2016.8.30

发现了这个函数，可以直接获得摄像机的位置和旋转。

  1. Controller->GetPlayerViewPoint(CamLoc, CamRot);

最近看了几天PlayerCameraManager的代码，大致看明白了，本着分享的原则，在此分享一些经验。

PlayerCameraManager，顾名思义就是管理角色摄像仪与视角的，你可以通过继承的方式，编写自己的PlayerCameraManager，之后在你角色的控制类中指定即可。

下面说一下主要的运行过程：

这里可以参考一下ShooterGame(ShooterPlayerCameraManager),从函数UpdateCamera开始看

  1. void AShooterPlayerCameraManager::UpdateCamera(float DeltaTime)
  2. {
    　　//尝试获取角色类指针，如果成功就执行一些第一人称视角相关的修正
  3.     AShooterCharacter* MyPawn = PCOwner ? Cast<AShooterCharacter>(PCOwner->GetPawn()) : NULL;
  4.     if (MyPawn && MyPawn->IsFirstPerson())
  5.     {
    　　　　//Fov切换的相关逻辑，（右键的微瞄切换）
  6.         const float TargetFOV = MyPawn->IsTargeting() ? TargetingFOV : NormalFOV;
  7.         DefaultFOV = FMath::FInterpTo(DefaultFOV, TargetFOV, DeltaTime, 20.0f);
  8.     }
  9. 　　//执行父类函数
  10.     Super::UpdateCamera(DeltaTime);
  11. 　　//对角色类的模型进行变换
  12.     if (MyPawn && MyPawn->IsFirstPerson())
  13.     {
  14.         MyPawn->OnCameraUpdate(GetCameraLocation(), GetCameraRotation());
  15.     }
  16. }

　　这里并没有视角的相关逻辑，所以进一步看父类的UpdateCamera函数。

  1. void APlayerCameraManager::UpdateCamera(float DeltaTime)
  2. {
  3.     if ((PCOwner->Player && PCOwner->IsLocalPlayerController()) || !bUseClientSideCameraUpdates || bDebugClientSideCamera)
  4.     {
  5.         DoUpdateCamera(DeltaTime);
  6.  
  7.         if (GetNetMode() == NM_Client && bShouldSendClientSideCameraUpdate)
  8.         {
  9.             // compress the rotation down to 4 bytes
  10.             int32 const ShortYaw = FRotator::CompressAxisToShort(CameraCache.POV.Rotation.Yaw);
  11.             int32 const ShortPitch = FRotator::CompressAxisToShort(CameraCache.POV.Rotation.Pitch);
  12.             int32 const CompressedRotation = (ShortYaw << ) | ShortPitch;
  13.  
  14.             PCOwner->ServerUpdateCamera(CameraCache.POV.Location, CompressedRotation);
  15.             bShouldSendClientSideCameraUpdate = false;
  16.         }
  17.     }
  18. }

　　这里是一些网络的逻辑，继续看DoUpdateCamera函数

  1. void APlayerCameraManager::DoUpdateCamera(float DeltaTime)
  2. {
    　　//一些后期效果融合
  3.     // update color scale interpolation
  4.     if (bEnableColorScaleInterp)
  5.     {
  6.         float BlendPct = FMath::Clamp((GetWorld()->TimeSeconds - ColorScaleInterpStartTime) / ColorScaleInterpDuration, .f, 1.0f);
  7.         ColorScale = FMath::Lerp(OriginalColorScale, DesiredColorScale, BlendPct);
  8.         // if we've maxed
  9.         if (BlendPct == 1.0f)
  10.         {
  11.             // disable further interpolation
  12.             bEnableColorScaleInterp = false;
  13.         }
  14.     }
  15. 　　
    　　
    　　//是否停止工作，不然就执行UpdateViewTarget
  16.     // Don't update outgoing viewtarget during an interpolation when bLockOutgoing is set.
  17.     if ((PendingViewTarget.Target == NULL) || !BlendParams.bLockOutgoing)
  18.     {
  19.         // Update current view target
  20.         ViewTarget.CheckViewTarget(PCOwner);
  21.         UpdateViewTarget(ViewTarget, DeltaTime);
  22.     }
  23. 　　//下面都是一些视角更新的循环逻辑，看到最后你会发现他们一直都是用的引用，设置新的视角的逻辑并不在这
  24.     // our camera is now viewing there
  25.     FMinimalViewInfo NewPOV = ViewTarget.POV;
  26.  
  27.     // if we have a pending view target, perform transition from one to another.
  28.     if (PendingViewTarget.Target != NULL)
  29.     {
  30.         BlendTimeToGo -= DeltaTime;
  31.  
  32.         // Update pending view target
  33.         PendingViewTarget.CheckViewTarget(PCOwner);
  34.         UpdateViewTarget(PendingViewTarget, DeltaTime);
  35.  
  36.         // blend....
  37.         if (BlendTimeToGo > )
  38.         {
  39.             float DurationPct = (BlendParams.BlendTime - BlendTimeToGo) / BlendParams.BlendTime;
  40.  
  41.             float BlendPct = .f;
  42.             switch (BlendParams.BlendFunction)
  43.             {
  44.             case VTBlend_Linear:
  45.                 BlendPct = FMath::Lerp(.f, .f, DurationPct);
  46.                 break;
  47.             case VTBlend_Cubic:
  48.                 BlendPct = FMath::CubicInterp(.f, .f, .f, .f, DurationPct);
  49.                 break;
  50.             case VTBlend_EaseIn:
  51.                 BlendPct = FMath::Lerp(.f, .f, FMath::Pow(DurationPct, BlendParams.BlendExp));
  52.                 break;
  53.             case VTBlend_EaseOut:
  54.                 BlendPct = FMath::Lerp(.f, .f, FMath::Pow(DurationPct, .f / BlendParams.BlendExp));
  55.                 break;
  56.             case VTBlend_EaseInOut:
  57.                 BlendPct = FMath::InterpEaseInOut(.f, .f, DurationPct, BlendParams.BlendExp);
  58.                 break;
  59.             default:
  60.                 break;
  61.             }
  62.  
  63.             // Update pending view target blend
  64.             NewPOV = ViewTarget.POV;
  65.             NewPOV.BlendViewInfo(PendingViewTarget.POV, BlendPct);//@TODO: CAMERA: Make sure the sense is correct!  BlendViewTargets(ViewTarget, PendingViewTarget, BlendPct);
  66.         }
  67.         else
  68.         {
  69.             // we're done blending, set new view target
  70.             ViewTarget = PendingViewTarget;
  71.  
  72.             // clear pending view target
  73.             PendingViewTarget.Target = NULL;
  74.  
  75.             BlendTimeToGo = ;
  76.  
  77.             // our camera is now viewing there
  78.             NewPOV = PendingViewTarget.POV;
  79.         }
  80.     }
  81.  
  82.     // Cache results
  83.     FillCameraCache(NewPOV);
  84.  
  85.     if (bEnableFading)
  86.     {
  87.         if (bAutoAnimateFade)
  88.         {
  89.             FadeTimeRemaining = FMath::Max(FadeTimeRemaining - DeltaTime, 0.0f);
  90.             if (FadeTime > 0.0f)
  91.             {
  92.                 FadeAmount = FadeAlpha.X + ((.f - FadeTimeRemaining / FadeTime) * (FadeAlpha.Y - FadeAlpha.X));
  93.             }
  94.  
  95.             if ((bHoldFadeWhenFinished == false) && (FadeTimeRemaining <= .f))
  96.             {
  97.                 // done
  98.                 StopCameraFade();
  99.             }
  100.         }
  101.  
  102.         if (bFadeAudio)
  103.         {
  104.             ApplyAudioFade();
  105.         }
  106.     }
  107. }

　　接下来看UpdateViewTarget函数，计算视角的逻辑都在里面

  1. void APlayerCameraManager::UpdateViewTarget(FTViewTarget& OutVT, float DeltaTime)
  2. {
  3.     // Don't update outgoing viewtarget during an interpolation
  4.     if ((PendingViewTarget.Target != NULL) && BlendParams.bLockOutgoing && OutVT.Equal(ViewTarget))
  5.     {
  6.         return;
  7.     }
  8. 　　//设置默认属性的摄像机
  9.     // store previous POV, in case we need it later
  10.     FMinimalViewInfo OrigPOV = OutVT.POV;
  11. 　　
  12.     //@TODO: CAMERA: Should probably reset the view target POV fully here
  13.     OutVT.POV.FOV = DefaultFOV;
  14.     OutVT.POV.OrthoWidth = DefaultOrthoWidth;
  15.     OutVT.POV.bConstrainAspectRatio = false;
  16.     OutVT.POV.bUseFieldOfViewForLOD = true;
  17.     OutVT.POV.ProjectionMode = bIsOrthographic ? ECameraProjectionMode::Orthographic : ECameraProjectionMode::Perspective;
  18.     OutVT.POV.PostProcessSettings.SetBaseValues();
  19.     OutVT.POV.PostProcessBlendWeight = 1.0f;
  20.  
  21.     bool bDoNotApplyModifiers = false;
  22. 　　//如果ViewTarget是个摄像机的话，就直接获取摄像机的视角
  23.     if (ACameraActor* CamActor = Cast<ACameraActor>(OutVT.Target))
  24.     {
  25.         // Viewing through a camera actor.
  26.         CamActor->GetCameraComponent()->GetCameraView(DeltaTime, OutVT.POV);
  27.     }
  28.     else
  29.     {
  30. 　　　　//下面都是一些不同模式的摄像机的逻辑，你可以在游戏中按下~，输入Camera XXXX的方式切换这个摄像机
    　　　　//默认的摄像机是Default
  31.         static const FName NAME_Fixed = FName(TEXT("Fixed"));
  32.         static const FName NAME_ThirdPerson = FName(TEXT("ThirdPerson"));
  33.         static const FName NAME_FreeCam = FName(TEXT("FreeCam"));
  34.         static const FName NAME_FreeCam_Default = FName(TEXT("FreeCam_Default"));
  35.         static const FName NAME_FirstPerson = FName(TEXT("FirstPerson"));
  36.  
  37.         if (CameraStyle == NAME_Fixed)
  38.         {
  39.             // do not update, keep previous camera position by restoring
  40.             // saved POV, in case CalcCamera changes it but still returns false
  41.             OutVT.POV = OrigPOV;
  42.  
  43.             // don't apply modifiers when using this debug camera mode
  44.             bDoNotApplyModifiers = true;
  45.         }
  46.         else if (CameraStyle == NAME_ThirdPerson || CameraStyle == NAME_FreeCam || CameraStyle == NAME_FreeCam_Default)
  47.         {
  48.             // Simple third person view implementation
  49.             FVector Loc = OutVT.Target->GetActorLocation();
  50.             FRotator Rotator = OutVT.Target->GetActorRotation();
  51.  
  52.             if (OutVT.Target == PCOwner)
  53.             {
  54.                 Loc = PCOwner->GetFocalLocation();
  55.             }
  56.  
  57.             // Take into account Mesh Translation so it takes into account the PostProcessing we do there.
  58.             // @fixme, can crash in certain BP cases where default mesh is null
  59. //            APawn* TPawn = Cast<APawn>(OutVT.Target);
  60. //             if ((TPawn != NULL) && (TPawn->Mesh != NULL))
  61. //             {
  62. //                 Loc += FQuatRotationMatrix(OutVT.Target->GetActorQuat()).TransformVector(TPawn->Mesh->RelativeLocation - GetDefault<APawn>(TPawn->GetClass())->Mesh->RelativeLocation);
  63. //             }
  64.  
  65.             //OutVT.Target.GetActorEyesViewPoint(Loc, Rot);
  66.             if( CameraStyle == NAME_FreeCam || CameraStyle == NAME_FreeCam_Default )
  67.             {
  68.                 Rotator = PCOwner->GetControlRotation();
  69.             }
  70.  
  71.             FVector Pos = Loc + ViewTargetOffset + FRotationMatrix(Rotator).TransformVector(FreeCamOffset) - Rotator.Vector() * FreeCamDistance;
  72.             FCollisionQueryParams BoxParams(NAME_FreeCam, false, this);
  73.             BoxParams.AddIgnoredActor(OutVT.Target);
  74.             FHitResult Result;
  75.  
  76.             GetWorld()->SweepSingleByChannel(Result, Loc, Pos, FQuat::Identity, ECC_Camera, FCollisionShape::MakeBox(FVector(.f)), BoxParams);
  77.             OutVT.POV.Location = !Result.bBlockingHit ? Pos : Result.Location;
  78.             OutVT.POV.Rotation = Rotator;
  79.  
  80.             // don't apply modifiers when using this debug camera mode
  81.             bDoNotApplyModifiers = true;
  82.         }
  83.         else if (CameraStyle == NAME_FirstPerson)
  84.         {
  85.             // Simple first person, view through viewtarget's 'eyes'
  86.             OutVT.Target->GetActorEyesViewPoint(OutVT.POV.Location, OutVT.POV.Rotation);
  87.  
  88.             // don't apply modifiers when using this debug camera mode
  89.             bDoNotApplyModifiers = true;
  90.         }
  91.         else
  92.         {
    　　　　　　　//默认摄像机会执行这个函数
  93.             UpdateViewTargetInternal(OutVT, DeltaTime);
  94.         }
  95.     }
  96. 　　//这个应该是执行CameraShakes的逻辑
  97.     if (!bDoNotApplyModifiers || bAlwaysApplyModifiers)
  98.     {
  99.         // Apply camera modifiers at the end (view shakes for example)
  100.         ApplyCameraModifiers(DeltaTime, OutVT.POV);
  101.     }
  102. 　　//头戴设备的视角逻辑
  103.     if (bFollowHmdOrientation)
  104.     {
  105.         if (GEngine->HMDDevice.IsValid() && GEngine->HMDDevice->IsHeadTrackingAllowed())
  106.         {
  107.             GEngine->HMDDevice->UpdatePlayerCameraRotation(this, OutVT.POV);
  108.         }
  109.     }
  110.  
  111.     // Synchronize the actor with the view target results
  112.     SetActorLocationAndRotation(OutVT.POV.Location, OutVT.POV.Rotation, false);
  113. 　　
  114.     UpdateCameraLensEffects(OutVT);
  115. }

　　综上所述，你应该把摄像机逻辑写在这，如果想了解得更加清楚，可以继续从UpdateViewTargetInternal函数看下去，一直看到CalcCamera为止。

下面大致说一下编写思路：

在使用编辑器新建完自己的CameraManager后，在控制类中制定，例如：

PlayerCameraManagerClass = ADemoCameraManager::StaticClass();

然后我贴一下自己写的代码，这里我实现了一个固定视角：

  1. // Fill out your copyright notice in the Description page of Project Settings.
  2.  
  3. #pragma once
  4.  
  5. #include "Camera/PlayerCameraManager.h"
  6. #include "DemoCameraManager.generated.h"
  7.  
  8. /**
  9.  *
  10.  */
  11. UCLASS()
  12. class DEMO_API ADemoCameraManager : public APlayerCameraManager
  13. {
  14.     GENERATED_BODY()
  15. protected:
  16.     virtual void UpdateViewTarget(FTViewTarget& OutVT, float DeltaTime) override;
  17.  
  18.     //UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = TViewTarget)
  19.     //struct FMinimalViewInfo SceneFixedPOV;
  20.  
  21. };
  1. // Fill out your copyright notice in the Description page of Project Settings.
  2.  
  3. #include "Demo.h"
  4. #include "DemoCameraManager.h"
  5. #include "DemoCharacter.h"
  6.  
  7. void ADemoCameraManager::UpdateViewTarget(FTViewTarget& OutVT, float DeltaTime)
  8. {
  9.     if (bFollowHmdOrientation)
  10.     {
  11.         //如果有VR设备就直接运行引擎原始函数
  12.         Super::UpdateViewTarget(OutVT, DeltaTime);
  13.         return;
  14.     }
  15.     // Don't update outgoing viewtarget during an interpolation
  16.     if ((PendingViewTarget.Target != NULL) && BlendParams.bLockOutgoing && OutVT.Equal(ViewTarget))
  17.     {
  18.         return;
  19.     }
  20.     bool bDoNotApplyModifiers = false;
  21.  
  22.     if (ACameraActor* CamActor = Cast<ACameraActor>(OutVT.Target))
  23.     {
  24.         // Viewing through a camera actor.
  25.         CamActor->GetCameraComponent()->GetCameraView(DeltaTime, OutVT.POV);
  26.     }
  27.     else
  28.     {
  29.         if (CameraStyle == FName("SceneFixed"))
  30.         {
    　　　　　　　//这里我感觉可能用PendingViewTarget来传递摄像机坐标和旋转比较好，但是还没测试过
  31.             //自己定义一个场景固定视角
  32.             ADemoCharacter *Character = Cast<ADemoCharacter>(GetOwningPlayerController()->GetPawn());
  33.             OutVT.POV.Location = Character->ViewTargetLocation;
  34.             OutVT.POV.Rotation = Character->ViewTargetRotator;
  35.             //DesiredView.FOV = FieldOfView;
  36.             //DesiredView.AspectRatio = AspectRatio;
  37.             // don't apply modifiers when using this debug camera mode
  38.             bDoNotApplyModifiers = true;
  39.         }else if (CameraStyle==FName("Default"))
  40.         {
  41.             //默认方式是直接取得摄像机的参数来设置FTViewTarget.pov,而摄像机被控制类、SpringArm控制。
  42.             UpdateViewTargetInternal(OutVT, DeltaTime);
  43.         }
  44.         else
  45.         {
  46.             Super::UpdateViewTarget(OutVT, DeltaTime);
  47.         }
  48.     }
  49.     if (!bDoNotApplyModifiers || bAlwaysApplyModifiers)
  50.     {
  51.         // Apply camera modifiers at the end (view shakes for example)
  52.         ApplyCameraModifiers(DeltaTime, OutVT.POV);
  53.     }
  54.     // Synchronize the actor with the view target results
  55.     SetActorLocationAndRotation(OutVT.POV.Location, OutVT.POV.Rotation, false);
  56.     UpdateCameraLensEffects(OutVT);
  57. }

后面是固定视角VolumeActor的代码：

  1. // Fill out your copyright notice in the Description page of Project Settings.
  2.  
  3. #pragma once
  4.  
  5. #include "GameFramework/Actor.h"
  6. #include "Character/DemoCharacter.h"
  7. #include "Character/DemoCameraManager.h"
  8. #include "Character/DemoPlayerController.h"
  9. #include "Runtime/Engine/Classes/Kismet/KismetMathLibrary.h"
  10. #include "BaseSceneFixedViewVolume.generated.h"
  11.  
  12. UCLASS()
  13. class DEMO_API ABaseSceneFixedViewVolume : public AActor
  14. {
  15.     GENERATED_BODY()
  16.  
  17. public:
  18.     // Sets default values for this actor's properties
  19.     ABaseSceneFixedViewVolume();
  20.  
  21.     // Called when the game starts or when spawned
  22.     virtual void BeginPlay() override;
  23.  
  24.     // Called every frame
  25.     virtual void Tick( float DeltaSeconds ) override;
  26.  
  27.     FVector Lcation;
  28.     FRotator Rotator;
  29.  
  30.     UPROPERTY(EditDefaultsOnly, Category = "SceneFixedView", meta = (AllowPrivateAccess = "true"))
  31.     UBoxComponent* Triggers;
  32.  
  33.     UPROPERTY(VisibleAnywhere, BlueprintReadWrite, Category = "SceneFixedView", meta = (AllowPrivateAccess = "true"))
  34.     UCameraComponent* Camera;
  35.  
  36.     UFUNCTION()
  37.     virtual void OnBeginOverlap(class AActor* OtherActor, class UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweeoResult);
  38.  
  39.     UFUNCTION()
  40.     virtual void OnEndOverlap(class AActor* OtherActor, class UPrimitiveComponent* OtherComp, int32 OtherBodyIndex);
  41.  
  42.     UPROPERTY(VisibleAnywhere, BlueprintReadWrite, Category = "SceneFixedView")
  43.     bool bCalView=false;
  44.  
  45.     UPROPERTY(EditDefaultsOnly,Category="SceneFixedView")
  46.     FVector VolumeSize = FVector(, , );
  47.  
  48.     ADemoCharacter* Character;
  49.  
  50.     ADemoCameraManager* CameraManage;
  51.  
  52.     FName OriginMode;
  53. };
  1. // Fill out your copyright notice in the Description page of Project Settings.
  2.  
  3. #include "Demo.h"
  4. #include "BaseSceneFixedViewVolume.h"
  5.  
  6. // Sets default values
  7. ABaseSceneFixedViewVolume::ABaseSceneFixedViewVolume()
  8. {
  9.      // Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
  10.     PrimaryActorTick.bCanEverTick = true;
  11.  
  12.     Triggers = CreateDefaultSubobject<UBoxComponent>(TEXT("Triggers"));
  13.     Triggers->SetBoxExtent(VolumeSize);
  14.     Triggers->SetRelativeLocation(FVector(,,VolumeSize.Z/));
  15.     RootComponent = Triggers;
  16.  
  17.     Camera= CreateDefaultSubobject<UCameraComponent>(TEXT("Camera"));
  18.     Camera->SetRelativeLocation(FVector(VolumeSize.X,VolumeSize.Y,VolumeSize.Z));
  19.     Camera->AttachTo(RootComponent);
  20.  
  21.     //FollowCamera = CreateDefaultSubobject<UCameraComponent>(TEXT("FollowCamera"));
  22.     //FollowCamera->AttachTo(CameraBoom, USpringArmComponent::SocketName); // Attach the camera to the end of the boom and let the boom adjust to match the controller orientation
  23.     //FollowCamera->bUsePawnControlRotation = false; // Camera does not rotate relative to arm
  24.  
  25.     Triggers->OnComponentBeginOverlap.AddDynamic(this, &ABaseSceneFixedViewVolume::OnBeginOverlap);
  26.     Triggers->OnComponentEndOverlap.AddDynamic(this, &ABaseSceneFixedViewVolume::OnEndOverlap);
  27. }
  28.  
  29. // Called when the game starts or when spawned
  30. void ABaseSceneFixedViewVolume::BeginPlay()
  31. {
  32.     Super::BeginPlay();
  33.  
  34. }
  35.  
  36. // Called every frame
  37. void ABaseSceneFixedViewVolume::Tick( float DeltaTime )
  38. {
  39.     Super::Tick( DeltaTime );
  40.     if (bCalView)
  41.     {
  42.         if (Character)
  43.         {
  44.             Character->ViewTargetLocation = Camera->K2_GetComponentLocation();
  45.             Character->ViewTargetRotator = UKismetMathLibrary::FindLookAtRotation(Camera->K2_GetComponentLocation(), Character->GetActorLocation());
  46.         }
  47.     }
  48. }
  49. void ABaseSceneFixedViewVolume::OnBeginOverlap(class AActor* OtherActor, class UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweeoResult)
  50. {
  51.     Character = Cast<ADemoCharacter>(OtherActor);
  52.     if (Character)
  53.     {
  54.         bCalView = true;
  55.         ADemoPlayerController* Controller = Cast<ADemoPlayerController>(Character->GetController());
  56.         if (Controller)
  57.         {
  58.             OriginMode=Controller->PlayerCameraManager->CameraStyle;
  59.             Controller->SetCameraMode(FName("SceneFixed"));
  60.             //因为我使用控制类来管理视角，为了解决一些视角问题，所以在进入时，必须重新设置视角,屏蔽鼠标修改视角
  61.             Controller->SetControlRotation(FRotator(0.0f,90.0f,0.0f));
  62.             Controller->SetIgnoreLookInput(true);
  63.         }
  64.     }
  65. }
  66.  
  67. void ABaseSceneFixedViewVolume::OnEndOverlap(class AActor* OtherActor ,class UPrimitiveComponent* OtherComp, int32 OtherBodyIndex)
  68. {
  69.     if (OtherActor==Character)
  70.     {
  71.         bCalView = false;
  72.         ADemoPlayerController* Controller = Cast<ADemoPlayerController>(Character->GetController());
  73.         if (Controller)
  74.         {
  75.             if (OriginMode!=FName(""))
  76.             {
  77.                 Controller->SetCameraMode(OriginMode);
  78.             }
  79.             else
  80.             {
  81.                 Controller->SetCameraMode(FName("Default"));
  82.             }
  83.             Controller->SetIgnoreLookInput(false);
  84.         }
  85.     }
  86.     Character= nullptr;
  87. }

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