Produce collisions for a particle pair A FParticlePairMidPhase object is created for every particle pair whose bounds overlap. It is responsible for building a set of potentially colliding shape pairs and running collision detection on those pairs each tick. More...

#include <ParticlePairMidPhase.h>

Inheritance diagram for Chaos::FParticlePairMidPhase:

Classes
union	FFlags

Public Member Functions
	UE_NONCOPYABLE (FParticlePairMidPhase)

CHAOS_API	FParticlePairMidPhase (const EParticlePairMidPhaseType InMidPhaseType)

virtual CHAOS_API	~FParticlePairMidPhase ()

EParticlePairMidPhaseType	GetMidPhaseType () const

CHAOS_API void	Init (FGeometryParticleHandle InParticle0, FGeometryParticleHandle InParticle1, const Private::FCollisionParticlePairKey &InKey, const FCollisionContext &Context)
	Set up the midphase based on the ShapesArrays of the two particles Only intended to be called once right after constructor. We don't do this work in the constructor so that we can reduce the time that the lock is held when allocating new MidPhases.

FGeometryParticleHandle *	GetParticle0 () const

FGeometryParticleHandle *	GetParticle1 () const

const Private::FCollisionParticlePairKey &	GetKey () const

bool	IsValid () const

void	CachePrefetch ()

bool	IsUsedSince (const int32 Epoch) const
	Have we run collision detection since this Epoch (inclusive)

bool	IsSleeping () const
	Whether the particle pair is sleeping and therefore contacts should not be culled (they will be reused on wake)

CHAOS_API void	SetIsSleeping (const bool bInIsSleeping, const int32 CurrentEpoch)
	Update the sleeping state If this switches the state to Awake, it will reactivate any collisions between the particle pair that were active when they went to sleep.

CHAOS_API bool	IsInConstraintGraph () const

CHAOS_API void	DetachParticle (FGeometryParticleHandle *Particle)
	Destroy all collisions and prevent this midphasae from being used any more. Called when one of its particles is destoyed. It will be culled at the next Prune in the CollisionConstraintAllocator. We don't delete it immediately so that we don't have to remove it from either Particle's ParticleCollisions array (which is O(N) and unnecessary when the particles are being destroyed)

CHAOS_API void	Reset ()
	Delete all cached data and collisions. Should be called when a particle changes its shapes.

CHAOS_API void	ResetModifications ()

CHAOS_API void	GenerateCollisions (const FReal CullDistance, const FReal Dt, const FCollisionContext &Context)
	Create collision constraints for all colliding shape pairs.

CHAOS_API void	InjectCollision (const FPBDCollisionConstraint &Constraint, const FCollisionContext &Context)
	Copy a collision and activate it This is used by the Resim system to restore saved colisions. If there is already a matching constraint it will be overwritten, otherwise a new constraint will be added.

template<typename TLambda >
ECollisionVisitorResult	VisitCollisions (const TLambda &Visitor, const ECollisionVisitorFlags VisitFlags=ECollisionVisitorFlags::VisitDefault)
	Call a lambda on each active collision constraint This includes sleeping constraints, but skips constraints that are were not used on the last awake tick but are still kept around as an optimization.

template<typename TLambda >
ECollisionVisitorResult	VisitConstCollisions (const TLambda &Visitor, const ECollisionVisitorFlags VisitFlags=ECollisionVisitorFlags::VisitDefault) const
	Call a lambda on each active collision constraint.

int32	GetParticleCollisionsIndex (FGeometryParticleHandle *InParticle) const
	Cookie for use by FParticleCollisions.

void	SetParticleCollisionsIndex (FGeometryParticleHandle *InParticle, const int32 InIndex)
	Cookie for use by FParticleCollisions.

void	SetIsActive (bool bIsActive)
	By default midphases are active. If IsActive is set to false, this midphase will not generate a narrow phase.

void	SetCCDIsActive (bool bCCDIsActive)
	Override the CCD condition for this mid-phase. Used by the MidPhase modifier and gets reset every frame.

void	SetConvexOptimizationIsActive (bool bSetConvexOptimizationIsActive)

virtual void	SetConvexOptimizationIsActive (bool bSetConvexOptimizationIsActive, TFunctionRef< void(FPBDCollisionConstraint *)> OnDestroyingCollision)
	Override whether convex optimization if used this mid-phase. Used by the MidPhase modifier and gets reset every frame. NOTE: when this setting is changed, collisions will be destroyed so any external systems referencing them will need to drop their references.

bool	IsCCD () const

bool	IsCCDActive () const

Static Public Member Functions
static CHAOS_API EParticlePairMidPhaseType	CalculateMidPhaseType (FGeometryParticleHandle InParticle0, FGeometryParticleHandle InParticle1)

static CHAOS_API FParticlePairMidPhase *	Make (FGeometryParticleHandle InParticle0, FGeometryParticleHandle InParticle1)

Protected Member Functions
virtual void	ResetImpl ()=0

virtual void	BuildDetectorsImpl ()=0
	Build the list of potentially colliding shape pairs. This is all the shape pairs in the partilces' shapes arrays that pass the collision filter.

virtual int32	GenerateCollisionsImpl (const FRealSingle Dt, const FRealSingle CullDistance, const FVec3f &RelativeMovement, const FCollisionContext &Context)=0

virtual void	WakeCollisionsImpl (const int32 CurrentEpoch)=0

virtual void	InjectCollisionImpl (const FPBDCollisionConstraint &Constraint, const FCollisionContext &Context)=0

CHAOS_API bool	ShouldEnableCCDSweep (const FReal Dt)
	Decide whether we should have CCD enabled on this constraint.

CHAOS_API void	InitThresholds ()

Detailed Description

Produce collisions for a particle pair A FParticlePairMidPhase object is created for every particle pair whose bounds overlap. It is responsible for building a set of potentially colliding shape pairs and running collision detection on those pairs each tick.

Note: The lifetime of midphase objects is handled entirely by the CollisionConstraintAllocator. Nothing outside of the CollisionConstraintAllocator should hold a pointer to the detector or any constraints it creates for more than the duration of the tick.

See also: FShapePairParticlePairMidPhase, FGenericParticlePairMidPhase

Constructor & Destructor Documentation

◆ FParticlePairMidPhase()

Chaos::FParticlePairMidPhase::FParticlePairMidPhase ( const EParticlePairMidPhaseType InMidPhaseType )

◆ ~FParticlePairMidPhase()

Chaos::FParticlePairMidPhase::~FParticlePairMidPhase ( )

virtual

Member Function Documentation

◆ BuildDetectorsImpl()

virtual void Chaos::FParticlePairMidPhase::BuildDetectorsImpl ( )

protectedpure virtual

Build the list of potentially colliding shape pairs. This is all the shape pairs in the partilces' shapes arrays that pass the collision filter.

Implemented in Chaos::FShapePairParticlePairMidPhase, Chaos::FGenericParticlePairMidPhase, and Chaos::FSphereApproximationParticlePairMidPhase.

◆ CachePrefetch()

void Chaos::FParticlePairMidPhase::CachePrefetch ( )

inline

◆ CalculateMidPhaseType()

EParticlePairMidPhaseType Chaos::FParticlePairMidPhase::CalculateMidPhaseType	(	FGeometryParticleHandle *	InParticle0,
		FGeometryParticleHandle *	InParticle1
	)

static

◆ DetachParticle()

void Chaos::FParticlePairMidPhase::DetachParticle ( FGeometryParticleHandle * Particle )

Destroy all collisions and prevent this midphasae from being used any more. Called when one of its particles is destoyed. It will be culled at the next Prune in the CollisionConstraintAllocator. We don't delete it immediately so that we don't have to remove it from either Particle's ParticleCollisions array (which is O(N) and unnecessary when the particles are being destroyed)

◆ GenerateCollisions()

void Chaos::FParticlePairMidPhase::GenerateCollisions	(	const FReal	CullDistance,
		const FReal	Dt,
		const FCollisionContext &	Context
	)

Create collision constraints for all colliding shape pairs.

◆ GenerateCollisionsImpl()

virtual int32 Chaos::FParticlePairMidPhase::GenerateCollisionsImpl	(	const FRealSingle	Dt,
		const FRealSingle	CullDistance,
		const FVec3f &	RelativeMovement,
		const FCollisionContext &	Context
	)

protectedpure virtual

Implemented in Chaos::FShapePairParticlePairMidPhase, Chaos::FGenericParticlePairMidPhase, and Chaos::FSphereApproximationParticlePairMidPhase.

◆ GetKey()

const Private::FCollisionParticlePairKey & Chaos::FParticlePairMidPhase::GetKey ( ) const

inline

◆ GetMidPhaseType()

EParticlePairMidPhaseType Chaos::FParticlePairMidPhase::GetMidPhaseType ( ) const

inline

◆ GetParticle0()

FGeometryParticleHandle * Chaos::FParticlePairMidPhase::GetParticle0 ( ) const

inline

◆ GetParticle1()

FGeometryParticleHandle * Chaos::FParticlePairMidPhase::GetParticle1 ( ) const

inline

◆ GetParticleCollisionsIndex()

int32 Chaos::FParticlePairMidPhase::GetParticleCollisionsIndex ( FGeometryParticleHandle * InParticle ) const

inline

Cookie for use by FParticleCollisions.

◆ Init()

void Chaos::FParticlePairMidPhase::Init	(	FGeometryParticleHandle *	InParticle0,
		FGeometryParticleHandle *	InParticle1,
		const Private::FCollisionParticlePairKey &	InKey,
		const FCollisionContext &	Context
	)

Set up the midphase based on the ShapesArrays of the two particles Only intended to be called once right after constructor. We don't do this work in the constructor so that we can reduce the time that the lock is held when allocating new MidPhases.

◆ InitThresholds()

void Chaos::FParticlePairMidPhase::InitThresholds ( )

protected

◆ InjectCollision()

void Chaos::FParticlePairMidPhase::InjectCollision	(	const FPBDCollisionConstraint &	Constraint,
		const FCollisionContext &	Context
	)

Copy a collision and activate it This is used by the Resim system to restore saved colisions. If there is already a matching constraint it will be overwritten, otherwise a new constraint will be added.

◆ InjectCollisionImpl()

virtual void Chaos::FParticlePairMidPhase::InjectCollisionImpl	(	const FPBDCollisionConstraint &	Constraint,
		const FCollisionContext &	Context
	)

protectedpure virtual

Implemented in Chaos::FShapePairParticlePairMidPhase, Chaos::FGenericParticlePairMidPhase, and Chaos::FSphereApproximationParticlePairMidPhase.

◆ IsCCD()

bool Chaos::FParticlePairMidPhase::IsCCD ( ) const

inline

◆ IsCCDActive()

bool Chaos::FParticlePairMidPhase::IsCCDActive ( ) const

inline

◆ IsInConstraintGraph()

bool Chaos::FParticlePairMidPhase::IsInConstraintGraph ( ) const

◆ IsSleeping()

bool Chaos::FParticlePairMidPhase::IsSleeping ( ) const

inline

Whether the particle pair is sleeping and therefore contacts should not be culled (they will be reused on wake)

◆ IsUsedSince()

bool Chaos::FParticlePairMidPhase::IsUsedSince ( const int32 Epoch ) const

inline

Have we run collision detection since this Epoch (inclusive)

◆ IsValid()

bool Chaos::FParticlePairMidPhase::IsValid ( ) const

inline

◆ Make()

FParticlePairMidPhase * Chaos::FParticlePairMidPhase::Make	(	FGeometryParticleHandle *	InParticle0,
		FGeometryParticleHandle *	InParticle1
	)

static

◆ Reset()

void Chaos::FParticlePairMidPhase::Reset ( )

Delete all cached data and collisions. Should be called when a particle changes its shapes.

◆ ResetImpl()

virtual void Chaos::FParticlePairMidPhase::ResetImpl ( )

protectedpure virtual

Implemented in Chaos::FShapePairParticlePairMidPhase, Chaos::FGenericParticlePairMidPhase, and Chaos::FSphereApproximationParticlePairMidPhase.

◆ ResetModifications()

void Chaos::FParticlePairMidPhase::ResetModifications ( )

◆ SetCCDIsActive()

void Chaos::FParticlePairMidPhase::SetCCDIsActive ( bool bCCDIsActive )

inline

Override the CCD condition for this mid-phase. Used by the MidPhase modifier and gets reset every frame.

◆ SetConvexOptimizationIsActive() [1/2]

void Chaos::FParticlePairMidPhase::SetConvexOptimizationIsActive ( bool bSetConvexOptimizationIsActive )

inline

◆ SetConvexOptimizationIsActive() [2/2]

virtual void Chaos::FParticlePairMidPhase::SetConvexOptimizationIsActive	(	bool	bSetConvexOptimizationIsActive,
		TFunctionRef< void(FPBDCollisionConstraint *)>	OnDestroyingCollision
	)

inlinevirtual

Override whether convex optimization if used this mid-phase. Used by the MidPhase modifier and gets reset every frame. NOTE: when this setting is changed, collisions will be destroyed so any external systems referencing them will need to drop their references.

◆ SetIsActive()

void Chaos::FParticlePairMidPhase::SetIsActive ( bool bIsActive )

inline

By default midphases are active. If IsActive is set to false, this midphase will not generate a narrow phase.

◆ SetIsSleeping()

void Chaos::FParticlePairMidPhase::SetIsSleeping	(	const bool	bInIsSleeping,
		const int32	CurrentEpoch
	)

Update the sleeping state If this switches the state to Awake, it will reactivate any collisions between the particle pair that were active when they went to sleep.

◆ SetParticleCollisionsIndex()

void Chaos::FParticlePairMidPhase::SetParticleCollisionsIndex	(	FGeometryParticleHandle *	InParticle,
		const int32	InIndex
	)

inline

Cookie for use by FParticleCollisions.

◆ ShouldEnableCCDSweep()

bool Chaos::FParticlePairMidPhase::ShouldEnableCCDSweep ( const FReal Dt )

protected

Decide whether we should have CCD enabled on this constraint.

Returns: true if CCD is enabled this tick, false otherwise This may return false, even for collisions on CCD-enabled bodies when the bodies are moving slowly

◆ UE_NONCOPYABLE()

Chaos::FParticlePairMidPhase::UE_NONCOPYABLE ( FParticlePairMidPhase )

◆ VisitCollisions()

template<typename TLambda >

ECollisionVisitorResult Chaos::FParticlePairMidPhase::VisitCollisions	(	const TLambda &	Visitor,
		const ECollisionVisitorFlags	VisitFlags = `ECollisionVisitorFlags::VisitDefault`
	)

inline

Call a lambda on each active collision constraint This includes sleeping constraints, but skips constraints that are were not used on the last awake tick but are still kept around as an optimization.

Parameters

Visitor functor with signature ECollisionVisitorResult(FPBDCollisionConstraint& Constraint)

◆ VisitConstCollisions()

template<typename TLambda >

ECollisionVisitorResult Chaos::FParticlePairMidPhase::VisitConstCollisions	(	const TLambda &	Visitor,
		const ECollisionVisitorFlags	VisitFlags = `ECollisionVisitorFlags::VisitDefault`
	)		const

inline

Call a lambda on each active collision constraint.

Parameters

Visitor functor with signature ECollisionVisitorResult(const FPBDCollisionConstraint& Constraint)

◆ WakeCollisionsImpl()

virtual void Chaos::FParticlePairMidPhase::WakeCollisionsImpl ( const int32 CurrentEpoch )

protectedpure virtual

Implemented in Chaos::FShapePairParticlePairMidPhase, Chaos::FGenericParticlePairMidPhase, and Chaos::FSphereApproximationParticlePairMidPhase.

Member Data Documentation

◆ CullDistanceScale

FRealSingle Chaos::FParticlePairMidPhase::CullDistanceScale

protected

◆ Flags

FFlags Chaos::FParticlePairMidPhase::Flags

protected

◆ LastUsedEpoch

int32 Chaos::FParticlePairMidPhase::LastUsedEpoch

protected

◆ MidPhaseType

EParticlePairMidPhaseType Chaos::FParticlePairMidPhase::MidPhaseType

protected

◆ NumActiveConstraints

int32 Chaos::FParticlePairMidPhase::NumActiveConstraints

protected

◆ Particle0

FGeometryParticleHandle* Chaos::FParticlePairMidPhase::Particle0

protected

◆ Particle1

FGeometryParticleHandle* Chaos::FParticlePairMidPhase::Particle1

protected

◆ ParticleCollisionsIndex0

int32 Chaos::FParticlePairMidPhase::ParticleCollisionsIndex0

protected

◆ ParticleCollisionsIndex1

int32 Chaos::FParticlePairMidPhase::ParticleCollisionsIndex1

protected

◆ ParticlePairKey

Private::FCollisionParticlePairKey Chaos::FParticlePairMidPhase::ParticlePairKey

protected

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

Engine/Source/Runtime/Experimental/Chaos/Public/Chaos/Collision/ParticlePairMidPhase.h
Engine/Source/Runtime/Experimental/Chaos/Private/Chaos/Collision/ParticlePairMidPhase.cpp
Engine/Source/Runtime/Experimental/Chaos/Public/Chaos/Collision/CollisionConstraintAllocator.h

Protected Attributes
EParticlePairMidPhaseType	MidPhaseType

FFlags	Flags

FGeometryParticleHandle *	Particle0

FGeometryParticleHandle *	Particle1

FRealSingle	CullDistanceScale

Private::FCollisionParticlePairKey	ParticlePairKey

int32	LastUsedEpoch

int32	NumActiveConstraints

int32	ParticleCollisionsIndex0

int32	ParticleCollisionsIndex1

Classes

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ FParticlePairMidPhase()

◆ ~FParticlePairMidPhase()

Member Function Documentation

◆ BuildDetectorsImpl()

◆ CachePrefetch()

◆ CalculateMidPhaseType()

◆ DetachParticle()

◆ GenerateCollisions()

◆ GenerateCollisionsImpl()

◆ GetKey()

◆ GetMidPhaseType()

◆ GetParticle0()

◆ GetParticle1()

◆ GetParticleCollisionsIndex()

◆ Init()

◆ InitThresholds()

◆ InjectCollision()

◆ InjectCollisionImpl()

◆ IsCCD()

◆ IsCCDActive()

◆ IsInConstraintGraph()

◆ IsSleeping()

◆ IsUsedSince()

◆ IsValid()

◆ Make()

◆ Reset()

◆ ResetImpl()

◆ ResetModifications()

◆ SetCCDIsActive()

◆ SetConvexOptimizationIsActive() [1/2]

◆ SetConvexOptimizationIsActive() [2/2]

◆ SetIsActive()

◆ SetIsSleeping()

◆ SetParticleCollisionsIndex()

◆ ShouldEnableCCDSweep()

◆ UE_NONCOPYABLE()

◆ VisitCollisions()

◆ VisitConstCollisions()

◆ WakeCollisionsImpl()

Member Data Documentation

◆ CullDistanceScale

◆ Flags

◆ LastUsedEpoch

◆ MidPhaseType

◆ NumActiveConstraints

◆ Particle0

◆ Particle1

◆ ParticleCollisionsIndex0

◆ ParticleCollisionsIndex1

◆ ParticlePairKey