData()

void Constraint::SetUserData ( uint64 inUserData )

inline

◆ SolvePositionConstraint()

virtual bool Constraint::SolvePositionConstraint	(	float	inDeltaTime,
		float	inBaumgarte )

pure virtual

Implemented in ConeConstraint, DistanceConstraint, FixedConstraint, GearConstraint, HingeConstraint, PathConstraint, PointConstraint, PulleyConstraint, RackAndPinionConstraint, SixDOFConstraint, SliderConstraint, SwingTwistConstraint, and VehicleConstraint.

◆ SolveVelocityConstraint()

virtual bool Constraint::SolveVelocityConstraint ( float inDeltaTime )

pure virtual

Implemented in ConeConstraint, DistanceConstraint, FixedConstraint, GearConstraint, HingeConstraint, PathConstraint, PointConstraint, PulleyConstraint, RackAndPinionConstraint, SixDOFConstraint, SliderConstraint, SwingTwistConstraint, and VehicleConstraint.

◆ ToConstraintSettings()

void Constraint::ToConstraintSettings ( ConstraintSettings & outSettings ) const

protected

Helper function to copy settings back to constraint settings for this base class.

◆ WarmStartVelocityConstraint()

virtual void Constraint::WarmStartVelocityConstraint ( float inWarmStartImpulseRatio )

pure virtual

Implemented in ConeConstraint, DistanceConstraint, FixedConstraint, GearConstraint, HingeConstraint, PathConstraint, PointConstraint, PulleyConstraint, RackAndPinionConstraint, SixDOFConstraint, SliderConstraint, SwingTwistConstraint, and VehicleConstraint.

Friends And Related Symbol Documentation

◆ ConstraintManager

friend class ConstraintManager

friend

Member Data Documentation

◆ mDrawConstraintSize

float Constraint::mDrawConstraintSize

protected

Size of constraint when drawing it through the debug renderer.

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

Jolt/Physics/Constraints/Constraint.h
Jolt/Physics/Constraints/Constraint.cpp

Public Member Functions

Protected Member Functions

Protected Attributes

Friends

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Constraint()

◆ ~Constraint()

Member Function Documentation

◆ BuildIslands()

◆ BuildIslandSplits()

◆ DrawConstraint()

◆ DrawConstraintLimits()

◆ DrawConstraintReferenceFrame()

◆ GetConstraintPriority()

◆ GetConstraintSettings()

◆ GetDrawConstraintSize()

◆ GetEnabled()

◆ GetNumPositionStepsOverride()

◆ GetNumVelocityStepsOverride()

◆ GetSubType()

◆ GetType()

◆ GetUserData()

◆ IsActive()

◆ NotifyShapeChanged()

◆ ResetWarmStart()

◆ RestoreState()

◆ SaveState()

◆ SetConstraintPriority()

◆ SetDrawConstraintSize()

◆ SetEnabled()

◆ SetNumPositionStepsOverride()

◆ SetNumVelocityStepsOverride()

◆ SetupVelocityConstraint()

◆ SetUserData()

◆ SolvePositionConstraint()

◆ SolveVelocityConstraint()

◆ ToConstraintSettings()

◆ WarmStartVelocityConstraint()

Friends And Related Symbol Documentation

◆ ConstraintManager

Member Data Documentation

◆ mDrawConstraintSize