FAdaptiveVirtualTexture Class Reference

#include <AdaptiveVirtualTexture.h>

Inheritance diagram for FAdaptiveVirtualTexture:

Classes
struct	FAllocatedInfo
struct	FProducerInfo

Public Member Functions
	FAdaptiveVirtualTexture (FAdaptiveVTDescription const &InAdaptiveDesc, FAllocatedVTDescription const &InAllocatedDesc)
void	Init (FRHICommandListBase &RHICmdList, FVirtualTextureSystem *InSystem)
uint32	GetPackedAllocationRequest (uint32 vAddress, uint32 vLevelPlusOne, uint32 Frame) const
void	QueuePackedAllocationRequests (TConstArrayView< uint32 > InRequests, uint32 InFrame)
void	UpdateAllocations (FVirtualTextureSystem *InSystem, FRHICommandListImmediate &RHICmdList, uint32 InFrame)
void	ApplyPageTableUpdates (FVirtualTextureSystem *InSystem, FRDGBuilder &GraphBuilder, FRDGExternalAccessQueue &ExternalAccessQueue)
virtual IAllocatedVirtualTexture *	GetAllocatedVirtualTexture () override
virtual int32	GetSpaceID () const override
void	GetProducers (FIntRect const &InTextureRegion, uint32 InMaxLevel, TArray< FProducerInfo > &OutProducerInfos) const
void	GetAllocatedVirtualTextures (FBox2D const &InUVRegion, uint32 InLevel, TArray< FAllocatedInfo > &OutInfos, TArray< uint32 > &OutAllocationRequests)

Static Public Member Functions
static void	QueuePackedAllocationRequests (FVirtualTextureSystem *InSystem, TConstArrayView< uint32 > InRequests, uint32 InFrame)

Protected Member Functions
virtual void	Destroy (class FVirtualTextureSystem *InSystem) override
Protected Member Functions inherited from IAdaptiveVirtualTexture
virtual	~IAdaptiveVirtualTexture ()

Detailed Description

Concrete implementation of an adaptive virtual texture. This allocates multiple virtual textures within the same space: one each for a grid of UV ranges, and an additional persistent one for the low resolution mips. We then use an additional page table indirection texture in the shader to select the correct page table address range for our sampled UV. We use the virtual texture feedback to decide when to increase or decrease the resolution of each UV range. When we change resolution for a range we directly remap the page table entires. This removes the cost and any visual glitch from regenerating the pages.

Constructor & Destructor Documentation

FAdaptiveVirtualTexture()

FAdaptiveVirtualTexture::FAdaptiveVirtualTexture	(	FAdaptiveVTDescription const &	InAdaptiveDesc,
		FAllocatedVTDescription const &	InAllocatedDesc
	)

Member Function Documentation

ApplyPageTableUpdates()

void FAdaptiveVirtualTexture::ApplyPageTableUpdates	(	FVirtualTextureSystem *	InSystem,
		FRDGBuilder &	GraphBuilder,
		FRDGExternalAccessQueue &	ExternalAccessQueue
	)

Apply any page table updates.

RDG parameters for update pass.

Destroy()

void FAdaptiveVirtualTexture::Destroy ( class FVirtualTextureSystem *  InSystem )

overrideprotectedvirtual

Implements IAdaptiveVirtualTexture.

GetAllocatedVirtualTexture()

IAllocatedVirtualTexture * FAdaptiveVirtualTexture::GetAllocatedVirtualTexture ( )

overridevirtual

Get the persistent allocated virtual texture for low mips from the adaptive virtual texture.

Implements IAdaptiveVirtualTexture.

GetAllocatedVirtualTextures()

void FAdaptiveVirtualTexture::GetAllocatedVirtualTextures	(	FBox2D const &	InUVRegion,
		uint32	InLevel,
		TArray< FAllocatedInfo > &	OutInfos,
		TArray< uint32 > &	OutAllocationRequests
	)

Get internal allocated virtual textures that touch the texture UV region.

GetPackedAllocationRequest()

uint32 FAdaptiveVirtualTexture::GetPackedAllocationRequest	(	uint32	vAddress,
		uint32	vLevelPlusOne,
		uint32	Frame
	)		const

Get a packed allocation key based on a virtual texture feedback request. The virtual texture system collects these opaque keys before queuing them for processing.

GetProducers()

void FAdaptiveVirtualTexture::GetProducers	(	FIntRect const &	InTextureRegion,
		uint32	InMaxLevel,
		TArray< FProducerInfo > &	OutProducerInfos
	)		const

Get internal producers that touch the texture texel region.

GetSpaceID()

int32 FAdaptiveVirtualTexture::GetSpaceID ( ) const

overridevirtual

Implements IAdaptiveVirtualTexture.

Init()

void FAdaptiveVirtualTexture::Init	(	FRHICommandListBase &	RHICmdList,
		FVirtualTextureSystem *	InSystem
	)

Initialize the object. This creates the persistent low mips allocated VT.

QueuePackedAllocationRequests() [1/2]

void FAdaptiveVirtualTexture::QueuePackedAllocationRequests ( FVirtualTextureSystem *  InSystem, TConstArrayView< uint32 >  InRequests, uint32  InFrame  )

static

Queue a batch of allocation requests. This static function relays the global requests to the individual object queues. Internally it sorts the requests.

QueuePackedAllocationRequests() [2/2]

void FAdaptiveVirtualTexture::QueuePackedAllocationRequests	(	TConstArrayView< uint32 >	InRequests,
		uint32	InFrame
	)

Queue a batch of allocation requests. These will be used to reallocate any virtual textures during the next call to UpdateAllocations().

UpdateAllocations()

void FAdaptiveVirtualTexture::UpdateAllocations	(	FVirtualTextureSystem *	InSystem,
		FRHICommandListImmediate &	RHICmdList,
		uint32	InFrame
	)

Update any allocations based on recent requests.

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

• Engine/Source/Runtime/Renderer/Private/VT/AdaptiveVirtualTexture.h
• Engine/Source/Runtime/Renderer/Private/VT/AdaptiveVirtualTexture.cpp