UE4【C++】子弹伤害系统使用

可能很多初学者如果想知道UE4的这种伤害系统如何使用起来会有点迷茫。

我自己做了demo给大家参考下。

首先要有个子弹类。

.h代码如下

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;    //烟火，开枪时

    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代码如下

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"));    //生成组件
    ProjectileMovementComponent->bAutoActivate = false;        //自动飞行调成false

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

    LaunchParticle = CreateDefaultSubobject<UParticleSystemComponent>(FName("LaunchParticle"));
    LaunchParticle->SetupAttachment(ProjectileMesh);    //将粒子效果绑定在根结点上（即ProjectileMesh）
    LaunchParticle->SetAutoActivate(true);                //创建好就启动

    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();    //可以飞行了
}
//碰撞后发生的事件
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());    //撞击后给个提示

    ProjectileMesh->SetNotifyRigidBodyCollision(false);    //碰撞之后再也不发生碰撞事件
    //CollisionMesh->DestroyComponent();    //不是DestroyActor，Component是单一一个

    //受伤害源OtherActor的TakeDamage()会被调用
    UGameplayStatics::ApplyPointDamage(OtherActor, 10.0f, GetActorLocation(), Hit,NULL,NULL, UDamageType::StaticClass());

    Destroy();
}

伤害的入口从OnHit看出，调用了UGameplayStatics::ApplyPointDamage；

第一个参数就是受伤害源，UE4的伤害系统会调用受伤害源的TakeDamege接口；

此时子弹有了伤害力，那么受伤害源就要被伤害；

每个actor都有这个接口virtual float TakeDamage(float DamageAmount, struct FDamageEvent const& DamageEvent, class AController* EventInstigator, AActor* DamageCauser);

只要重写这个接口，写上自己的处理逻辑。

受伤害源部分代码如下：

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;
}

 

以上就是简单的使用UE4的伤害系统。