$ bIgnoreOutdatedImportLibraries : Whether to ignore import library files that are out of date when building targets. Set this to true to improve iteration time. By default, we do not bother re-linking targets if only a dependent .lib has changed, as chances are that the import library was not actually different unless a dependent header file of this target was also changed, in which case the target would automatically be rebuilt.
$ bUseUBTMakefiles : Enables support for very fast iterative builds by caching target data. Turning this on causes Unreal Build Tool to emit 'UBT Makefiles' for targets when they are built the first time. Subsequent builds will load these Makefiles and begin outdatedness checking and build invocation very quickly. The caveat is that if source files are added or removed to the project, UBT will need to gather information about those in order for your build to complete successfully. Currently, you must run the project file generator after adding/removing source files to tell UBT to re-gather this information.
* Events that can invalidate the 'UBT Makefile':
* Adding/removing .cpp files
* Adding/removing .h files with UObjects
* Adding new UObject types to a file that did not previously have any
* Changing global build settings (most settings in this file qualify)
* Changed code that affects how Unreal Header Tool works
* You can force regeneration of the 'UBT Makefile' by passing the '-gather' argument, or simply regenerating project files.
* This also enables the fast include file dependency scanning and caching system that allows Unreal Build Tool to detect out of date dependencies very quickly. When enabled, a deep C++ include graph does not have to be generated, and instead, we only scan and cache indirect includes for after a dependent build product was already found to be out of date. During the next build, we will load those cached indirect includes and check for outdatedness.
$ MaxParallelActions : Number of actions that can be executed in parallel. If 0 then code will pick a default based on the number of cores and memory available. Applies to the ParallelExecutor, HybridExecutor, and LocalExecutor
$ bCompactOutput : Instruct the executor to write compact output e.g. only errors, if supported by the executor. This field is used to hold the value when specified from the command line or XML
$ bDebugBuildsActuallyUseDebugCRT : Enables the debug C++ runtime (CRT) for debug builds. By default we always use the release runtime, since the debug version isn't particularly useful when debugging Unreal Engine projects, and linking against the debug CRT libraries forces our third party library dependencies to also be compiled using the debug CRT (and often perform more slowly). Often it can be inconvenient to require a separate copy of the debug versions of third party static libraries simply so that you can debug your program's code.
$ bLegalToDistributeBinary : Whether the output from this target can be publicly distributed, even if it has dependencies on modules that are in folders with special restrictions (eg. CarefullyRedist, NotForLicensees, NoRedist).
$ bUseDebugLiveCodingConsole : Whether to enable support for live coding
$ bUseXGEController : Whether the XGE controller worker and modules should be included in the engine build. These are required for distributed shader compilation using the XGE interception interface.
$ bUseAdaptiveUnityBuild : Use a heuristic to determine which files are currently being iterated on and exclude them from unity blobs, result in faster incremental compile times. The current implementation uses the read-only flag to distinguish the working set, assuming that files will be made writable by the source control system if they are being modified. This is true for Perforce, but not for Git.
$ bAdaptiveUnityDisablesOptimizations : Disable optimization for files that are in the adaptive non-unity working set.
$ bAdaptiveUnityDisablesPCH : Disables force-included PCHs for files that are in the adaptive non-unity working set.
$ bAdaptiveUnityDisablesProjectPCHForProjectPrivate : Backing storage for bAdaptiveUnityDisablesProjectPCH.
$ bAdaptiveUnityCreatesDedicatedPCH : Creates a dedicated PCH for each source file in the working set, allowing faster iteration on cpp-only changes.
$ bAdaptiveUnityEnablesEditAndContinue : Creates a dedicated PCH for each source file in the working set, allowing faster iteration on cpp-only changes.
$ MinGameModuleSourceFilesForUnityBuild : The number of source files in a game module before unity build will be activated for that module. This allows small game modules to have faster iterative compile times for single files, at the expense of slower full rebuild times. This setting can be overridden by the bFasterWithoutUnity option in a module's Build.cs file.
$ bWarningsAsErrors : Whether to enable all warnings as errors. UE enables most warnings as errors already, but disables a few (such as deprecation warnings).
$ UnsafeTypeCastWarningLevel : Indicates what warning/error level to treat unsafe type casts as on platforms that support it (e.g., double->float or int64->int32)
$ bDisableDebugInfo : Whether to globally disable debug info generation; see DebugInfoHeuristics.cs for per-config and per-platform options.
$ bDisableDebugInfoForGeneratedCode : Whether to disable debug info generation for generated files. This improves link times for modules that have a lot of generated glue code.
$ bOmitPCDebugInfoInDevelopment : Whether to disable debug info on PC/Mac in development builds (for faster developer iteration, as link times are extremely fast with debug info disabled).
$ bDeterministic : Set flags require for determinstic linking (experimental, may not be fully supported). Deterministic compiling is controlled via ModuleRules.
$ bForceDeterministic : Force set flags require for determinstic compiling and linking (experimental, may not be fully supported). This setting is only recommended for testing, instead:
* Set bDeterministic on a per module basis in ModuleRules to control deterministic compiling.
* Set bDeterministic on a per target basis in TargetRules to control deterministic linking.
$ StaticAnalyzerMode : The mode to use for the static analyzer. This is only supported for Clang. Shallow mode completes quicker but is generally not recommended.
$ MinFilesUsingPrecompiledHeader : The minimum number of files that must use a pre-compiled header before it will be created and used.
$ bForcePrecompiledHeaderForGameModules : When enabled, a precompiled header is always generated for game modules, even if there are only a few source files in the module. This greatly improves compile times for iterative changes on a few files in the project, at the expense of slower full rebuild times for small game projects. This can be overridden by setting MinFilesUsingPrecompiledHeaderOverride in a module's Build.cs file.
$ bUseIncrementalLinking : Whether to use incremental linking or not. Incremental linking can yield faster iteration times when making small changes. Currently disabled by default because it tends to behave a bit buggy on some computers (PDB-related compile errors).
$ bAllowLTCG : Whether to allow the use of link time code generation (LTCG).
$ ThinLTOCacheDirectory : Directory where to put the ThinLTO cache on supported platforms.
$ ThinLTOCachePruningArguments : Arguments that will be applied to prune the ThinLTO cache on supported platforms. Arguments will only be applied if ThinLTOCacheDirectory is set.
$ bShaderCompilerWorkerTrace : If true, then enable Unreal Insights (utrace) profiling in the build for the Shader Compiler Worker (defines USE_SHADER_COMPILER_WORKER_TRACE=1).
$ bUseSharedPCHs : Enables "Shared PCHs", a feature which significantly speeds up compile times by attempting to share certain PCH files between modules that UBT detects is including those PCH's header files.
$ bUseShippingPhysXLibraries : True if Development and Release builds should use the release configuration of PhysX/APEX.
$ bUseCheckedPhysXLibraries : True if Development and Release builds should use the checked configuration of PhysX/APEX. if bUseShippingPhysXLibraries is true this is ignored.
$ bCheckLicenseViolations : Tells the UBT to check if module currently being built is violating EULA.
$ bBreakBuildOnLicenseViolation : Tells the UBT to break build if module currently being built is violating EULA.
$ bUseFastPDBLinking : Whether to use the :FASTLINK option when building with /DEBUG to create local PDBs on Windows. Fast, but currently seems to have problems finding symbols in the debugger.
$ bCreateMapFile : Outputs a map file as part of the build.
$ bAllowRuntimeSymbolFiles : True if runtime symbols files should be generated as a post build step for some platforms. These files are used by the engine to resolve symbol names of callstack backtraces in logs.
$ PackagePath : Package full path (directory + filename) where to store input files used at link time Normally used to debug a linker crash for platforms that support it
$ bStopSNDBSCompilationAfterErrors : When enabled, SN-DBS will stop compiling targets after a compile error occurs. Recommended, as it saves computing resources for others.
$ bXGENoWatchdogThread : Whether to use the no_watchdog_thread option to prevent VS2015 toolchain stalls.
$ bShowXGEMonitor : Whether to display the XGE build monitor.
$ bStopXGECompilationAfterErrors : When enabled, XGE will stop compiling targets after a compile error occurs. Recommended, as it saves computing resources for others.
$ BaseLogFileName : Specifies the file to use for logging.
$ MaxRootPathLength : Maximum recommended root path length.
$ MaxNestedPathLength : Maximum length of a path relative to the root directory. Used on Windows to ensure paths are portable between machines. Defaults to off.
$ Compiler : Version of the compiler toolchain to use on Windows platform. A value of "default" will be changed to a specific version at UBT start up.
$ CompilerVersion : The specific toolchain version to use. This may be a specific version number (for example, "14.13.26128"), the string "Latest" to select the newest available version, or the string "Preview" to select the newest available preview version. By default, and if it is available, we use the toolchain version indicated by WindowsPlatform.DefaultToolChainVersion (otherwise, we use the latest version).
$ bAllowClangLinker : True if we should use the Clang linker (LLD) when we are compiling with Clang, or Intel linker (xilink\xilib) when we are compiling with Intel oneAPI, otherwise we use the MSVC linker.
$ WindowsSdkVersion : The specific Windows SDK version to use. This may be a specific version number (for example, "8.1", "10.0" or "10.0.10150.0"), or the string "Latest", to select the newest available version. By default, and if it is available, we use the Windows SDK version indicated by WindowsPlatform.DefaultWindowsSdkVersion (otherwise, we use the latest version).
$ bClangTimeTrace : (Experimental) Appends the -ftime-trace argument to the command line for Clang to output a JSON file containing a timeline for the compile. See http://aras-p.info/blog/2019/01/16/time-trace-timeline-flame-chart-profiler-for-Clang/ for more info.
$ bCompilerTrace : Outputs compile timing information so that it can be analyzed.
$ bShowIncludes : Print out files that are included by each source file
$ FBuildCoordinator : Used to specify the FASTBuild coordinator IP or network name. If null, FASTBuild will fall back to checking FASTBUILD_COORDINATOR
$ MaxProcessorCount : Maximum processor count for local execution.
$ ProcessorCountMultiplier : Processor count multiplier for local execution. Can be below 1 to reserve CPU for other tasks. When using the local executor (not XGE), run a single action on each CPU core. Note that you can set this to a larger value to get slightly faster build times in many cases, but your computer's responsiveness during compiling may be much worse. This value is ignored if the CPU does not support hyper-threading.
$ MemoryPerActionBytes : Free memory per action in bytes, used to limit the number of parallel actions if the machine is memory starved. Set to 0 to disable free memory checking.
$ bAllowOverVpn : When set to false, SNDBS will not be enabled when running connected to the coordinator over VPN. Configure VPN-assigned subnets via the VpnSubnets parameter.
$ VpnSubnets : List of subnets containing IP addresses assigned by VPN
$ bAllowOverVpn : When set to false, XGE will not be enabled when running connected to the coordinator over VPN. Configure VPN-assigned subnets via the VpnSubnets parameter.
$ MinActions : Minimum number of actions to use XGE execution.
$ bUnavailableIfInUse : Check for a concurrent XGE build and treat the XGE executor as unavailable if it's in use. This will allow UBT to fall back to another executor such as the parallel executor.
$ bIgnoreJunk : Whether to skip checking for files identified by the junk manifest.
### ProjectFileGenerator
$ DisablePlatformProjectGenerators : Disable native project file generators for platforms. Platforms with native project file generators typically require IDE extensions to be installed.
$ Format : Default list of project file formats to generate.
$ bGenerateIntelliSenseData : True if intellisense data should be generated (takes a while longer).
$ bIncludeDocumentation : True if we should include documentation in the generated projects.
$ bAllDocumentationLanguages : True if all documentation languages should be included in generated projects, otherwise only INT files will be included.
$ bUsePrecompiled : True if build targets should pass the -useprecompiled argument.
$ bIncludeEngineSource : True if we should include engine source in the generated solution.
$ bIncludeShaderSource : True if shader source files should be included in generated projects.
$ bIncludeBuildSystemFiles : True if build system files should be included.
$ bIncludeConfigFiles : True if we should include config (.ini) files in the generated project.
$ bIncludeLocalizationFiles : True if we should include localization files in the generated project.
$ bIncludeTemplateFiles : True if we should include template files in the generated project.
$ bKeepSourceSubDirectories : True if we should reflect "Source" sub-directories on disk in the primary project as project directories. This (arguably) adds some visual clutter to the primary project but it is truer to the on-disk file organization.
$ PrimaryProjectName : Name of the primary project file -- for example, the base file name for the Visual Studio solution file, or the Xcode project file on Mac.
$ bIncludeTestAndShippingConfigs : Whether we should include configurations for "Test" and "Shipping" in generated projects. Pass "-NoShippingConfigs" to disable this.
$ bIncludeDebugConfigs : Whether we should include configurations for "Debug" and "DebugGame" in generated projects. Pass "-NoDebugConfigs" to disable this.
$ bIncludeDevelopmentConfigs : Whether we should include configurations for "Development" in generated projects. Pass "-NoDevelopmentConfigs" to disable this.
$ PrimaryProjectName : Name of the primary project file -- for example, the base file name for the Visual Studio solution file, or the Xcode project file on Mac.
$ PrimaryProjectName : Name of the primary project file -- for example, the base file name for the Visual Studio solution file, or the Xcode project file on Mac.
$ PrimaryProjectName : Name of the primary project file -- for example, the base file name for the Visual Studio solution file, or the Xcode project file on Mac.
$ PrimaryProjectName : Name of the primary project file -- for example, the base file name for the Visual Studio solution file, or the Xcode project file on Mac.
$ PrimaryProjectName : Name of the primary project file -- for example, the base file name for the Visual Studio solution file, or the Xcode project file on Mac.
$ PrimaryProjectName : Name of the primary project file -- for example, the base file name for the Visual Studio solution file, or the Xcode project file on Mac.
$ PrimaryProjectName : Name of the primary project file -- for example, the base file name for the Visual Studio solution file, or the Xcode project file on Mac.
$ PrimaryProjectName : Name of the primary project file -- for example, the base file name for the Visual Studio solution file, or the Xcode project file on Mac.
$ NoCompileCommands : Do not create compile commands json files with compiler arguments for each file; works better with VS Code extension using UBT server mode.
$ PrimaryProjectName : Name of the primary project file -- for example, the base file name for the Visual Studio solution file, or the Xcode project file on Mac.
$ PrimaryProjectName : Name of the primary project file -- for example, the base file name for the Visual Studio solution file, or the Xcode project file on Mac.
$ MaxSharedIncludePaths : Puts the most common include paths in the IncludePath property in the MSBuild project. This significantly reduces Visual Studio memory usage (measured 1.1GB -> 500mb), but seems to be causing issues with Visual Assist. Value here specifies maximum length of the include path list in KB.
$ ExcludedIncludePaths : Semi-colon separated list of paths that should not be added to the projects include paths. Useful for omitting third-party headers (e.g ThirdParty/WebRTC) from intellisense suggestions and reducing memory footprints.
$ ExcludedFilePaths : Semi-colon separated list of paths that should not be added to the projects. Useful for omitting third-party files (e.g ThirdParty/WebRTC) from intellisense suggestions and reducing memory footprints.
$ PrimaryProjectName : Name of the primary project file -- for example, the base file name for the Visual Studio solution file, or the Xcode project file on Mac.
$ PrimaryProjectName : Name of the primary project file -- for example, the base file name for the Visual Studio solution file, or the Xcode project file on Mac.
$ Provider : Sets the provider to use for determining the working set.
$ RepositoryPath : Sets the path to use for the repository. Interpreted relative to the Unreal Engine root directory (the folder above the Engine folder) -- if relative.
$ GitPath : Sets the path to use for the Git executable. Defaults to "git" (assuming it is in the PATH).
### RemoteMac
$ ServerName : These two variables will be loaded from the XML config file in XmlConfigLoader.Init().
$ UserName : The remote username.
$ SshPrivateKey : If set, instead of looking for RemoteToolChainPrivate.key in the usual places (Documents/Unreal, Engine/UnrealBuildTool/SSHKeys or Engine/Build/SSHKeys), this private key will be used.
$ RsyncAuthentication : The authentication used for Rsync (for the -e rsync flag).
$ SshAuthentication : The authentication used for SSH (probably similar to RsyncAuthentication).