UE::Geometry::FImageOccupancyMap Class Reference

#include <ImageOccupancyMap.h>

Public Types
using	FGridSampler = TGridSampler< double >

Public Member Functions
void	Initialize (FImageDimensions DimensionsIn, int32 SamplesPerPixel=1)
void	Initialize (FImageDimensions DimensionsIn, const FImageTile &TileIn, int32 SamplesPerPixel=1)
bool	IsInterior (int64 LinearIndex) const
int32	TexelNumSamples (int64 LinearIndex) const
template<typename MeshType , typename GetTriangleIDFuncType >
bool	ClassifySamplesFromUVSpaceMesh (const MeshType &UVSpaceMesh, GetTriangleIDFuncType GetTriangleIDFunc=[](int32 TriangleID) { return TriangleID;}, const TArray< int32 > *UVSpaceMeshTriCharts=nullptr)
template<typename MeshType , typename GetTriangleIDFuncType >
bool	ClassifySamplesFromUVSpaceMesh (const MeshType &UVSpaceMesh, const TMeshAABBTree3< MeshType > &UVSpaceMeshSpatial, GetTriangleIDFuncType GetTriangleIDFunc=[](int32 TriangleID) { return TriangleID;}, const TArray< int32 > *UVSpaceMeshTriCharts=nullptr)
bool	ComputeGutterTexelsFromGutterSamples ()
template<typename MeshType , typename GetTriangleIDFuncType >
bool	ComputeFromUVSpaceMesh (const MeshType &UVSpaceMesh, GetTriangleIDFuncType GetTriangleIDFunc=[](int32 TriangleID) { return TriangleID;}, const TArray< int32 > *UVSpaceMeshTriCharts=nullptr)
template<typename TexelValueType >
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

Public Attributes
FImageDimensions	Dimensions
FImageTile	Tile
int32	GutterSize = 4
TArray64< int8 >	TexelType
TArray64< int32 >	TexelInteriorSamples
TArray64< FVector2f >	TexelQueryUV
TArray64< int32 >	TexelQueryTriangle
TArray64< int32 >	TexelQueryUVChart
TArray64< TTuple< int64, int64 > >	BorderTexels
TArray64< TTuple< int64, int64 > >	GutterTexels
FGridSampler	PixelSampler = FGridSampler(1)
bool	bParallel = true

Static Public Attributes
static constexpr int8	EmptyTexel = 0
static constexpr int8	InteriorTexel = 1
static constexpr int8	BorderTexel = 2
static constexpr int8	GutterTexel = 3

Protected Member Functions
void	InitializePixelSampler (const int32 SamplesPerPixelIn)

Detailed Description

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

Member Typedef Documentation

FGridSampler

using UE::Geometry::FImageOccupancyMap::FGridSampler = TGridSampler<double>

Member Function Documentation

ClassifySamplesFromUVSpaceMesh() [1/2]

template<typename MeshType , typename GetTriangleIDFuncType >

bool UE::Geometry::FImageOccupancyMap::ClassifySamplesFromUVSpaceMesh ( const MeshType &  UVSpaceMesh, const TMeshAABBTree3< MeshType > &  UVSpaceMeshSpatial, GetTriangleIDFuncType  GetTriangleIDFunc = [](int32 TriangleID) { return TriangleID; }, const TArray< int32 > *  UVSpaceMeshTriCharts = nullptr  )

inline

ClassifySamplesFromUVSpaceMesh() [2/2]

template<typename MeshType , typename GetTriangleIDFuncType >

bool UE::Geometry::FImageOccupancyMap::ClassifySamplesFromUVSpaceMesh ( const MeshType &  UVSpaceMesh, GetTriangleIDFuncType  GetTriangleIDFunc = [](int32 TriangleID) { return TriangleID; }, const TArray< int32 > *  UVSpaceMeshTriCharts = nullptr  )

inline

Set texel type at the given X/Y

ComputeFromUVSpaceMesh()

template<typename MeshType , typename GetTriangleIDFuncType >

bool UE::Geometry::FImageOccupancyMap::ComputeFromUVSpaceMesh ( const MeshType &  UVSpaceMesh, GetTriangleIDFuncType  GetTriangleIDFunc = [](int32 TriangleID) { return TriangleID; }, const TArray< int32 > *  UVSpaceMeshTriCharts = nullptr  )

inline

Computes the image occupancy map from a UV space mesh. This function classifies all the samples in the image, and computes the GutterTexels mapping, if you dont want the mapping you can call ClassifySamplesFromUVSpaceMesh and compute it yourself (eg for texture baking we use filter kernel coverage to compute the GutterTexels mapping)

Parameters

UVSpaceMesh	UV space mesh to compute the occupancy map from.
GetTriangleIDFunc	Lambda to remap a texel's nearest triangle ID
UVSpaceMeshTriCharts	Optional UVSpaceMesh triangle ID to UV chart map

ComputeGutterTexelsFromGutterSamples()

bool UE::Geometry::FImageOccupancyMap::ComputeGutterTexelsFromGutterSamples ( )

inline

Initialize() [1/2]

void UE::Geometry::FImageOccupancyMap::Initialize ( FImageDimensions  DimensionsIn, const FImageTile &  TileIn, int32  SamplesPerPixel = 1  )

inline

Initialize() [2/2]

void UE::Geometry::FImageOccupancyMap::Initialize ( FImageDimensions  DimensionsIn, int32  SamplesPerPixel = 1  )

inline

InitializePixelSampler()

void UE::Geometry::FImageOccupancyMap::InitializePixelSampler ( const int32  SamplesPerPixelIn )

inlineprotected

Initialize the pixel sampler.

Parameters

SamplesPerPixelIn

The desired number of samples per pixel

IsInterior()

bool UE::Geometry::FImageOccupancyMap::IsInterior ( int64  LinearIndex ) const

inline

Returns

true if texel sample at this sample linear index is an Interior texel

ParallelProcessingPass()

template<typename TexelValueType >

void UE::Geometry::FImageOccupancyMap::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

inline

TexelNumSamples()

int32 UE::Geometry::FImageOccupancyMap::TexelNumSamples ( int64  LinearIndex ) const

inline

Returns

number of interior samples for the texel at this image linear index.

Member Data Documentation

BorderTexel

constexpr int8 UE::Geometry::FImageOccupancyMap::BorderTexel = 2

staticconstexpr

BorderTexels

TArray64<TTuple<int64, int64> > UE::Geometry::FImageOccupancyMap::BorderTexels

Set of Border Texels, Pair is <LinearIndexOfBorderTexel, LinearIndexOfNearestInteriorTexel>, so Border can be filled by directly copying from source to target.

bParallel

bool UE::Geometry::FImageOccupancyMap::bParallel = true

Dimensions

FImageDimensions UE::Geometry::FImageOccupancyMap::Dimensions

Image Dimensions

EmptyTexel

constexpr int8 UE::Geometry::FImageOccupancyMap::EmptyTexel = 0

staticconstexpr

GutterSize

int32 UE::Geometry::FImageOccupancyMap::GutterSize = 4

Width of the gutter. This is actually multiplied by the diagonal length of a texel, so the gutter is generally larger than this number of pixels

GutterTexel

constexpr int8 UE::Geometry::FImageOccupancyMap::GutterTexel = 3

staticconstexpr

GutterTexels

TArray64<TTuple<int64, int64> > UE::Geometry::FImageOccupancyMap::GutterTexels

Set of Gutter Texels. Pair is <LinearIndexOfGutterTexel, LinearIndexOfNearestInteriorTexel>, so Gutter can be filled by directly copying from source to target.

InteriorTexel

constexpr int8 UE::Geometry::FImageOccupancyMap::InteriorTexel = 1

staticconstexpr

PixelSampler

FGridSampler UE::Geometry::FImageOccupancyMap::PixelSampler = FGridSampler(1)

TexelInteriorSamples

TArray64<int32> UE::Geometry::FImageOccupancyMap::TexelInteriorSamples

Count of interior samples for each texel in Tile. Size = Tile.GetWidth() x Tile.GetHeight().

TexelQueryTriangle

TArray64<int32> UE::Geometry::FImageOccupancyMap::TexelQueryTriangle

Integer/Triangle ID for each sample in Tile. Size = Tile.GetWidth() x Tile.GetHeight() x SamplesPerPixel.

TexelQueryUV

TArray64<FVector2f> UE::Geometry::FImageOccupancyMap::TexelQueryUV

UV for each sample in Tile. Size = Tile.GetWidth() x Tile.GetHeight() x SamplesPerPixel.

TexelQueryUVChart

TArray64<int32> UE::Geometry::FImageOccupancyMap::TexelQueryUVChart

UV Chart ID for each texel in Tile. Only set if UVSpaceMeshTriCharts is provided Size = Tile.GetWidth() x Tile.GetHeight().

TexelType

TArray64<int8> UE::Geometry::FImageOccupancyMap::TexelType

Classification of each sample in Tile. Size = Tile.GetWidth() x Tile.GetHeight() x SamplesPerPixel.

Tile

FImageTile UE::Geometry::FImageOccupancyMap::Tile

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The documentation for this class was generated from the following file:

• Engine/Source/Runtime/GeometryCore/Public/Image/ImageOccupancyMap.h