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(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actorTArray 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();}
}

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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(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(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。

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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();}
}

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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actorTArray 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(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

创建cue， cue实际上就是声音文件的子类

设置声音衰减

我们还可以做一个音效衰减

创建之后打开，设为自然音

这里选择衰减 

在蓝图中选择声音

然后添加一个声音组件，选择滚动声效

 编译测试成功