Note: This page is still a work in progress.
This is an early preview of a page documenting all command line arguments.
The aim is to:
- create an exhaustive list of all command line arguments
- clarify whether they are used for the editor exe or built game exe
- comment on the usage and purpose of arguments
Debug
-
WaitForDebugger
Type:
flag
Causes Unreal to wait for a debugger to be connected before continuing execution.
Logging
-
Log
="abc"
Type:
string
Related:
When used as a switch (-log), opens a separate window to display the contents of the log in real time. When used as a setting (LOG=filename.log), tells the engine to use the log filename of the string that immediately follows.
-
LogTimes
Type:
flag
Incompatible with:
Opposite:
There are a bunch of different ways to display log times.
Print time with log output. (Default, same as setting LogTimes=True in the [LogFiles] section of *Engine.ini.)
-
UTCLogTimes
Type:
flag
Incompatible with:
Opposite:
-
LocalLogTimes
Type:
flag
Incompatible with:
Opposite:
-
LogTimesSinceStart
-
LogTimeCode
Type:
flag
Incompatible with:
Opposite:
-
NoLogTimes
Type:
flag
Incompatible with:
Do not print time with log output. (Same as setting LogTimes=False in the [LogFiles] section of *Engine.ini.)
-
AbsLog
="abc"
Type:
string
Related:
Same as LOG= but without a filename length check.
-
LogCmds
="abc"
Type:
string
Change the verbosity of log categories
-
ForceLogFlush
Type:
flag
Force a log flush after each line.
-
NoPause
Type:
flag
Related:
Close the log window automatically on exit.
-
NoPauseOnSuccess
Type:
flag
Related:
Close the log window automatically on exit as long as no errors were present.
-
NoWrite
Type:
flag
Disable output to log.
Stats
-
LightMassStats
Type:
flag
Force all lightmass agents to report detailed stats to the log.
Developer
-
Auto
Type:
flag
Assume yes on all questions. (for example during compile)
-
AutoCheckoutPackages
Type:
flag
Used on ResavePackagesCommandlet.
Automatically checkout packages that need to be saved.
-
AutomatedMapBuild
Type:
flag
The second argument to the exe is the map, so this flag uses that. As to what an "automated build" means, I have no idea.
Perform an automated build of a specified map.
-
BuildMachine
Type:
flag
If this is set, it implies some other arguments?
Set as build machine. Used for deciding if debug output is enabled.
-
CrashReports
Type:
flag
Always report crashes of the engine.
-
D3DDebug
Type:
flag
Use a d3d debug device.
-
Deterministic
Type:
flag
Related:
Shortcut for -UseFixedTimeStep -FixedSeed
.
-
FixedSeed
Type:
flag
Initialize the random number generator with a fixed value, 0.
-
UseFixedTimeStep
Type:
flag
-
FixUpTangents
Type:
flag
Fix legacy tangents in distributions automatically.
-
ForcePVRTC
Type:
flag
Found a reference to "bForcePVRTC".
Force pvrtc texture compression for mobile platform.
-
Installed
Type:
flag
Opposite:
For development purposes, run the game as if installed.
-
NotInstalled
Type:
flag
Opposite:
-
InstallFW
Type:
flag
Opposite:
Shows the Windows firewall popup maybe?
Set whether the handling of the firewall integration should be performed.
-
UninstallFW
Type:
flag
Opposite:
Set whether the handling of the firewall integration should be performed.
-
InstallGE
Game Explorer seems to be some old Windows thing for managing installed games. Not sure if it's really relevant any more.
Add the game to the Game Explorer.
-
UninstallGE
Type:
flag
Opposite:
Remove the game from the Game Explorer.
-
AllUsers
Type:
flag
does this mean this requires InstallGe?
Add the game for all users when INSTALLGE is specified.
-
LightMassDebug
Type:
flag
Launch lightmass manually with -debug and allow lightmass to be executed multiple times.
-
NoContentBrowser
Type:
flag
Surely this is editor-only? Why would you want to disable the content browser?
Disable the Content Browser.
-
NoInnerException
Type:
flag
Seems to only be enabled with the define _WIN64
?Why might you do this? S
Disable the exception handler within native C++.
#ifdef _WIN64
if ( FParse::Param(CmdLine,TEXT("noinnerexception")) || FApp::IsBenchmarking() || bNoExceptionHandler)
{
GEnableInnerException = false;
}
#endif
-
NoLoadStartupPackages
Type:
flag
There is a log message that mentions it but I cannot find any code that actually uses it.
Force startup packages not to be loaded. You can use this if objects in a startup package must be deleted from within the editor.
-
NoRC
Type:
flag
Disable the remote control. Used for dedicated servers.
-
VerifyGC
Type:
flag
Opposite:
Force garbage compiler assumptions to be verified.
-
NoVerifyGC
Type:
flag
Opposite:
Do not verify garbage compiler assumptions.
-
SeekFreeLoading
Type:
flag
Only use cooked data.
-
SeekFreePackageMap
Type:
flag
Override the package map with the seekfree (cooked) version.
-
SeekFreeloadingPCConsole
Type:
flag
Only use cooked data for PC console mode.
-
SeekFreeLoadingServer
Type:
flag
Only use cooked data for server.
-
SetThreadNames
Type:
flag
(Xbox only) Force thread names to be set. This can mess up the XDK COM API which is why it must be explicitly set to be performed if desired.
-
ShowMissingLoc
Type:
flag
Can't find this in the source. Also, I thought that error strings are already returned instead of English. Maybe this is editor-only?
If missing localized text, return error string instead of English text.
-
Silent
Type:
flag
Disable output and feedback.
-
TreatLoadWarningsAsErrors
Type:
flag
What happens if there's an error?
Force load warnings to be treated as errors.
-
WarningsAsErrors
Type:
flag
Related:
Treat warnings as errors.
-
Unattended
Type:
flag
What kinds of things require feedback? When might you want to use this?
Set as unattended. Disable anything requiring feedback from user.
-
UseUnpublished
Type:
flag
Force packages in the Unpublished folder to be used.
-
VADebug
Type:
flag
Use the Visual Studio debugger interface.
-
Verbose
Type:
flag
Set compiler to use verbose output.
-
ExecCmds
="abc"
Type:
string
It looks like this can be used to execute cheat console commands, separated with commas.
Deprecated
-
BiasCompressionForSize
Type:
flag
Can't find this in the engine.
Override compression settings with respect to size.
-
BulkImportingSounds
Type:
flag
Can't find this in the engine.
Use when importing sounds in bulk. (Content Browser specific.)
-
Check_Native_Class_Sizes
Type:
flag
Can't find in source.
Enable checking of native class sizes. Note: Native classes on console platforms will cause native class size checks to fail even though they are assumed to be correct.
-
CoderMode
Type:
flag
Couldn't find it in the codebase for UE5. Possibly for Unreal Engine 3?
Enables Coder mode.
-
CompatScale
Type:
flag
Couldn't find in source.
Set compatibility settings manually to override PCCompat tool settings.
-
ConformDir
Type:
flag
Can't find either ConformDir or ConfirmDir in UE5 source.
Directory to use when conforming packages.
-
CookForDemo
Type:
flag
Cannot find in source.
Specify as cooking packages for the demo.
-
CookPackages
Type:
flag
Cannot find in source.
Tag to specify cooking packages.
-
DevCon
Type:
flag
Cannot find in source
Disable secure connections for developers. (Uses unencrypted sockets.)
-
DumpFileIOStats
Type:
flag
Cannot find in source
Track and log File IO statistics.
-
ForceSoundRecook
Type:
flag
Can't find any reference to this. Deprecated?
Force a complete re-cook of all sounds.
-
GenericBrowser
Type:
flag
Can't find any reference to this. Deprecated?
Use the Generic Browser.
-
NoConform
Type:
flag
Cannot find in source.
Tell the engine not to conform packages as they are compiled.
-
TraceAnimUsage
Type:
flag
Cannot find in source.
Trace animation usage.
-
Seconds
Type:
I couldn't find this in the Unreal Engine 5 codebase.
Set the maximum tick time.
-
PrimaryNet
Type:
flag
Couldn't find this in the source code, deprecated?
Affect how the engine handles network binding.
-
PreferredProcessor
Type:
flag
Can't find in source.
Set the thread affinity for a specific processor.
-
EnglishCoalesced
Type:
flag
Couldn't find in source.
Revert to the default (English) coalesced .ini if the language-localized version cannot be found.
Localization
-
Culture
="abc"
Type:
string
Related:
When this is set, the text localization manager uses the specified culture and does not look at ini files.
It seems like it might be useful for testing localization, to force the game to launch with a specific culture without having to mess around with settings.
-
CultureForCooking
="abc"
Type:
string
Related:
Does the same as Culture
but can has the option to work with FirstInstall
.
Set language to be used for cooking.
-
FirstInstall
Type:
Related:
Based on the code, if CultureForCooking
and FirstInstall
are set, it writes the culture specified by CultureForCooking
to the Internationalization
part of the engine .ini file.
Rendering
-
ConsoleX
=123
Type:
integer
Set the horizontal position for console output window.
-
ConsoleY
=123
Type:
integer
Set the vertical position for console output window.
-
ConsoleWidth
=123
Type:
integer
-
ConsoleHeight
=123
Type:
integer
-
WinX
=123
Type:
integer
Set the horizontal position of the game window on the screen.
-
WinY
=123
Type:
integer
Set the vertical position of the game window on the screen.
-
ResX
=123
Type:
integer
Set horizontal resolution for game window.
-
ResY
=123
Type:
integer
Set vertical resolution for game window.
-
VSync
Type:
flag
Opposite:
Activate the VSYNC via command line. Pprevents tearing of the image but costs fps and causes input latency.)
-
NoVSync
Type:
flag
Opposite:
Deactivate the VSYNC via command line.
-
Benchmark
Type:
flag
Run game at fixed-step in order to process each frame without skipping any frames. This is useful in conjunction with DUMPMOVIE options.
-
DumpMovie
Type:
flag
Sets the GIsDumpingMovie
variable to -1
so it dumps for an unspecified time. Can also be set through the console variable r.DumpingMovie
Is a flag, cannot set it to dump for a defined amoutn of time like the console variable or global variable.
Dump rendered frames to files using current resolution of game.
- IConsoleManager::Get().RegisterConsoleVariableRef(TEXT("r.DumpingMovie"),
GIsDumpingMovie,
TEXT("Allows to dump each rendered frame to disk (slow fps, names MovieFrame..).\n")
TEXT("<=0:off (default), <0:remains on, >0:remains on for n frames (n is the number specified)"),
ECVF_Cheat);
-
Exec
Type:
flag
What is an exec file? Is it really related to rendering?
Executes the specified exec file.
-
FPS
=123
Type:
integer
Set the frames per second for benchmarking.
-
Fullscreen
Type:
flag
Opposite:
Set game to run in fullscreen mode.
-
Windowed
Type:
flag
Opposite:
Set game to run in windowed mode.
Network
-
LanPlay
Type:
flag
Tell the engine to not cap client bandwidth when connecting to servers. Causes double the amount of server updates and can saturate client's bandwidth.
-
LimitClientTicks
Type:
flag
See NetDriver.cpp
. This flag seems to be on by default if GetNetMode() == NM_ListenServer
Force throttling of network updates.
#if WITH_SERVER_CODE
int32 UNetDriver::ServerReplicateActors_PrepConnections( const float DeltaSeconds )
{
int32 NumClientsToTick = ClientConnections.Num();
// by default only throttle update for listen servers unless specified on the commandline
static bool bForceClientTickingThrottle = FParse::Param( FCommandLine::Get(), TEXT( "limitclientticks" ) );
if ( bForceClientTickingThrottle || GetNetMode() == NM_ListenServer )
{
// ...
-
MultiHome
Type:
flag
Tell the engine to use a multihome address for networking.
-
MultiHomeHttp
Type:
flag
Tell the engine to use a multihome address for networking.
-
NetworkProfiler
Type:
flag
Enable network profiler tracking.
-
NoSteam
Type:
flag
Set steamworks to not be used.
-
Port
="abc"
Type:
string
Tell the engine to use a specific port number.
User
-
NoHomeDir
Type:
flag
So what does it do instead?
Override use of My Documents folder as home directory.
-
NoForceFeedback
Type:
flag
Disable force feedback in the engine.
-
NoSound
Type:
flag
Disable any sound output from the engine.
-
NoSplash
Type:
flag
Disable use of splash image when loading the game.
-
NoTextureStreaming
Type:
flag
Disable texture streaming. Highest quality textures are always loaded.
-
OneThread
Type:
flag
Run the engine using a single thread instead of multi-threading.
-
Paths
="abc"
Type:
string
Set what paths to use for testing wrangled content. Not used for shipping releases.
-
UseAllAvailableCores
Type:
flag
Can only find it with reference to archiving.
Force the use of all available cores on the target platform.
Server Switches
-
Login
="abc"
Type:
string
Set username to use when logging in.
-
Password
="abc"
Type:
string
Set password to use when logging in.
Game Stats/Database
-
NoDatabase
Type:
flag
Do not use database, and ignore database connection errors.
-
NoLiveTags
Type:
flag
Skip loading unverified tag changes from SQL database. Only load for current user.
INI/Config Files
-
NoAutoINIUpdate
Type:
flag
Incompatible with:
Suppress prompts to update .ini files.
-
NoINI
Type:
flag
Do not update the .ini files.
-
RegenerateINIs
Type:
flag
Incompatible with:
Be careful with plurals
Forces .ini files to be regenerated.
Graphics
-
PreferAMD
Type:
flag
Related:
Windows DX11
-
PreferIntel
Type:
flag
Related:
Part of the Windows D3D12, D3D11 and Vulkan Render Hardware Interfaces, this lets you set a preferred adapter vendor. I guess you might want to use it if you've optimised for one over another, and the user has multiple installed?
-
PreferNVidia
Type:
flag
Related:
Part of the Windows D3D12, D3D11 and Vulkan Render Hardware Interfaces, this lets you set a preferred adapter vendor. I guess you might want to use it if you've optimised for one over another, and the user has multiple installed?
-
PreferMS
Type:
flag
Related:
Part of the Windows D3D11 Render Hardware Interface only, this lets you set a preferred adapter vendor. I guess you might want to use it if you've optimised for one over another, and the user has multiple installed?
-
AllowSoftwareRendering
Type:
flag
In the D3D11 and D3D12 RHI, setting this allows it to fall back to software rendering. By default it seem this is disabled.
VR
-
NoHMD
Type:
flag
Disables head-mounted display. Useful for disabling SteamVR.
Unknown
-
Multiprocess
Type:
flag
-
MultiprocessSaveConfig
Type:
flag
-
SkipCompile
Type:
flag
-
SystemMalloc
Type:
flag
-
NumThreads
=123
Type:
integer
Minimum 1.
-
NumRuns
=123
Type:
integer
Minimum 1.
-
MemPerThread
=123
Type:
integer
In kilobytes.
-
TouchMem
Type:
flag