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  3. FImageOccupancyMap

FImageOccupancyMap

ImageOccupancyMap calculates and stores coverage information for a 2D image/texture, for example coverage derived from UV islands of a mesh, 2D polygons, etc.

API > API/Runtime > API/Runtime/GeometryCore

ImageOccupancyMap calculates and stores coverage information for a 2D image/texture, for example coverage derived from UV islands of a mesh, 2D polygons, etc.

An optional set of gutter texels can be calculated, and correspondence between gutter texels and the nearest interior texel is stored.

In addition, a 2D coordinate (eg UV) and integer ID (eg Triangle ID) of each texel can be calculated/stored. This is not just a cache. For 'border' texels where the texel center is technically outside the mesh/polygon, but the texel rectangle may still overlap the shape, the nearest UV/Triangle is stored. This simplifies computing samples around the borders such that the shape is covered under linear interpolatione/etc.

TODO Some of the names in this class are misleading because the name mentions "Texel" but should actually say "Sample" this is because the class initially supported only one sample per texel but later multi-sampling was added

   
Name FImageOccupancyMap
Type class
Header File /Engine/Source/Runtime/GeometryCore/Public/Image/ImageOccupancyMap.h
Include Path #include "Image/ImageOccupancyMap.h"

Syntax

class FImageOccupancyMap

Typedefs

Name Type Remarks Include Path
FGridSampler TGridSampler< double >   Image/ImageOccupancyMap.h

Constants

Name Type Remarks Include Path
BorderTexel int8   Image/ImageOccupancyMap.h
EmptyTexel int8 Texel types Image/ImageOccupancyMap.h
GutterTexel int8   Image/ImageOccupancyMap.h
InteriorTexel int8   Image/ImageOccupancyMap.h

Variables

Public

Name Type Remarks Include Path Unreal Specifiers
BorderTexels TArray64< TTuple< int64, int64 > > Set of Border Texels, Pair is , so Border can be filled by directly copying from source to target. Image/ImageOccupancyMap.h  
bParallel bool   Image/ImageOccupancyMap.h  
Dimensions FImageDimensions Image Dimensions Image/ImageOccupancyMap.h  
GutterSize int32 Width of the gutter. Image/ImageOccupancyMap.h  
GutterTexels TArray64< TTuple< int64, int64 > > Set of Gutter Texels. Image/ImageOccupancyMap.h  
PixelSampler FGridSampler   Image/ImageOccupancyMap.h  
TexelInteriorSamples TArray64< int32 > Count of interior samples for each texel in Tile. Size = Tile.GetWidth() x Tile.GetHeight(). Image/ImageOccupancyMap.h  
TexelQueryTriangle TArray64< int32 > Integer/Triangle ID for each sample in Tile. Image/ImageOccupancyMap.h  
TexelQueryUV TArray64< FVector2f > UV for each sample in Tile. Size = Tile.GetWidth() x Tile.GetHeight() x SamplesPerPixel. Image/ImageOccupancyMap.h  
TexelQueryUVChart TArray64< int32 > UV Chart ID for each texel in Tile. Image/ImageOccupancyMap.h  
TexelType TArray64< int8 > Classification of each sample in Tile. Size = Tile.GetWidth() x Tile.GetHeight() x SamplesPerPixel. Image/ImageOccupancyMap.h  
Tile FImageTile   Image/ImageOccupancyMap.h  

Functions

Public

Name Remarks Include Path Unreal Specifiers

bool ClassifySamplesFromUVSpaceMesh ( const MeshType& UVSpaceMesh,
GetTriangleIDFuncType GetTriangleIDFunc,
const TArray< int32 >* UVSpaceMeshTriCharts
)

 Void SetTexelType(int64 X, int64 Y, int8 Type) Image/ImageOccupancyMap.h  

bool ClassifySamplesFromUVSpaceMesh ( const MeshType& UVSpaceMesh,
const TMeshAABBTree3< MeshType >& UVSpaceMeshSpatial,
GetTriangleIDFuncType GetTriangleIDFunc,
const TArray< int32 >* UVSpaceMeshTriCharts
)

   Image/ImageOccupancyMap.h  

bool ComputeFromUVSpaceMesh ( const MeshType& UVSpaceMesh,
GetTriangleIDFuncType GetTriangleIDFunc,
const TArray< int32 >* UVSpaceMeshTriCharts
)

 Computes the image occupancy map from a UV space mesh. Image/ImageOccupancyMap.h  

bool ComputeGutterTexelsFromGutterSamples()

   Image/ImageOccupancyMap.h  

void Initialize ( FImageDimensions DimensionsIn,
int32 SamplesPerPixel
)

   Image/ImageOccupancyMap.h  

void Initialize ( FImageDimensions DimensionsIn,
const FImageTile& TileIn,
int32 SamplesPerPixel
)

   Image/ImageOccupancyMap.h  

bool IsInterior ( int64 LinearIndex
) const

   Image/ImageOccupancyMap.h  

void ParallelProcessingPass ( TFunctionRef< TexelValueType(int64 LinearIdx)> BeginTexel,
TFunctionRef< void(int64 LinearIdx, float Weight, TexelValueType&)> AccumulateTexel,
TFunctionRef< void(int64 LinearIdx, float Weight, TexelValueType&)> CompleteTexel,
TFunctionRef< void(int64 LinearIdx, TexelValueType&)> WriteTexel,
TFunctionRef< float(const FVector2i&TexelOffset)> WeightFunction,
int32 FilterWidth,
TArray< TexelValueType >& PassBuffer
) const

   Image/ImageOccupancyMap.h  

int32 TexelNumSamples ( int64 LinearIndex
) const

   Image/ImageOccupancyMap.h  

Protected

Name Remarks Include Path Unreal Specifiers

void InitializePixelSampler ( const int32 SamplesPerPixelIn
)

 Initialize the pixel sampler. Image/ImageOccupancyMap.h  

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