UE::Geometry::FMeshSelfUnion Class Reference

#include <MeshSelfUnion.h>

Public Member Functions
	FMeshSelfUnion (FDynamicMesh3 *MeshIn)
virtual	~FMeshSelfUnion ()
EOperationValidationResult	Validate ()
GEOMETRYCORE_API bool	Compute ()

Public Attributes
bool	bCollapseDegenerateEdgesOnCut = true
double	DegenerateEdgeTolFactor = 1.5
double	SnapTolerance = FMathf::ZeroTolerance * 1.0
double	NormalOffset = FMathf::ZeroTolerance * 1.0
double	WindingThreshold = .5
bool	bTrimFlaps = false
bool	bWeldSharedEdges = true
bool	bTrackAllNewEdges = false
FProgressCancel *	Progress = nullptr
bool	bSimplifyAlongNewEdges = false
double	SimplificationAngleTolerance = .1
double	TryToImproveTriQualityThreshold = .25
bool	bPreserveTriangleGroups = true
bool	bPreserveVertexUVs = true
bool	bPreserveOverlayUVs = true
float	UVDistortTolerance = FMathf::ZeroTolerance
bool	bPreserveVertexNormals = true
float	NormalDistortTolerance = .01f
FDynamicMesh3 *	Mesh
TArray< int >	CreatedBoundaryEdges
TSet< int32 >	AllNewEdges

Protected Member Functions
virtual bool	Cancelled ()

Detailed Description

MeshSelfUnion – perform a "Mesh Boolean" style union of a mesh on itself, resolving any self intersections and welding the new boundaries as needed

Constructor & Destructor Documentation

FMeshSelfUnion()

UE::Geometry::FMeshSelfUnion::FMeshSelfUnion ( FDynamicMesh3 *  MeshIn )

inline

~FMeshSelfUnion()

virtual UE::Geometry::FMeshSelfUnion::~FMeshSelfUnion ( )

inlinevirtual

Member Function Documentation

Cancelled()

virtual bool UE::Geometry::FMeshSelfUnion::Cancelled ( )

inlineprotectedvirtual

If this returns true, abort computation.

Compute()

bool FMeshSelfUnion::Compute

(

)

Compute the plane cut by splitting mesh edges that cross the cut plane, and then deleting any triangles on the positive side of the cutting plane.

Returns

true if operation succeeds

Validate()

EOperationValidationResult UE::Geometry::FMeshSelfUnion::Validate ( )

inline

Returns

EOperationValidationResult::Ok if we can apply operation, or error code if we cannot

Member Data Documentation

AllNewEdges

TSet<int32> UE::Geometry::FMeshSelfUnion::AllNewEdges

All edges created by mesh boolean algorithm. Only populated if bTrackAllNewEdges = true

bCollapseDegenerateEdgesOnCut

bool UE::Geometry::FMeshSelfUnion::bCollapseDegenerateEdgesOnCut = true

Whether to do additional processing to try to remove degenerate edges

bPreserveOverlayUVs

bool UE::Geometry::FMeshSelfUnion::bPreserveOverlayUVs = true

Prevent simplification from distorting overlay UVs

bPreserveTriangleGroups

bool UE::Geometry::FMeshSelfUnion::bPreserveTriangleGroups = true

Prevent simplification from distorting triangle groups

bPreserveVertexNormals

bool UE::Geometry::FMeshSelfUnion::bPreserveVertexNormals = true

Prevent simplification from distorting vertex normals

bPreserveVertexUVs

bool UE::Geometry::FMeshSelfUnion::bPreserveVertexUVs = true

Prevent simplification from distorting vertex UVs

bSimplifyAlongNewEdges

bool UE::Geometry::FMeshSelfUnion::bSimplifyAlongNewEdges = false

Control whether we attempt to auto-simplify the small planar triangles that the boolean operation tends to generate

bTrackAllNewEdges

bool UE::Geometry::FMeshSelfUnion::bTrackAllNewEdges = false

Control whether new edges should be tracked

bTrimFlaps

bool UE::Geometry::FMeshSelfUnion::bTrimFlaps = false

Whether to remove visible "open" geometry

bWeldSharedEdges

bool UE::Geometry::FMeshSelfUnion::bWeldSharedEdges = true

Weld newly-created cut edges where the mesh is unioned with itself. If false, newly joined surfaces remain topologically disconnected.

CreatedBoundaryEdges

TArray<int> UE::Geometry::FMeshSelfUnion::CreatedBoundaryEdges

Boundary edges created by the mesh boolean algorithm failing to cleanly weld (doesn't include boundaries that already existed in source mesh)

DegenerateEdgeTolFactor

double UE::Geometry::FMeshSelfUnion::DegenerateEdgeTolFactor = 1.5

Tolerance factor (multiplied by SnapTolerance) for removing short edges created by the cutting process; should be no more than 2

Mesh

FDynamicMesh3* UE::Geometry::FMeshSelfUnion::Mesh

NormalDistortTolerance

float UE::Geometry::FMeshSelfUnion::NormalDistortTolerance = .01f

When preserving normals, sets maximum allowed change in normals from collapsing an edge, measured at the removed vertex in degrees

NormalOffset

double UE::Geometry::FMeshSelfUnion::NormalOffset = FMathf::ZeroTolerance * 1.0

Amount we nudge samples off the surface when evaluating winding number, to avoid numerical issues

Progress

FProgressCancel* UE::Geometry::FMeshSelfUnion::Progress = nullptr

Set this to be able to cancel running operation

SimplificationAngleTolerance

double UE::Geometry::FMeshSelfUnion::SimplificationAngleTolerance = .1

Degrees of deviation from coplanar that we will still simplify

SnapTolerance

double UE::Geometry::FMeshSelfUnion::SnapTolerance = FMathf::ZeroTolerance * 1.0

Tolerance distance for considering a point to be on a vertex or edge, especially during mesh-mesh cutting

TryToImproveTriQualityThreshold

double UE::Geometry::FMeshSelfUnion::TryToImproveTriQualityThreshold = .25

If triangle quality (aspect ratio) is worse than this threshold, only simplify in ways that improve quality. If <= 0, triangle quality is ignored. Note: For aspect ratio we use definition: 4*TriArea / (sqrt(3)*MaxEdgeLen^2), ref: https://people.eecs.berkeley.edu/~jrs/papers/elemj.pdf p.53 Equilateral triangles have value 1; Smaller values -> lower quality

UVDistortTolerance

float UE::Geometry::FMeshSelfUnion::UVDistortTolerance = FMathf::ZeroTolerance

When preserving UVs, sets maximum allowed change in UV coordinates from collapsing an edge, measured at the removed vertex

WindingThreshold

double UE::Geometry::FMeshSelfUnion::WindingThreshold = .5

Threshold to determine whether triangle in one mesh is inside or outside of the other

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

• Engine/Source/Runtime/GeometryCore/Public/Operations/MeshSelfUnion.h
• Engine/Source/Runtime/GeometryCore/Private/Operations/MeshSelfUnion.cpp