20uec++多人游戏【小球与玩家互动】

为小球添加生命值组件和伤害处理函数

//生命值组件
	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = "Components")
	class USHealthComponent * HealthComp;

	//伤害处理函数
	UFUNCTION()
	void HandleTakeAnyDamage(USHealthComponent * OwnerHealthComp, float Health, float HealthDelta, const UDamageType * DamageType, AController * InstigatedBy, AActor * DamageCauser);

创建组件并定义函数

HealthComp = CreateDefaultSubobject<USHealthComponent>(TEXT("HealthComp"));

void AASTrackerBot::HandleTakeAnyDamage(USHealthComponent * OwnerHealthComp, float Health, float HealthDelta, const UDamageType * DamageType, AController * InstigatedBy, AActor * DamageCauser)
{
	
	UKismetSystemLibrary::PrintString(this, FString::SanitizeFloat(HealthComp->Health));

}

添加与爆炸相关的成员变量和函数

	//自爆函数
	void SelfDestruct();

	//爆炸特效
	UPROPERTY(EditDefaultsOnly, Category = "TracerBot")
	class UParticleSystem * ExplorEffect;

	//是否已经爆炸
	bool bExplored;

	//爆炸半径
	UPROPERTY(EditDefaultsOnly, Category = "TracerBot")
	float ExplorRadius;

	//爆炸伤害
	UPROPERTY(EditDefaultsOnly, Category = "TracerBot")
	float ExplorDamage;

在构造函数中初始化一下

	bExplored = false;
	ExplorRadius = 200;
	ExplorDamage = 100;

定义自爆函数

void AASTrackerBot::SelfDestruct()
{
	//检查是否已经爆炸了
	if (bExplored)
	{
		return;
	}
	bExplored = true;
	//发生爆炸
	UGameplayStatics::SpawnEmitterAtLocation(GetWorld(), ExplorEffect, GetActorLocation());
	//设置要忽略的actor
	TArray<AActor * > IgnoredActors;
	IgnoredActors.Add(this);

	//对自身进行伤害
	UGameplayStatics::ApplyRadialDamage(this, ExplorDamage, GetActorLocation(), ExplorRadius, nullptr, IgnoredActors, this, GetInstigatorController(), true);

	//画出伤害范围
	DrawDebugSphere(GetWorld(), GetActorLocation(), ExplorRadius, 12, FColor::Green, false, 2.0f, 0, 1.0f);
	//自毁
	Destroy();
}

在伤害处理中，调用该函数

void AASTrackerBot::HandleTakeAnyDamage(USHealthComponent * OwnerHealthComp, float Health, float HealthDelta, const UDamageType * DamageType, AController * InstigatedBy, AActor * DamageCauser)
{
	
	UKismetSystemLibrary::PrintString(this, FString::SanitizeFloat(HealthComp->Health));
	if (HealthComp->Health <= 0)
	{
		SelfDestruct();
	}
}

===========================================

现在实现靠近玩家定时自爆功能

创建相关的变量和函数

	//球形碰撞组件
	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = "Components")
	class USphereComponent* CollisionComponent;

	//自爆倒计时句柄
	FTimerHandle TimerHandle_SelfDamage;

	//倒计时自爆函数
	void DamageSelf();

	//是否已经开始自毁倒计时
	bool bStartSelfDamge;

	//游戏重叠函数
	virtual void NotifyActorBeginOverlap(AActor * OtherActor) override;

在构造函数中创建球形组件，并设置相关参数

	CollisionComponent = CreateDefaultSubobject<USphereComponent>(TEXT("SphereComponent"));
	CollisionComponent->SetSphereRadius(200);
	CollisionComponent->SetCollisionEnabled(ECollisionEnabled::QueryOnly);
	CollisionComponent->SetCollisionResponseToAllChannels(ECR_Ignore);
	CollisionComponent->SetCollisionResponseToChannel(ECC_Pawn, ECR_Overlap);
	CollisionComponent->SetupAttachment(RootComponent);

定义倒计时自爆函数

void AASTrackerBot::DamageSelf()
{
	UGameplayStatics::ApplyDamage(this, 20, GetInstigatorController(), this, nullptr);
}

定义重叠函数

void AASTrackerBot::NotifyActorBeginOverlap(AActor * OtherActor)
{
	if (!bStartSelfDamge)
	{
		ASCharacter * PlayerPawn = Cast<ASCharacter>(OtherActor);
		if (PlayerPawn)
		{
			GetWorld()->GetTimerManager().SetTimer(TimerHandle_SelfDamage, this, &AASTrackerBot::DamageSelf, 0.5f, true , 0.0f);
			bStartSelfDamge = true;
		}
	}
}

编译，然后打开小球的蓝图，选择特效

编译，测试，发现小球不会爆炸。

将构造函数的事件绑定函数放到游戏开始函数。就可以了

// Called when the game starts or when spawned
void AASTrackerBot::BeginPlay()
{
	Super::BeginPlay();
	NextPathPoint = GetNextPathPoint();
	//伤害事件绑定函数
	HealthComp->OnHealthChanged.AddDynamic(this, &AASTrackerBot::HandleTakeAnyDamage);
}

我也不知道为啥。

同时也可以炸死人。

========================================

现在我们为小球完善一下材质

按住T，点击鼠标左键

然后选择一个材质

按U，然后点击鼠标左键

将这两个设成4

这样可以让材质变得密集

按住M，然后点击鼠标左键，得到乘节点，然后连线

按住1，然后点击鼠标左键，生成常数节点，然后连接到自发光上面

这是将值设为0.5的效果

添加一个Time节点

然后按住s，点击鼠标左键，生成参数节点

我们用（时间-参数）*4，然后约束一下乘积。

然后1-上述结果

然后再得到一个指数

然后将其赋予到自发光上面

回到小球类，我们添加一个小球材质的变量

	//动态材质
	class UMaterialInstanceDynamic * MatInst;

#include "Materials/MaterialInstanceDynamic.h"

完善伤害处理函数

void AASTrackerBot::HandleTakeAnyDamage(USHealthComponent * OwnerHealthComp, float Health, float HealthDelta, const UDamageType * DamageType, AController * InstigatedBy, AActor * DamageCauser)
{
	//UKismetSystemLibrary::PrintString(this, FString::SanitizeFloat(HealthComp->Health));

	//得到MeshComponent组件的材质
	if (MatInst == nullptr)
	{
		MatInst = MeshComponent->CreateAndSetMaterialInstanceDynamicFromMaterial(0, MeshComponent->GetMaterial(0));
		UKismetSystemLibrary::PrintString(this, FString::SanitizeFloat(HealthComp->Health));
	}
	//将参数设为当前时间，让材质发光
	if (MatInst)
	{
		MatInst->SetScalarParameterValue("LastTimeDamageTaken", GetWorld()->TimeSeconds);
	}
	//自爆
	if (HealthComp->Health <= 0)
	{
		
		SelfDestruct();
	}
}

==========================================

现在加一下声音特效

添加两个成员变量

	//自爆中声音特效
	UPROPERTY(EditDefaultsOnly, Category = "TracerBot")
	class USoundCue * SelfDestructSound;

	//爆炸特效
	UPROPERTY(EditDefaultsOnly, Category = "TracerBot")
	class USoundCue * ExploedSound;

#include "Sound/SoundCue.h"

更新一下SelfDestruct函数和NotifyActorBeginOverlap函数

void AASTrackerBot::SelfDestruct()
{
	//检查是否已经爆炸了
	if (bExplored)
	{
		return;
	}
	bExplored = true;
	//发生爆炸
	UGameplayStatics::SpawnEmitterAtLocation(GetWorld(), ExplorEffect, GetActorLocation());
	//设置要忽略的actor
	TArray<AActor * > IgnoredActors;
	IgnoredActors.Add(this);
//	UKismetSystemLibrary::PrintString(this, FString::SanitizeFloat(222.0f));

	//对自身进行伤害
	UGameplayStatics::ApplyRadialDamage(this, ExplorDamage, GetActorLocation(), ExplorRadius, nullptr, IgnoredActors, this, GetInstigatorController(), true);

	//画出伤害范围
	DrawDebugSphere(GetWorld(), GetActorLocation(), ExplorRadius, 12, FColor::Green, false, 2.0f, 0, 1.0f);
	//发生爆炸声,在actor的位置
	UGameplayStatics::PlaySoundAtLocation(this, ExploedSound, GetActorLocation());
	//自毁
	Destroy();
}

void AASTrackerBot::NotifyActorBeginOverlap(AActor * OtherActor)
{
	if (!bStartSelfDamge)
	{
		ASCharacter * PlayerPawn = Cast<ASCharacter>(OtherActor);
		if (PlayerPawn)
		{
			GetWorld()->GetTimerManager().SetTimer(TimerHandle_SelfDamage, this, &AASTrackerBot::DamageSelf, 0.5f, true , 0.0f);
			bStartSelfDamge = true;
		}

		//将自爆警告声音绑定到根组件
		UGameplayStatics::SpawnSoundAttached(SelfDestructSound, RootComponent);
	}
}

删掉这些成品，我们自己做一个