LevelSequence.DefaultLockEngineToDisplayRate
LevelSequence.DefaultLockEngineToDisplayRate
#Overview
name: LevelSequence.DefaultLockEngineToDisplayRate
This variable is created as a Console Variable (cvar).
- type:
Var - help:
0: Playback locked to playback frames\n1: Unlocked playback with sub frame interpolation
It is referenced in 8 C++ source files.
#Summary
#Usage in the C++ source code
The purpose of LevelSequence.DefaultLockEngineToDisplayRate is to control the playback behavior of level sequences in Unreal Engine 5. It determines whether the playback is locked to playback frames or uses unlocked playback with sub-frame interpolation.
This setting variable is primarily used by the LevelSequence module, which is part of Unreal Engine’s cinematics and sequencer system. It affects how level sequences are initialized and played back.
The value of this variable is set in multiple places:
- As a console variable (CVarDefaultLockEngineToDisplayRate) with a default value of 0.
- In the ULevelSequenceProjectSettings class as a configurable property (bDefaultLockEngineToDisplayRate).
- It can be modified through project settings or console commands.
The associated variable CVarDefaultLockEngineToDisplayRate interacts directly with LevelSequence.DefaultLockEngineToDisplayRate. They share the same value and purpose.
Developers should be aware that:
- This setting affects all newly created level sequences.
- Changing this value can impact the smoothness and accuracy of sequence playback.
- It has implications for performance and visual fidelity.
Best practices when using this variable include:
- Consider the target platform and performance requirements when choosing the setting.
- Use frame-locked playback (value 0) for precise frame-by-frame control.
- Use unlocked playback with sub-frame interpolation (value 1) for smoother motion, especially at higher frame rates.
- Ensure consistency across the project by setting this value in the project settings rather than modifying it at runtime.
Regarding the associated variable CVarDefaultLockEngineToDisplayRate:
- It’s a console variable that directly corresponds to LevelSequence.DefaultLockEngineToDisplayRate.
- It’s used in the ULevelSequence::Initialize function to determine the evaluation type of the MovieScene.
- The value is read using GetValueOnGameThread(), indicating it’s accessed during gameplay.
- Developers can modify this value through console commands for debugging or testing purposes.
- When changing this value, be aware that it will affect all subsequent level sequence initializations until changed again.
#References in C++ code
#Callsites
This variable is referenced in the following C++ source code:
#Loc: <Workspace>/Engine/Source/Runtime/LevelSequence/Private/LevelSequence.cpp:62
Scope: file
Source code excerpt:
static TAutoConsoleVariable<int32> CVarDefaultLockEngineToDisplayRate(
TEXT("LevelSequence.DefaultLockEngineToDisplayRate"),
0,
TEXT("0: Playback locked to playback frames\n1: Unlocked playback with sub frame interpolation"),
ECVF_Default);
static TAutoConsoleVariable<FString> CVarDefaultTickResolution(
TEXT("LevelSequence.DefaultTickResolution"),
#Loc: <Workspace>/Engine/Source/Runtime/LevelSequence/Private/LevelSequenceProjectSettings.h:18
Scope (from outer to inner):
file
class class ULevelSequenceProjectSettings : public UDeveloperSettings
Source code excerpt:
ULevelSequenceProjectSettings();
UPROPERTY(config, EditAnywhere, Category=Timeline, meta=(ConsoleVariable="LevelSequence.DefaultLockEngineToDisplayRate", Tooltip="0: Playback locked to playback frames\n1: Unlocked playback with sub frame interpolation"))
bool bDefaultLockEngineToDisplayRate;
UPROPERTY(config, EditAnywhere, Category=Timeline, meta=(ConsoleVariable="LevelSequence.DefaultDisplayRate", Tooltip="Specifies default display frame rate for newly created level sequences; also defines frame locked frame rate where sequences are set to be frame locked. Examples: 30 fps, 120/1 (120 fps), 30000/1001 (29.97), 0.01s (10ms)."))
FString DefaultDisplayRate;
UPROPERTY(config, EditAnywhere, Category=Timeline, meta=(ConsoleVariable="LevelSequence.DefaultTickResolution", Tooltip="Specifies default tick resolution for newly created level sequences. Examples: 30 fps, 120/1 (120 fps), 30000/1001 (29.97), 0.01s (10ms)."))
#Loc: <Workspace>/Engine/Source/Runtime/LevelSequence/Private/LevelSequenceProjectSettings.cpp:27
Scope (from outer to inner):
file
function void ULevelSequenceProjectSettings::PostInitProperties
Source code excerpt:
// ImportConsoleVariableValues();
if (IConsoleVariable* ConsoleVariable = IConsoleManager::Get().FindConsoleVariable(TEXT("LevelSequence.DefaultLockEngineToDisplayRate")))
{
ConsoleVariable->Set((int32)bDefaultLockEngineToDisplayRate, ECVF_SetByProjectSetting);
}
if (IConsoleVariable* ConsoleVariable = IConsoleManager::Get().FindConsoleVariable(TEXT("LevelSequence.DefaultTickResolution")))
{
#Associated Variable and Callsites
This variable is associated with another variable named CVarDefaultLockEngineToDisplayRate. They share the same value. See the following C++ source code.
#Loc: <Workspace>/Engine/Source/Runtime/LevelSequence/Private/LevelSequence.cpp:61
Scope: file
Source code excerpt:
#endif
static TAutoConsoleVariable<int32> CVarDefaultLockEngineToDisplayRate(
TEXT("LevelSequence.DefaultLockEngineToDisplayRate"),
0,
TEXT("0: Playback locked to playback frames\n1: Unlocked playback with sub frame interpolation"),
ECVF_Default);
static TAutoConsoleVariable<FString> CVarDefaultTickResolution(
#Loc: <Workspace>/Engine/Source/Runtime/LevelSequence/Private/LevelSequence.cpp:96
Scope (from outer to inner):
file
function void ULevelSequence::Initialize
Source code excerpt:
MovieScene = NewObject<UMovieScene>(this, NAME_None, RF_Transactional);
const bool bFrameLocked = CVarDefaultLockEngineToDisplayRate.GetValueOnGameThread() != 0;
MovieScene->SetEvaluationType( bFrameLocked ? EMovieSceneEvaluationType::FrameLocked : EMovieSceneEvaluationType::WithSubFrames );
FFrameRate TickResolution(60000, 1);
TryParseString(TickResolution, *CVarDefaultTickResolution.GetValueOnGameThread());
MovieScene->SetTickResolutionDirectly(TickResolution);
#Loc: <Workspace>/Engine/Source/Runtime/LevelSequence/Private/LevelSequenceProjectSettings.cpp:7
Scope (from outer to inner):
file
function ULevelSequenceProjectSettings::ULevelSequenceProjectSettings
Source code excerpt:
ULevelSequenceProjectSettings::ULevelSequenceProjectSettings()
: bDefaultLockEngineToDisplayRate(false)
, DefaultDisplayRate("30fps")
, DefaultTickResolution("24000fps")
, DefaultClockSource(EUpdateClockSource::Tick)
{ }
#Loc: <Workspace>/Engine/Source/Runtime/LevelSequence/Private/LevelSequenceProjectSettings.cpp:29
Scope (from outer to inner):
file
function void ULevelSequenceProjectSettings::PostInitProperties
Source code excerpt:
if (IConsoleVariable* ConsoleVariable = IConsoleManager::Get().FindConsoleVariable(TEXT("LevelSequence.DefaultLockEngineToDisplayRate")))
{
ConsoleVariable->Set((int32)bDefaultLockEngineToDisplayRate, ECVF_SetByProjectSetting);
}
if (IConsoleVariable* ConsoleVariable = IConsoleManager::Get().FindConsoleVariable(TEXT("LevelSequence.DefaultTickResolution")))
{
ConsoleVariable->Set(*DefaultTickResolution, ECVF_SetByProjectSetting);
}
#Loc: <Workspace>/Engine/Source/Runtime/LevelSequence/Private/LevelSequenceProjectSettings.h:19
Scope (from outer to inner):
file
class class ULevelSequenceProjectSettings : public UDeveloperSettings
Source code excerpt:
UPROPERTY(config, EditAnywhere, Category=Timeline, meta=(ConsoleVariable="LevelSequence.DefaultLockEngineToDisplayRate", Tooltip="0: Playback locked to playback frames\n1: Unlocked playback with sub frame interpolation"))
bool bDefaultLockEngineToDisplayRate;
UPROPERTY(config, EditAnywhere, Category=Timeline, meta=(ConsoleVariable="LevelSequence.DefaultDisplayRate", Tooltip="Specifies default display frame rate for newly created level sequences; also defines frame locked frame rate where sequences are set to be frame locked. Examples: 30 fps, 120/1 (120 fps), 30000/1001 (29.97), 0.01s (10ms)."))
FString DefaultDisplayRate;
UPROPERTY(config, EditAnywhere, Category=Timeline, meta=(ConsoleVariable="LevelSequence.DefaultTickResolution", Tooltip="Specifies default tick resolution for newly created level sequences. Examples: 30 fps, 120/1 (120 fps), 30000/1001 (29.97), 0.01s (10ms)."))
FString DefaultTickResolution;