Unreal Engine 4.26 Documentation

Unreal Engine 4.27 Documentation

Unreal Engine 5.0 Documentation

Unreal Engine 5.1 Documentation

Unreal Engine 5.2 Documentation

Unreal Engine 5.3 Documentation

> Unreal Engine API Reference > Plugins > Niagara > FNiagaraSystemSimulation

Light Theme

Dark Theme

FNiagaraSystemSimulation

Simulation performing all system and emitter scripts for a instances of a [UNiagaraSystem](API\Plugins\Niagara\UNiagaraSystem) in a world.

Windows

MacOS

Linux

Inheritance Hierarchy

TSharedFromThis

FGCObject

FNiagaraSystemSimulation

References

Module	Niagara
Header	/Engine/Plugins/FX/Niagara/Source/Niagara/Public/NiagaraSystemSimulation.h
Include	#include "NiagaraSystemSimulation.h"

Syntax

class FNiagaraSystemSimulation :
public TSharedFromThis< FNiagaraSystemSimulation, ESPMode::ThreadSafe >,
private FGCObject

Remarks

Simulation performing all system and emitter scripts for a instances of a UNiagaraSystem in a world.

Variables

	Name	Description
uint32: 1	bBindingsInitialized
uint32: 1	bCanExecute
uint32: 1	bInSpawnPhase
uint32: 1	bIsSolo
FNiagaraConstan...	ConstantBufferToDataSetBinding
FString	CrashReporterTag
TArray< TArray<...	DataSetToEmitterEventParameters	Binding to push system attributes into each emitter event parameters.
TArray< FNiagar...	DataSetToEmitterGPUParameters	Binding to push system attributes into each emitter gpu parameters.
TArray< FNiagar...	DataSetToEmitterSpawnParameters	Binding to push system attributes into each emitter spawn parameters.
TArray< FNiagar...	DataSetToEmitterUpdateParameters	Binding to push system attributes into each emitter update parameters.
UNiagaraEffectT...	EffectType	We cache off the effect type in the unlikely even that someone GCs the System from under us so that we can keep the effect types instance count etc accurate.
TArray< FNiagar...	EmitterExecutionStateAccessors
TArray< TArray<...	EmitterSpawnInfoAccessors
FNiagaraDataSet	MainDataSet	Main dataset containing system instance attribute data.
TOptional< floa...	MaxDeltaTime
FNiagaraDataSet	PausedInstanceData	DataSet used to store pausing instance data.
TArray< FNiagar...	PausedSystemInstances	System instances that are paused.
TArray< FNiagar...	PendingSystemInstances	System instances that are pending to be spawned.
TArray< FNiagar...	PendingTickGroupPromotions	List of instances that are pending a tick group promotion.
FNiagaraParamet...	ScriptDefinedDataInterfaceParameters	A parameter store which contains the data interfaces parameters which were defined by the scripts.
FNiagaraScriptE...	SpawnExecContext
FNiagaraParamet...	SpawnGlobalSpawnCountScaleParam
FNiagaraParamet...	SpawnGlobalSystemCountScaleParam
FNiagaraDataSet	SpawningDataSet	DataSet used if we have to spawn instances outside of their tick.
TArray< FNiagar...	SpawningInstances	System instances that are about to be spawned outside of regular ticking.
FNiagaraDataSet	SpawnInstanceParameterDataSet	As there's a 1 to 1 relationship between system instance and their execution in this simulation we must pull all that instances parameters into a dataset for simulation.
FNiagaraParamet...	SpawnInstanceParameterToDataSetBinding	Bindings that pull per component parameters into the spawn parameter dataset.
FNiagaraParamet...	SpawnNumSystemInstancesParam	Direct bindings for Engine variables in System Spawn and Update scripts.
FNiagaraDataSet...	SystemExecutionStateAccessor
TArray< FNiagar...	SystemInstances	System instances that have been spawned and are now simulating.
FGraphEventRef	SystemTickGraphEvent	Current task that is executing
ETickingGroup	SystemTickGroup	Which tick group we are in, only valid when not in Solo mode.
FNiagaraSystemT...	TickBatch	Current tick batch we're filling ready for processing, potentially in an async task.
FNiagaraScriptE...	UpdateExecContext
FNiagaraParamet...	UpdateGlobalSpawnCountScaleParam
FNiagaraParamet...	UpdateGlobalSystemCountScaleParam
FNiagaraDataSet	UpdateInstanceParameterDataSet
FNiagaraParamet...	UpdateInstanceParameterToDataSetBinding	Bindings that pull per component parameters into the update parameter dataset.
FNiagaraParamet...	UpdateNumSystemInstancesParam
TWeakObjectPtr<...	WeakSystem	System of instances being simulated.
UWorld *	World	World this system simulation belongs to.

Constructors

	Name	Description
	FNiagaraSystemSimulation()

Destructors

	Name	Description
	~FNiagaraSystemSimulation()

Functions

	Name	Description
void	AddInstance ( FNiagaraSystemInstance* Instan... )
void	AddSystemToTickBatch ( FNiagaraSystemInstance* Instan..., FNiagaraSystemSimulationTickContext... )
void	AddTickGroupPromotion ( FNiagaraSystemInstance* Instan... )
void	BuildConstantBufferTable ( const FNiagaraGlobalParameters& Gl..., FNiagaraScriptExecutionContext& Ex..., FScriptExecutionConstantBufferTable... )	Builds the constant buffer table for a given script execution
void	Destroy()
void	DumpInstance ( const FNiagaraSystemInstance* ... )
void	DumpTickInfo ( FOutputDevice& Ar )	Dump information about all instances tick
void	FlushTickBatch ( FNiagaraSystemSimulationTickContext... )
const FStrin...	GetCrashReporterTag()
bool	GetIsSolo()
UNiagaraPara...	GetParameterCollectionInstance ( UNiagaraParameterCollection* C... )
FNiagaraPara...	GetScriptDefinedDataInterfaceParameters()
FNiagaraScri...	GetSpawnExecutionContext()
UNiagaraSyst...	GetSystem()
FNiagaraScri...	GetUpdateExecutionContext()
bool	Init ( UNiagaraSystem* InSystem, UWorld* InWorld, bool bInIsSolo, ETickingGroup TickGroup )
void	InitParameterDataSetBindings ( FNiagaraSystemInstance* System... )
bool	IsValid()
void	PauseInstance ( FNiagaraSystemInstance* Instan... )
void	PrepareForSystemSimulate ( FNiagaraSystemSimulationTickContext... )	Does any prep work for system simulation such as pulling instance parameters into a dataset.
void	RemoveInstance ( FNiagaraSystemInstance* Instan... )
void	SetupParameters_GameThread ( float DeltaSeconds )	Sets constant parameter values
bool	ShouldTickAsync ( const FNiagaraSystemSimulationTickC... )	Should we push the system sim tick off the game thread.
bool	ShouldTickInstancesAsync ( const FNiagaraSystemSimulationTickC... )	Should we push the system instance ticks off the game thread.
void	Spawn_GameThread ( float DeltaSeconds )	Spawn any pending instances, assumes that you have update tick groups ahead of time.
void	SpawnSystemInstances ( FNiagaraSystemSimulationTickContext... )	Runs the system spawn script for new system instances.
bool	Tick ( float DeltaSeconds )
void	Tick_Concurrent ( FNiagaraSystemSimulationTickContext... )	Second phase of system sim tick that can run on any thread.
void	Tick_GameThread ( float DeltaSeconds, const FGraphEventRef& MyCompletion... )	First phase of system sim tick. Must run on GameThread.
void	TransferInstance ( FNiagaraSystemSimulation* Sour..., FNiagaraSystemInstance* System... )	Transfers a system instance from SourceSimulation.
void	TransferSystemSimResults ( FNiagaraSystemSimulationTickContext... )	Transfers the results of the system simulation into the emitter instances.
void	UnpauseInstance ( FNiagaraSystemInstance* Instan... )
void	UpdateSystemInstances ( FNiagaraSystemSimulationTickContext... )	Runs the system update script.
void	UpdateTickGroups_GameThread()	Update TickGroups for pending instances and execute tick group promotions.
void	WaitForInstancesTickComplete ( bool bEnsureComplete )	Wait for instances tick to complete.
void	WaitForSystemTickComplete ( bool bEnsureComplete )	Promote instances that have ticked during Wait for system simulation tick to complete.

Overridden from FGCObject

		Name	Description
	void	AddReferencedObjects ( FReferenceCollector& Collector )	Pure virtual that must be overloaded by the inheriting class.

Help shape the future of Unreal Engine documentation! Tell us how we're doing so we can serve you better.

Take our survey

Dismiss