FDeformableEdgePath | Unreal Engine 5.2 Documentation

API > API/Plugins > API/Plugins/DynamicMesh > API/Plugins/DynamicMesh/Operations

References


Module	DynamicMesh
Header	/Engine/Plugins/Runtime/GeometryProcessing/Source/DynamicMesh/Public/Operations/GeodesicPath.h
Include	#include "Operations/GeodesicPath.h"

Syntax

class FDeformableEdgePath

Remarks

Given a single path initially defined by edges on a FDynamicMesh (the SurfaceMesh), this class uses an intrinsic mesh with the same vertex set to minimize the length of the path on the surface mesh. This is done iteratively by a succession of local path deformations comprised of (local) intrisic edge flips and path re-routing, each deformation locally reduces the path length. The resulting path is comprised of intrinsic mesh edges.

This is an implementation of the ideas in "You Can Find Geodesic Paths in Triangle Meshes by Just Flipping Edges" by Nicholas Sharp and Keenan Crane ACM Trans. Graph. Vol. 39, No. 6, 2020

The original path is constructed as a sequence of mesh edges relative to the SurfaceMesh ( the FDynamicMesh3 ), these edges are encoded with path direction as FDirectedSegments. Note: The current implementation does not support closed paths or multiple paths.

Variables

	Type	Name	Description
	IntrinsicMeshType	EdgeFlipMesh
	FEdgePath	EdgePath
	TMap< int32, TArray< int32 > >	EIDToSIDsMap
	FBinaryHeap< double >	JointAngleQueue
	int32	NumFlips
	TDynamicVector< FPathJoint >	PathJoints
	double	PathLength

Constructors

	Type	Name	Description
		FDeformableEdgePath ()	Only allow construction from a path and mesh.
		FDeformableEdgePath ( const FDeformableEdgePath& )
		FDeformableEdgePath ( const FDynamicMesh3& SurfaceMeshIn, const TArray< FEdgePath::FDirectedSegment >& OriginalPathAsDirectedSegments )	Constructor assumes the directed segments are ordered from tail (at index 0) to head

Destructors

	Type	Name	Description
		~FDeformableEdgePath ()

Functions

Type	Name	Description
TArray< FSurfacePoint >	AsSurfacePoints ( double CoalesceThreshold )
void	ComputeWedgeAngles ( int32 IncomingEID, int32 OutgoingEID, int32 CenterVID, double& LeftSideAngle, double& RightSideAngle )	Compute the two angles formed at the vertex CenterVID by the two wedges formed by splitting the local one-ring by local path specified as incoming and outgoing edges.
bool	DeformJoint ( const int32 IncomingEID, const int32 OutgoingEID, int32 JointVID, TArray< FEdgePath::FDirectedSegment >& DeformedPath, const bool bClockwise )	Edge flip the adjacent edges to the JointVID and collect the DeformedPath that can be used to replace the local incoming and outgoing edge path
void	DeformJoint ( FPathJoint& PathJoint )	Replace the specified two connected edge segments (FPathJoint) in the main path with a new sub-path that connects the same end points.
const FEdgePath &	GetEdgePath ()
const FIntrinsicEdgeFlipMesh &	GetIntrinsicMesh ()
double	GetPathLength ()
bool	IsJointFlexible ( const FPathJoint& PathJoint )
void	Minimize ( FEdgePathDeformationInfo& DeformedPathInfo, const int32 MaxNumIterations )	Minimize the deformable edge path with respect to the total path length.
bool	OuterArcFlipEdges ( int32 StartEID, int32 EndEID, int32 CenterVID, bool bClockwise )	Traveling either CCW or CW around vertex CenterVID, from edge StartEID to edge EndEID, flip edges adjacent to CVID.
void	RemoveSegment ( int32 SID )	Remove specified segment from the linked-list path and clean up joint-related data for the joint that ends with this segment.
void	ReplaceJointWithPath ( const FPathJoint PathJoint, const TArray< FEdgePath::FDirectedSegment >& PathAsDirectedEdges )	Splice in a path to replace the joint and update the joint angle queue.
int32	SegmentHeadVID ( int32 SID )
int32	SegmentTailVID ( int32 SID )
void	UpdateJointAndQueue ( int32 OutgoingSegmentID )	Compute data associated with the joint formed by the specified segment (outgoing), and the preceding segment (incoming) in the path.