#include <ConvexDecomposition3.h>

Classes
struct	FConvexPart

struct	FMergeSettings

struct	FPreprocessMeshOptions

struct	FProximity

Public Member Functions
	FConvexDecomposition3 ()

	FConvexDecomposition3 (const FDynamicMesh3 &SourceMesh, bool bMergeEdges=true)

	FConvexDecomposition3 (const FDynamicMesh3 &SourceMesh, const FPreprocessMeshOptions &Options)

bool	IsInputSolid ()

GEOMETRYCORE_API void	InitializeFromHulls (int32 NumHulls, TFunctionRef< double(int32)> HullVolumes, TFunctionRef< int32(int32)> HullNumVertices, TFunctionRef< FVector3d(int32, int32)> HullVertices, TArrayView< const TPair< int32, int32 > > Proximity)

GEOMETRYCORE_API void	InitializeProximityFromDecompositionBoundingBoxOverlaps (double BoundsExpandByMinDimFactor, double BoundsExpandByMaxDimFactor, double MinBoundsExpand)

GEOMETRYCORE_API void	InitializeFromMesh (const FDynamicMesh3 &SourceMesh, bool bMergeEdges)

GEOMETRYCORE_API void	InitializeFromMesh (const FDynamicMesh3 &SourceMesh, const FPreprocessMeshOptions &Options)

GEOMETRYCORE_API void	InitializeFromIndexMesh (TArrayView< const FVector3f > Vertices, TArrayView< const FIntVector > Faces, bool bMergeEdges, int32 FaceVertexOffset=0)

GEOMETRYCORE_API void	InitializeFromIndexMesh (TArrayView< const FVector3f > Vertices, TArrayView< const FIntVector > Faces, const FPreprocessMeshOptions &Options, int32 FaceVertexOffset=0)

GEOMETRYCORE_API bool	InitializeNegativeSpace (const FNegativeSpaceSampleSettings &Settings, TArrayView< const FVector3d > RequestedSamples=TArrayView< const FVector3d >())

GEOMETRYCORE_API void	Compute (int32 NumOutputHulls, int32 NumAdditionalSplits=10, double ErrorTolerance=0.0, double MinThicknessTolerance=0, int32 MaxOutputHulls=-1, bool bOnlySplitIfNegativeSpaceCovered=false)

GEOMETRYCORE_API int32	SplitWorst (bool bCanSkipUnreliableGeoVolumes=false, double ErrorTolerance=0.0, bool bOnlySplitIfNegativeSpaceCovered=false, double MinSplitSizeInWorldSpace=-1)

GEOMETRYCORE_API int32	MergeBest (int32 TargetNumParts, double ErrorTolerance=0, double MinThicknessTolerance=0, bool bAllowCompact=true, bool bRequireHullTriangles=false, int32 MaxOutputHulls=-1, const FSphereCovering OptionalNegativeSpace=nullptr, const FTransform OptionalTransformIntoNegativeSpace=nullptr)

GEOMETRYCORE_API int32	MergeBest (const FMergeSettings &Settings)

double	ConvertDistanceToleranceToLocalVolumeTolerance (double DistTolerance) const

double	ConvertDistanceToleranceToLocalSpace (double DistTolerance) const

void	Compact ()

int32	NumHulls () const

TArray< FIndex3i > const &	GetTriangles (int32 HullIdx) const

template<typename RealType >
TArray< TVector< RealType > >	GetVertices (int32 HullIdx, bool bTransformedToOutput=true) const

FDynamicMesh3	GetHullMesh (int32 HullIdx) const

const FDynamicMesh3 &	GetInternalMesh (int32 HullIdx) const

const int32	GetHullSourceID (int32 HullIdx) const

const int32	CountMergedParts () const

GEOMETRYCORE_API void	DeleteProximity (TArray< int32 > &&ToRemove, bool bDeleteMapReferences)

GEOMETRYCORE_API void	UpdateProximitiesAfterSplit (int32 SplitIdx, int32 NewIdxStart, FPlane3d CutPlane, int32 SecondSideIdxStart, double OrigHullVolume)

GEOMETRYCORE_API void	FixHullOverlapsInNegativeSpace (double NegativeSpaceTolerance=UE_DOUBLE_KINDA_SMALL_NUMBER, double NegativeSpaceMinRadius=UE_DOUBLE_KINDA_SMALL_NUMBER)

const FSphereCovering &	GetNegativeSpace () const

Static Public Member Functions
static GEOMETRYCORE_API bool	ConvexPartVsSphereOverlap (const FConvexPart &Part, FVector3d Center, double Radius, const FTransform TransformIntoSphereSpace=nullptr, double OutDistanceSq=nullptr)

Public Attributes
double	ProximityTolerance = 1e-3

double	ConnectedComponentTolerance = 1e-3

double	OnPlaneTolerance = 1e-7

double	CutLargestAxisErrorScale = .99

double	ConvexEdgeAngleMoreSamplesThreshold = 30

double	ConvexEdgeAngleThreshold = 170

double	BiasToRemoveTooThinParts = .1

int32	MaxConvexEdgePlanes = 50

bool	bSplitDisconnectedComponents = true

bool	bTreatAsSolid = true

double	ThickenAfterHullFailure = 0

int32	RestrictMergeSearchToLocalAfterTestNumConnections = -1

TIndirectArray< FConvexPart >	Decomposition

FTransformSRT3d	ResultTransform = FTransformSRT3d::Identity()
	Transform taking the result hull vertices back to the original space of the inputs; automatically applied by GetVertices()

TArray< FProximity >	Proximities

TMultiMap< int32, int32 >	DecompositionToProximity

Constructor & Destructor Documentation

◆ FConvexDecomposition3() [1/3]

UE::Geometry::FConvexDecomposition3::FConvexDecomposition3 ( )

inline

◆ FConvexDecomposition3() [2/3]

UE::Geometry::FConvexDecomposition3::FConvexDecomposition3	(	const FDynamicMesh3 &	SourceMesh,
		bool	bMergeEdges = `true`
	)

inline

◆ FConvexDecomposition3() [3/3]

UE::Geometry::FConvexDecomposition3::FConvexDecomposition3	(	const FDynamicMesh3 &	SourceMesh,
		const FPreprocessMeshOptions &	Options
	)

inline

Member Function Documentation

◆ Compact()

void UE::Geometry::FConvexDecomposition3::Compact ( )

inline

◆ Compute()

void UE::Geometry::FConvexDecomposition3::Compute	(	int32	NumOutputHulls,
		int32	NumAdditionalSplits = `10`,
		double	ErrorTolerance = `0.0`,
		double	MinThicknessTolerance = `0`,
		int32	MaxOutputHulls = `-1`,
		bool	bOnlySplitIfNegativeSpaceCovered = `false`
	)

Compute a decomposition with the desired number of hulls Note: A future version of this function may replace NumOutputHulls with MaxOutputHulls, but this version keeps both parameters for compatibility / consistent behavior.

Parameters

NumOutputHulls	Number of convex hulls to use in the final convex decomposition
NumAdditionalSplits	How far to go beyond the target number of hulls when initially the mesh into pieces – larger values will require more computation but can find better convex decompositions
ErrorTolerance	Stop splitting when hulls have error less than this (expressed in cm; will be cubed for volumetric error). Overrides NumOutputHulls if specified
MinThicknessTolerance	Optionally specify a minimum thickness (in cm) for convex parts; parts below this thickness will always be merged away. Overrides NumOutputHulls and ErrorTolerance when needed
MaxOutputHulls	If > 0, maximum number of convex hulls to generate. Overrides ErrorTolerance and TargetNumParts when needed
bOnlySplitIfOverlapNegativeSpace	If true, use NegativeSpace to guide splits, and only split parts that overlap negative space

◆ ConvertDistanceToleranceToLocalSpace()

double UE::Geometry::FConvexDecomposition3::ConvertDistanceToleranceToLocalSpace ( double DistTolerance ) const

inline

◆ ConvertDistanceToleranceToLocalVolumeTolerance()

double UE::Geometry::FConvexDecomposition3::ConvertDistanceToleranceToLocalVolumeTolerance ( double DistTolerance ) const

inline

◆ ConvexPartVsSphereOverlap()

bool UE::Geometry::FConvexDecomposition3::ConvexPartVsSphereOverlap	(	const FConvexPart &	Part,
		FVector3d	Center,
		double	Radius,
		const FTransform *	TransformIntoSphereSpace = `nullptr`,
		double *	OutDistanceSq = `nullptr`
	)

static

◆ CountMergedParts()

const int32 UE::Geometry::FConvexDecomposition3::CountMergedParts ( ) const

inline

◆ DeleteProximity()

void UE::Geometry::FConvexDecomposition3::DeleteProximity	(	TArray< int32 > &&	ToRemove,
		bool	bDeleteMapReferences
	)

◆ FixHullOverlapsInNegativeSpace()

void UE::Geometry::FConvexDecomposition3::FixHullOverlapsInNegativeSpace	(	double	NegativeSpaceTolerance = `UE_DOUBLE_KINDA_SMALL_NUMBER`,
		double	NegativeSpaceMinRadius = `UE_DOUBLE_KINDA_SMALL_NUMBER`
	)

◆ GetHullMesh()

FDynamicMesh3 UE::Geometry::FConvexDecomposition3::GetHullMesh ( int32 HullIdx ) const

inline

◆ GetHullSourceID()

const int32 UE::Geometry::FConvexDecomposition3::GetHullSourceID ( int32 HullIdx ) const

inline

◆ GetInternalMesh()

const FDynamicMesh3 & UE::Geometry::FConvexDecomposition3::GetInternalMesh ( int32 HullIdx ) const

inline

◆ GetNegativeSpace()

const FSphereCovering & UE::Geometry::FConvexDecomposition3::GetNegativeSpace ( ) const

inline

◆ GetTriangles()

TArray< FIndex3i > const & UE::Geometry::FConvexDecomposition3::GetTriangles ( int32 HullIdx ) const

inline

Returns: convex hull triangles

◆ GetVertices()

template<typename RealType >

TArray< TVector< RealType > > UE::Geometry::FConvexDecomposition3::GetVertices	(	int32	HullIdx,
		bool	bTransformedToOutput = `true`
	)		const

inline

◆ InitializeFromHulls()

void UE::Geometry::FConvexDecomposition3::InitializeFromHulls	(	int32	NumHulls,
		TFunctionRef< double(int32)>	HullVolumes,
		TFunctionRef< int32(int32)>	HullNumVertices,
		TFunctionRef< FVector3d(int32, int32)>	HullVertices,
		TArrayView< const TPair< int32, int32 > >	Proximity
	)

Initialize from convex hulls allows the caller to only use the hull merging phase of the algorithm

Parameters

NumHulls	Number of convex hulls in the initial decomposition
HullVolumes	Function from Hull Index -> Hull Volume
HullNumVertices	Function from Hull Index -> Hull Vertex Count
HullVertices	Function from Hull Index, Vertex Index -> Hull Vertex Position
Proximity	All the local proximities for the hulls. Hulls will not be merged unless they are connected by this proximity graph.

◆ InitializeFromIndexMesh() [1/2]

void UE::Geometry::FConvexDecomposition3::InitializeFromIndexMesh	(	TArrayView< const FVector3f >	Vertices,
		TArrayView< const FIntVector >	Faces,
		bool	bMergeEdges,
		int32	FaceVertexOffset = `0`
	)

Initialize convex decomposition with a triangle index mesh

Parameters

Vertices	Vertex buffer for mesh to decompose
Faces	Triangle buffer for mesh to decompose
bMergeEdges	Whether to attempt to weld matching edges before computing the convex hull; this can help the convex decomposition find better cutting planes for meshes that have boundaries e.g. due to seams
FaceVertexOffset	Indices from the Faces array are optionally offset by this value. Useful e.g. to take slices of the multi-geometry vertex and face buffers of FGeometryCollection.

◆ InitializeFromIndexMesh() [2/2]

void UE::Geometry::FConvexDecomposition3::InitializeFromIndexMesh	(	TArrayView< const FVector3f >	Vertices,
		TArrayView< const FIntVector >	Faces,
		const FPreprocessMeshOptions &	Options,
		int32	FaceVertexOffset = `0`
	)

Initialize convex decomposition with a triangle index mesh

Parameters

Vertices	Vertex buffer for mesh to decompose
Faces	Triangle buffer for mesh to decompose
Options	Options for pre-processing the mesh before decomposition (e.g., to weld matching edges, thicken degenerate inputs, or to run a general pre-process lambda function)
FaceVertexOffset	Indices from the Faces array are optionally offset by this value. Useful e.g. to take slices of the multi-geometry vertex and face buffers of FGeometryCollection.

◆ InitializeFromMesh() [1/2]

void UE::Geometry::FConvexDecomposition3::InitializeFromMesh	(	const FDynamicMesh3 &	SourceMesh,
		bool	bMergeEdges
	)

◆ InitializeFromMesh() [2/2]

void UE::Geometry::FConvexDecomposition3::InitializeFromMesh	(	const FDynamicMesh3 &	SourceMesh,
		const FPreprocessMeshOptions &	Options
	)

◆ InitializeNegativeSpace()

bool UE::Geometry::FConvexDecomposition3::InitializeNegativeSpace	(	const FNegativeSpaceSampleSettings &	Settings,
		TArrayView< const FVector3d >	RequestedSamples = `TArrayView<const FVector3d>()`
	)

Find negative space that should be protected. Uses the mesh passed on construction or to InitializeFromMesh or InitializeFromIndexMesh

Parameters

Settings Settings to use to find the negative space

Returns: False on failure – e.g., if there was no mesh available

◆ InitializeProximityFromDecompositionBoundingBoxOverlaps()

void UE::Geometry::FConvexDecomposition3::InitializeProximityFromDecompositionBoundingBoxOverlaps	(	double	BoundsExpandByMinDimFactor,
		double	BoundsExpandByMaxDimFactor,
		double	MinBoundsExpand
	)

Create the proximity graph from the current decomposition, using bounding box overlaps. To consider non-overlapping proximity, the bounding boxes can be expanded by a factor of their own size or by an absolute amount.

Parameters

BoundsExpandByMinDimFactor	Part bounds will be expanded by at least this factor of their own min dimension, before finding overlaps
BoundsExpandByMaxDimFactor	Part bounds will be expanded by at least this factor of their own max dimension, before finding overlaps
MinBoundsExpand	Part bounds will be expanded by at least this fixed amount, before finding overlaps

◆ IsInputSolid()

bool UE::Geometry::FConvexDecomposition3::IsInputSolid ( )

inline

Test whether the input mesh (after preprocessing) is solid. Must be called after initialization, but before decomposition is computed.

◆ MergeBest() [1/2]

int32 UE::Geometry::FConvexDecomposition3::MergeBest ( const FMergeSettings & Settings )

◆ MergeBest() [2/2]

int32 UE::Geometry::FConvexDecomposition3::MergeBest	(	int32	TargetNumParts,
		double	ErrorTolerance = `0`,
		double	MinThicknessTolerance = `0`,
		bool	bAllowCompact = `true`,
		bool	bRequireHullTriangles = `false`,
		int32	MaxOutputHulls = `-1`,
		const FSphereCovering *	OptionalNegativeSpace = `nullptr`,
		const FTransform *	OptionalTransformIntoNegativeSpace = `nullptr`
	)

◆ NumHulls()

int32 UE::Geometry::FConvexDecomposition3::NumHulls ( ) const

inline

◆ SplitWorst()

int32 UE::Geometry::FConvexDecomposition3::SplitWorst	(	bool	bCanSkipUnreliableGeoVolumes = `false`,
		double	ErrorTolerance = `0.0`,
		bool	bOnlySplitIfNegativeSpaceCovered = `false`,
		double	MinSplitSizeInWorldSpace = `-1`
	)

◆ UpdateProximitiesAfterSplit()

void UE::Geometry::FConvexDecomposition3::UpdateProximitiesAfterSplit	(	int32	SplitIdx,
		int32	NewIdxStart,
		FPlane3d	CutPlane,
		int32	SecondSideIdxStart,
		double	OrigHullVolume
	)

Member Data Documentation

◆ BiasToRemoveTooThinParts

double UE::Geometry::FConvexDecomposition3::BiasToRemoveTooThinParts = .1

◆ bSplitDisconnectedComponents

bool UE::Geometry::FConvexDecomposition3::bSplitDisconnectedComponents = true

◆ bTreatAsSolid

bool UE::Geometry::FConvexDecomposition3::bTreatAsSolid = true

◆ ConnectedComponentTolerance

double UE::Geometry::FConvexDecomposition3::ConnectedComponentTolerance = 1e-3

◆ ConvexEdgeAngleMoreSamplesThreshold

double UE::Geometry::FConvexDecomposition3::ConvexEdgeAngleMoreSamplesThreshold = 30

◆ ConvexEdgeAngleThreshold

double UE::Geometry::FConvexDecomposition3::ConvexEdgeAngleThreshold = 170

◆ CutLargestAxisErrorScale

double UE::Geometry::FConvexDecomposition3::CutLargestAxisErrorScale = .99

◆ Decomposition

TIndirectArray<FConvexPart> UE::Geometry::FConvexDecomposition3::Decomposition

◆ DecompositionToProximity

TMultiMap<int32, int32> UE::Geometry::FConvexDecomposition3::DecompositionToProximity

◆ MaxConvexEdgePlanes

int32 UE::Geometry::FConvexDecomposition3::MaxConvexEdgePlanes = 50

◆ OnPlaneTolerance

double UE::Geometry::FConvexDecomposition3::OnPlaneTolerance = 1e-7

◆ Proximities

TArray<FProximity> UE::Geometry::FConvexDecomposition3::Proximities

◆ ProximityTolerance

double UE::Geometry::FConvexDecomposition3::ProximityTolerance = 1e-3

◆ RestrictMergeSearchToLocalAfterTestNumConnections

int32 UE::Geometry::FConvexDecomposition3::RestrictMergeSearchToLocalAfterTestNumConnections = -1

◆ ResultTransform

FTransformSRT3d UE::Geometry::FConvexDecomposition3::ResultTransform = FTransformSRT3d::Identity()

Transform taking the result hull vertices back to the original space of the inputs; automatically applied by GetVertices()

◆ ThickenAfterHullFailure

double UE::Geometry::FConvexDecomposition3::ThickenAfterHullFailure = 0

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

Engine/Source/Runtime/GeometryCore/Public/CompGeom/ConvexDecomposition3.h
Engine/Source/Runtime/GeometryCore/Private/CompGeom/ConvexDecomposition3.cpp

Classes

Public Member Functions

Static Public Member Functions

Public Attributes

Constructor & Destructor Documentation

◆ FConvexDecomposition3() [1/3]

◆ FConvexDecomposition3() [2/3]

◆ FConvexDecomposition3() [3/3]

Member Function Documentation

◆ Compact()

◆ Compute()

◆ ConvertDistanceToleranceToLocalSpace()

◆ ConvertDistanceToleranceToLocalVolumeTolerance()

◆ ConvexPartVsSphereOverlap()

◆ CountMergedParts()

◆ DeleteProximity()

◆ FixHullOverlapsInNegativeSpace()

◆ GetHullMesh()

◆ GetHullSourceID()

◆ GetInternalMesh()

◆ GetNegativeSpace()

◆ GetTriangles()

◆ GetVertices()

◆ InitializeFromHulls()

◆ InitializeFromIndexMesh() [1/2]

◆ InitializeFromIndexMesh() [2/2]

◆ InitializeFromMesh() [1/2]

◆ InitializeFromMesh() [2/2]

◆ InitializeNegativeSpace()

◆ InitializeProximityFromDecompositionBoundingBoxOverlaps()

◆ IsInputSolid()

◆ MergeBest() [1/2]

◆ MergeBest() [2/2]

◆ NumHulls()

◆ SplitWorst()

◆ UpdateProximitiesAfterSplit()

Member Data Documentation

◆ BiasToRemoveTooThinParts

◆ bSplitDisconnectedComponents

◆ bTreatAsSolid

◆ ConnectedComponentTolerance

◆ ConvexEdgeAngleMoreSamplesThreshold

◆ ConvexEdgeAngleThreshold

◆ CutLargestAxisErrorScale

◆ Decomposition

◆ DecompositionToProximity

◆ MaxConvexEdgePlanes

◆ OnPlaneTolerance

◆ Proximities

◆ ProximityTolerance

◆ RestrictMergeSearchToLocalAfterTestNumConnections

◆ ResultTransform

◆ ThickenAfterHullFailure