Before we modify the game startup code, we'll need to tell the compiler where to find the CryMono interfaces.

Start by right-clicking on the CryGame project in Visual Studio's Solution Explorer and select Properties. This should bring up the following CryGame Property Pages window:

Now, click on C/C++ and select General. This will bring up a screen of general compiler settings, which we'll use to add an additional include folder as shown in the following screenshot:

Now all we have to do is add ..\..\CryMono\MonoDll\Headers to the Additional Include Directories menu. This will tell the compiler to search CryMono's Headers folder when the #include macro is used, allowing us to find the CryMono C++ interfaces.

Open GameStartup.h in the CryGame project and add the following to the bottom of the class declaration:

static HMODULE
m_cryMonoDll;

Then open GameStartup.cpp and add the following before the CGameStartup constructor:

HMODULE CGameStartup::m_cryMonoDll = 0;

Now navigate to the CGameStartup destructor and add the following code:

if(m_cryMonoDll)
{
  CryFreeLibrary(m_cryMonoDll);
  m_cryMonoDll = 0;
}

Now navigate to the CGameStartup::Init function declaration, and add the following prior to the REGISTER_COMMAND("g_loadMod", RequestLoadMod,VF_NULL,""); snippet:

m_cryMonoDll = CryLoadLibrary("CryMono.dll");
if(!m_cryMonoDll)
{
  CryFatalError("Could not locate CryMono DLL! %i", GetLastError());
  return false;
}

auto InitMonoFunc = (IMonoScriptSystem::TEntryFunction)CryGetProcAddress(m_cryMonoDll, "InitCryMono");
if(!InitMonoFunc)
{
  CryFatalError("Specified CryMono DLL is not valid!");
  return false;
}

InitMonoFunc(gEnv->pSystem, m_pFramework);

Now all we have to do is compile CryGame in order to have CryMono loaded and initialized at startup.

Due to a recent change in the flow system, flow nodes have to be registered at a certain point during game startup. To make sure that our C# nodes are registered, we'll need to call IMonoScriptSysetm::RegisterFlownodes from IGame::RegisterGameFlowNodes.

To do this, open Game.cpp and add the following inside the CGame::RegisterGameFlowNodes function:

GetMonoScriptSystem()->RegisterFlownodes();

Now, after compiling, all managed flow nodes should appear in the Flowgraph Editor.