UE4【C++】子彈傷害系統使用

可能很多初學者如果想知道UE4的這種傷害系統如何使用起來會有點迷茫。

我自己做了demo給大家參考下。

首先要有個子彈類。

.h代碼如下

UCLASS()
class SNVRCLAYSHOOTING_API AProjectile : public AActor
{
    GENERATED_BODY()
    
public:    
    // Sets default values for this actor's properties
    AProjectile();

    UPROPERTY(VisibleAnywhere, BlueprintReadWrite, Category = "Projectile")
        UStaticMeshComponent* ProjectileMesh;

    UPROPERTY(VisibleAnywhere, BlueprintReadWrite, Category = "Projectile")
        UParticleSystemComponent* LaunchParticle;    //煙火，開槍時

    UPROPERTY(VisibleAnywhere, BlueprintReadWrite, Category = "Projectile")
        UProjectileMovementComponent *ProjectileMovementComponent = nullptr;

protected:
    // Called when the game starts or when spawned
    virtual void BeginPlay() override;

    UFUNCTION()
        void OnHit(UPrimitiveComponent* HitComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, FVector NormalImpulse, const FHitResult& Hit);

public:    
    // Called every frame
    virtual void Tick(float DeltaTime) override;

    UFUNCTION(BlueprintCallable, Category = "Projectile_Fun")
        void LaunchProjectile(FVector Speed);
    
};

.cpp代碼如下

AProjectile::AProjectile()
{
     // 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;

    ProjectileMovementComponent = CreateDefaultSubobject<UProjectileMovementComponent>(FName("ProjectileMovement"));    //生成組件
    ProjectileMovementComponent->bAutoActivate = false;        //自動飛行調成false

    ProjectileMesh = CreateDefaultSubobject<UStaticMeshComponent>(FName("ProjectileMesh"));
    RootComponent = ProjectileMesh;
    ProjectileMesh->SetNotifyRigidBodyCollision(true);
    ProjectileMesh->SetVisibility(true);

    LaunchParticle = CreateDefaultSubobject<UParticleSystemComponent>(FName("LaunchParticle"));
    LaunchParticle->SetupAttachment(ProjectileMesh);    //將粒子效果綁定在根結點上（即ProjectileMesh）
    LaunchParticle->SetAutoActivate(true);                //創建好就啟動

    ProjectileMesh->OnComponentHit.AddDynamic(this, &AProjectile::OnHit);

    InitialLifeSpan = 5.0f;
}

// Called when the game starts or when spawned
void AProjectile::BeginPlay()
{
    Super::BeginPlay();
    
}

// Called every frame
void AProjectile::Tick(float DeltaTime)
{
    Super::Tick(DeltaTime);

}
void AProjectile::LaunchProjectile(FVector Speed) 
{
    ProjectileMovementComponent->SetVelocityInLocalSpace(Speed);
    ProjectileMovementComponent->Activate();    //可以飛行了
}
//碰撞后發生的事件
void AProjectile::OnHit(UPrimitiveComponent* HitComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, FVector NormalImpulse, const FHitResult& Hit)
{
    UE_LOG(LogTemp, Warning, TEXT("AProjectile::OnHit--OtherActor.Name=%s"),*OtherActor->GetName());    //撞擊后給個提示

    ProjectileMesh->SetNotifyRigidBodyCollision(false);    //碰撞之后再也不發生碰撞事件
    //CollisionMesh->DestroyComponent();    //不是DestroyActor，Component是單一一個

    //受傷害源OtherActor的TakeDamage()會被調用
    UGameplayStatics::ApplyPointDamage(OtherActor, 10.0f, GetActorLocation(), Hit,NULL,NULL, UDamageType::StaticClass());

    Destroy();
}

傷害的入口從OnHit看出，調用了UGameplayStatics::ApplyPointDamage；

第一個參數就是受傷害源，UE4的傷害系統會調用受傷害源的TakeDamege接口；

此時子彈有了傷害力，那么受傷害源就要被傷害；

每個actor都有這個接口virtual float TakeDamage(float DamageAmount, struct FDamageEvent const& DamageEvent, class AController* EventInstigator, AActor* DamageCauser);

只要重寫這個接口，寫上自己的處理邏輯。

受傷害源部分代碼如下：

float ADamagedActor::TakeDamage(float DamageAmount, struct FDamageEvent const& DamageEvent, class AController* EventInstigator, AActor* DamageCauser)
{
    float actuallyApplied = 0.0f;

    MaxHP -= DamageAmount;

    UE_LOG(LogTemp,Warning,TEXT("ADamagedActor::TakeDamage--MaxHP=%f"),MaxHP);

    actuallyApplied = FMath::Clamp<float>(MaxHP, 0.0f, 100.0f);

    return actuallyApplied;
}

 

以上就是簡單的使用UE4的傷害系統。