Classes
struct	FNewTriangle

struct	FVisiblePoints

Public Member Functions
void	BuildNeighbors (const TArray< FIndex3i > &Triangles)

bool	IsVisible (const TVector< RealType > TriPts[3], const TVector< RealType > &Pt)

void	SetTriPts (const FIndex3i &Tri, TFunctionRef< TVector< RealType >(int32)> GetPointFunc, TVector< RealType > TriPtsOut[3])

void	InitVisibility (const TArray< FIndex3i > &Triangles, int32 NumPoints, TFunctionRef< TVector< RealType >(int32)> GetPointFunc, TFunctionRef< bool(int32)> FilterFunc)

void	UpdateNeighbors (int32 TriIdx, int32 NewIdx)

void	UpdateNeighbor (TArray< FIndex3i > &Triangles, int32 TriIdx, int32 EdgeFirstVertex, int32 NewNbrIdx)

bool	ValidateConnectivity (TArray< FIndex3i > &Triangles, TSet< int32 > Skip=TSet< int32 >())

void	DeleteTriangles (TArray< FIndex3i > &Triangles, const TSet< int32 > &ToDelete)

FIndex2i	ChooseVisiblePoint (bool bChooseBestPoint)

void	RemoveVisiblePoint (FIndex2i TriPointPair, TFunctionRef< TVector< RealType >(int32)> GetPointFunc)

void	ClearVisiblePointsData (int32 TriIdx, TArray< int32 > &NewlyUnclaimed)

bool	HorizonHelper (const TArray< FIndex3i > &Triangles, TFunctionRef< TVector< RealType >(int32)> GetPointFunc, const TVector< RealType > &Pt, TArray< int32 > &NewlyUnclaimed, TSet< int32 > &ToDelete, TArray< FNewTriangle > &ToAdd, int32 TriIdx, int32 CrossedEdgeFirstVertex, bool bCouldSkipPoint=false)

bool	UpdateHullWithNewPoint (TArray< FIndex3i > &Triangles, int32 NumPoints, TFunctionRef< TVector< RealType >(int32)> GetPointFunc, int32 StartTriIdx, int32 PtIdx, RealType DegenerateEdgeToleranceSq=(RealType) 0)

Public Attributes
TArray< FIndex3i >	TriNeighbors

TArray< FVisiblePoints >	VisiblePoints

TSet< int32 >	TrisWithPoints

double	VisibleDistanceThreshold = -FMathd::MaxReal

Member Function Documentation

◆ BuildNeighbors()

template<typename RealType >

void UE::Geometry::FHullConnectivity< RealType >::BuildNeighbors ( const TArray< FIndex3i > & Triangles )

inline

Fully build neighbor connectivity; only on the initial tet, as after that we can incrementally update connectivity w/ mesh changes

◆ ChooseVisiblePoint()

template<typename RealType >

FIndex2i UE::Geometry::FHullConnectivity< RealType >::ChooseVisiblePoint ( bool bChooseBestPoint )

inline

Parameters

bChooseBestPoint Whether to choose the point with the highest value, rather than the first found point

Returns: A triangle index and visible-from-that-triangle point index that can be added to the hull next

◆ ClearVisiblePointsData()

template<typename RealType >

void UE::Geometry::FHullConnectivity< RealType >::ClearVisiblePointsData	(	int32	TriIdx,
		TArray< int32 > &	NewlyUnclaimed
	)

inline

◆ DeleteTriangles()

template<typename RealType >

void UE::Geometry::FHullConnectivity< RealType >::DeleteTriangles	(	TArray< FIndex3i > &	Triangles,
		const TSet< int32 > &	ToDelete
	)

inline

Remove a triangle and update connectivity accordingly. Removes by swapping, and updates references as needed. Note: removes a whole set at a time, because indices change during deletion

Parameters

Triangles	All triangles
ToDelete	All triangles to be deleted

◆ HorizonHelper()

template<typename RealType >

bool UE::Geometry::FHullConnectivity< RealType >::HorizonHelper	(	const TArray< FIndex3i > &	Triangles,
		TFunctionRef< TVector< RealType >(int32)>	GetPointFunc,
		const TVector< RealType > &	Pt,
		TArray< int32 > &	NewlyUnclaimed,
		TSet< int32 > &	ToDelete,
		TArray< FNewTriangle > &	ToAdd,
		int32	TriIdx,
		int32	CrossedEdgeFirstVertex,
		bool	bCouldSkipPoint = `false`
	)

inline

Recursive traversal strategy that starts from a 'visible' triangle and walks to the connected set of all visible triangles, s.t. it visits the boundary in order See explanation here: http://algolist.ru/maths/geom/convhull/qhull3d.php

Parameters

Triangles	All triangles
GetPointFunc	Point access function
Pt	Current 'eye point'; triangles will be deleted if this point is on the 'positive' side of the triangle
NewlyUnclaimed	(Output) As we mark triangles for deletion, we move the visible points stored on the triangles to this giant list of points that need to be re-assigned (or culled) wrt the new triangles
ToDelete	(Output) Set of all triangles that we will delete
ToAdd	(Output) Info required to add and connect up new triangles to the eye point
TriIdx	Index of triangle to currently process
CrossedEdgeFirstVertex	The first vertex of the edge that was 'crossed over' to traverse to this TriIdx, or -1 for the initial call

Returns: false if triangle is beyond horizon (so we don't need to search through it / remove it), true otherwise

◆ InitVisibility()

template<typename RealType >

void UE::Geometry::FHullConnectivity< RealType >::InitVisibility	(	const TArray< FIndex3i > &	Triangles,
		int32	NumPoints,
		TFunctionRef< TVector< RealType >(int32)>	GetPointFunc,
		TFunctionRef< bool(int32)>	FilterFunc
	)

inline

Bucket all points based on which triangles can see them

◆ IsVisible()

template<typename RealType >

bool UE::Geometry::FHullConnectivity< RealType >::IsVisible	(	const TVector< RealType >	TriPts[3],
		const TVector< RealType > &	Pt
	)

inline

Returns: true if Pt is on the 'positive' side of the triangle

◆ RemoveVisiblePoint()

template<typename RealType >

void UE::Geometry::FHullConnectivity< RealType >::RemoveVisiblePoint	(	FIndex2i	TriPointPair,
		TFunctionRef< TVector< RealType >(int32)>	GetPointFunc
	)

inline

Parameters

TriPointPair A tri point pair, as returned from ChooseVisiblePoint, that should be removed from consideration

◆ SetTriPts()

template<typename RealType >

void UE::Geometry::FHullConnectivity< RealType >::SetTriPts	(	const FIndex3i &	Tri,
		TFunctionRef< TVector< RealType >(int32)>	GetPointFunc,
		TVector< RealType >	TriPtsOut[3]
	)

inline

Set triangle positions to prep for IsVisible calls

◆ UpdateHullWithNewPoint()

template<typename RealType >

bool UE::Geometry::FHullConnectivity< RealType >::UpdateHullWithNewPoint	(	TArray< FIndex3i > &	Triangles,
		int32	NumPoints,
		TFunctionRef< TVector< RealType >(int32)>	GetPointFunc,
		int32	StartTriIdx,
		int32	PtIdx,
		RealType	DegenerateEdgeToleranceSq = `(RealType)0`
	)

inline

◆ UpdateNeighbor()

template<typename RealType >

void UE::Geometry::FHullConnectivity< RealType >::UpdateNeighbor	(	TArray< FIndex3i > &	Triangles,
		int32	TriIdx,
		int32	EdgeFirstVertex,
		int32	NewNbrIdx
	)

inline

Rewrite one neighbor connection (and NOT the backwards connection)

Parameters

Triangles	All triangles
TriIdx	The triangle to update
EdgeFirstVertex	The first vertex of the edge that should be connected to the new neighbor
NewNbrIdx	The new neighbor to connect to

◆ UpdateNeighbors()

template<typename RealType >

void UE::Geometry::FHullConnectivity< RealType >::UpdateNeighbors	(	int32	TriIdx,
		int32	NewIdx
	)

inline

Update any neighbor "back pointers" to TriIdx to instead point to NewIdx Used during triangle deletion when we swap a triangle to a new index

◆ ValidateConnectivity()

template<typename RealType >

bool UE::Geometry::FHullConnectivity< RealType >::ValidateConnectivity	(	TArray< FIndex3i > &	Triangles,
		TSet< int32 >	Skip = `TSet<int32>()`
	)

inline

Debugging aid to validate the neighbor connectivity

Member Data Documentation

◆ TriNeighbors

template<typename RealType >

TArray<FIndex3i> UE::Geometry::FHullConnectivity< RealType >::TriNeighbors

◆ TrisWithPoints

template<typename RealType >

TSet<int32> UE::Geometry::FHullConnectivity< RealType >::TrisWithPoints

◆ VisibleDistanceThreshold

template<typename RealType >

double UE::Geometry::FHullConnectivity< RealType >::VisibleDistanceThreshold = -FMathd::MaxReal

◆ VisiblePoints

template<typename RealType >

TArray<FVisiblePoints> UE::Geometry::FHullConnectivity< RealType >::VisiblePoints

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

Engine/Source/Runtime/GeometryCore/Private/CompGeom/ConvexHull3.cpp

Classes

Public Member Functions

Public Attributes

Member Function Documentation

◆ BuildNeighbors()

◆ ChooseVisiblePoint()

◆ ClearVisiblePointsData()

◆ DeleteTriangles()

◆ HorizonHelper()

◆ InitVisibility()

◆ IsVisible()

◆ RemoveVisiblePoint()

◆ SetTriPts()

◆ UpdateHullWithNewPoint()

◆ UpdateNeighbor()

◆ UpdateNeighbors()

◆ ValidateConnectivity()

Member Data Documentation

◆ TriNeighbors

◆ TrisWithPoints

◆ VisibleDistanceThreshold

◆ VisiblePoints