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> Unreal Engine API Reference > Plugins > Niagara > UNiagaraDataInterface

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UNiagaraDataInterface

Base class for all Niagara data interfaces.

Inheritance Hierarchy

UObjectBase

UObjectBaseUtility

UObject

UNiagaraMergeable

UNiagaraDataInterfaceBase

UNiagaraDataInterface

UNiagaraDataInterface2DArrayTexture

UNiagaraDataInterfaceAsyncGpuTrace

UNiagaraDataInterfaceAudioOscilloscope

UNiagaraDataInterfaceAudioPlayer

UNiagaraDataInterfaceAudioSubmix

UNiagaraDataInterfaceAudioSpectrum

UNiagaraDataInterfaceCamera

UNiagaraDataInterfaceChaosDestruction

UNiagaraDataInterfaceCollisionQuery

UNiagaraDataInterfaceCubeTexture

UNiagaraDataInterfaceCurlNoise

UNiagaraDataInterfaceCurveBase

	UNiagaraDataInterfaceColorCurve
	UNiagaraDataInterfaceCurve
	UNiagaraDataInterfaceVector2DCurve
	UNiagaraDataInterfaceVector4Curve
	UNiagaraDataInterfaceVectorCurve

UNiagaraDataInterfaceExport

UNiagaraDataInterfaceGeometryCollection

UNiagaraDataInterfaceHairStrands

UNiagaraDataInterfaceLandscape

UNiagaraDataInterfaceMeshRendererInfo

UNiagaraDataInterfaceOcclusion

UNiagaraDataInterfacePhysicsAsset

UNiagaraDataInterfacePhysicsField

UNiagaraDataInterfacePlatformSet

UNiagaraDataInterfaceRigidMeshCollisionQuery

UNiagaraDataInterfaceRWBase

UNiagaraDataInterfaceArray

	UNiagaraDataInterfaceArrayBool
	UNiagaraDataInterfaceArrayColor
	UNiagaraDataInterfaceArrayFloat
	UNiagaraDataInterfaceArrayFloat2
	UNiagaraDataInterfaceArrayFloat3
	UNiagaraDataInterfaceArrayFloat4
	UNiagaraDataInterfaceArrayInt32
	UNiagaraDataInterfaceArrayNiagaraID
	UNiagaraDataInterfaceArrayPosition
	UNiagaraDataInterfaceArrayQuat
	UNiagaraDataInterfaceArrayUInt8

UNiagaraDataInterfaceGrid2D

UNiagaraDataInterfaceGrid2DCollection

UNiagaraDataInterfaceGrid2DCollectionReader

UNiagaraDataInterfaceGrid3D

UNiagaraDataInterfaceGrid3DCollection

UNiagaraDataInterfaceGrid3DCollectionReader

UNiagaraDataInterfaceNeighborGrid3D

UNiagaraDataInterfaceRasterizationGrid3D

UNiagaraDataInterfaceIntRenderTarget2D

UNiagaraDataInterfaceParticleRead

UNiagaraDataInterfaceRenderTarget2D

UNiagaraDataInterfaceRenderTarget2DArray

UNiagaraDataInterfaceRenderTargetCube

UNiagaraDataInterfaceRenderTargetVolume

UNiagaraDataInterfaceVelocityGrid

UNiagaraDataInterfacePressureGrid

UNiagaraDataInterfaceSkeletalMesh

UNiagaraDataInterfaceSpline

UNiagaraDataInterfaceSpriteRendererInfo

UNiagaraDataInterfaceTexture

UNiagaraDataInterfaceVectorField

UNiagaraDataInterfaceVolumeCache

UNiagaraDataInterfaceVolumeTexture

UNiagaraDataInterfaceWater

References

Module	Niagara
Header	/Engine/Plugins/FX/Niagara/Source/Niagara/Classes/NiagaraDataInterface.h
Include	#include "NiagaraDataInterface.h"

Syntax

UCLASS(Abstract, EditInlineNew)
class UNiagaraDataInterface : public UNiagaraDataInterfaceBase

Remarks

Base class for all Niagara data interfaces.

Variables

		Name	Description
	uint32: 1	bRenderDataDirty
	uint32: 1	bUsedByCPUEmitter
	uint32: 1	bUsedByGPUEmitter
	TUniquePtr< FNi...	Proxy

Constructors

	Name	Description
	UNiagaraDataInterface ( const FObjectInitializer& ObjectIn... )

Destructors

	Name	Description
	~UNiagaraDataInterface()

Functions

	Name	Description
bool	AppendCompileHash ( FNiagaraCompileHashVisitor* In... )	Allows the generic class defaults version of this class to specify any dependencies/version/etc that might invalidate the compile.
void	AppendTemplateHLSL ( FString& OutHLSL, const TCHAR* TemplateShaderFil..., const TMap< FString, FStringFormatA... )	Formats and appends a template file onto the output HLSL
void	CacheStaticBuffers ( FNiagaraSystemStaticBuffers& Stati..., const FNiagaraScriptDataInterfaceIn..., bool bUsedByCPU, bool bUsedByGPU )	Allows data interfaces to cache any static data that may be shared between instances
ETickingGrou...	CalculateTickGroup ( const void* PerInstanceData )
bool	CanExecuteOnTarget ( ENiagaraSimTarget Target )
bool	CanExposeVariables()
bool	CanRenderVariablesToCanvas()
bool	CopyTo ( UNiagaraDataInterface* Destina... )	Copies the contents of this DataInterface to another.
bool	CopyToInternal ( UNiagaraDataInterface* Destina... )
void	DestroyPerInstanceData ( void* PerInstanceData, FNiagaraSystemInstance* System... )	Destroys the per instance data for this interface.
void	DrawDebugHud ( UCanvas* Canvas, FNiagaraSystemInstance* System..., FString& VariableDataString, bool bVerbose )	Override this function to provide additional context to the debug HUD.
bool	Equals ( const UNiagaraDataInterface* O... )	Determines if this DataInterface is the same as another.
bool	GenerateCompilerTagPrefix ( const FNiagaraFunctionSignature& I..., FString& OutPrefix )	Used by the translator when dealing with signatures that turn into compiler tags to figure out the precise compiler tag.
bool	GenerateIterationSourceNamespaceReadAttributesHLSL ( FNiagaraDataInterfaceGPUParamInfo&..., const FNiagaraVariable& InIteratio..., TConstArrayView< FNiagaraVariable >..., TConstArrayView< FNiagaraVariable >..., TConstArrayView< FString > InAttrib..., bool bInSetToDefaults, bool bSpawnOnly, bool bPartialWrites, TArray< FText >& OutErrors, FString& OutHLSL )	Generate the necessary plumbing HLSL at the beginning of the stage where this is used as a sim stage iteration source.
bool	GenerateIterationSourceNamespaceWriteAttributesHLSL ( FNiagaraDataInterfaceGPUParamInfo&..., const FNiagaraVariable& InIteratio..., TConstArrayView< FNiagaraVariable >..., TConstArrayView< FNiagaraVariable >..., TConstArrayView< FString > InAttrib..., TConstArrayView< FNiagaraVariable >..., bool bSpawnOnly, bool bPartialWrites, TArray< FText >& OutErrors, FString& OutHLSL )	Generate the necessary plumbing HLSL at the end of the stage where this is used as a sim stage iteration source.
bool	GenerateSetupHLSL ( FNiagaraDataInterfaceGPUParamInfo&..., TConstArrayView< FNiagaraVariable >..., bool bSpawnOnly, bool bPartialWrites, TArray< FText >& OutErrors, FString& OutHLSL )	Generate the necessary HLSL to set up data when being added as a sim stage sim source.
bool	GenerateTeardownHLSL ( FNiagaraDataInterfaceGPUParamInfo&..., TConstArrayView< FNiagaraVariable >..., bool bSpawnOnly, bool bPartialWrites, TArray< FText >& OutErrors, FString& OutHLSL )	Generate the necessary HLSL to tear down data when being added as a sim stage sim source.
void	GetAssetTagsForContext ( const UObject* InAsset, FGuid AssetVersion, const TArray< const UNiagaraDataInt..., TMap< FName, uint32 >& NumericKeys, TMap< FName, FString >& StringKeys )	Method to add asset tags that are specific to this data interface.
void	GetCanvasVariables ( TArray< FNiagaraVariableBase >& Ou... )
void	GetCommonHLSL ( FString& OutHLSL )	Allows data interfaces to provide common functionality that will be shared across interfaces on that type.
void	GetEmitterDependencies ( UNiagaraSystem* Asset, TArray< FVersionedNiagaraEmitter > ... )	Allows a DI to specify data dependencies between emitters, so the system can ensure that the emitter instances are executed in the correct order.
TArray< FNia...	GetErrors()	Refreshes and returns the errors detected with the corresponding data, if any.
void	GetExposedVariables ( TArray< FNiagaraVariableBase >& Ou... )
bool	GetExposedVariableValue ( const FNiagaraVariableBase& InVari..., void* InPerInstanceData, FNiagaraSystemInstance* InSyst..., void* OutData )
void	GetFeedback ( UNiagaraDataInterface* DataInt..., TArray< FNiagaraDataInterfaceError ..., TArray< FNiagaraDataInterfaceFeedba..., TArray< FNiagaraDataInterfaceFeedba... )
void	GetFeedback ( UNiagaraSystem* InAsset, UNiagaraComponent* InComponent, TArray< FNiagaraDataInterfaceError ..., TArray< FNiagaraDataInterfaceFeedba..., TArray< FNiagaraDataInterfaceFeedba... )	Query the data interface to give feedback to the end user.
bool	GetFunctionHLSL ( FNiagaraDataInterfaceHlslGeneration..., FString& OutHLSL )
bool	GetFunctionHLSL ( const FNiagaraDataInterfaceGPUParam..., const FNiagaraDataInterfaceGenerate..., int FunctionInstanceIndex, FString& OutHLSL )
void	GetFunctions ( TArray< FNiagaraFunctionSignature >... )	Gets all the available functions for this data interface.
FIntVector	GetGpuDispatchNumThreads()
ENiagaraGpuD...	GetGpuDispatchType()
bool	GetGpuUseIndirectDispatch()
void	GetParameterDefinitionHLSL ( const FNiagaraDataInterfaceGPUParam..., FString& OutHLSL )
void	GetParameterDefinitionHLSL ( FNiagaraDataInterfaceHlslGeneration..., FString& OutHLSL )
FNiagaraData...	GetProxy()
T *	GetProxyAs()
const T *...	GetProxyAs()
void	GetVMExternalFunction ( const FVMExternalFunctionBindingInf..., void* InstanceData, FVMExternalFunction& OutFunc )	Returns the delegate for the passed function signature.
bool	GPUContextInit ( const FNiagaraScriptDataInterfaceCo..., void* PerInstanceData, FNiagaraSystemInstance* System... )
bool	HasPostSimulateTick()
bool	HasPreSimulateTick()
bool	HasTickGroupPrereqs()
bool	InitPerInstanceData ( void* PerInstanceData, FNiagaraSystemInstance* System... )	Initializes the per instance data for this interface.
bool	IsDataInterfaceType ( const FNiagaraTypeDefinition& Type... )	Determines if this type definition matches to a known data interface type.
bool	IsUsedByCPUEmitter()
bool	IsUsedByGPUEmitter()
bool	IsUsedWithCPUEmitter()	Used to determine if we need to create CPU resources for the emitter.
bool	IsUsedWithGPUEmitter()	Used to determine if we need to create GPU resources for the emitter.
void	MarkRenderDataDirty()
void	ModifyCompilationEnvironment ( EShaderPlatform ShaderPlatform, FShaderCompilerEnvironment& OutEnv... )	Allows data interfaces to influence the compilation of GPU shaders and is only called on the CDO object not the instance.
bool	NeedsGPUContextInit()
FSimpleMulti...	OnErrorsRefreshed()
int32	PerInstanceDataPassedToRenderThreadSize()	The size of the data this class will provide to ProvidePerInstanceDataForRenderThread.
int32	PerInstanceDataSize()	Returns the size of the per instance data for this interface.
bool	PerInstanceTick ( void* PerInstanceData, FNiagaraSystemInstance* System..., float DeltaSeconds )	Ticks the per instance data for this interface, if it has any.
bool	PerInstanceTickPostSimulate ( void* PerInstanceData, FNiagaraSystemInstance* System..., float DeltaSeconds )
void	PostCompile()	Called after system compilation completes. Useful for caching any constant, compile dependent data.
bool	PostSimulateCanOverlapFrames()	When set to true the simulation may not complete in the same frame it started, allowing maximum overlap with the GameThread.
void	ProvidePerInstanceDataForRenderThread ( void* DataForRenderThread, void* PerInstanceData, const FNiagaraSystemInstanceID& Sy... )	Subclasses that wish to work with GPU systems/emitters must implement this.
void	PushToRenderThread()
void	PushToRenderThreadImpl()
bool	ReadsEmitterParticleData ( const FString& EmitterName )
void	RefreshErrors()
bool	RenderVariableToCanvas ( FNiagaraSystemInstanceID SystemInst..., FName VariableName, FCanvas* Canvas, const FIntRect& DrawRect )
bool	RequiresDepthBuffer()
bool	RequiresDistanceFieldData()
bool	RequiresEarlyViewData()
bool	RequiresRayTracingScene()
void	SetShaderParameters ( const FNiagaraDataInterfaceSetShade... )	Set the shader parameters will only be called if the data interface provided shader parameters.
void	SetUsedByCPUEmitter ( bool bUsed )
void	SetUsedByGPUEmitter ( bool bUsed )
bool	ShouldCompile ( EShaderPlatform ShaderPlatform )	Allows data interfaces to prevent compilation of GPU shaders and is only called on the CDO object not the instance.
bool	SupportsIterationSourceNamespaceAttributesHLSL()	Can this data interface be used as a StackContext parameter map replacement when being used as a sim stage iteration source?
bool	SupportsSetupAndTeardownHLSL()	Does this data interface need setup and teardown for each stage when working a sim stage sim source?
bool	UpgradeFunctionCall ( FNiagaraFunctionSignature& Functio... )	Allows data interfaces the opportunity to rename / change the function signature and perform an upgrade.
void	ValidateFunction ( const FNiagaraFunctionSignature& F..., TArray< FText >& OutValidationErro... )	Validates a function being compiled and allows interface classes to post custom compile errors when their API changes.

Overridden from UObject

		Name	Description
	void	PostEditChangeProperty ( FPropertyChangedEvent& PropertyCha... )	Called when a property on this object has been modified externally
	void	PostLoad()	Do any object-specific cleanup required immediately after loading an object.

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