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> Unreal Engine API Reference > Runtime > Engine > Engine > UDemoNetDriver

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UDemoNetDriver

Simulated network driver for recording and playing back game sessions.

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Inheritance Hierarchy

UObjectBase

UObjectBaseUtility

UObject

UNetDriver

UDemoNetDriver

References

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

Syntax

class UDemoNetDriver : public UNetDriver

Remarks

Simulated network driver for recording and playing back game sessions.

Variables

	Name	Description
double	AccumulatedRecordTime	Internal debug timing/tracking
bool	bIsWaitingForHeaderDownload
bool	bIsWaitingForStream
double	LastRecordAvgFlush
int64	MaxArchiveReadPos
double	MaxRecordTime
TArray< FPlayba...	PlaybackPackets	PlaybackPackets are used to buffer packets up when we read a demo frame, which we can then process when the time is right
TArray< FQueued...	QueuedPacketsBeforeTravel
int32	RecordCountSinceFlush

Constructors

	Name	Description
	UDemoNetDriver ( const FObjectInitializer& ObjectIn... )
	UDemoNetDriver ( FVTableHelper& Helper )

Destructors

	Name	Description
	~UDemoNetDriver()

Functions

	Name	Description
void	AddEvent ( const FString& Group, const FString& Meta, const TArray< uint8 >& Data )
void	AddNonQueuedActorForScrubbing ( AActor const* Actor )	If a channel is associated with Actor, adds the channel's GUID to the list of GUIDs excluded from queuing bunches during scrubbing.
void	AddNonQueuedGUIDForScrubbing ( FNetworkGUID InGUID )	Adds the channel's GUID to the list of GUIDs excluded from queuing bunches during scrubbing.
void	AddOrUpdateEvent ( const FString& EventName, const FString& Group, const FString& Meta, const TArray< uint8 >& Data )
void	AddReplayTask ( FQueuedReplayTask* NewTask )
void	AddUserToReplay ( const FString& UserString )	Adds a join-in-progress user to the set of users associated with the currently recording replay (if any)
void	ClearReplayTasks()
bool	ComparePropertyState ( const FDemoSavedPropertyState& Sta... )	Compares the values of replicated properties stored in State with the current values of the object replicators.
bool	ConditionallyProcessPlaybackPackets()
bool	ConditionallyReadDemoFrameIntoPlaybackPackets ( FArchive& Ar )
bool	ContinueListen ( FURL& ListenURL )	Called when we are already recording but have traveled to a new map to start recording again
bool	DemoReplicateActor ( AActor* Actor, UNetConnection* Connection, bool bMustReplicate )
void	EnumerateEvents ( const FString& Group, const FEnumerateEventsCallback& De... )
void	EnumerateEventsForActiveReplay ( const FString& Group, const int32 UserIndex, const FEnumerateEventsCallback& De... )	In most cases, this is desirable over EnumerateEvents because it will explicitly use ActiveReplayName instead of letting the streamer decide.
void	EnumerateEventsForActiveReplay ( const FString& Group, const FEnumerateEventsCallback& De... )	In most cases, this is desirable over EnumerateEvents because it will explicitly use ActiveReplayName instead of letting the streamer decide.
void	FinalizeFastForward ( const double StartTime )
const FStrin...	GetActiveReplayName()	Gets the actively recording or playback replay (stream) name.
bool	GetChannelsArePaused()
double	GetCurrentLevelIndex()
float	GetDemoCurrentTime()	Current record/playback position in seconds
uint32	GetDemoCurrentTimeInMS()
int32	GetDemoFrameNum()
FString	GetDemoPath()
const FStrin...	GetDemoSessionID()
float	GetDemoTotalTime()	Total time of demo in seconds
FString	GetDemoURL()
FReplayExter...	GetExternalDataArrayForObject ( UObject* Object )
double	GetLastCheckpointTime()
float	GetLastReplayFrameFidelity()	Replay frame fidelity.
const TArray...	GetLevelNameAndTimeList()
FName	GetNextQueuedTaskName()
uint32	GetPlaybackDemoVersion()
TSharedPtr< ...	GetReplayStreamer()
APlayerContr...	GetSpectatorController()
void	GotoTimeInSeconds ( const float TimeInSeconds, const FOnGotoTimeDelegate& InOnGot... )	Scrubs playback to the given time.
bool	HasDeltaCheckpoints()	Returns whether or not this replay was recorded / is playing with delta checkpoints.
bool	HasGameSpecificFrameData()	Returns whether or not this replay was recorded / is playing with the game specific per frame data feature.
bool	HasLevelStreamingFixes()	Returns whether or not this replay was recorded / is playing with Level Streaming fixes.
bool	InitConnectInternal ( FString& Error )
bool	IsAnyTaskPending()
bool	IsFastForwarding()
bool	IsFinalizingFastForward()
bool	IsLoadingCheckpoint()
bool	IsNamedTaskInQueue ( const FName& Name )
bool	IsPlaying()
bool	IsPlayingClientReplay()
bool	IsRecording()
bool	IsRecordingMapChanges()
bool	IsRecordingPaused()
bool	IsSavingCheckpoint()	Returns true if we're in the process of saving a checkpoint.
void	JumpToEndOfLiveReplay()
void	NotifyDemoPlaybackFailure ( EDemoPlayFailure::Type FailureType )
void	NotifyGotoTimeFinished ( bool bWasSuccessful )	Called when a "go to time" operation is completed.
void	OnSeamlessTravelStartDuringRecording ( const FString& LevelName )	Called when seamless travel begins when recording a replay.
void	PauseChannels ( const bool bPause )
void	PauseRecording ( const bool bInPauseRecording )
void	ProcessAllPlaybackPackets()
bool	ProcessPacket ( const uint8* Data, int32 Count )
bool	ProcessPacket ( const FPlaybackPacket& PlaybackPac... )
bool	ProcessReplayTasks()
void	ProcessSeamlessTravel ( int32 LevelIndex )
void	QueueNetStartupActorForRollbackViaDeletion ( AActor* Actor )	Call this function during playback to track net startup actors that need a hard reset when scrubbing, which is done by destroying and then re-spawning
bool	ReadDemoFrameIntoPlaybackPackets ( FArchive& Ar, TArray< FPlaybackPacket >& Packets, const bool bForLevelFastForward, float* OutTime )
bool	ReadDemoFrameIntoPlaybackPackets ( FArchive& Ar )
bool	RemoveSplitscreenViewer ( APlayerController* RemovePlaye..., bool bMarkOwnerForDeletion )	Removes a splitscreen demo viewer and cleans up its connection.
void	ReplayStreamingReady ( const FStartStreamingResult& Resul... )
void	RequestEventData ( const FString& EventID, const FRequestEventDataCallback& D... )
void	RequestEventDataForActiveReplay ( const FString& EventID, const int32 UserIndex, const FRequestEventDataCallback& D... )	In most cases, this is desirable over RequestEventData because it will explicitly use ActiveReplayName instead of letting the streamer decide.
void	RequestEventDataForActiveReplay ( const FString& EventID, const FRequestEventDataCallback& D... )	In most cases, this is desirable over RequestEventData because it will explicitly use ActiveReplayName instead of letting the streamer decide.
void	RequestEventGroupDataForActiveReplay ( const FString& Group, const int32 UserIndex, const FRequestEventGroupDataCallbac... )	Retrieve data for all events matching the requested group, and call the passed in delegate on completion.
void	RequestEventGroupDataForActiveReplay ( const FString& Group, const FRequestEventGroupDataCallbac... )	Retrieve data for all events matching the requested group, and call the passed in delegate on completion.
void	ResetDemoState()
void	RespawnNecessaryNetStartupActors ( TArray< AActor* >& SpawnedAct..., ULevel* Level )
void	RestoreConnectionPostScrub ( APlayerController* PC, UNetConnection* NetConnection )	Restores the given player controller so that it properly points to the given NetConnection after scrubbing when viewing a replay.
FDemoSavedPr...	SavePropertyState()	Returns the replicated state of every object on a current actor channel.
void	SetActorPrioritizationEnabled ( const bool bInPrioritizeActors )	Enable or disable prioritization of actors for recording.
void	SetCheckpointSaveMaxMSPerFrame ( const float InCheckpointSaveMaxMSPe... )	Sets CheckpointSaveMaxMSPerFrame.
void	SetCurrentLevelIndex ( int32 Index )
void	SetDemoCurrentTime ( float CurrentTime )
void	SetDemoTotalTime ( float TotalTime )
void	SetLastCheckpointTime ( double CheckpointTime )
void	SetMaxDesiredRecordTimeMS ( const float InMaxDesiredRecordTimeM... )	Sets the desired maximum recording time in milliseconds.
void	SetPlayingPlaylist ( TSharedPtr< struct FReplayPlaylistT... )
void	SetSpectatorController ( APlayerController* PC )	Sets the main spectator controller to be used and adds them to the spectator control array
void	SetViewerOverride ( APlayerController*const InView... )	Sets the controller to use as the viewpoint for recording prioritization purposes.
bool	ShouldTickFlushAsyncEndOfFrame()	Returns true if TickFlush can be called in parallel with the Slate tick.
void	SkipTime ( const float InTimeToSkip )
void	SkipTimeInternal ( const float SecondsToSkip, const bool InFastForward, const bool InIsForCheckpoint )
void	SpawnDemoRecSpectator ( UNetConnection* Connection, const FURL& ListenURL )
bool	SpawnSplitscreenViewer ( ULocalPlayer* NewPlayer, UWorld* InWorld )	Creates a new splitscreen replay viewer.
void	StopDemo()
void	TickDemoPlayback ( float DeltaSeconds )
void	TickDemoRecord ( float DeltaSeconds )
void	TickFlushAsyncEndOfFrame ( float DeltaSeconds )	Called by a task thread if the engine is doing async end of frame tasks in parallel with Slate.
void	WriteDemoFrameFromQueuedDemoPackets ( FArchive& Ar, TArray< FQueuedDemoPacket >& Queue..., float FrameTime, EWriteDemoFrameFlags Flags )
void	WritePacket ( FArchive& Ar, uint8* Data, int32 Count )

Overridden from UNetDriver

	Name	Description
void	ForceNetUpdate ( AActor* Actor )	Game code API for updating server Actor Replication State
AActor *	GetActorForGUID ( FNetworkGUID InGUID )	Returns the actor that corresponds to InGUID, if one can be found.
FNetworkGUID	GetGUIDForActor ( const AActor* InActor )	Returns the existing FNetworkGUID of InActor, if it has one.
ISocketSubsy...	GetSocketSubsystem()	Get the socket subsytem appropriate for this net driver
bool	InitBase ( bool bInitAsClient, FNetworkNotify* InNotify, const FURL& URL, bool bReuseAddressAndPort, FString& Error )	Common initialization between server and client connection setup
bool	InitConnect ( FNetworkNotify* InNotify, const FURL& ConnectURL, FString& Error )	Initialize the net driver in client mode
void	InitDestroyedStartupActors()	Initialize the list of destroyed net startup actors from the current World
bool	InitListen ( FNetworkNotify* InNotify, FURL& ListenURL, bool bReuseAddressAndPort, FString& Error )	Initialize the network driver in server mode (listener)
UChannel ...	InternalCreateChannelByName ( const FName& ChName )	Subclasses may override this to customize channel creation.
bool	IsAvailable()	Returns true if this net driver is valid for the current configuration.
bool	IsLevelInitializedForActor ( const AActor* InActor, const UNetConnection* InConnec... )	Returns true if this actor is considered to be in a loaded level
bool	IsNetResourceValid()
bool	IsServer()
FString	LowLevelGetNetworkNumber()
void	LowLevelSend ( TSharedPtr< const FInternetAddr > A..., void* Data, int32 CountBits, FOutPacketTraits& Traits )	Sends a 'connectionless' (not associated with a UNetConection) packet, to the specified address.
void	NotifyActorChannelCleanedUp ( UActorChannel* Channel, EChannelCloseReason CloseReason )	Called when an actor channel is cleaned up foor an actor.
void	NotifyActorChannelOpen ( UActorChannel* Channel, AActor* Actor )	Called when an actor channel is remotely opened for an actor.
void	NotifyActorDestroyed ( AActor* Actor, bool IsSeamlessTravel )	Called when a spawned actor is destroyed.
void	NotifyActorLevelUnloaded ( AActor* Actor )	Called when an actor is being unloaded during a seamless travel or do due level streaming The main point is that it calls the normal NotifyActorDestroyed to destroy the channel on the server but also removes the Actor reference, sets broken flag, and cleans up actor class references on clients.
void	NotifyStreamingLevelUnload ( ULevel* )
void	ProcessLocalClientPackets()	Process any local talker packets that need to be sent to the server
void	ProcessLocalServerPackets()	Process any local talker packets that need to be sent to clients
void	ProcessRemoteFunction ( AActor* Actor, UFunction* Function, void* Parameters, FOutParmRec* OutParms, FFrame* Stack, UObject* SubObject )	Process a remote function call on some actor destined for a remote location
void	SetAnalyticsProvider ( TSharedPtr< IAnalyticsProvider > In... )	Sets the analytics provider
void	SetWorld ( UWorld* InWorld )	Associate a world with this net driver. Disassociates any previous world first.
bool	ShouldClientDestroyTearOffActors()	Returns true if the client should destroy immediately any actor that becomes torn-off
bool	ShouldForwardFunction ( AActor* Actor, UFunction* Function, void* Parms )	Returns true if this network driver will forward a received remote function call to other active net drivers.
bool	ShouldIgnoreRPCs()	Returns whether or not RPCs processed by this driver should be ignored.
bool	ShouldQueueBunchesForActorGUID ( FNetworkGUID InGUID )	Returns true if actor channels with InGUID should queue up bunches, even if they wouldn't otherwise be queued.
bool	ShouldReceiveRepNotifiesForObject ( UObject* Object )	Returns true if RepNotifies should be checked and generated when receiving properties for the given object.
bool	ShouldReplicateActor ( AActor* Actor )	Returns true if this network driver will replicate the given actor.
bool	ShouldReplicateFunction ( AActor* Actor, UFunction* Function )	Returns true if this network driver will handle the remote function call for the given actor.
bool	ShouldSkipRepNotifies()	Returns whether or not properties that are replicating using this driver should not call RepNotify functions.
void	TickDispatch ( float DeltaTime )	Handle time update: read and process packets
void	TickFlush ( float DeltaSeconds )	ReplicateActors and Flush

Overridden from UObject

		Name	Description
	void	FinishDestroy()	Called to finish destroying the object.
	void	Serialize ( FArchive& Ar )	Handles reading, writing, and reference collecting using FArchive.

Constants

Name	Description
OnDemoFailedToStart	Public delegate to be notified when a replay failed to start.
OnDemoStarted	Public delegate for external systems to be notified when a replay begins.

Deprecated Variables

	Name	Description
bool	bChannelsArePaused	Please use GetChannelsArePaused instead.
bool	bIsLocalReplay	No longer used
bool	bRecordMapChanges	Please use IsRecordingMapChanges() instead.
int32	CurrentLevelIndex	Please use GetCurrentLevelIndex/SetCurrentLevelIndex instead.
TSet< FNetworkG...	DeletedNetStartupActorGUIDs	Moved into FReplayHelper
TSet< FString >	DeletedNetStartupActors	Moved into FReplayHelper
float	DemoCurrentTime	Please use GetDemoCurrentTime/SetDemoCurrentTime instead.
int32	DemoFrameNum	Please use GetDemoFrameNum instead.
int32	DemoTotalFrames	No longer used.
float	DemoTotalTime	Please use GetDemoTotalTime/SetDemoTotalTime instead.
TMap< FNetworkG...	ExternalDataToObjectMap	Moved to FReplayHelper.
double	LastCheckpointTime	Please use GetLastCheckpointTime/SetLastCheckpointTime instead.
float	OldDemoCurrentTime	No longer used.
FOnDemoFinishPl...	OnDemoFinishPlaybackDelegate	Moving to FNetworkReplayDelegates.
FOnDemoFinishRe...	OnDemoFinishRecordingDelegate	Moving to FNetworkReplayDelegates.
FOnGotoTimeMCDe...	OnGotoTimeDelegate	Moving to FNetworkReplayDelegates.
FOnPauseChannel...	OnPauseChannelsDelegate	Moving to FNetworkReplayDelegates.
TSharedPtr< cla...	ReplayStreamer	Please use GetReplayStreamer() instead.
TMap< FString, ...	RollbackNetStartupActors	Will be made private in a future release.
APlayerControll...	SpectatorController	Please use GetSpectatorController() instead.

Deprecated Functions

	Name	Description
void	LoadExternalData ( FArchive& Ar, const float TimeSeconds )	Will be removed in a future release.
void	PendingNetGameLoadMapCompleted()	No longer used.
void	SaveCheckpoint()	Will be removed in a future release.
void	SaveExternalData ( FArchive& Ar )	Will be removed in a future release.
bool	ShouldSaveCheckpoint()	Will be removed in a future release.
void	TickCheckpoint()	Will be removed in a future release.
void	WriteDemoFrameFromQueuedDemoPackets ( FArchive& Ar, TArray< FQueuedDemoPacket >& Queue..., float FrameTime )	WriteDemoFrameFromQueuedDemoPackets now takes an additional flag value

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