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  3. UNiagaraDataInterface

UNiagaraDataInterface

Base class for all Niagara data interfaces.

API > API/Plugins > API/Plugins/Niagara

Base class for all Niagara data interfaces.

   
Name UNiagaraDataInterface
Type class
Header File /Engine/Plugins/FX/Niagara/Source/Niagara/Classes/NiagaraDataInterface.h
Include Path #include "NiagaraDataInterface.h"

Syntax

UCLASS (Abstract, EditInlineNew, MinimalAPI)  
class UNiagaraDataInterface : public UNiagaraDataInterfaceBase

Inheritance Hierarchy

Derived Classes

UNiagaraDataInterface derived class hierarchy

Constructors

Name Remarks Include Path Unreal Specifiers

UNiagaraDataInterface ( const FObjectInitializer& ObjectInitializer
)

   NiagaraDataInterface.h  

Destructors

Name Remarks Include Path Unreal Specifiers

virtual ~UNiagaraDataInterface()

   NiagaraDataInterface.h  

Variables

Protected

Name Type Remarks Include Path Unreal Specifiers
CachedFunctionSignatureLock FRWLock   NiagaraDataInterface.h  
CachedFunctionSignatures TArray< FNiagaraFunctionSignature >   NiagaraDataInterface.h  
OnErrorsRefreshedDelegate FSimpleMulticastDelegate   NiagaraDataInterface.h  

Functions

Public

Name Remarks Include Path Unreal Specifiers

virtual bool AppendCompileHash ( FNiagaraCompileHashVisitor* InVisitor
) const

 Allows the generic class defaults version of this class to specify any dependencies/version/etc that might invalidate the compile. NiagaraDataInterface.h  

void AppendTemplateHLSL ( FString& OutHLSL,
const TCHAR* TemplateShaderFile,
const TMap< FString, FStringFormatArg >& TemplateArgs
) const

 Formats and appends a template file onto the output HLSL NiagaraDataInterface.h  

virtual void CacheStaticBuffers ( FNiagaraSystemStaticBuffers& StaticBuffers,
const FNiagaraVariable& ResolvedVariable,
bool bUsedByCPU,
bool bUsedByGPU
)

 Allows data interfaces to cache any static data that may be shared between instances NiagaraDataInterface.h  

virtual ETickingGroup CalculateFinalTickGroup ( const void* PerInstanceData
) const

   NiagaraDataInterface.h  

virtual ETickingGroup CalculateTickGroup ( const void* PerInstanceData
) const

   NiagaraDataInterface.h  

virtual bool CanExecuteOnTarget ( ENiagaraSimTarget Target
) const

   NiagaraDataInterface.h  

virtual bool CanExposeVariables()

   NiagaraDataInterface.h  

virtual bool CanRenderVariablesToCanvas()

   NiagaraDataInterface.h  

bool CopyTo ( UNiagaraDataInterface* Destination
) const

 Copies the contents of this DataInterface to another. NiagaraDataInterface.h  

virtual void DestroyPerInstanceData ( void* PerInstanceData,
FNiagaraSystemInstance* SystemInstance
)

 Destroys the per instance data for this interface. NiagaraDataInterface.h  

virtual bool Equals ( const UNiagaraDataInterface* Other
) const

 Determines if this DataInterface is the same as another. NiagaraDataInterface.h  

virtual bool GenerateCompilerTagPrefix ( const FNiagaraFunctionSignature& InSignature,
FString& OutPrefix
) const

 Used by the translator when dealing with signatures that turn into compiler tags to figure out the precise compiler tag. NiagaraDataInterface.h  

virtual bool GenerateIterationSourceNamespaceReadAttributesHLSL ( FNiagaraDataInterfaceGPUParamInfo& DIInstanceInfo,
const FNiagaraVariable& InIterationSourceVariable,
TConstArrayView< FNiagaraVariable > InArguments,
TConstArrayView< FNiagaraVariable > InAttributes,
TConstArrayView< FString > InAttributeHLSLNames,
bool bInSetToDefaults,
bool bSpawnOnly,
bool bPartialWrites,
TArray< FText >& OutErrors,
FString& OutHLSL
) const

 Generate the necessary plumbing HLSL at the beginning of the stage where this is used as a sim stage iteration source. NiagaraDataInterface.h  

virtual bool GenerateIterationSourceNamespaceWriteAttributesHLSL ( FNiagaraDataInterfaceGPUParamInfo& DIInstanceInfo,
const FNiagaraVariable& InIterationSourceVariable,
TConstArrayView< FNiagaraVariable > InArguments,
TConstArrayView< FNiagaraVariable > InAttributes,
TConstArrayView< FString > InAttributeHLSLNames,
TConstArrayView< FNiagaraVariable > InAllAttributes,
bool bSpawnOnly,
bool bPartialWrites,
TArray< FText >& OutErrors,
FString& OutHLSL
) const

 Generate the necessary plumbing HLSL at the end of the stage where this is used as a sim stage iteration source. NiagaraDataInterface.h  

virtual bool GenerateSetupHLSL ( FNiagaraDataInterfaceGPUParamInfo& DIInstanceInfo,
TConstArrayView< FNiagaraVariable > InArguments,
bool bSpawnOnly,
bool bPartialWrites,
TArray< FText >& OutErrors,
FString& OutHLSL
) const

 Generate the necessary HLSL to set up data when being added as a sim stage sim source. NiagaraDataInterface.h  

virtual bool GenerateTeardownHLSL ( FNiagaraDataInterfaceGPUParamInfo& DIInstanceInfo,
TConstArrayView< FNiagaraVariable > InArguments,
bool bSpawnOnly,
bool bPartialWrites,
TArray< FText >& OutErrors,
FString& OutHLSL
) const

 Generate the necessary HLSL to tear down data when being added as a sim stage sim source. NiagaraDataInterface.h  

virtual void GetAssetTagsForContext ( const UObject* InAsset,
FGuid AssetVersion,
const TArray< const UNiagaraDataInterface* >& InProperties,
TMap< FName, uint32 >& NumericKeys,
TMap< FName, FString >& StringKeys
) const

 Method to add asset tags that are specific to this data interface. NiagaraDataInterface.h  

virtual void GetCanvasVariables ( TArray< FNiagaraVariableBase >& OutVariables
) const

   NiagaraDataInterface.h  

virtual void GetCommonHLSL ( FString& OutHLSL
)

 Allows data interfaces to provide common functionality that will be shared across interfaces on that type. NiagaraDataInterface.h  

virtual void GetEmitterDependencies ( UNiagaraSystem* Asset,
TArray< FVersionedNiagaraEmitter >& Dependencies
) const

 Allows a DI to specify data dependencies between emitters, so the system can ensure that the emitter instances are executed in the correct order. NiagaraDataInterface.h  

virtual void GetEmitterReferencesByName ( TArray< FString >& EmitterReferences
) const

   NiagaraDataInterface.h  

virtual TArray< FNiagaraDataInterfaceError > GetErrors()

 Refreshes and returns the errors detected with the corresponding data, if any. NiagaraDataInterface.h  

virtual void GetExposedVariables ( TArray< FNiagaraVariableBase >& OutVariables
) const

   NiagaraDataInterface.h  

virtual bool GetExposedVariableValue ( const FNiagaraVariableBase& InVariable,
void* InPerInstanceData,
FNiagaraSystemInstance* InSystemInstance,
void* OutData
) const

   NiagaraDataInterface.h  
Query the data interface to give feedback to the end user. NiagaraDataInterface.h  

virtual bool GetFunctionHLSL ( const FNiagaraDataInterfaceHlslGenerationContext& HlslGenContext,
FString& OutHLSL
)

   NiagaraDataInterface.h  

virtual bool GetFunctionHLSL ( const FNiagaraDataInterfaceGPUParamInfo& ParamInfo,
const FNiagaraDataInterfaceGeneratedFunction& FunctionInfo,
int FunctionInstanceIndex,
FString& OutHLSL
)

   NiagaraDataInterface.h  

void GetFunctionSignatures ( TArray< FNiagaraFunctionSignature >& OutFunctions
) const

 Gets all the available functions for this data interface. NiagaraDataInterface.h  

virtual uint32 GetGpuCountBufferEstimate()

 Returns an estimate allocation count for the GPU instance count manager. This is experimental and will likely be modified in the future. NiagaraDataInterface.h  

virtual FIntVector GetGpuDispatchNumThreads()

   NiagaraDataInterface.h  

virtual ENiagaraGpuDispatchType GetGpuDispatchType()

   NiagaraDataInterface.h  

virtual bool GetGpuUseIndirectDispatch()

   NiagaraDataInterface.h  

virtual void GetParameterDefinitionHLSL ( const FNiagaraDataInterfaceHlslGenerationContext& HlslGenContext,
FString& OutHLSL
)

   NiagaraDataInterface.h  

virtual void GetParameterDefinitionHLSL ( const FNiagaraDataInterfaceGPUParamInfo& ParamInfo,
FString& OutHLSL
)

   NiagaraDataInterface.h  
  NiagaraDataInterface.h  

virtual void GetVMExternalFunction ( const FVMExternalFunctionBindingInfo& BindingInfo,
void* InstanceData,
FVMExternalFunction& OutFunc
)

 Returns the delegate for the passed function signature. NiagaraDataInterface.h  

virtual bool GPUContextInit ( const FNiagaraScriptDataInterfaceCompileInfo& InInfo,
void* PerInstanceData,
FNiagaraSystemInstance* SystemInstance
) const

   NiagaraDataInterface.h  

virtual bool HasPostSimulateTick()

   NiagaraDataInterface.h  

virtual bool HasPostStageTick ( ENiagaraScriptUsage Usage
) const

   NiagaraDataInterface.h  

virtual bool HasPreSimulateTick()

   NiagaraDataInterface.h  

virtual bool HasPreStageTick ( ENiagaraScriptUsage Usage
) const

   NiagaraDataInterface.h  

virtual bool HasTickGroupPostreqs()

   NiagaraDataInterface.h  

virtual bool HasTickGroupPrereqs()

   NiagaraDataInterface.h  

virtual bool InitPerInstanceData ( void* PerInstanceData,
FNiagaraSystemInstance* SystemInstance
)

 Initializes the per instance data for this interface. NiagaraDataInterface.h  

bool IsUsedByCPUEmitter()

   NiagaraDataInterface.h  

bool IsUsedByGPUEmitter()

   NiagaraDataInterface.h  

bool IsUsedWithCPUEmitter()

   NiagaraDataInterface.h  

bool IsUsedWithCPUScript()

 Used to determine if we need to create CPU resources for the emitter. NiagaraDataInterface.h  

bool IsUsedWithGPUEmitter()

   NiagaraDataInterface.h  

bool IsUsedWithGPUScript()

 Used to determine if we need to create GPU resources for the emitter. NiagaraDataInterface.h  

void MarkRenderDataDirty()

   NiagaraDataInterface.h  

virtual void ModifyCompilationEnvironment ( EShaderPlatform ShaderPlatform,
FShaderCompilerEnvironment& OutEnvironment
) const

 Allows data interfaces to influence the compilation of GPU shaders and is only called on the CDO object not the instance. NiagaraDataInterface.h  

virtual bool NeedsGPUContextInit()

   NiagaraDataInterface.h  

FSimpleMulticastDelegate & OnErrorsRefreshed()

   NiagaraDataInterface.h  
The size of the data this class will provide to ProvidePerInstanceDataForRenderThread. NiagaraDataInterface.h  

virtual int32 PerInstanceDataSize ()

 Returns the size of the per instance data for this interface. NiagaraDataInterface.h  

virtual bool PerInstanceTick ( void* PerInstanceData,
FNiagaraSystemInstance* SystemInstance,
float DeltaSeconds
)

 Ticks the per instance data for this interface, if it has any. NiagaraDataInterface.h  

virtual bool PerInstanceTickPostSimulate ( void* PerInstanceData,
FNiagaraSystemInstance* SystemInstance,
float DeltaSeconds
)

   NiagaraDataInterface.h  

virtual void PostCompile ()

   NiagaraDataInterface.h  

virtual void PostCompile ( const UNiagaraSystem& OwningSystem
)

 Called after system compilation completes. Useful for caching any constant, compile dependent data. NiagaraDataInterface.h  
When set to true the simulation may not complete in the same frame it started, allowing maximum overlap with the GameThread. NiagaraDataInterface.h  
When set to true simulation may not complete in the same tick group it started. NiagaraDataInterface.h  

virtual void PostStageTick ( FNDICpuPostStageContext& Context
)

 Called per instance for each DI after each execution state in which it is used. NiagaraDataInterface.h  

virtual void PreStageTick ( FNDICpuPreStageContext& Context
)

 Called per instance for each DI before each execution state in which it is used. NiagaraDataInterface.h  

virtual void ProvidePerInstanceDataForRenderThread ( void* DataForRenderThread,
void* PerInstanceData,
const FNiagaraSystemInstanceID& SystemInstance
)

 Subclasses that wish to work with GPU systems/emitters must implement this. NiagaraDataInterface.h  

void PushToRenderThread()

   NiagaraDataInterface.h  

virtual bool ReadsEmitterParticleData ( const FString& EmitterName
) const

   NiagaraDataInterface.h  

void RefreshErrors()

   NiagaraDataInterface.h  

virtual bool RenderVariableToCanvas ( FNiagaraSystemInstanceID SystemInstanceID,
FName VariableName,
FCanvas* Canvas,
const FIntRect& DrawRect
) const

   NiagaraDataInterface.h  

virtual bool RequiresCurrentFrameNDC()

   NiagaraDataInterface.h  

virtual bool RequiresDepthBuffer()

   NiagaraDataInterface.h  

virtual bool RequiresDistanceFieldData()

   NiagaraDataInterface.h  

virtual bool RequiresEarlyViewData()

   NiagaraDataInterface.h  

virtual bool RequiresGlobalDistanceField()

   NiagaraDataInterface.h  

virtual bool RequiresRayTracingScene()

   NiagaraDataInterface.h  
Set the shader parameters will only be called if the data interface provided shader parameters. NiagaraDataInterface.h  

void SetUsedWithCPUScript ( bool bUsed
)

   NiagaraDataInterface.h  

void SetUsedWithGPUScript ( bool bUsed
)

   NiagaraDataInterface.h  

virtual bool ShouldCompile ( EShaderPlatform ShaderPlatform
) const

 Allows data interfaces to prevent compilation of GPU shaders and is only called on the CDO object not the instance. NiagaraDataInterface.h  

virtual bool SupportsIterationSourceNamespaceAttributesHLSL()

 Can this data interface be used as a StackContext parameter map replacement when being used as a sim stage iteration source? NiagaraDataInterface.h  

virtual bool SupportsSetupAndTeardownHLSL()

 Does this data interface need setup and teardown for each stage when working a sim stage sim source? NiagaraDataInterface.h  

virtual bool UpgradeFunctionCall ( FNiagaraFunctionSignature& FunctionSignature
)

 Allows data interfaces the opportunity to rename / change the function signature and perform an upgrade. NiagaraDataInterface.h  

virtual void ValidateFunction ( const FNiagaraFunctionSignature& Function,
TArray< FText >& OutValidationErrors
)

 Validates a function being compiled and allows interface classes to post custom compile errors when their API changes. NiagaraDataInterface.h  

Overridden from UObject

Name Remarks Include Path Unreal Specifiers

virtual void PostEditChangeProperty ( FPropertyChangedEvent& PropertyChangedEvent
)

   NiagaraDataInterface.h  

virtual void PostLoad()

   NiagaraDataInterface.h  

Protected

Name Remarks Include Path Unreal Specifiers

virtual bool CopyToInternal ( UNiagaraDataInterface* Destination
) const

   NiagaraDataInterface.h  

virtual void GetFunctions ( TArray< FNiagaraFunctionSignature >& OutFunctions
)

 Deprecated function for backwards compatibility. NiagaraDataInterface.h  

virtual void GetFunctionsInternal ( TArray< FNiagaraFunctionSignature >& OutFunctions
) const

   NiagaraDataInterface.h  

const T * GetProxyAs ()

   NiagaraDataInterface.h  

T * GetProxyAs ()

   NiagaraDataInterface.h  

virtual void PushToRenderThreadImpl()

   NiagaraDataInterface.h  

Static

Name Remarks Include Path Unreal Specifiers

static EObjectFlags BuildObjectFlagsForOwner ( UObject* OwnerObject,
EObjectFlags DefaultFlags
)

   NiagaraDataInterface.h  
  NiagaraDataInterface.h  

static bool IsDataInterfaceType ( const FNiagaraTypeDefinition& TypeDef
)

 Determines if this type definition matches to a known data interface type. NiagaraDataInterface.h  

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