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  3. UNiagaraDataInterface

UNiagaraDataInterface

Base class for all Niagara data interfaces.

Unreal Engine C++ API Reference > Plugins > Niagara

Inheritance Hierarchy

References

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

Syntax

UCLASS&40;Abstract, EditInlineNew, MinimalAPI&41;  
class UNiagaraDataInterface : public UNiagaraDataInterfaceBase

Remarks

Base class for all Niagara data interfaces.

Variables

  Type Name Description
Protected variable uint32: 1 bRenderDataDirty  
Protected variable uint32: 1 bUsedWithCPUScript  
Protected variable uint32: 1 bUsedWithGPUScript  
Protected variable TUniquePtr< FNiagaraDataInterfaceProxy > Proxy  

Constructors

  Type Name Description
Public function  

UNiagaraDataInterface ( const FObjectInitializer& ObjectInitializer
)

  

Destructors

  Type Name Description
Public function Virtual    

Functions

  Type Name Description
Public function Virtual Const bool Allows the generic class defaults version of this class to specify any dependencies/version/etc that might invalidate the compile.
Public function Const void

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

 Formats and appends a template file onto the output HLSL
Public function 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
Public function Virtual Const ETickingGroup

CalculateTickGroup ( const void* PerInstanceData
)

  
Public function Virtual Const bool  
Public function Virtual Const bool  
Public function Virtual Const bool  
Public function Const bool

CopyTo ( UNiagaraDataInterface* Destination
)

 Copies the contents of this DataInterface to another.
Protected function Virtual Const bool  
Public function Virtual void

DestroyPerInstanceData ( void* PerInstanceData,
FNiagaraSystemInstance* SystemInstance
)

 Destroys the per instance data for this interface.
Public function Virtual Const void

DrawDebugHud ( FNDIDrawDebugHudContext& DebugHudContext
)

 Override this function to provide additional context to the debug HUD.
Public function Virtual Const bool

Equals ( const UNiagaraDataInterface* Other
)

 Determines if this DataInterface is the same as another.
Public function Virtual Const bool

GenerateCompilerTagPrefix ( const FNiagaraFunctionSignature& InSignature,
FString& OutPrefix
)

 Used by the translator when dealing with signatures that turn into compiler tags to figure out the precise compiler tag.
Public function Virtual Const 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
)

 Generate the necessary plumbing HLSL at the beginning of the stage where this is used as a sim stage iteration source.
Public function Virtual Const 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
)

 Generate the necessary plumbing HLSL at the end of the stage where this is used as a sim stage iteration source.
Public function Virtual Const bool

GenerateSetupHLSL ( FNiagaraDataInterfaceGPUParamInfo& DIInstanceInfo,
TConstArrayView< FNiagaraVariable > InArguments,
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.
Public function Virtual Const bool

GenerateTeardownHLSL ( FNiagaraDataInterfaceGPUParamInfo& DIInstanceInfo,
TConstArrayView< FNiagaraVariable > InArguments,
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.
Public function Virtual Const void

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

 Method to add asset tags that are specific to this data interface.
Public function Virtual Const void  
Public function Virtual void

GetCommonHLSL ( FString& OutHLSL
)

 Allows data interfaces to provide common functionality that will be shared across interfaces on that type.
Public function Virtual Const void Allows a DI to specify data dependencies between emitters, so the system can ensure that the emitter instances are executed in the correct order.
Public function Virtual Const void

GetEmitterReferencesByName ( TArray< FString >& EmitterReferences
)

  
Public function Virtual TArray< FNiagaraDataInterfaceError > Refreshes and returns the errors detected with the corresponding data, if any.
Public function Virtual Const void  
Public function Virtual Const bool

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

  
Public function Static void  
Public function Virtual void Query the data interface to give feedback to the end user.
Public function Virtual bool

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

  
Public function Virtual bool  
Public function Virtual void Gets all the available functions for this data interface.
Public function Virtual Const FIntVector  
Public function Virtual Const ENiagaraGpuDispatchType  
Public function Virtual Const bool  
Public function Virtual void  
Public function Virtual void  
Public function FNiagaraDataInterfaceProxy *  
Protected function T *  
Protected function Const const T *  
Public function Virtual void

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

 Returns the delegate for the passed function signature.
Public function Virtual Const bool

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

  
Public function Virtual Const bool  
Public function Virtual Const bool  
Public function Virtual Const bool  
Public function Virtual Const bool  
Public function Virtual Const bool  
Public function Virtual bool

InitPerInstanceData ( void* PerInstanceData,
FNiagaraSystemInstance* SystemInstance
)

 Initializes the per instance data for this interface.
Public function Static bool Determines if this type definition matches to a known data interface type.
Public function Const bool Used to determine if we need to create CPU resources for the emitter.
Public function Const bool Used to determine if we need to create GPU resources for the emitter.
Public function void  
Public function Virtual Const void

ModifyCompilationEnvironment ( EShaderPlatform ShaderPlatform,
FShaderCompilerEnvironment& OutEnvironment
)

 Allows data interfaces to influence the compilation of GPU shaders and is only called on the CDO object not the instance.
Public function Virtual Const bool  
Public function FSimpleMulticastDelegate &  
Public function Virtual Const int32 The size of the data this class will provide to ProvidePerInstanceDataForRenderThread.
Public function Virtual Const int32 Returns the size of the per instance data for this interface.
Public function Virtual bool

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

 Ticks the per instance data for this interface, if it has any.
Public function Virtual bool

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

  
Public function Virtual void Called after system compilation completes. Useful for caching any constant, compile dependent data.
Public function Virtual Const bool When set to true the simulation may not complete in the same frame it started, allowing maximum overlap with the GameThread.
Public function Virtual Const bool When set to true simulation may not complete in the same tick group it started.
Public function Virtual void Called per instance for each DI after each execution state in which it is used.
Public function Virtual void Called per instance for each DI before each execution state in which it is used.
Public function Virtual void

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

 Subclasses that wish to work with GPU systems/emitters must implement this.
Public function void  
Protected function Virtual void  
Public function void  
Public function Virtual Const bool

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

  
Public function Virtual Const bool  
Public function Virtual Const bool  
Public function Virtual Const bool  
Public function Virtual Const bool  
Public function Virtual Const void Set the shader parameters will only be called if the data interface provided shader parameters.
Public function void

SetUsedWithCPUScript ( bool bUsed
)

  
Public function void

SetUsedWithGPUScript ( bool bUsed
)

  
Public function Virtual Const bool

ShouldCompile ( EShaderPlatform ShaderPlatform
)

 Allows data interfaces to prevent compilation of GPU shaders and is only called on the CDO object not the instance.
Public function Virtual Const bool Can this data interface be used as a StackContext parameter map replacement when being used as a sim stage iteration source?
Public function Virtual Const bool Does this data interface need setup and teardown for each stage when working a sim stage sim source?
Public function Virtual bool Allows data interfaces the opportunity to rename / change the function signature and perform an upgrade.
Public function 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.

Overridden from UObject

  Type Name Description
Public function Virtual void

PostEditChangeProperty ( FPropertyChangedEvent& PropertyChangedEvent
)

 Called when a property on this object has been modified externally
Public function Virtual void Do any object-specific cleanup required immediately after loading an object.

Deprecated Functions

  Type Name Description
Public function Virtual Const void

DrawDebugHud ( UCanvas* Canvas,
FNiagaraSystemInstance* SystemInstance,
FString& VariableDataString,
bool bVerbose
)

 Please update to the context based DrawDebugHud as this will be removed in a future version.
Public function Const bool Please update your code to use IsUsedWithCPUScript
Public function Const bool Please update your code to use IsUsedWithGPUScript
Public function Const bool Please update your code to use IsUsedWithCPUScript
Public function Const bool Please update your code to use IsUsedWithGPUScript
Public function Virtual Const bool

ReadsEmitterParticleData ( const FString& EmitterName
)

 Implement GetEmitterReferencesByName() instead as this will be removed in a future version.

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