设置Cook的步骤后，断点进入到如下堆栈：

UCookOnTheFlyServer::StartCookByTheBook(const UCookOnTheFlyServer::FCookByTheBookStartupOptions &) CookOnTheFlyServer.cpp:7723
UCookCommandlet::CookByTheBook(const TArray<…> &, TArray<…> &) CookCommandlet.cpp:897
UCookCommandlet::Main(const FString &) CookCommandlet.cpp:602
FEngineLoop::PreInitPostStartupScreen(const wchar_t *) LaunchEngineLoop.cpp:3419
FEngineLoop::PreInit(const wchar_t *) LaunchEngineLoop.cpp:3645
EnginePreInit(const wchar_t *) Launch.cpp:124
GuardedMain(const wchar_t *, HINSTANCE__ *, HINSTANCE__ *, int) Launch.cpp:222
WinMain(HINSTANCE__ *, HINSTANCE__ *, char *, int) LaunchWindows.cpp:262

接着进入到

void UCookOnTheFlyServer::CleanSandbox(const bool bIterative)

接着进入到

void UCookOnTheFlyServer::PopulateCookedPackagesFromDisk(const TArray<ITargetPlatform*>& Platforms)
 

这个方法实现了UE4增量Cook：