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> Unreal Engine API Reference > Runtime > Engine > Components > UActorComponent

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UActorComponent

ActorComponent is the base class for components that define reusable behavior that can be added to different types of Actors.

Inheritance Hierarchy

UObjectBase

UObjectBaseUtility

UObject

UActorComponent

+ 403 derived classes

References

Module	Engine
Header	/Engine/Source/Runtime/Engine/Classes/Components/ActorComponent.h
Include	#include "Components/ActorComponent.h"

Syntax

class UActorComponent :
public UObject,
public IInterface_AssetUserData

Remarks

ActorComponent is the base class for components that define reusable behavior that can be added to different types of Actors. ActorComponents that have a transform are known as SceneComponents and those that can be rendered are PrimitiveComponents.

Variables

	Name	Description
TArray< TObject...	AssetUserData	Array of user data stored with the component
uint8: 1	bAllowAnyoneToDestroyMe	Can this component be destroyed (via K2_DestroyComponent) by any parent
uint8: 1	bAllowConcurrentTick	Can we tick this concurrently on other threads?
uint8: 1	bAllowReregistration	Check whether the component class allows reregistration during ReregisterAllComponents
uint8: 1	bAutoActivate	Whether the component is activated at creation or must be explicitly activated.
uint8: 1	bAutoRegister	Does this component automatically register with its owner
uint8: 1	bCanEverAffectNavigation	Whether this component can potentially influence navigation
uint8: 1	bEditableWhenInherited	True if this component can be modified when it was inherited from a parent actor class
uint8: 1	bIsEditorOnly	If true, the component will be excluded from non-editor builds
uint8: 1	bNavigationRelevant	Cached navigation relevancy flag for collision updates
uint8: 1	bNetAddressable	Is this component safe to ID over the network by name?
uint8: 1	bNeverNeedsRenderUpdate	If true, this component never needs a render update.
uint8: 1	bPhysicsStateCreated	If the physics state is currently created for this component
uint8: 1	bRegistered	Indicates if this ActorComponent is currently registered with a scene.
uint8: 1	bRenderStateCreated	If the render state is currently created for this component
uint8: 1	bReplicateUsingRegisteredSubObjectList	When true the replication system will only replicate the registered subobjects list When false the replication system will instead call the virtual ReplicateSubObjects() function where the subobjects need to be manually replicated.
uint8: 1	bTickInEditor	Should this component be ticked in the editor
uint8: 1	bWantsInitializeComponent	If true, we call the virtual InitializeComponent
TArray< FName >	ComponentTags	Array of tags that can be used for grouping and categorizing. Can also be accessed from scripting.
EComponentCreat...	CreationMethod	Describes how a component instance will be created
FActorComponent...	OnComponentActivated	Called when the component has been activated, with parameter indicating if it was from a reset
FActorComponent...	OnComponentDeactivated	Called when the component has been deactivated
FActorComponent...	PrimaryComponentTick	Main tick function for the Component

Constructors

	Name	Description
	UActorComponent ( const FObjectInitializer& ObjectIn... )	Default UObject constructor that takes an optional ObjectInitializer.

Functions

	Name	Description
void	Activate ( bool bReset )	Activates the SceneComponent, should be overridden by native child classes.
UObject cons...	AdditionalStatObject()	Give a readable name for this component, including asset name if applicable
void	AddReferencedObjects ( UObject* InThis, FReferenceCollector& Collector )
void	AddReplicatedSubObject ( UObject* SubObject, ELifetimeCondition NetCondition )	Register a SubObject that will get replicated along with the actor component.
void	AddTickPrerequisiteActor ( AActor* PrerequisiteActor )	Make this component tick after PrerequisiteActor
void	AddTickPrerequisiteComponent ( UActorComponent* PrerequisiteC... )	Make this component tick after PrerequisiteComponent.
bool	AllowReregistration()	Check whether the component class allows reregistration during ReregisterAllComponents
void	ApplyWorldOffset ( const FVector& InOffset, bool bWorldShift )	Called by owner actor on position shifting Component should update all relevant data structures to reflect new actor location
void	AsyncPhysicsTickComponent ( float DeltaTime, float SimTime )	Override this function to implement custom logic to be executed every physics step.
void	BeginPlay()	Begins Play for the component.
bool	CanEverAffectNavigation()	Can this component potentially influence navigation
void	CheckForErrors()	Function that gets called from within Map_Check to allow this actor component to check itself for any potential errors and register them with map check dialog.
void	ClearNeedEndOfFrameUpdate()	If we belong to a world, clear the request to do a deferred update.
void	ClearUCSModifiedProperties()	Clears the component's UCS modified properties
bool	ComponentHasTag ( FName Tag )	See if this component contains the supplied tag
bool	ComponentIsInLevel ( const ULevel* TestLevel )	Returns true if this actor is contained by TestLevel.
bool	ComponentIsInPersistentLevel ( bool bIncludeLevelStreamingPersiste... )	See if this component is in the persistent level
void	CreatePhysicsState ( bool bAllowDeferral )	Create any physics engine information for this component
void	CreateRenderState_Concurrent ( FRegisterComponentContext* Con... )	Used to create any rendering thread information for this component
void	Deactivate()	Deactivates the SceneComponent.
void	DestroyComponent ( bool bPromoteChildren )	Unregister the component, remove it from its outer Actor's Components array and mark for pending kill.
void	DestroyPhysicsState()	Shut down any physics engine structure for this component
void	DestroyRenderState_Concurrent()	Used to shut down any rendering thread structure for this component
void	DestroyReplicatedSubObjectOnRemotePeers ( UObject* SubObject )	Stop replicating a subobject and tell actor channels to delete the replica of this subobject next time the Actor gets replicated Note it is up to the caller to delete the local object on the authority.
void	DetermineUCSModifiedProperties()	Initializes the list of properties that are modified by the UserConstructionScript
void	DoDeferredRenderUpdates_Concurrent()	Uses the bRenderStateDirty/bRenderTransformDirty/bRenderInstancesDirty to perform any necessary work on this component.
void	EndPlay ( const EEndPlayReason::Type EndPlayR... )	Ends gameplay for this component.
bool	ForceActorNonSpatiallyLoaded()
void	GetActorDescProperties ( FPropertyPairsMap& PropertyPairsMa... )	Add properties to the component owner's actor desc.
void	GetComponentChildElements ( TArray< FTypedElementHandle >& Out..., const bool bAllowCreate )	Get the logical child elements of this component, if any.
bool	GetComponentClassCanReplicate()	Returns true if this type of component can ever replicate, override to disable the default behavior
TStructOnSco...	GetComponentInstanceData()	Called before we throw away components during RerunConstructionScripts, to cache any data we wish to persist across that operation
ULevel *	GetComponentLevel()	Return the ULevel that this Component is part of.
float	GetComponentTickInterval()	Returns the tick interval for this component's primary tick function, which is the frequency in seconds at which it will be executed
TSharedPtr< ...	GetCustomEditorPreviewWidget()	If this component is set up to provide a preview window in editor (see GetEditorPreviewInfo), you can use this to customize the preview (to be something other than a world viewport).
TSubclassOf<...	GetCustomHLODBuilderClass()	Return the custom HLODBuilder class that should be used to generate HLODs for components of this type.
bool	GetEditorPreviewInfo ( float DeltaTime, FMinimalViewInfo& ViewOut )	Supplies the editor with a view specific to this component (think a view from a camera components POV, a render, etc.).
bool	GetIsReplicated()	Returns whether replication is enabled or not.
uint32	GetMarkedForEndOfFrameUpdateState()	Tracks whether the component has been added to one of the world's end of frame update lists
uint32	GetMarkedForPreEndOfFrameSync()	Tracks whether the component has been added to one of the world's end of frame update lists
ENetMode	GetNetMode()	Get the network mode (dedicated server, client, standalone, etc) for this component.
AActor *	GetOwner()	Follow the Outer chain to get the AActor that 'Owns' this component
T *	GetOwner()	Templated version of GetOwner(), will return nullptr if cast fails
ENetRole	GetOwnerRole()	Get the network role of the Owner, or ROLE_None if there is no owner.
FString	GetReadableName()	Returns a readable name for this component, including the asset name if applicable By default this appends a space plus AdditionalStatObject()
const FName	GetReplicatesPropertyName()	Gets the property name for bReplicates.
ELifetimeCon...	GetReplicationCondition()	Returns the replication condition for the component.
FSceneInterf...	GetScene()	Returns the rendering scene associated with this component
FBox	GetStreamingBounds()
void	GetUCSModifiedProperties ( TSet< const FProperty* >& Mod... )	Returns the list of properties that are modified by the UserConstructionScript
int32	GetUCSSerializationIndex()	Returns the UCS serialization index.
UWorld *	GetWorld()	Getter for the cached world pointer, will return null if the component is not actually spawned in a level
void	HandleCanEverAffectNavigationChange ( bool bForceUpdate )	Makes sure navigation system has up to date information regarding component's navigation relevancy and if it can affect navigation at all
bool	HasBeenCreated()	Indicates that OnCreatedComponent has been called, but OnDestroyedComponent has not yet
bool	HasBeenInitialized()	Indicates that InitializeComponent has been called, but UninitializeComponent has not yet
bool	HasBegunPlay()	Indicates that BeginPlay has been called, but EndPlay has not yet
bool	HasValidPhysicsState()	Used to check that DestroyPhysicsState() is working correctly
void	InitializeComponent()	Initializes the component.
void	InvalidateLightingCache()	Invalidate lighting cache with default options.
void	InvalidateLightingCacheDetailed ( bool bInvalidateBuildEnqueuedLighti..., bool bTranslationOnly )	Called when this actor component has moved, allowing it to discard statically cached lighting information.
bool	IsActive()	Returns whether the component is active or not
bool	IsBeingDestroyed()	Returns whether the component is in the process of being destroyed.
bool	IsComponentTickEnabled()	Returns whether this component has tick enabled or not
bool	IsCreatedByConstructionScript()	Returns true if instances of this component are created by either the user or simple construction script
bool	IsEditableWhenInherited()	True if this component can be modified when it was inherited from a parent actor class
bool	IsHLODRelevant()	Override to specify that a component is relevant to the HLOD generation.
bool	IsNavigationRelevant()	Override to specify that a component is relevant to the navigation system
bool	IsNetMode ( ENetMode Mode )	Test whether net mode is the given mode.
bool	IsNetSimulating()	Returns true if we are replicating and this client is not authoritative
bool	IsNetStartupComponent()	Returns true if this component was owned by a net startup actor during level load.
bool	IsOwnerRunningUserConstructionScript()	See if the owning Actor is currently running the UCS
bool	IsOwnerSelected()	Returns whether the component's owner is selected in the editor
bool	IsPhysicsStateCreated()	Returns true if the physics 'state' (e.g. physx bodies) are created for this component
bool	IsReadyForOwnerToAutoDestroy()	Overridable check for a component to indicate to its Owner that it should prevent the Actor from auto destroying when finished
bool	IsReadyForReplication()	Indicates that ReadyForReplication has been called
bool	IsRegistered()	See if this component is currently registered
bool	IsRenderInstancesDirty()	Is this component's instance data in need of sending to the renderer?
bool	IsRenderStateCreated()	Returns true if the render 'state' (e.g. scene proxy) is created for this component
bool	IsRenderStateDirty()	Is this component in need of its whole state being sent to the renderer?
bool	IsRenderTransformDirty()	Is this component's transform in need of sending to the renderer?
bool	IsReplicatedSubObjectRegistered ( const UObject* SubObject )	Tells if the object is registered to be replicated by this actor component.
bool	IsUsingRegisteredSubObjectList()	Returns if this component is replicating subobjects via the registration list or via the virtual ReplicateSubObjects method.
bool	IsVisualizationComponent()	Returns true if this component is only used for visualization, usually a sprite or text
void	K2_DestroyComponent ( UObject* Object )	Unregister and mark for pending kill a component.
void	MarkForNeededEndOfFrameRecreate()	If we belong to a world, mark this for a deferred update, otherwise do it now.
void	MarkForNeededEndOfFrameUpdate()	If we belong to a world, mark this for a deferred update, otherwise do it now.
void	MarkRenderDynamicDataDirty()	Indicate that dynamic data for this component needs to be sent at the end of the frame.
void	MarkRenderInstancesDirty()	Marks the instances as dirty - changes to instance transforms/custom data will be sent to the render thread at the end of the frame
void	MarkRenderStateDirty()	Mark the render state as dirty - will be sent to the render thread at the end of the frame.
void	MarkRenderTransformDirty()	Marks the transform as dirty - will be sent to the render thread at the end of the frame
bool	NeedsInitialization()	Convenience method for testing whether or not we are still be constructed / initialized.
void	OnActorEnableCollisionChanged()	Called on each component when the Actor's bEnableCollisionChanged flag changes
void	OnComponentCreated()	Called when a component is created (not loaded). This can happen in the editor or during gameplay
void	OnComponentDestroyed ( bool bDestroyingHierarchy )	Called when a component is destroyed
void	OnCreatedFromReplication()	We're using the same API as IInterface_ActorSubobject, but not using it directly as a size and performance optimization.
void	OnCreatePhysicsState()	Used to create any physics engine information for this component
void	OnDestroyedFromReplication()
void	OnDestroyPhysicsState()	Used to shut down and physics engine structure for this component
void	OnEndOfFrameUpdateDuringTick()	Allows components to handle an EOF update happening mid tick.
void	OnPreEndOfFrameSync()	Allows components to wait on outstanding tasks prior to sending EOF update data.
void	OnRegister()	Called when a component is registered, after Scene is set, but before CreateRenderState_Concurrent or OnCreatePhysicsState are called.
void	OnRep_IsActive()	Handles replication of active state, handles ticking by default but should be overridden as needed
void	OnUnregister()	Called when a component is unregistered.
bool	OwnerNeedsInitialization()	Convenience method for testing whether or not our owner is still being constructed / initialized.
void	PostApplyToComponent()	Called after ApplyToComponent has run.
void	PreReplication ( IRepChangedPropertyTracker& Change... )	Called on the component right before replication occurs
void	ReadyForReplication()	ReadyForReplication gets called on replicated components when their owning actor is officially ready for replication.
void	ReceiveAsyncPhysicsTick ( float DeltaSeconds, float SimSeconds )	Event called every async physics tick if bAsyncPhysicsTickEnabled is true
void	ReceiveBeginPlay()	Blueprint implementable event for when the component is beginning play, called before its owning actor's BeginPlay or when the component is dynamically created if the Actor has already BegunPlay.
void	ReceiveEndPlay ( EEndPlayReason::Type EndPlayReason )	Blueprint implementable event for when the component ends play, generally via destruction or its Actor's EndPlay.
void	ReceiveTick ( float DeltaSeconds )	Event called every frame if tick is enabled
void	RecreatePhysicsState()	Recreate the physics state right way.
void	RecreateRenderState_Concurrent()	Recreate the render state right away.
void	RegisterAllComponentTickFunctions ( bool bRegister )	When called, will call the virtual call chain to register all of the tick functions Do not override this function or make it virtual
void	RegisterComponent()	Register this component, creating any rendering/physics state.
void	RegisterComponentTickFunctions ( bool bRegister )	Virtual call chain to register all tick functions
void	RegisterComponentWithWorld ( UWorld* InWorld, FRegisterComponentContext* Con... )	Registers a component with a specific world, which creates any visual/physical state
void	RemoveReplicatedSubObject ( UObject* SubObject )	Unregister a SubObject to stop replicating it's properties to clients.
void	RemoveTickPrerequisiteActor ( AActor* PrerequisiteActor )	Remove tick dependency on PrerequisiteActor.
void	RemoveTickPrerequisiteComponent ( UActorComponent* PrerequisiteC... )	Remove tick dependency on PrerequisiteComponent.
void	RemoveUCSModifiedProperties ( const TArray< FProperty* >& P... )	Removes specified properties from the list of UCS-modified properties
bool	ReplicateSubobjects ( UActorChannel* Channel, FOutBunch* Bunch, FReplicationFlags* RepFlags )	Allows a component to replicate other subobject on the actor.
bool	RequiresGameThreadEndOfFrameRecreate()	Return true if this component requires end of frame recreates to happen from the game thread.
bool	RequiresGameThreadEndOfFrameUpdates()	Return true if this component requires end of frame updates to happen from the game thread.
bool	RequiresPreEndOfFrameSync()	Return true if this component needs to sync to tasks before end of frame updates are executed
void	ReregisterComponent()	Unregisters and immediately re-registers component.
void	SendRenderDynamicData_Concurrent()	Called to send dynamic data for this component to the rendering thread
void	SendRenderInstanceData_Concurrent()	Called to send instance data for this component to the rendering thread
void	SendRenderTransform_Concurrent()	Called to send a transform update for this component to the rendering thread
void	SetActive ( bool bNewActive, bool bReset )	Sets whether the component is active or not
void	SetActiveFlag ( const bool bNewIsActive )	Sets the value of bIsActive without causing other side effects to this instance.
void	SetAsyncPhysicsTickEnabled ( bool bEnabled )	Sets bAsyncPhysicsTickEnabled which determines whether to use use the async physics tick with this component.
void	SetAutoActivate ( bool bNewAutoActivate )	Sets whether the component should be auto activate or not. Only safe during construction scripts.
void	SetCanEverAffectNavigation ( bool bRelevant )	Set value of bCanEverAffectNavigation flag and update navigation octree if needed
void	SetComponentTickEnabled ( bool bEnabled )	Set this component's tick functions to be enabled or disabled.
void	SetComponentTickEnabledAsync ( bool bEnabled )	Spawns a task on GameThread that will call SetComponentTickEnabled
void	SetComponentTickInterval ( float TickInterval )	Sets the tick interval for this component's primary tick function.
void	SetComponentTickIntervalAndCooldown ( float TickInterval )	Sets the tick interval for this component's primary tick function.
void	SetIsNetStartupComponent ( const bool bInIsNetStartupComponent )	This should only be called by the engine in ULevel::InitializeNetworkActors to initialize bIsNetStartupComponent.
void	SetIsReplicated ( bool ShouldReplicate )	Enable or disable replication.
void	SetIsReplicatedByDefault ( const bool bNewReplicates )	Sets the value of bReplicates without causing other side effects to this instance.
void	SetIsVisualizationComponent ( const bool bInIsVisualizationCompon... )	Sets if this component is only used for visualization
void	SetNetAddressable()	This signifies the component can be ID'd by name over the network.
void	SetPackageExternal ( bool bExternal, bool bShouldDirty )
void	SetTickableWhenPaused ( bool bTickableWhenPaused )	Sets whether this component can tick when paused.
void	SetTickGroup ( ETickingGroup NewTickGroup )	Changes the ticking group for this component
bool	SetupActorComponentTickFunction ( FTickFunction* TickFunction )	Set up a tick function for a component in the standard way.
bool	ShouldActivate()	Return true if this component is in a state where it can be activated normally.
bool	ShouldCreatePhysicsState()	Return true if CreatePhysicsState() should be called.
bool	ShouldCreateRenderState()	Return true if CreateRenderState() should be called
void	TearOffReplicatedSubObjectOnRemotePeers ( UObject* SubObject )	Stop replicating a subobject and tell actor channels who spawned a replica of this subobject to release ownership over it.
void	TickComponent ( float DeltaTime, enum ELevelTick TickType, FActorComponentTickFunction* T... )	Function called every frame on this ActorComponent.
void	ToggleActive()	Toggles the active state of the component
void	UninitializeComponent()	Handle this component being Uninitialized.
void	UnregisterComponent()	Unregister this component, destroying any rendering/physics state.
void	UpdateComponentToWorld ( EUpdateTransformFlags UpdateTransfo..., ETeleportType Teleport )	Recalculate the value of our component to world transform

Overridden from UObject

	Name	Description
void	BeginDestroy()	Called before destroying the object.
bool	CallRemoteFunction ( UFunction* Function, void* Parms, FOutParmRec* OutParms, FFrame* Stack )	Call the actor's function remotely
bool	CanEditChange ( const FProperty* InProperty )	Called by the editor to query whether a property of this object is allowed to be modified.
int32	GetFunctionCallspace ( UFunction* Function, FFrame* Stack )	Return the space this function should be called.
void	GetLifetimeReplicatedProps ( TArray< FLifetimeProperty >& OutLi... )	Returns properties that are replicated for the lifetime of the actor channel
bool	IsEditorOnly()	Returns whether this component is an editor-only object or not
bool	IsNameStableForNetworking()	IsNameStableForNetworking means an object can be referred to its path name (relative to outer) over the network
bool	IsSelectedInEditor()	Test the selection state of a UObject
bool	IsSupportedForNetworking()	IsSupportedForNetworking means an object can be referenced over the network
void	MarkAsEditorOnlySubobject()	Called during component creation to mark this component as editor only
bool	Modify ( bool bAlwaysMarkDirty )	Note that the object will be modified.
bool	NeedsLoadForClient()	Called during saving to determine the load flags to save with the object.
bool	NeedsLoadForEditorGame()	Called during saving to include this object in client/servers running in editor builds, even if they wouldn't normally be.
bool	NeedsLoadForServer()	Called during saving to determine the load flags to save with the object.
void	PostEditChangeChainProperty ( FPropertyChangedChainEvent& Proper... )	This alternate version of PostEditChange is called when properties inside structs are modified.
void	PostEditChangeProperty ( FPropertyChangedEvent& PropertyCha... )	Called when a property on this object has been modified externally
void	PostEditUndo()	Called after applying a transaction to the object.
void	PostInitProperties()	Called after the C++ constructor and after the properties have been initialized, including those loaded from config.
void	PostLoad()	Do any object-specific cleanup required immediately after loading an object.
void	PostRename ( UObject* OldOuter, const FName OldName )	Called at the end of Rename(), but only if the rename was actually carried out
void	PreEditChange ( FProperty* PropertyAboutToChan... )	This is called when a property is about to be modified externally
void	PreEditUndo()	Called before applying a transaction to the object.
bool	Rename ( const TCHAR* NewName, UObject* NewOuter, ERenameFlags Flags )	Rename this object to a unique name, or change its outer.
void	Serialize ( FArchive& Ar )	Handles reading, writing, and reference collecting using FArchive.

Overridden from IInterface_AssetUserData

		Name	Description
	void	AddAssetUserData ( UAssetUserData* InUserData )
	UAssetUserDa...	GetAssetUserDataOfClass ( TSubclassOf< UAssetUserData > InUse... )
	void	RemoveUserDataOfClass ( TSubclassOf< UAssetUserData > InUse... )

Typedefs

Name	Description
FOnMarkRenderStateDirty

Constants

Name	Description
AllUCSModifiedProperties
AllUCSModifiedPropertiesLock
ComponentTemplateNameSuffix	Prefix used to identify template component instances
GlobalCreatePhysicsDelegate	Create component physics state global delegate.
GlobalDestroyPhysicsDelegate	Destroy component physics state global delegate.
MarkRenderStateDirtyEvent	Called When render state is marked dirty

Deprecated Variables

		Name	Description
	uint8: 1	bCreatedByConstructionScript_DEPRECATED	Replaced by CreationMethod
	uint8: 1	bInstanceComponent_DEPRECATED	Replaced by CreationMethod