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  3. FDynamicMeshEditor

FDynamicMeshEditor

[FDynamicMeshEditor](API\Runtime\GeometryCore\FDynamicMeshEditor) implements low-level mesh editing operations.

API > API/Runtime > API/Runtime/GeometryCore

References

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

Syntax

class FDynamicMeshEditor

Remarks

FDynamicMeshEditor implements low-level mesh editing operations. These operations can be used to construct higher-level operations. For example an Extrude operation could be implemented via DuplicateTriangles() and StitchLoopMinimal().

Variables

  Type Name Description
Public variable FDynamicMesh3 * Mesh The mesh we will be editing

Constructors

  Type Name Description
Public function    

Functions

  Type Name Description
Public function bool

AddTriangleFan_OrderedVertexLoop ( int CenterVertex,
const TArray< int >& VertexLoop,
int GroupID,
FDynamicMeshEditResult& ResultOut
)

 Fill hole with a triangle fan given an existing (unconnected) center vertex and an ordered loop of boundary vertices on the hole border.
Public function void

AppendColors ( const FDynamicMesh3* AppendMesh,
const FDynamicMeshColorOverlay* FromOverlay,
FDynamicMeshColorOverlay* ToOverlay,
const FIndexMapi& VertexMap,
const FIndexMapi& TriangleMap,
FIndexMapi& ColorMapOut
)

 Append Colors from one attribute overlay to another.
Public function void

AppendElementSubset ( const FDynamicMesh3* FromMesh,
const TSet< int >& TriangleROI,
const TSet< int >& VertexROI,
const TDynamicMeshOverlay< RealType, ElementSize >* FromOverlay,
TDynamicMeshOverlay< RealType, ElementSize >* ToOverlay
)

 Append overlay elements in both ROIs from one overlay to another
Public function void

AppendMesh ( const TTriangleMeshAdapter< double >* AppendMesh,
FMeshIndexMappings& IndexMapsOut,
TFunction< FVector3d(int, const FVector3d&)> PositionTransform
)

 Append input mesh to our internal Mesh.
Public function void

AppendMesh ( const FDynamicMesh3* AppendMesh,
FMeshIndexMappings& IndexMapsOut,
TFunction< FVector3d(int, const FVector3d&)> PositionTransform,
TFunction< FVector3d(int, const FVector3d&)> NormalTransform,
bool bReverseOrientation
)

 Append input mesh to our internal mesh
Public function void

AppendNormals ( const FDynamicMesh3* AppendMesh,
const FDynamicMeshNormalOverlay* FromNormals,
FDynamicMeshNormalOverlay* ToNormals,
const FIndexMapi& VertexMap,
const FIndexMapi& TriangleMap,
TFunction< FVector3d(int, const FVector3d&)> NormalTransform,
FIndexMapi& NormalMapOut
)

 Append normals from one attribute overlay to another.
Public function void

AppendTriangles ( const FDynamicMesh3* SourceMesh,
const TArrayView< const int >& SourceTriangles,
FMeshIndexMappings& IndexMaps,
FDynamicMeshEditResult& ResultOut,
bool bComputeTriangleMap
)

 Append triangles of an existing mesh.
Public function void

AppendUVs ( const FDynamicMesh3* AppendMesh,
const FDynamicMeshUVOverlay* FromUVs,
FDynamicMeshUVOverlay* ToUVs,
const FIndexMapi& VertexMap,
const FIndexMapi& TriangleMap,
FIndexMapi& UVMapOut
)

 Append UVs from one attribute overlay to another.
Public function FVector3f

ComputeAndSetQuadNormal ( const FIndex2i& QuadTris,
bool bIsPlanar
)

 Calculate and set the per-triangle normals of the two input quads.
Public function Static bool

ConvertLoopToTriVidPairSequence ( const FDynamicMesh3& Mesh,
const TArray< int32 >& VidLoop,
const TArray< int32 >& EdgeLoop,
TArray< TPair< int32, TPair< int8, int8 > > >& TriVertPairsOut
)

 Converts a loop to a sequence of edge identifiers that are both Vid and Eid independent.
Public function void

CopyAttributes ( int FromTriangleID,
int ToTriangleID,
FMeshIndexMappings& IndexMaps,
FDynamicMeshEditResult& ResultOut
)

 Copy all attribute-layer values from one triangle to another, using the IndexMaps to track and re-use shared attribute values.
Public function Static bool

CreateSeamsAtEdges ( const TSet< int32 >& EidsToMakeIntoSeams,
TDynamicMeshOverlay< float, 3 >* Overlay,
TArray< int32 >* AddedElementIDs
)

 Cut existing 3D attribute overlay topology with a set of edges.
Public function Static bool

CreateSeamsAtEdges ( const TSet< int32 >& EidsToMakeIntoSeams,
TDynamicMeshOverlay< float, 2 >* Overlay,
TArray< int32 >* AddedElementIDs
)

 Cut existing 2D attribute overlay topology with a set of edges.
Public function void

DisconnectTriangles ( const TArray< int >& Triangles,
bool bPreventBowties
)

 Disconnects triangles (without constructing boundary loops) such that the input Triangles are not connected to any other triangles in the mesh
Public function bool

DisconnectTriangles ( const TArray< int >& Triangles,
TArray< FLoopPairSet >& LoopSetOut,
bool bHandleBoundaryVertices
)

 Finds boundary loops of connected components of a set of triangles, and duplicates the vertices along the boundary, such that the triangles become disconnected.
Public function bool

DisconnectTriangles ( const TSet< int >& TriangleSet,
const TArray< FEdgeLoop >& BoundaryLoops,
TArray< FLoopPairSet >& LoopSetOut,
bool bAllowBoundaryVertices
)

 Variant of DisconnectTriangles that takes a precomputed set of BoundaryLoops of the triangles, and a TSet of Triangles.
Public function bool

DisconnectTrianglesAlongEdges ( const TSet< int32 >& Edges,
TArray< int32 >* AddedVertexIDs
)

 Disconnect triangles along the given Edges, so that all input edges become boundary edges.
Public function void

DuplicateTriangles ( const TArray< int >& Triangles,
FMeshIndexMappings& IndexMaps,
FDynamicMeshEditResult& ResultOut
)

 Duplicate triangles of a mesh.
Public function int

FindOrCreateDuplicateColor ( int ElementID,
FMeshIndexMappings& IndexMaps,
FDynamicMeshEditResult* ResultOut
)

 Find "new" color for input color element under Index mapping, or create new if missing
Public function int

FindOrCreateDuplicateGroup ( int TriangleID,
FMeshIndexMappings& IndexMaps,
FDynamicMeshEditResult& ResultOut
)

 Find "new" group for input group under Index mapping, or create new if missing
Public function int

FindOrCreateDuplicateNormal ( int ElementID,
int NormalLayerIndex,
FMeshIndexMappings& IndexMaps,
FDynamicMeshEditResult* ResultOut
)

 Find "new" normal for input normal element under Index mapping, or create new if missing
Public function int

FindOrCreateDuplicateUV ( int ElementID,
int UVLayerIndex,
FMeshIndexMappings& IndexMaps
)

 Find "new" UV for input UV element under Index mapping, or create new if missing
Public function int

FindOrCreateDuplicateVertex ( int VertexID,
FMeshIndexMappings& IndexMaps,
FDynamicMeshEditResult& ResultOut
)

 Mesh element copying / duplication
Public function void

InvertTriangleNormals ( const TArray< int >& Triangles
)

 Flip the normals of the given triangles.
Public function bool

ReinsertSubmesh ( const FDynamicSubmesh3& Submesh,
FOptionallySparseIndexMap& SubToNewV,
TArray< int >* NewTris,
EDuplicateTriBehavior DuplicateBehavior
)

 Update a Base Mesh from a Submesh; See FMeshRegionOperator::BackPropropagate for a usage example.
Public function bool Remove any vertices that are not used by any triangles
Public function Static bool

RemoveSeamsAtEdges ( const TSet< int32 >& EidsToRemoveAsSeams,
TDynamicMeshOverlay< float, 3 >* Overlay
)

 Merge any seams in the given (3D attribute) Overlay along the given mesh edge IDs
Public function Static bool

RemoveSeamsAtEdges ( const TSet< int32 >& EidsToRemoveAsSeams,
TDynamicMeshOverlay< float, 2 >* Overlay
)

 Merge any seams in the given 2D attribute Overlay along the given mesh edge IDs
Public function int

RemoveSmallComponents ( double MinVolume,
double MinArea,
int MinTriangleCount
)

 Remove any connected components with volume or area below the given thresholds
Public function bool

RemoveTriangles ( const TArray< int >& Triangles,
bool bRemoveIsolatedVerts,
TFunctionRef< void(int)> OnRemoveTriFunc
)

 Remove a list of triangles from the mesh, and optionally any vertices that are now orphaned
Public function bool

RemoveTriangles ( const TArray< int >& Triangles,
bool bRemoveIsolatedVerts
)

 Remove a list of triangles from the mesh, and optionally any vertices that are now orphaned
Public function void

RescaleAttributeUVs ( float UVScale,
bool bWorldSpace,
int UVLayerIndex,
TOptional< FTransformSRT3d > ToWorld
)

 Rescale UVs for the whole mesh, for the given UV attribute layer
Public function void

ReverseTriangleOrientations ( const TArray< int >& Triangles,
bool bInvertNormals
)

 Normal utility functions.
Public function void

SetGeneralTubeUVs ( const TArray< int >& Triangles,
const TArray< int >& VertexIDs1,
const TArray< int >& MatchedIndices1,
const TArray< int >& VertexIDs2,
const TArray< int >& MatchedIndices2,
const TArray< float >& UValues,
const FVector3f& VDir,
float UVScaleFactor,
const FVector2f& UVTranslation,
int UVLayerIndex
)

 For triangles connecting loops of corresponded vertices, set UVs in a cylindrical pattern so that the U coordinate starts at 0 for the first corresponded pair of vertices, and cycles around to 1 Assumes Triangles array stores indices of triangles in progressively filling the tube, starting with VertexIDs*[0].
Public function void

SetQuadNormals ( const FIndex2i& QuadTris,
const FVector3f& Normal
)

 Create and set new shared per-triangle normals for a pair of triangles that share one edge (ie a quad)
Public function void

SetQuadUVsFromProjection ( const FIndex2i& QuadTris,
const FFrame3d& ProjectionFrame,
float UVScaleFactor,
const FVector2f& UVTranslation,
int UVLayerIndex
)

 UV utility functions.
Public function void

SetTriangleNormals ( const TArray< int >& Triangles
)

 Create and set new shared per-triangle normals for a list of triangles.
Public function void

SetTriangleNormals ( const TArray< int >& Triangles,
const FVector3f& Normal
)

 Create and set new shared per-triangle normals for a list of triangles
Public function void

SetTriangleUVsFromProjection ( const TArray< int32 >& Triangles,
const FFrame3d& ProjectionFrame,
float UVScaleFactor,
const FVector2f& UVTranslation,
bool bShiftToOrigin,
int32 UVLayerIndex
)

 Project triangles onto a plane defined by the ProjectionFrame and use that to create/set new shared per-triangle UVs.
Public function void

SetTriangleUVsFromProjection ( const TArray< int >& Triangles,
const FFrame3d& ProjectionFrame,
const FVector2f& UVScale,
const FVector2f& UVTranslation,
int UVLayerIndex,
bool bShiftToOrigin,
bool bNormalizeBeforeScaling
)

 Project triangles onto a plane defined by the ProjectionFrame and use that to create/set new shared per-triangle UVs.
Public function void

SetTubeNormals ( const TArray< int >& Triangles,
const TArray< int >& VertexIDs1,
const TArray< int >& MatchedIndices1,
const TArray< int >& VertexIDs2,
const TArray< int >& MatchedIndices2,
bool bReverseNormals
)

 For a 'tube' of triangles connecting loops of corresponded vertices, set smooth normals such that corresponding vertices have corresponding normals
Public function void

SplitBowties ( int VertexID,
TArray< int32 >* NewVertices
)

 Splits any bowties specifically on the given vertex, and (if not null) updates (does not reset!) NewVertices with any added vertices
Public function void Splits all bowties across the whole mesh
Public function void

SplitBowties ( int VertexID,
FDynamicMeshEditResult& ResultOut
)

 Splits any bowties specifically on the given vertex, and updates (does not reset!) ResultOut with any added vertices
Public function void

SplitBowtiesAtTriangles ( const TArray< int32 >& TriangleIDs,
FDynamicMeshEditResult& ResultOut
)

 Splits bowties attached to any of the given triangles, and updates (does not reset!) ResultOut with any added vertices
Public function Static bool

SplitMesh ( const FDynamicMesh3* SourceMesh,
TArray< FDynamicMesh3 >& SplitMeshes,
TFunctionRef< int(int)> TriIDToMeshID,
int DeleteMeshID
)

 Create multiple meshes out of the source mesh by splitting triangles out.
Public function bool

StitchSparselyCorrespondedVertexLoops ( const TArray< int >& VertexIDs1,
const TArray< int >& MatchedIndices1,
const TArray< int >& VertexIDs2,
const TArray< int >& MatchedIndices2,
FDynamicMeshEditResult& ResultOut,
bool bReverseOrientation
)

 Stitch together two loops of vertices where vertices are only sparsely corresponded
Public function bool

StitchVertexLoopsMinimal ( const TArray< int >& VertexLoop1,
const TArray< int >& VertexLoop2,
FDynamicMeshEditResult& ResultOut
)

 Create and Remove Triangle Functions.
Public function bool

StitchVertexLoopToTriVidPairSequence ( const TArray< TPair< int32, TPair< int8, int8 > > >& TriVidPairs1,
const TArray< int >& VertexLoop2,
FDynamicMeshEditResult& ResultOut
)

 Given a sequence of edges in the form given by ConvertLoopToTriVidPairSequence and a loop of vertices, stitch the two together.
Public function bool

WeldVertexLoops ( const TArray< int32 >& VertexLoop1,
const TArray< int32 >& VertexLoop2
)

 Weld together two loops of vertices. Loops must be oriented (ordered) correctly for your use case.

Classes

  Type Name Description
Public struct FLoopPairSet Pair of associated vertex and edge loops.  

Enums

  Type Name Description
Public enum EDuplicateTriBehavior In ReinsertSubmesh, a problem can arise where the mesh we are inserting has duplicate triangles of the base mesh.  

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