UE::Geometry::FMeshConnectedComponents Class Reference

#include <MeshConnectedComponents.h>

Classes
struct	FComponent

Public Member Functions
	FMeshConnectedComponents (const FDynamicMesh3 *MeshIn)
GEOMETRYCORE_API void	FindConnectedTriangles (TFunction< bool(int32, int32)> TrisConnectedPredicate=nullptr)
GEOMETRYCORE_API void	FindConnectedTriangles (const TArray< int > &TriangleROI, TFunction< bool(int32, int32)> TrisConnectedPredicate=nullptr)
GEOMETRYCORE_API void	FindConnectedTriangles (TFunctionRef< bool(int)> IndexFilterFunc, TFunction< bool(int32, int32)> TrisConnectedPredicate=nullptr)
GEOMETRYCORE_API void	FindTrianglesConnectedToSeeds (const TArray< int > &SeedTriangles, TFunction< bool(int32, int32)> TrisConnectedPredicate=nullptr)
GEOMETRYCORE_API bool	InitializeFromTriangleComponents (const TArray< TArray< int32 > > &ComponentLists, bool bValidateIDs)
GEOMETRYCORE_API bool	InitializeFromTriangleComponents (TArray< TArray< int32 > > &ComponentLists, bool bMoveSubLists, bool bValidateIDs)
GEOMETRYCORE_API void	FindConnectedVertices (TFunction< bool(int32, int32)> VertsConnectedPredicate=nullptr)
GEOMETRYCORE_API void	FindConnectedVertices (const TArray< int > &VertexROI, TFunction< bool(int32, int32)> VertsConnectedPredicate=nullptr)
GEOMETRYCORE_API void	FindConnectedVertices (TFunctionRef< bool(int)> IndexFilterFunc, TFunction< bool(int32, int32)>VertsConnectedPredicate=nullptr)
GEOMETRYCORE_API void	FindVerticesConnectedToSeeds (const TArray< int > &SeedVertices, TFunction< bool(int32, int32)> VertsConnectedPredicate=nullptr)
GEOMETRYCORE_API bool	InitializeFromVertexComponents (const TArray< TArray< int32 > > &ComponentLists, bool bValidateIDs)
GEOMETRYCORE_API bool	InitializeFromVertexComponents (TArray< TArray< int32 > > &ComponentLists, bool bMoveSubLists, bool bValidateIDs)
int32	Num () const
const FComponent &	GetComponent (int32 Index) const
FComponent &	GetComponent (int32 Index)
const FComponent &	operator[] (int32 Index) const
FComponent &	operator[] (int32 Index)
GEOMETRYCORE_API int32	GetLargestIndexByCount () const
GEOMETRYCORE_API void	SortByCount (bool bLargestFirst=true)
auto	begin ()
auto	begin () const
auto	end ()
auto	end () const

Static Public Member Functions
static GEOMETRYCORE_API void	GrowToConnectedTriangles (const FDynamicMesh3 *Mesh, const TArray< int > &InputROI, TArray< int > &ResultROI, TArray< int32 > *QueueBuffer=nullptr, TSet< int32 > *DoneBuffer=nullptr, TFunctionRef< bool(int32, int32)> CanGrowPredicate=[](int32, int32) { return true;})
static GEOMETRYCORE_API void	GrowToConnectedTriangles (const FDynamicMesh3 *Mesh, const TArray< int > &InputROI, TSet< int > &ResultROI, TArray< int32 > *QueueBuffer=nullptr, TFunctionRef< bool(int32, int32)> CanGrowPredicate=[](int32, int32) { return true;})
static GEOMETRYCORE_API void	GrowToConnectedVertices (const FDynamicMesh3 &Mesh, const TArray< int > &InputROI, TSet< int > &ResultROI, TArray< int32 > *QueueBuffer=nullptr, TFunctionRef< bool(int32, int32)> CanGrowPredicate=[](int32, int32) { return true;})
static GEOMETRYCORE_API void	GrowToConnectedEdges (const FDynamicMesh3 &Mesh, const TArray< int > &InputROI, TSet< int > &ResultROI, TArray< int32 > *QueueBuffer=nullptr, TFunctionRef< bool(int32, int32)> CanGrowPredicate=[](int32, int32) { return true;})

Public Attributes
const FDynamicMesh3 *	Mesh
TIndirectArray< FComponent >	Components

Protected Member Functions
GEOMETRYCORE_API void	FindTriComponents (FInterval1i ActiveRange, TArray< uint8 > &ActiveSet, TFunction< bool(int32, int32)> TriConnectedPredicate)
GEOMETRYCORE_API void	FindTriComponents (const TArray< int32 > &SeedList, TArray< uint8 > &ActiveSet, TFunction< bool(int32, int32)> TriConnectedPredicate)
GEOMETRYCORE_API void	FindTriComponent (FComponent *Component, TArray< int32 > &ComponentQueue, TArray< uint8 > &ActiveSet)
GEOMETRYCORE_API void	FindTriComponent (FComponent *Component, TArray< int32 > &ComponentQueue, TArray< uint8 > &ActiveSet, TFunctionRef< bool(int32, int32)> TriConnectedPredicate)
GEOMETRYCORE_API void	RemoveFromActiveSet (const FComponent *Component, TArray< uint8 > &ActiveSet)
GEOMETRYCORE_API void	FindVertComponents (FInterval1i ActiveRange, TArray< uint8 > &ActiveSet, TFunction< bool(int32, int32)> VertsConnectedPredicate)
GEOMETRYCORE_API void	FindVertComponents (const TArray< int32 > &SeedList, TArray< uint8 > &ActiveSet, TFunction< bool(int32, int32)> VertsConnectedPredicate)
GEOMETRYCORE_API void	FindVertComponent (FComponent *Component, TArray< int32 > &ComponentQueue, TArray< uint8 > &ActiveSet)
GEOMETRYCORE_API void	FindVertComponent (FComponent *Component, TArray< int32 > &ComponentQueue, TArray< uint8 > &ActiveSet, TFunctionRef< bool(int32, int32)> VertsConnectedPredicate)

Detailed Description

FMeshConnectedComponents calculates Connected Components of a Mesh, or sub-regions of a Mesh. By default the actual mesh connectivity is used, but an optional connectivity predicate can be provided to specify when two elements should be considered connected.

Constructor & Destructor Documentation

FMeshConnectedComponents()

UE::Geometry::FMeshConnectedComponents::FMeshConnectedComponents ( const FDynamicMesh3 *  MeshIn )

inline

Member Function Documentation

begin() [1/2]

auto UE::Geometry::FMeshConnectedComponents::begin ( )

inline

DO NOT USE DIRECTLY STL-like iterators to enable ranged-based for loop support (forwarding TIndirectArray declarations)

begin() [2/2]

auto UE::Geometry::FMeshConnectedComponents::begin ( ) const

inline

end() [1/2]

auto UE::Geometry::FMeshConnectedComponents::end ( )

inline

end() [2/2]

auto UE::Geometry::FMeshConnectedComponents::end ( ) const

inline

FindConnectedTriangles() [1/3]

void FMeshConnectedComponents::FindConnectedTriangles	(	const TArray< int > &	TriangleROI,
		TFunction< bool(int32, int32)>	TrisConnectedPredicate = nullptr
	)

Find all connected triangle components of a subset of triangles of the Mesh and store in Components array. Triangle connectivity is based on edge connectivity, ie bowtie-vertices are not connections between triangles.

Parameters

TriangleROI	list of triangles to search across
TrisConnectedPredicate	optional function that specifies whether two edge-connected triangles should be considered connected by the search

FindConnectedTriangles() [2/3]

void FMeshConnectedComponents::FindConnectedTriangles

(

TFunction< bool(int32, int32)>

TrisConnectedPredicate = nullptr

)

Find all connected triangle components of the Mesh and store in Components array. Triangle connectivity is based on edge connectivity, ie bowtie-vertices are not connections between triangles.

Parameters

TrisConnectedPredicate

optional function that specifies whether two edge-connected triangles should be considered connected by the search

FindConnectedTriangles() [3/3]

void FMeshConnectedComponents::FindConnectedTriangles	(	TFunctionRef< bool(int)>	IndexFilterFunc,
		TFunction< bool(int32, int32)>	TrisConnectedPredicate = nullptr
	)

Find all connected triangle components of a subset of triangles of the Mesh and store in Components array. Triangle connectivity is based on edge connectivity, ie bowtie-vertices are not connections between triangles.

Parameters

IndexFilterFunc	defines set of triangles to search across, return true for triangle IDs that are to be considered
TrisConnectedPredicate	optional function that specifies whether two edge-connected triangles should be considered connected by the search

FindConnectedVertices() [1/3]

void FMeshConnectedComponents::FindConnectedVertices	(	const TArray< int > &	VertexROI,
		TFunction< bool(int32, int32)>	VertsConnectedPredicate = nullptr
	)

Find all connected vertex components of a subset of vertices of the Mesh and store in Components array.

Parameters

VertexROI	list of vertices to search across
VertsConnectedPredicate	optional function that specifies whether two edge-connected vertices should be considered connected by the search

FindConnectedVertices() [2/3]

void FMeshConnectedComponents::FindConnectedVertices

(

TFunction< bool(int32, int32)>

VertsConnectedPredicate = nullptr

)

Find all connected vertex components of the Mesh and store in Components array.

Parameters

VertsConnectedPredicate

optional function that specifies whether two edge-connected vertices should be considered connected by the search

FindConnectedVertices() [3/3]

void FMeshConnectedComponents::FindConnectedVertices	(	TFunctionRef< bool(int)>	IndexFilterFunc,
		TFunction< bool(int32, int32)>	VertsConnectedPredicate = nullptr
	)

Find all connected vertex components of a subset of vertices of the Mesh and store in Components array.

Parameters

IndexFilterFunc	defines set of vertices to search across, return true for vertex IDs that are to be considered
VertsConnectedPredicate	optional function that specifies whether two edge-connected vertices should be considered connected by the search

FindTrianglesConnectedToSeeds()

void FMeshConnectedComponents::FindTrianglesConnectedToSeeds	(	const TArray< int > &	SeedTriangles,
		TFunction< bool(int32, int32)>	TrisConnectedPredicate = nullptr
	)

Find all connected triangle components that contain one or more Seed Triangles and store in Components array. Search only starts from Seed Triangles. Triangle connectivity is based on edge connectivity, ie bowtie-vertices are not connections between triangles.

Parameters

SeedTriangles	list of start triangles, each component contains at least one of these triangles
TrisConnectedPredicate	optional function that specifies whether two edge-connected triangles should be considered connected by the search

FindTriComponent() [1/2]

void FMeshConnectedComponents::FindTriComponent ( FComponent *  Component, TArray< int32 > &  ComponentQueue, TArray< uint8 > &  ActiveSet  )

protected

FindTriComponent() [2/2]

void FMeshConnectedComponents::FindTriComponent ( FComponent *  Component, TArray< int32 > &  ComponentQueue, TArray< uint8 > &  ActiveSet, TFunctionRef< bool(int32, int32)>  TriConnectedPredicate  )

protected

FindTriComponents() [1/2]

void FMeshConnectedComponents::FindTriComponents ( const TArray< int32 > &  SeedList, TArray< uint8 > &  ActiveSet, TFunction< bool(int32, int32)>  TriConnectedPredicate  )

protected

FindTriComponents() [2/2]

void FMeshConnectedComponents::FindTriComponents ( FInterval1i  ActiveRange, TArray< uint8 > &  ActiveSet, TFunction< bool(int32, int32)>  TriConnectedPredicate  )

protected

FindVertComponent() [1/2]

void FMeshConnectedComponents::FindVertComponent ( FComponent *  Component, TArray< int32 > &  ComponentQueue, TArray< uint8 > &  ActiveSet  )

protected

FindVertComponent() [2/2]

void FMeshConnectedComponents::FindVertComponent ( FComponent *  Component, TArray< int32 > &  ComponentQueue, TArray< uint8 > &  ActiveSet, TFunctionRef< bool(int32, int32)>  VertsConnectedPredicate  )

protected

FindVertComponents() [1/2]

void FMeshConnectedComponents::FindVertComponents ( const TArray< int32 > &  SeedList, TArray< uint8 > &  ActiveSet, TFunction< bool(int32, int32)>  VertsConnectedPredicate  )

protected

FindVertComponents() [2/2]

void FMeshConnectedComponents::FindVertComponents ( FInterval1i  ActiveRange, TArray< uint8 > &  ActiveSet, TFunction< bool(int32, int32)>  VertsConnectedPredicate  )

protected

FindVerticesConnectedToSeeds()

void FMeshConnectedComponents::FindVerticesConnectedToSeeds	(	const TArray< int > &	SeedVertices,
		TFunction< bool(int32, int32)>	VertsConnectedPredicate = nullptr
	)

Find all connected vertex components that contain one or more Seed Vertices and store in Components array. Search only starts from Seed Vertices.

Parameters

SeedVertices	list of start vertices, each component contains at least one of these vertices
VertsConnectedPredicate	optional function that specifies whether two edge-connected vertices should be considered connected by the search

GetComponent() [1/2]

FComponent & UE::Geometry::FMeshConnectedComponents::GetComponent ( int32  Index )

inline

Returns

element of Components array at given Index

GetComponent() [2/2]

const FComponent & UE::Geometry::FMeshConnectedComponents::GetComponent ( int32  Index ) const

inline

Returns

element of Components array at given Index

GetLargestIndexByCount()

int32 FMeshConnectedComponents::GetLargestIndexByCount

(

)

const

Returns

index of largest component by element count

GrowToConnectedEdges()

void FMeshConnectedComponents::GrowToConnectedEdges ( const FDynamicMesh3 &  Mesh, const TArray< int > &  InputROI, TSet< int > &  ResultROI, TArray< int32 > *  QueueBuffer = nullptr, TFunctionRef< bool(int32, int32)>  CanGrowPredicate = [](int32, int32) { return true; }  )

static

Utility function to expand an edge selection to all edges considered "connected".

Parameters

Mesh	Mesh to calculate on
InputROI	input set of edges
ResultROI	output set of edges connected to InputROI
QueueBuffer	optional buffer used as internal Queue. If passed as nullptr, a TArray will be locally allocated
CanGrowPredicate	determines whether two connected mesh edges should be considered connected while growing

GrowToConnectedTriangles() [1/2]

void FMeshConnectedComponents::GrowToConnectedTriangles ( const FDynamicMesh3 *  Mesh, const TArray< int > &  InputROI, TArray< int > &  ResultROI, TArray< int32 > *  QueueBuffer = nullptr, TSet< int32 > *  DoneBuffer = nullptr, TFunctionRef< bool(int32, int32)>  CanGrowPredicate = [](int32, int32) { return true; }  )

static

Utility function to expand a triangle selection to all triangles considered "connected". More efficient than using full FMeshConnectedComponents instance if ROI is small relative to Mesh size (or if temp buffers can be re-used)

Parameters

Mesh	Mesh to calculate on
InputROI	input set of triangles
ResultROI	output set of triangles connected to InputROI
QueueBuffer	optional buffer used as internal Queue. If passed as nullptr, a TArray will be locally allocated
DoneBuffer	optional set used to track which triangles have already been processed. If passed as nullptr, an TSet will be locally allocated
CanGrowPredicate	determines whether two connected mesh triangles should be considered connected while growing

GrowToConnectedTriangles() [2/2]

void FMeshConnectedComponents::GrowToConnectedTriangles ( const FDynamicMesh3 *  Mesh, const TArray< int > &  InputROI, TSet< int > &  ResultROI, TArray< int32 > *  QueueBuffer = nullptr, TFunctionRef< bool(int32, int32)>  CanGrowPredicate = [](int32, int32) { return true; }  )

static

Utility function to expand a triangle selection to all triangles considered "connected". More efficient than using full FMeshConnectedComponents instance if ROI is small relative to Mesh size (or if temp buffers can be re-used) This version computes an output TSet instead of output TArray, which is preferable in some cases.

Parameters

Mesh	Mesh to calculate on
InputROI	input set of triangles
ResultROI	output set of triangles connected to InputROI
QueueBuffer	optional buffer used as internal Queue. If passed as nullptr, a TArray will be locally allocated
CanGrowPredicate	determines whether two connected mesh triangles should be considered connected while growing

GrowToConnectedVertices()

void FMeshConnectedComponents::GrowToConnectedVertices ( const FDynamicMesh3 &  Mesh, const TArray< int > &  InputROI, TSet< int > &  ResultROI, TArray< int32 > *  QueueBuffer = nullptr, TFunctionRef< bool(int32, int32)>  CanGrowPredicate = [](int32, int32) { return true; }  )

static

Utility function to expand a vertex selection to all vertices considered "connected".

Parameters

Mesh	Mesh to calculate on
InputROI	input set of vertices
ResultROI	output set of vertices connected to InputROI
QueueBuffer	optional buffer used as internal Queue. If passed as nullptr, a TArray will be locally allocated
CanGrowPredicate	determines whether two connected mesh vertices should be considered connected while growing

InitializeFromTriangleComponents() [1/2]

bool FMeshConnectedComponents::InitializeFromTriangleComponents	(	const TArray< TArray< int32 > > &	ComponentLists,
		bool	bValidateIDs
	)

Initialize the internal FComponent list from the input ComponentLists, skipping any empty input lists

Parameters

bValidateIDs

if true, test that each value corresponds to a valid triangle ID on the Mesh

Returns

true if all IDs are valid, or if check was skipped

InitializeFromTriangleComponents() [2/2]

bool FMeshConnectedComponents::InitializeFromTriangleComponents	(	TArray< TArray< int32 > > &	ComponentLists,
		bool	bMoveSubLists,
		bool	bValidateIDs
	)

Initialize the internal FComponent list from the input ComponentLists, skipping any empty input lists

Parameters

bMoveSubLists	if true, steal the arrays inside the ComponentLists (via MoveTemp), to avoid memory copies
bValidateIDs	if true, test that each value corresponds to a valid triangle ID on the Mesh

Returns

true if all IDs are valid, or if check was skipped

InitializeFromVertexComponents() [1/2]

bool FMeshConnectedComponents::InitializeFromVertexComponents	(	const TArray< TArray< int32 > > &	ComponentLists,
		bool	bValidateIDs
	)

Initialize the internal FComponent list from the input ComponentLists, skipping any empty input lists

Parameters

bValidateIDs

if true, test that each value corresponds to a valid vertex ID on the Mesh

Returns

true if all IDs are valid, or if check was skipped

InitializeFromVertexComponents() [2/2]

bool FMeshConnectedComponents::InitializeFromVertexComponents	(	TArray< TArray< int32 > > &	ComponentLists,
		bool	bMoveSubLists,
		bool	bValidateIDs
	)

Initialize the internal FComponent list from the input ComponentLists, skipping any empty input lists

Parameters

bMoveSubLists	if true, steal the arrays inside the ComponentLists (via MoveTemp), to avoid memory copies
bValidateIDs	if true, test that each value corresponds to a valid vertex ID on the Mesh

Returns

true if all IDs are valid, or if check was skipped

Num()

int32 UE::Geometry::FMeshConnectedComponents::Num ( ) const

inline

Returns

Number of Components that were found

operator[]() [1/2]

FComponent & UE::Geometry::FMeshConnectedComponents::operator[] ( int32  Index )

inline

Returns

element of Components array at given Index

operator[]() [2/2]

const FComponent & UE::Geometry::FMeshConnectedComponents::operator[] ( int32  Index ) const

inline

Returns

element of Components array at given Index

RemoveFromActiveSet()

void FMeshConnectedComponents::RemoveFromActiveSet ( const FComponent *  Component, TArray< uint8 > &  ActiveSet  )

protected

SortByCount()

void FMeshConnectedComponents::SortByCount

(

bool

bLargestFirst = true

)

Sort the Components array by component element count

Parameters

bLargestFirst

if true, sort by decreasing count, otherwise by increasing count

Member Data Documentation

Components

TIndirectArray<FComponent> UE::Geometry::FMeshConnectedComponents::Components

List of Connected Components that have been found by one of the calculation functions

Mesh

const FDynamicMesh3* UE::Geometry::FMeshConnectedComponents::Mesh

---

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

• Engine/Source/Runtime/GeometryCore/Public/Selections/MeshConnectedComponents.h
• Engine/Source/Runtime/GeometryCore/Private/Selections/MeshConnectedComponents.cpp