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  3. TMeshLocalParam

TMeshLocalParam

[TMeshLocalParam](API\Runtime\GeometryCore\Parameterization\TMeshLocalParam) computes a local UV parameterization of a set of connected PointsWithNormals, where "local" means "in a geodesic disc around a starting point".

API > API/Runtime > API/Runtime/GeometryCore > API/Runtime/GeometryCore/Parameterization

References

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

Syntax

template<class PointSetType>  
class TMeshLocalParam

Remarks

TMeshLocalParam computes a local UV parameterization of a set of connected PointsWithNormals, where "local" means "in a geodesic disc around a starting point".

The computation is based on region-growing, and geodesic distances are actually graph distances, measured with Dijkstras algorithm.

Templated on the point set type, which must provide positions, normals, and neighbours. Currently will only work for FDynamicMesh3 and FDynamicPointSet3 because of call to PointSetType->VtxVerticesItr()

Variables

  Type Name Description
Protected variable TDynamicVector< FGraphNode > AllocatedNodes  
Public variable bool bEnableExternalNormals If true, ExternalNormalFunc will be used to fetch normals instead of requesting from PointSet->GetVertexNormal.
Public variable TFunction< FVector3d(int32)> ExternalNormalFunc Normals will be requested from this function if bEnableExternalNormals == true
Protected variable TMap< int32, int32 > IDToNodeIndexMap To avoid constructing FGraphNode for all input points (because we are computing a "local" param), we only allocate on demand, and then store a sparse mapping in IDToNodeIndexMap
Protected variable double MaxGraphDistance Max distances encountered during last compute
Protected variable double MaxUVDistance  
Public variable ELocalParamTypes ParamMode Type of local parameterization to compute
Public variable const PointSetType * PointSet  
Protected variable FIndexPriorityQueue Queue Queue of nodes to process (for dijkstra front propagation)
Protected variable FFrame3d SeedFrame Seed frame, unwrap is centered around this position/axes

Constructors

  Type Name Description
Public function  

TMeshLocalParam ( const PointSetType* PointSetIn
)

  

Functions

  Type Name Description
Public function Const void

ApplyUVs ( TFunctionRef< void(int32 PointID, const FVector2d&UV)> ApplyFunc
)

 Apply a function to each calculated UV
Protected function Const FVector2d

ComputeLocalUV ( const FFrame3d& Frame,
FVector3d Position
)

  
Public function void

ComputeToMaxDistance ( int32 CenterPointVtxID,
const FFrame3d& CenterPointFrame,
double ComputeToMaxDistanceIn
)

 Computes UVs outwards from seed vertex to all points that are less/equal to ComputeToMaxDistance from the seed.
Public function void

ComputeToMaxDistance ( const FFrame3d& SeedFrameIn,
const FIndex3i& SeedNbrs,
double ComputeToMaxDistanceIn
)

 Computes UVs outwards from seed frame/nbrs to all points that are less/equal to ComputeToMaxDistance from the seed.
Public function Const void

GetAllComputedUVs ( TArray< int32 >& PointIDsOut,
TArray< FVector2d >& PointUVsOut,
double MaxUVMagnitude,
double MaxGraphDist
)

 Find all computed UVs within the specified distances
Protected function Const FFrame3d

GetFrame ( const FGraphNode& Node
)

  
Public function Const double  
Public function Const double  
Protected function Const const FGraphNode *

GetNodeForPointSetID ( int32 PointSetID
)

  
Protected function FGraphNode *

GetNodeForPointSetID ( int32 PointSetID,
bool bCreateIfMissing
)

  
Protected function Const FVector3d

GetNormal ( const int32 PointID
)

  
Public function Const void

GetPointsWithUV ( TArray< int32 >& Points
)

  
Protected function Const FVector3d

GetPosition ( const int32 PointID
)

  
Public function Const FVector2d

GetUV ( int32 PointID
)

  
Public function Const FAxisAlignedBox2d  
Public function Const bool

HasUV ( int32 PointID
)

  
Protected function Static FVector2d  
Protected function void

ProcessQueueUntilTermination ( double MaxDistance
)

  
Protected function Const FVector2d

PropagateUV ( const FVector3d& Position,
const FVector2d& NbrUV,
const FFrame3d& NbrFrame,
const FFrame3d& SeedFrameIn
)

 Calculate the UV value at Position based on the existing NbrUV, using the frame at NbrFrame, and the original SeedFrame
Public function void

Reset ()

 Reset internal data structures but keep allocated memory
Public function void

TransformUV ( double Scale,
FVector2d Translate
)

 Scale and then Translate all calculated UV values
Protected function void Given new Distance/UV at Parent, check if any of its neighbours are in the queue, and if they are, and the new graph distance is shorter, update their queue position (this is basically the update step of Disjktras algorithm)
Protected function void  
Protected function void  
Protected function void  

Classes

  Type Name Description
Protected struct FGraphNode Information about each active/computed point  

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