1. Epic GamesDeveloper
  3. UNiagaraSimCache

UNiagaraSimCache

Recording of multiple frames of simulation data from a running Niagara system.

API > API/Plugins > API/Plugins/Niagara

Inheritance Hierarchy

References

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

Syntax

UCLASS (BlueprintType, MinimalAPI)  
class UNiagaraSimCache : public UObject

Remarks

Recording of multiple frames of simulation data from a running Niagara system. Can be used to play back the captured recording or to inspect the captured data for debug purposes. Depending on the capture settings, not all attributes from the simulation are present in the cache.

To capture a cache, either (1) use the baker tool in the system editor, (2) use the Niagara component cache track in sequencer or (3) manually capture a running system with the "CaptureNiagaraSimCache" Blueprint functions

Constructors

  Type Name Description
Public function  

UNiagaraSimCache ( const FObjectInitializer& ObjectInitializer
)

  

Functions

  Type Name Description
Public function bool

BeginAppend ( FNiagaraSimCacheCreateParameters InCreateParameters,
UNiagaraComponent* NiagaraComponent
)

  
Public function bool

BeginAppend ( FNiagaraSimCacheCreateParameters InCreateParameters,
UNiagaraComponent* NiagaraComponent,
FNiagaraSimCacheFeedbackContext& FeedbackContext
)

  
Public function bool

BeginWrite ( FNiagaraSimCacheCreateParameters InCreateParameters,
UNiagaraComponent* NiagaraComponent
)

  
Public function bool

BeginWrite ( FNiagaraSimCacheCreateParameters InCreateParameters,
UNiagaraComponent* NiagaraComponent,
FNiagaraSimCacheFeedbackContext& FeedbackContext
)

  
Public function bool

CanRead ( UNiagaraSystem* NiagaraSystem
)

  
Public function bool

EndWrite ( bool bAllowAnalytics
)

  
Public function Const void

ForEachEmitterAttribute ( int32 EmitterIndex,
TFunction< bool(const FNiagaraSimCacheVariable&)> Function
)

 Runs a function for each attribute for the provided emitter index.
Public function Const UFunction BlueprintCallable, Category ENiagaraSimCacheAttributeCaptureMode How were the attributes captured for this sim cache.
Public function Const const FGuid & Get the caches assigned GUID, this can be set from a user or will be auto created on first write of the cache.
Public function Const const UObject * Returns the actual data we have captured in the SimCache for the given data interface.
Public function Const const UNiagaraSimCacheDebugData * Returns the debug data stored inside the cache, intended for internal use only.
Public function Const float Get the duration the cache was recorded over.
Public function Const int

GetEmitterIndex ( FName EmitterName
)

 Get the emitter index from a name
Public function Const UFunction BlueprintCallable, Category FName

GetEmitterName ( int32 EmitterIndex
)

 Get the emitter name at the provided index.
Public function Const UFunction BlueprintCallable, Category TArray< FName > Returns a list of emitters we have captured in the SimCache.
Public function Const int

GetEmitterNumInstances ( int32 EmitterIndex,
int32 FrameIndex
)

 Get number of active instances for the emitter at the given frame.
Public function Const UFunction BlueprintCallable, Category int Get number of emitters stored inside the cache.
Public function Const UFunction BlueprintCallable, Category int Get number of frames stored in the cache.
Public function Const UFunction BlueprintCallable, Category float Get the time the simulation was at when recorded.
Public function Const TArray< FNiagaraVariableBase > Returns a list of data interfaces we have captured in the SimCache.
Public function UNiagaraSystem *

GetSystem ( bool bLoadSynchronous
)

 Get the system this cache is based on
Public function Const TSoftObjectPtr< UNiagaraSystem > Get the system asset this cache was created from.
Public function Const UFunction BlueprintCallable, Category, Meta bool A valid cache is one that contains at least 1 frames worth of data.
Public function Const UFunction BlueprintCallable, Category bool

IsEmpty ()

 An empty cache contains no frame data and can not be used
Public function Const bool

Read ( float TimeSeconds,
FNiagaraSystemInstance* SystemInstance
)

  
Public function Const void

ReadAttribute ( TArray< float >& OutFloats,
TArray< FFloat16 >& OutHalfs,
TArray< int32 >& OutInts,
FName AttributeName,
FName EmitterName,
int FrameIndex
)

 Reads Niagara attributes by name from the cache frame and appends them into the relevant arrays.
Public function Const UFunction BlueprintCallable, Category void

ReadColorAttribute ( TArray< FLinearColor >& OutValues,
FName AttributeName,
FName EmitterName,
int FrameIndex
)

 Reads Niagara Color attributes by name from the cache frame and appends them into the OutValues array.
Public function Const UFunction BlueprintCallable, Category UObject *

ReadDataInterfaceAs ( UClass* RequestedType,
FName AttributeName,
int FrameIndex
)

 Reads data interface data from the cache as the requested type.
Public function Const T *

ReadDataInterfaceAs ( FName AttributeName,
int FrameIndex
)

  
Public function Const UFunction BlueprintCallable, Category void

ReadFloatAttribute ( TArray< float >& OutValues,
FName AttributeName,
FName EmitterName,
int FrameIndex
)

 Reads Niagara float attributes by name from the cache frame and appends them into the OutValues array.
Public function Const bool

ReadFrame ( int32 FrameIndex,
float FrameFraction,
FNiagaraSystemInstance* SystemInstance
)

  
Public function Const UFunction BlueprintCallable, Category void

ReadIDAttribute ( TArray< FNiagaraID >& OutValues,
FName AttributeName,
FName EmitterName,
int FrameIndex
)

 Reads Niagara ID attributes by name from the cache frame and appends them into the OutValues array.
Public function Const UFunction BlueprintCallable, Category void

ReadIntAttribute ( TArray< int32 >& OutValues,
FName AttributeName,
FName EmitterName,
int FrameIndex
)

 Reads Niagara int attributes by name from the cache frame and appends them into the OutValues array.
Public function Const UFunction BlueprintCallable, Category, Meta void

ReadPositionAttribute ( TArray< FVector >& OutValues,
FName AttributeName,
FName EmitterName,
bool bLocalSpaceToWorld,
int FrameIndex
)

 Reads Niagara Position attributes by name from the cache frame and appends them into the OutValues array.
Public function Const UFunction BlueprintCallable, Category void

ReadPositionAttributeWithRebase ( TArray< FVector >& OutValues,
FTransform Transform,
FName AttributeName,
FName EmitterName,
int FrameIndex
)

 Reads Niagara Position attributes by name from the cache frame and appends them into the OutValues array.
Public function Const UFunction BlueprintCallable, Category, Meta void

ReadQuatAttribute ( TArray< FQuat >& OutValues,
FName AttributeName,
FName EmitterName,
bool bLocalSpaceToWorld,
int FrameIndex
)

 Reads Niagara Quaternion attributes by name from the cache frame and appends them into the OutValues array.
Public function Const UFunction BlueprintCallable, Category void

ReadQuatAttributeWithRebase ( TArray< FQuat >& OutValues,
FQuat Quat,
FName AttributeName,
FName EmitterName,
int FrameIndex
)

 Reads Niagara Quaternion attributes by name from the cache frame and appends them into the OutValues array.
Public function Const UFunction BlueprintCallable, Category void

ReadVector2Attribute ( TArray< FVector2D >& OutValues,
FName AttributeName,
FName EmitterName,
int FrameIndex
)

 Reads Niagara Vec2 attributes by name from the cache frame and appends them into the OutValues array.
Public function Const UFunction BlueprintCallable, Category void

ReadVector4Attribute ( TArray< FVector4 >& OutValues,
FName AttributeName,
FName EmitterName,
int FrameIndex
)

 Reads Niagara Vec4 attributes by name from the cache frame and appends them into the OutValues array.
Public function Const UFunction BlueprintCallable, Category void

ReadVectorAttribute ( TArray< FVector >& OutValues,
FName AttributeName,
FName EmitterName,
int FrameIndex
)

 Reads Niagara Vec3 attributes by name from the cache frame and appends them into the OutValues array.
Public function void

SetCacheGuid ( const FGuid& InGuid
)

 Set the caches GUID to use.
Public function bool

WriteFrame ( UNiagaraComponent* NiagaraComponent
)

  
Public function bool

WriteFrame ( UNiagaraComponent* NiagaraComponent,
FNiagaraSimCacheFeedbackContext& FeedbackContext
)

  

Overridden from UObject

  Type Name Description
Public function Virtual bool Called to check if the object is ready for FinishDestroy.
Public function Virtual void Handles reading, writing, and reference collecting using FArchive.

Typedefs

Name Description
FOnCacheBeginWrite  
FOnCacheEndWrite  

Constants

Name Description
CacheAgeResolution Used to reduce rounding issues with age.
OnCacheBeginWrite  
OnCacheEndWrite  

Ask questions and help your peers Developer Forums

Write your own tutorials or read those from others Learning Library

On this page