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  3. FMeshRegionBoundaryLoops

FMeshRegionBoundaryLoops

Extract FEdgeLoops on the boundary of a set of triangles of a mesh.

API > API/Runtime > API/Runtime/GeometryCore

References

   
Module GeometryCore
Header /Engine/Source/Runtime/GeometryCore/Public/MeshRegionBoundaryLoops.h
Include #include "MeshRegionBoundaryLoops.h"

Syntax

class FMeshRegionBoundaryLoops

Remarks

Extract FEdgeLoops on the boundary of a set of triangles of a mesh.

Variables

  Type Name Description
Public variable bool bFailed If true, we did not completely succeed in extracting all loops
Protected variable FIndexFlagSet Edges  
Protected variable TArray< int > edges_roi  
Public variable TArray< FEdgeLoop > Loops Resulting set of loops filled by Compute()
Public variable const FDynamicMesh3 * Mesh Mesh we are finding loops on
Protected variable FIndexFlagSet Triangles Sets of included triangles and edges

Constructors

  Type Name Description
Public function    
Public function  

FMeshRegionBoundaryLoops ( const FDynamicMesh3* MeshIn,
const TArray< int >& RegionTris,
bool bAutoCompute
)

  

Functions

  Type Name Description
Public function bool

Compute ()

 Find set of FEdgeLoops on the border of the input triangle set
Protected function int

FindLeftTurnEdge ( int incoming_e,
int bowtie_v,
TArray< int >& bdry_edges,
int bdry_edges_count,
const FIndexFlagSet& used_edges
)

 Ok, bdry_edges[0...bdry_edges_count] contains the boundary edges coming out of bowtie_v.
Protected function int

GetAllVertexBoundaryEdges ( int vID,
TArray< int >& e
)

 E needs to be large enough (ie call GetVtxBoundaryEdges, or as large as max one-ring) returns count, ie number of elements of e that were filled
Public function Const int32  
Public function bool

GetLoopOverlayMap ( const FEdgeLoop& LoopIn,
const TDynamicMeshOverlay< StorageType, ElementSize >& Overlay,
VidOverlayMap< ElementType >& LoopVidsToOverlayElementsOut
)

 Generates a map from vertex ID's of the loop vertices to corresponding overlay element ID's and values.
Public function Const const TArray< FEdgeLoop > &  
Public function Const int  
Protected function FIndex2i

GetOrientedEdgeVerts ( int eID,
int tid_in
)

 Return same indices as GetEdgeV, but oriented based on attached triangle
Public function Static bool

GetTriangleSetBoundaryLoop ( const FDynamicMesh3& Mesh,
const TArray< int32 >& Tris,
FEdgeLoop& Loop
)

 Find the edge loop border around a set of triangles of a Mesh.
Protected function int

GetVertexBoundaryEdges ( int vID,
int& e0,
int& e1
)

 Returns first two boundary edges, and count of total boundary edges
Protected function FVector3d

GetVertexNormal ( int vid
)

 [TODO] cache this : a dictionary? we will not need very many, but we will need each multiple times!
Protected function Const bool

IsEdgeOnBoundary ( int eid
)

  
Protected function Const bool

IsEdgeOnBoundary ( int eid,
int& tid_in,
int& tid_out
)

 Returns true for both internal and mesh boundary edges tid_in and tid_out are triangles 'in' and 'out' of set, respectively
Public function Const int32

Num ()

  
Public function void

SetMesh ( const FDynamicMesh3* MeshIn,
const TArray< int >& RegionTris
)

  
Protected function bool

TryExtractSubloops ( TArray< int >& loopV,
const TArray< int >& loopE,
const TArray< int >& bowties,
TArray< FEdgeLoop >& SubLoopsOut
)

 This is called when loopV contains one or more "bowtie" vertices.
Public function void

UpdateLoopOverlayMapValidity ( VidOverlayMap< ElementType >& LoopVidsToOverlayElements,
const TDynamicMeshOverlay< StorageType, ElementSize >& Overlay
)

 Given a map generated by GetLoopOverlayMap(), checks that the overlay elements pointed to by the map still exist in the overlay, and sets the ID to be invalid if not.

Operators

  Type Name Description
Public function Const const FEdgeLoop &

operator[] ( int Index
)

  

Typedefs

Name Description
ElementIDAndValue  
VidOverlayMap  

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