C++代码实现OnComponentHit事件粒子消失蓝图--斯坦福

蓝图节点

OnComponentBeginOverlap，OnComponentHit等等之类如何迁移到C++中

方法

这些蓝图节点实际上就是一个UE4已经定义好的事件，在蓝图中使用模块的连接来实现事件的触发后续操作。在C++中通过AddDynamic()，进行函数绑定，实现蓝图中的模块操作

动态委托

操作

可以从蓝图中看到OnCompponent*事件是需要绑定在一个Component的，所以对于事件的操作需要在构造函数中进行

SphereComp->OnComponentHit.AddDynamic(this,&ClassName::Func)

而最需要注意的是，对于不同的OnComponent事件，Func的参数是需要调整的，否则会报错，具体的方法可以从源码中获得参数

DECLARE_DYNAMIC_MULTICAST_SPARSE_DELEGATE_FiveParams( FComponentHitSignature, UPrimitiveComponent, OnComponentHit, UPrimitiveComponent*, HitComponent, AActor*, OtherActor, UPrimitiveComponent*, OtherComp, FVector, NormalImpulse, const FHitResult&, Hit );

接下来就是定义函数，将蓝图中后续的操作编写到函数中。

其中蓝图对销毁粒子时增加了一个粒子特效，利用SpawnEmitterAtLocation，获取接触位置，然后导入粒子特效，接着Destroy。

SpawnEmitterAtLocation是在GameplayStatics类中定义的方法，需要#include "Kismet\GameplayStatics.h"

void ATMagicProjectile::OnActorHit(UPrimitiveComponent* HitComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, FVector Normallpulse, const FHitResult& SweepResult)
{
	FVector Loc = this->GetActorLocation();
	FRotator Rot = this->GetActorRotation();

	if (OtherActor && OtherActor != GetInstigator()) {
		UGameplayStatics::SpawnEmitterAtLocation(this->EffectComp, HitFX, Loc, Rot);
		Destroy();
	}
}

HitFX为粒子效果，使用FObjectFinder进行资源的加载，但我的操作提示CDO Failue，没法正常加载资源┭┮﹏┭┮。



参考

完整代码

.h文件

// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include "TMagicProjectile.generated.h"

class USphereComponent;
class UProjectileMovementComponent;
class UParticleSystem;

UCLASS()
class PHONETEST1_API ATMagicProjectile : public AActor
{
	GENERATED_BODY()

public:
	// Sets default values for this actor's properties
	ATMagicProjectile();

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

	//球体体积，粒子的模型放置
	UPROPERTY(VisibleAnywhere)
		USphereComponent* SphereComp;

	//抛体运动组件
	UPROPERTY(VisibleAnywhere)
		UProjectileMovementComponent* MovementComp;

	//粒子的状态，后续可以集合在粒子组件中
	UPROPERTY(VisibleAnywhere)
		UParticleSystemComponent* EffectComp;

	//添加粒子效果
	UPROPERTY(EditDefaultsOnly)
		UParticleSystem* HitFX;

	//粒子碰撞后销毁
	UFUNCTION()
		void OnActorHit(UPrimitiveComponent* HitComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, FVector Normallpulse, const FHitResult& SweepResult);

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

.cpp文件

// Fill out your copyright notice in the Description page of Project Settings.

#include "TMagicProjectile.h"
#include "Components\SphereComponent.h"
#include "Particles\ParticleSystemComponent.h"
#include "GameFramework\ProjectileMovementComponent.h"
#include "TCharacterComponent.h"
#include "Kismet\GameplayStatics.h"

// Sets default values
ATMagicProjectile::ATMagicProjectile()
{
 	// 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;

	SphereComp = CreateDefaultSubobject<USphereComponent>("SphereComp");
	RootComponent = SphereComp;

	SphereComp->SetCollisionProfileName("Projectile");

	EffectComp = CreateDefaultSubobject<UParticleSystemComponent>("EffectComp");
	EffectComp->SetupAttachment(SphereComp);

	MovementComp = CreateDefaultSubobject<UProjectileMovementComponent>("MovementComp");
	MovementComp->InitialSpeed = 1000.0f;
	MovementComp->bRotationFollowsVelocity = true;
	MovementComp->bInitialVelocityInLocalSpace = true;

	SphereComp->OnComponentHit.AddDynamic(this, &ATMagicProjectile::OnActorHit);

	static ConstructorHelpers::FObjectFinder<UParticleSystem> ParticleAsset(TEXT("/Content/StarterContent/Particles/P_Fire.P_Fire_C"));
	if (ParticleAsset.Succeeded())
	{
		HitFX = ParticleAsset.Object;
	}
}

// Called when the game starts or when spawned
void ATMagicProjectile::BeginPlay()
{
	Super::BeginPlay();
	ObjToSpawn.Broadcast();

}

void ATMagicProjectile::OnActorHit(UPrimitiveComponent* HitComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, FVector Normallpulse, const FHitResult& SweepResult)
{
	FVector Loc = this->GetActorLocation();
	FRotator Rot = this->GetActorRotation();

	if (OtherActor && OtherActor != GetInstigator()) {
		UGameplayStatics::SpawnEmitterAtLocation(this->EffectComp, HitFX, Loc, Rot);
		Destroy();
	}
}

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

}