UEngine和Level的Tick函数

函数

void UWorld::Tick( ELevelTick TickType, float DeltaSeconds )

UWorld的pawn成员：

    /** List of all the pawns in the world. */
    TArray<TWeakObjectPtr<class APawn> > PawnList;

Controller成员ControllerList

    /** List of all the controllers in the world. */
    TArray<TWeakObjectPtr<class AController> > ControllerList;

SpectatorPawn为我们在edit模式未启动play时使用的pawn（用来控制相机），当我们启动play以后会将我们gamemode指定的pawn添加入world（或叫level）

void UWorld::AddPawn( APawn* Pawn )
{
    check( Pawn );
    PawnList.AddUnique( Pawn );
}

当我们退出game状态回到edit模式则相反

void UWorld::RemovePawn( APawn* Pawn )
{
    check( Pawn );
    
    AController* Controller = Pawn->GetController();
    if (Controller && (Controller->GetPawn() == Pawn))
    {
        Controller->UnPossess();
    }

    PawnList.Remove( Pawn );    
}

 ///////编辑器引擎的Tick函数

void UEditorEngine::Tick( float DeltaSeconds, bool bIdleMode )
{
        for (auto ContextIt = WorldList.CreateIterator(); ContextIt; ++ContextIt)
        {
            FWorldContext &PieContext = *ContextIt;
            if (PieContext.WorldType != EWorldType::PIE || PieContext.World() == NULL || !PieContext.World()->ShouldTick())
            {
                continue;
            }　　
    　　　　　　TickWorldTravel(PieContext, DeltaSeconds);
　　　　　}
}

的是否打算

void UEngine::TickWorldTravel(FWorldContext& Context, float DeltaSeconds)
{
    if( Context.PendingNetGame )
    {
        Context.PendingNetGame->Tick( DeltaSeconds );
        if ( Context.PendingNetGame && Context.PendingNetGame->ConnectionError.Len() > 0 )
        {
            BroadcastNetworkFailure(NULL, Context.PendingNetGame->NetDriver, ENetworkFailure::PendingConnectionFailure, Context.PendingNetGame->ConnectionError);
            CancelPending(Context);
        }
        else if (Context.PendingNetGame && Context.PendingNetGame->bSuccessfullyConnected && !Context.PendingNetGame->bSentJoinRequest && (Context.OwningGameInstance == NULL || !Context.OwningGameInstance->DelayPendingNetGameTravel()))
        {
            if (!MakeSureMapNameIsValid(Context.PendingNetGame->URL.Map))
            {
                BrowseToDefaultMap(Context);
                BroadcastTravelFailure(Context.World(), ETravelFailure::PackageMissing, Context.PendingNetGame->URL.RedirectURL);
            }
            else
            {
                // Attempt to load the map.
                FString Error;

                const bool bLoadedMapSuccessfully = LoadMap(Context, Context.PendingNetGame->URL, Context.PendingNetGame, Error);

                Context.PendingNetGame->LoadMapCompleted(this, Context, bLoadedMapSuccessfully, Error);

                // Kill the pending level.
                Context.PendingNetGame = NULL;
            }
        }
    }
}