// Called every frame
void ACameraDirector::Tick(float DeltaTime)
{
	Super::Tick(DeltaTime);
    const float TimeBetweenCameraChanges = 2.0f;
    const float SmoothBlendTime = 0.75f;
    TimeToNextCameraChange -= DeltaTime;
    if (TimeToNextCameraChange <= 0.0f)
    {
        TimeToNextCameraChange += TimeBetweenCameraChanges;

        // 查找处理本地玩家控制的actor。
        APlayerController* OurPlayerController = UGameplayStatics::GetPlayerController(this, 0);
        if (OurPlayerController)
        {
            if ((OurPlayerController->GetViewTarget() != CameraOne) && (CameraOne != nullptr))
            {
                // 立即切换到摄像机1。
                OurPlayerController->SetViewTarget(CameraOne);
            }
            else if ((OurPlayerController->GetViewTarget() != CameraTwo) && (CameraTwo != nullptr))
            {
                // 平滑地混合到摄像机2。
                OurPlayerController->SetViewTargetWithBlend(CameraTwo, SmoothBlendTime);
            }
        }
    }
}