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> Unreal Engine API Reference > Runtime > Engine > Engine > ULevelStreaming

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ULevelStreaming

Abstract base class of container object encapsulating data required for streaming and providing interface for when a level should be streamed in and out of memory.

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Inheritance Hierarchy

UObjectBase

UObjectBaseUtility

UObject

ULevelStreaming

	ULevelStreamingAlwaysLoaded
	ULevelStreamingDynamic
	ULevelStreamingPersistent

References

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

Syntax

class ULevelStreaming : public UObject

Remarks

Abstract base class of container object encapsulating data required for streaming and providing interface for when a level should be streamed in and out of memory.

Variables

	Name	Description
uint8: 1	bDisableDistanceStreaming	Whether this level streaming object should be ignored by world composition distance streaming, so streaming state can be controlled by other systems (ex: in blueprints)
uint8: 1	bDrawOnLevelStatusMap	If true, will be drawn on the 'level streaming status' map (STAT LEVELMAP console command)
uint8: 1	bIsStatic	Whether this level only contains static actors that aren't affected by gameplay or replication.
uint8: 1	bLocked	Whether this level is locked; that is, its actors are read-only.
uint8: 1	bShouldBeLoaded	Whether the level should be loaded
uint8: 1	bShouldBlockOnLoad	Whether we want to force a blocking load
uint8: 1	bShouldBlockOnUnload	Whether we want to force a blocking unload
TArray< ALevelS...	EditorStreamingVolumes	The level streaming volumes bound to this level.
TArray< FString...	Keywords	List of keywords to filter on in the level browser
float	LastVolumeUnloadRequestTime	Time of last volume unload request. Used in preventing spurious unload requests.
FLinearColor	LevelColor	The level color used for visualization. (Show -> Advanced -> Level Coloration)
FTransform	LevelTransform	Transform applied to actors after loading.
TArray< FName >	LODPackageNames	LOD versions of this level
TArray< FName >	LODPackageNamesToLoad	LOD package names on disk
float	MinTimeBetweenVolumeUnloadRequests	Cooldown time in seconds between volume-based unload requests.
FLevelStreaming...	OnLevelHidden	Called when level is removed from the world
FLevelStreaming...	OnLevelLoaded	Called when level is streamed in
FLevelStreaming...	OnLevelShown	Called when level is added to the world
FLevelStreaming...	OnLevelUnloaded	Called when level is streamed out
FName	PackageNameToLoad	If this isn't Name_None, then we load from this package on disk to the new package named PackageName

Constructors

	Name	Description
	ULevelStreaming ( const FObjectInitializer& ObjectIn... )

Functions

	Name	Description
void	AddLevelToCollectionAfterReload()
void	BroadcastLevelLoadedStatus ( UWorld* PersistentWorld, FName LevelPackageName, bool bLoaded )	Traverses all streaming level objects in the persistent world and in all inner worlds and calls appropriate delegate for streaming objects that refer specified level
void	BroadcastLevelVisibleStatus ( UWorld* PersistentWorld, FName LevelPackageName, bool bVisible )	Traverses all streaming level objects in the persistent world and in all inner worlds and calls appropriate delegate for streaming objects that refer specified level
void	ClearLoadedLevel()	Sets the LoadedLevel value to NULL
ULevelStream...	CreateInstance ( const FString& UniqueInstanceName )	Creates a new instance of this streaming level with a provided unique instance name
const TCHAR ...	EnumToString ( ECurrentState InCurrentState )
ECurrentStat...	GetCurrentState()	Returns the current loaded/visible state of the streaming level.
const FName ...	GetFolderPath()	Get the folder path for this level for use in the world browser. Only available in editor builds
bool	GetIsRequestingUnloadAndRemoval()	Returns if the streaming level has requested to be unloaded and removed.
int32	GetLevelLODIndex()	Returns the world composition level LOD index.
ALevelScript...	GetLevelScriptActor()	Returns the Level Script Actor of the level if the level is loaded and valid
ULevel *	GetLoadedLevel()	Gets a pointer to the LoadedLevel value
int32	GetPriority()	Sets the relative priority of considering the streaming level.
bool	GetShouldBeVisibleFlag()	Returns the value of bShouldBeVisible.
bool	GetShouldBeVisibleInEditor()	Returns if the streaming level should be visible in the editor.
FBox	GetStreamingVolumeBounds()	Get a bounding box around the streaming volumes associated with this LevelStreaming object
UWorld *	GetWorld()
const TSoftO...	GetWorldAsset()	Returns a constant reference to the world asset this streaming level object references
FName	GetWorldAssetPackageFName()	Gets the package name for the world asset referred to by this level streaming as an FName
FString	GetWorldAssetPackageName()	Gets the package name for the world asset referred to by this level streaming
bool	HasLoadedLevel()	Returns whether the streaming level has loaded a level.
bool	HasLoadRequestPending()	Returns whether the streaming level is in the loading state.
bool	IsLevelLoaded()	Returns whether streaming level is loaded
bool	IsLevelVisible()	Returns whether streaming level is visible
bool	IsStreamingStatePending()	Returns whether level has streaming state change pending
bool	IsValidStreamingLevel()	Returns false if the level package associated to that streaming level is invalid.
void	RemoveLevelFromCollectionForReload()	After a sub level is reloaded in the editor the cache state needs to be refreshed.
void	RemoveStreamingVolumeDuplicates()	Remove duplicates in EditorStreamingVolumes list
void	RenameForPIE ( int PIEInstanceID )	Rename package name to PIE appropriate name
void	SetFolderPath ( const FName& InFolderPath )	Sets the folder path for this level in the world browser. Only available in editor builds
void	SetIsRequestingUnloadAndRemoval ( bool bInIsRequestingUnloadAndRemova... )	Sets if the streaming level should be unloaded and removed.
void	SetLevelLODIndex ( int32 LODIndex )	Sets the world composition level LOD index and marks the streaming level as requiring consideration.
void	SetPriority ( int32 NewPriority )	Sets the relative priority of considering the streaming level.
void	SetShouldBeLoaded ( bool bInShouldBeLoaded )	Virtual that can be overriden to change whether a streaming level should be loaded.
void	SetShouldBeVisible ( bool bInShouldBeVisible )	Sets the should be visible flag and marks the streaming level as requiring consideration.
void	SetShouldBeVisibleInEditor ( bool bInShouldBeVisibleInEditor )	Sets if the streaming level should be visible in the editor.
void	SetWorldAsset ( const TSoftObjectPtr< UWorld >& Ne... )	Setter for WorldAsset.
void	SetWorldAssetByPackageName ( FName InPackageName )	Sets the world asset based on the package name assuming it contains a world of the same name.
bool	ShouldBeAlwaysLoaded()
bool	ShouldBeLoaded()	Return whether this level should be present in memory which in turn tells the streaming code to stream it in.
bool	ShouldBeVisible()	Return whether this level should be visible/ associated with the world if it is loaded.

Overridden from UObject

	Name	Description
void	PostEditChangeProperty ( FPropertyChangedEvent& PropertyCha... )	Called when a property on this object has been modified externally
void	PostEditUndo()	Override Pre/PostEditUndo functions to handle editor transform
void	PostLoad()	Do any object-specific cleanup required immediately after loading an object.
void	Serialize ( FArchive& Ar )	Handles reading, writing, and reference collecting using FArchive.

Classes

	Name	Description
	FPackageNameMatcher	Matcher for searching streaming levels by PackageName

Enums

	Name	Description
	ECurrentState
	EReqLevelBlock
	ETargetState

Deprecated Variables

		Name	Description
	FColor	DrawColor_DEPRECATED	Deprecated level color used for visualization.
	FName	PackageName_DEPRECATED	Deprecated name of the package containing the level to load.

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