Engine inner working

Player loaded into the game

 UPreGameHelper::RequestCharacter click on the selected character, then click on PLAY
   SpawnedChar = SpawnActor() creates the 3d model into the world
   SpawnedChar->Load()
   Assign the actor to the player controller
   PlayerController->Possess(SpawnedChar);
   SpawnedChar->PlayerTeleportToMainWorld() -> calls the BP function to iniatilize the timers client side

Wander Operation

 WanderOperation::Run()
    CalculateEdgeList()
         FindNearestWaypoint() finds start point
         GetActiveLocate() finds end point
         FindEdgeRoute() finds the route between start and end
    dest = GetNextPathPoint() gets the next path point (not the current one) and returns it
    StartMoveTo(dest) 
    

NPC Brain

 APlaneShiftGameState::BeginPlay()
  calls psNPCManager::Initialize()
      calls ReadNPCsFromDatabase()
         select * from sc_npc_definitions
         populates npcs TMap
    
 spawnManager->RepopulateLive();
   LoadAllNPCCharacterData
      SELECT characters.* where npc_spawn_rule>0
           char = SpawnActor()
           char->Load()
               if (IsNPC()) psAIController->SetBrain( using npcs TMap above)

When a perception happens it goes through:

  psNPCManager::TriggerEvent()
    checks all reactions with this event and it finds also the brains without pawn associated, so I added a check there to skip

Main engine loop on startup

	MyProjectServer.exe!UIpNetDriver::InitListen(FNetworkNotify * InNotify, FURL & LocalURL, bool bReuseAddressAndPort, FString & Error) Line 152	C++
	MyProjectServer.exe!UWorld::Listen(FURL & InURL) Line 3927	C++
	MyProjectServer.exe!UEngine::LoadMap(FWorldContext & WorldContext, FURL URL, UPendingNetGame * Pending, FString & Error) Line 8983	C++
	MyProjectServer.exe!UEngine::Browse(FWorldContext & WorldContext, FURL URL, FString & Error) Line 8144	C++
	MyProjectServer.exe!UGameInstance::StartGameInstance() Line 262	C++
	MyProjectServer.exe!UGameEngine::Init(IEngineLoop * InEngineLoop) Line 465	C++
	MyProjectServer.exe!FEngineLoop::Init() Line 1967	C++
	MyProjectServer.exe!GuardedMain(const wchar_t * CmdLine, HINSTANCE__ * hInInstance, HINSTANCE__ * hPrevInstance, int nCmdShow) Line 138	C++
	MyProjectServer.exe!WinMain(HINSTANCE__ * hInInstance, HINSTANCE__ * hPrevInstance, char * __formal, int nCmdShow) Line 191	C++

Open level command

When you execute the "open" command from console, it will queue the travel to open the map:

	MyProject2.exe!UGameInstance::HandleOpenCommand(const wchar_t * Cmd, FOutputDevice & Ar, UWorld * InWorld) Line 295	C++
	MyProject2.exe!UGameInstance::Exec(UWorld * InWorld, const wchar_t * Cmd, FOutputDevice & Ar) Line 323	C++
	MyProject2.exe!UGameViewportClient::Exec(UWorld * InWorld, const wchar_t * Cmd, FOutputDevice & Ar) Line 2014	C++
	MyProject2.exe!ULocalPlayer::Exec(UWorld * InWorld, const wchar_t * Cmd, FOutputDevice & Ar) Line 1457	C++
	MyProject2.exe!APlayerController::ConsoleCommand(const FString & Cmd, bool bWriteToLog) Line 350	C++
	MyProject2.exe!UConsole::ConsoleCommand(const FString & Command) Line 394	C++
	MyProject2.exe!UConsole::InputKey_InputLine(int ControllerId, FKey Key, EInputEvent Event, float AmountDepressed, bool bGamepad) Line 651	C++
	MyProject2.exe!UConsole::InputKey(int ControllerId, FKey Key, EInputEvent Event, float AmountDepressed, bool bGamepad) Line 1062	C++
	MyProject2.exe!UGameViewportClient::InputKey(FViewport * InViewport, int ControllerId, FKey Key, EInputEvent EventType, float AmountDepressed, bool bGamepad) Line 265	C++

Then at the next tick it will do this:

	MyProject2.exe!UEngine::Browse(FWorldContext & WorldContext, FURL URL, FString & Error) Line 8161	C++
	MyProject2.exe!UEngine::TickWorldTravel(FWorldContext & Context, float DeltaSeconds) Line 8311	C++
	MyProject2.exe!UGameEngine::Tick(float DeltaSeconds, bool bIdleMode) Line 812	C++
	MyProject2.exe!FEngineLoop::Tick() Line 2257	C++
	MyProject2.exe!GuardedMain(const wchar_t * CmdLine, HINSTANCE__ * hInInstance, HINSTANCE__ * hPrevInstance, int nCmdShow) Line 142	C++

Collision Tests

 Inside ApsItemActor::ApsItemActor()
   no special code

 Character collides with items

  Inside ApsItemActor::ApsItemActor()
   mesh->SetCollisionProfileName("NoCollision");
   mesh->SetCollisionEnabled(ECollisionEnabled::NoCollision);

  Character does not collide with items

  Inside EntityManager::CreateItem() after SpawnActor
   mesh->SetCollisionProfileName("NoCollision");
   mesh->SetCollisionEnabled(ECollisionEnabled::NoCollision);

  Character collides with items (code seems to have no effect)

Quest interaction sequence

When the player is clicking on the talk icon , this happens, and sends back to the client all the possible quest options:

 APlaneshiftPlayerControllerBase::TalkInteraction()
    ApsCharacter::ShowPopupMenu
       NpcDialogMenu::ShowMenu
          eventManager->SendDialogMenuMessageDelayed

When the player is selecting one option in the npc bubble menu, he sends a chat message to the NPC

  APlaneshiftPlayerControllerBase::SendChatMessage
    ChatManager::HandleChatMessage with type CHAT_NPC
      NpcResponse::ExecuteScript (based on the response found, we execute the script, which may include a number of steps, like say something, do an animation, etc...)
          If there is no delay the ShowMenu is called instantly, otherwise its the client who has to call it when he finished displaying all text (old client was calling /npcmenu from pawsNpcDialogWindow::Draw()