【UE4 C++】碰撞檢測與事件綁定

概念

碰撞對象通道與預設

• 默認提供碰撞對象類型，如 WorldStatic、WorldDynamic等。允許用戶自定義

• 默認提供碰撞預設，如 NoCollision、BloackAll、OverlapAll。允許用戶自定義

  

碰撞響應設置

• 可以用來設置是否模擬物理碰撞以及觸發 Overlap 事件

  

碰撞響應類型

• 物體發生碰撞后，會有三種碰撞相響應類型

  

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C++ 實現

Component 碰撞

• 注意 Overlap Begin/End 的函數參數

• 注意 OnHit 的函數參數

• 注意甚至 Generated Hit Event 的函數名

• 綁定函數可以用 AddDynamic，也可以用 FScriptDelegate 委托

• 部分設置可不寫，藍圖使用時再手動設置

• 寫法支持 UShapeComponent及其派生類，如 USphereComponent 、UBoxComponent 等

  UPROPERTY(EditAnywhere)
  		USceneComponent* Root;
  
  	UPROPERTY(EditAnywhere)
  		UStaticMeshComponent* Cube;
  
  	UFUNCTION()
  		virtual void OnOverlapBegin(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult);
  
  	UFUNCTION()
  		virtual void OnOverlapEnd(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult);
  
  	UFUNCTION()
  		virtual void OnHit(UPrimitiveComponent* HitComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, FVector NormalImpulse, const FHitResult& Hit);
  

  ACollisionActor::ACollisionActor()
  {
   	// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
  	PrimaryActorTick.bCanEverTick = true;
  
  	Root = CreateDefaultSubobject<USceneComponent>(TEXT("RootScene"));
  	SetRootComponent(Root);
  
  	Cube = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("Cube"));
  	Cube->SetupAttachment(Root);
  	static ConstructorHelpers::FObjectFinder<UStaticMesh> mesh(TEXT("StaticMesh'/Engine/BasicShapes/Cube.Cube'"));
  	if (mesh.Succeeded())
  	{
  		Cube->SetStaticMesh(mesh.Object);
  	}
  
  	// 設置是否開啟物理模擬
  	Cube->SetSimulatePhysics(false);
  
  	// 開啟 Generated Hit Event
  	Cube->SetNotifyRigidBodyCollision(true);
  	
  	// 開啟CCD Continuous collision detection (CCD) 連續式碰撞檢測
  	Cube->BodyInstance.SetUseCCD(true);
  	
  	// 開啟Generate Overlap Events
  	Cube->SetGenerateOverlapEvents(true);
  
  	// 設置碰撞預設
  	Cube->SetCollisionProfileName(TEXT("OverlapAll"));
  	//Cube->SetCollisionResponseToAllChannels(ECR_Overlap);
  
  	// 設置碰撞響應設置
  	Cube->SetCollisionEnabled(ECollisionEnabled::QueryAndPhysics);
  
  	// 綁定函數
  	Cube->OnComponentBeginOverlap.AddDynamic(this, &ACollisionActor::OnOverlapBegin);
  
  	// 綁定函數 使用委托
  	FScriptDelegate OverlapEndDelegate;
  	OverlapEndDelegate.BindUFunction(this, TEXT("OnOverlapEnd"));
  	Cube->OnComponentBeginOverlap.Add(OverlapEndDelegate);
  	
  	// 綁定碰撞函數
  	Cube->OnComponentHit.AddDynamic(this, &ACollisionActor::OnHit);
  }
  
  void ACollisionActor::OnOverlapBegin(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult)
  {
  	UE_LOG(LogTemp, Warning, TEXT("Overlap Begin"));
  }
  
  void ACollisionActor::OnOverlapEnd(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult)
  {
  	UE_LOG(LogTemp, Warning, TEXT("Overlap End"));
  }
  
  void ACollisionActor::OnHit(UPrimitiveComponent* HitComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, FVector NormalImpulse, const FHitResult& Hit)
  {
  	UE_LOG(LogTemp, Warning, TEXT("Hit"));
  	Destroy();
  }
  

ATriggerBox 碰撞

• OnActorBeginOverlap

• OnActorEndOverlap

  UFUNCTION()
  	void HandleOverlap(AActor* OverlappedActor, AActor* OtherActor );
  

  void AMyTriggerBox::BeginPlay()
  {
  	//放在構造函數好像不起作用
  	OnActorBeginOverlap.AddDynamic(this, &AMyTriggerBox::HandleOverlap);
  }
  
  void AMyTriggerBox::HandleOverlap(AActor* OverlappedActor, AActor* OtherActor )
  {
  	UClass* ActorClass = OtherActor->GetClass();
  	// 其他處理邏輯
  }
  

參考

• 碰撞響應參考