UE4 C++ ActionRoguelike开发记录

目录

角色类：SCharacter

设置摄像机

弹簧臂和摄像机设置

设置人物移动和动作绑定

移动与朝向：MoveForward/MoveRight、Turn/LoopUp

为人物绑定设置子弹类：SpawnProjectile适配器类

设置攻击动画以及攻击特效

普通攻击

黑洞攻击

闪现攻击

❗为角色添加属性组件：USAttributeComponent

为角色添加交互组件接口：USInteractionComponent* InteractionComp;

子弹类：SProejctileBase

胶囊碰撞体：USphereComponent* SphereComp;

子弹移动组件：UProjectileMovementComponent* MoveComp;

粒子系统组件（平A效果）：UParticleSystemComponent* EffectComp;

粒子系统组件（爆炸效果）：UParticleSystem* ImpactVFX;

子弹爆炸音效组件：USoundCue* ImpactSound;

？子弹播放声音组件：UAudioComponent* AudioComp;

子弹击中画面震动效果：TSubclassOf ImpactShake;

⭐碰撞事件&爆炸（虚函数）：void Explode();（BlueprintNativeEvent）

普通攻击：SMagicProjectile

设置并重写OnActorOverlap逻辑：

设置子弹伤害：DamageAmount

❗闪现：SDashProjectile

重写BeginPlay：设置子弹存活时间

重写爆炸逻辑Explode_Implementation

实现闪现传送效果：TeleportInstigator

设置定时器：FTimerHandle

黑洞攻击（蓝图）：Proj_BlackHole

径向力Force Strength

可影响物体Object Types to Affect

吸进黑洞后要杀掉物体：

❗接口类：USGameplayInterface

USInteractionComponent

世界中的物体

爆炸油桶：ASExplosiveBarrel

设置StaticMesh，径向力

初始化Actor组件（添加碰撞事件）

宝箱（实现交互接口）：ASItemChest

血包（实现交互接口）：ASPowerupActor

血包有很多种，因此接口实现逻辑由子类实现：

吃掉后隐藏血包（计时器）：

血包子类：ASPowerup_HealthPotion

UI：Widget

十字准星

创建Widget并设置：

游戏开始时添加到屏幕上

人物血条、Credits、游戏进行时间：Main_HUD

血条

Credits：

游戏进行时间：

AI

UE中的AI系统

行为树：

添加导航网格体：NavMeshBoundsVolume​编辑

游戏AI角色：SAICharacter

游戏AI控制器：SAIController

设置行为树

为SAICharacter设置控制器

游戏AI逻辑-范围内攻击：USBTService_CheckAttackRange（UBTService）

范围查询逻辑

在行为树添加此Service

游戏AI范围内攻击任务结点：USBTTask_RangedAttack

AI朝向玩家：Set default focus

环境查询系统：

创建EQS

在玩家周围半径内设置EQS生成移动目的地

AI死亡

---

角色类：SCharacter

设置摄像机

弹簧臂和摄像机设置

	UPROPERTY(VisibleAnywhere)
	USpringArmComponent* SpringArmComp;

	UPROPERTY(VisibleAnywhere)
	UCameraComponent* CameraComp;

在构造函数中创建这两个类，并设置依赖关系：

弹簧臂附着在RootComponent，摄像机附着在弹簧臂上

	SpringArmComp = CreateDefaultSubobject("SpringArmComp");
	SpringArmComp->bUsePawnControlRotation = true;
	SpringArmComp->SetupAttachment(RootComponent);

	CameraComp = CreateDefaultSubobject("CameraComp");
	CameraComp->SetupAttachment(SpringArmComp);

    GetCharacterMovement()->bOrientRotationToMovement = true;
	bUseControllerRotationYaw = false;

注意 bUseControllerRotationYaw =false；其效果为：

bUseControllerRotationYaw=true；

bUseControllerRotationYaw=false； 

应该设置为false， 

同时注意GetCharacterMovement()->bOrientRotationToMovement = true;

GetCharacterMovement()->bOrientRotationToMovement = false;如下

 GetCharacterMovement()->bOrientRotationToMovement = true;如下

类似黑暗之魂这种第三人称的移动朝向方式。

设置人物移动和动作绑定

void ASCharacter::SetupPlayerInputComponent(UInputComponent* PlayerInputComponent)
{
	Super::SetupPlayerInputComponent(PlayerInputComponent);

	PlayerInputComponent->BindAxis("MoveForward", this, &ASCharacter::MoveForward);
	PlayerInputComponent->BindAxis("MoveRight", this, &ASCharacter::MoveRight);

	PlayerInputComponent->BindAxis("Turn", this, &APawn::AddControllerYawInput);
	PlayerInputComponent->BindAxis("LookUp", this, &APawn::AddControllerPitchInput);

	PlayerInputComponent->BindAction("PrimaryAttack", IE_Pressed, this, &ASCharacter::PrimaryAttack);
	// Used generic name 'SecondaryAttack' for binding
	PlayerInputComponent->BindAction("SecondaryAttack", IE_Pressed, this, &ASCharacter::BlackHoleAttack);
	PlayerInputComponent->BindAction("Dash", IE_Pressed, this, &ASCharacter::Dash);
	PlayerInputComponent->BindAction("PrimaryInteract", IE_Pressed, this, &ASCharacter::PrimaryInteract);

	PlayerInputComponent->BindAction("Jump", IE_Pressed, this, &ACharacter::Jump);
}

移动与朝向：MoveForward/MoveRight、Turn/LoopUp

void ASCharacter::MoveForward(float Value)
{
	FRotator ControlRot = GetControlRotation();
	ControlRot.Pitch = 0.0f;
	ControlRot.Roll = 0.0f;

	AddMovementInput(ControlRot.Vector(), Value);
}


void ASCharacter::MoveRight(float Value)
{
	FRotator ControlRot = GetControlRotation();
	ControlRot.Pitch = 0.0f;
	ControlRot.Roll = 0.0f;

	// X = Forward (Red)
	// Y = Right (Green)
	// Z = Up (Blue)

	FVector RightVector = FRotationMatrix(ControlRot).GetScaledAxis(EAxis::Y);

	AddMovementInput(RightVector, Value);
}

 其中Turn和LookUp绑定的函数是由APawn中已经写好的内容。

&APawn::AddControllerYawInput
&APawn::AddControllerPitchInput

这里附上Yaw、Roll、Pitch的内容，结合代码理解：

UE是左手坐标系：拇指X，食指Y，中指Z（中指向上摆放）
X：Roll翻滚角
Y：Pitch俯仰角
Z：Yaw偏航角

动图：

1.俯仰:（Pitch）

2.翻滚：(Roll)

3.偏航：(Yaw)

所以，MoveForward和MoveRight只与Yaw有关，控制偏航角度；Turn也和Yaw有关，控制偏航角度；而LoopUp与Pitch有关，控制上下移动视角。

为人物绑定设置子弹类：SpawnProjectile适配器类

• 生成位置：手部Socket（HandLocation）
• Actor生成：设置碰撞，instigator为角色自身
• 碰撞预设：
• 子弹轨迹：起点为手部，终点为十字准星方向

void ASCharacter::SpawnProjectile(TSubclassOf ClassToSpawn)
{
	if (ensureAlways(ClassToSpawn))
	{
		FVector HandLocation = GetMesh()->GetSocketLocation(HandSocketName);

		FActorSpawnParameters SpawnParams;
		SpawnParams.SpawnCollisionHandlingOverride = ESpawnActorCollisionHandlingMethod::AlwaysSpawn;
		SpawnParams.Instigator = this;

		FCollisionShape Shape;
		Shape.SetSphere(20.0f);

		// Ignore Player
		FCollisionQueryParams Params;
		Params.AddIgnoredActor(this);

		FCollisionObjectQueryParams ObjParams;
		ObjParams.AddObjectTypesToQuery(ECC_WorldDynamic);
		ObjParams.AddObjectTypesToQuery(ECC_WorldStatic);
		ObjParams.AddObjectTypesToQuery(ECC_Pawn);

		FVector TraceStart = CameraComp->GetComponentLocation();

		// endpoint far into the look-at distance (not too far, still adjust somewhat towards crosshair on a miss)
		FVector TraceEnd = CameraComp->GetComponentLocation() + (GetControlRotation().Vector() * 5000);

		FHitResult Hit;
		// returns true if we got to a blocking hit
		if (GetWorld()->SweepSingleByObjectType(Hit, TraceStart, TraceEnd, FQuat::Identity, ObjParams, Shape, Params))
		{
			// Overwrite trace end with impact point in world
			TraceEnd = Hit.ImpactPoint;
		}

		// find new direction/rotation from Hand pointing to impact point in world.
		FRotator ProjRotation = FRotationMatrix::MakeFromX(TraceEnd - HandLocation).Rotator();

		FTransform SpawnTM = FTransform(ProjRotation, HandLocation);
		GetWorld()->SpawnActor(ClassToSpawn, SpawnTM, SpawnParams);
	}
}

设置攻击动画以及攻击特效

void ASCharacter::StartAttackEffects()
{
	PlayAnimMontage(AttackAnim);

	UGameplayStatics::SpawnEmitterAttached(CastingEffect, GetMesh(), HandSocketName, FVector::ZeroVector, FRotator::ZeroRotator, EAttachLocation::SnapToTarget);
}

普通攻击

void ASCharacter::PrimaryAttack()
{
	StartAttackEffects();

	GetWorldTimerManager().SetTimer(TimerHandle_PrimaryAttack, this, &ASCharacter::PrimaryAttack_TimeElapsed, AttackAnimDelay);
}


void ASCharacter::PrimaryAttack_TimeElapsed()
{
	SpawnProjectile(ProjectileClass);
}

黑洞攻击

void ASCharacter::BlackHoleAttack()
{
	StartAttackEffects();

	GetWorldTimerManager().SetTimer(TimerHandle_BlackholeAttack, this, &ASCharacter::BlackholeAttack_TimeElapsed, AttackAnimDelay);
}


void ASCharacter::BlackholeAttack_TimeElapsed()
{
	SpawnProjectile(BlackHoleProjectileClass);
}

闪现攻击

void ASCharacter::Dash()
{
	StartAttackEffects();

	GetWorldTimerManager().SetTimer(TimerHandle_Dash, this, &ASCharacter::Dash_TimeElapsed, AttackAnimDelay);
}


void ASCharacter::Dash_TimeElapsed()
{
	SpawnProjectile(DashProjectileClass);
}

❗为角色添加属性组件：USAttributeComponent

为角色添加交互组件接口：USInteractionComponent* InteractionComp;

子弹类：SProejctileBase

ASProjectileBase::ASProjectileBase()
{
	SphereComp = CreateDefaultSubobject("SphereComp");
	SphereComp->SetCollisionProfileName("Projectile");
	SphereComp->OnComponentHit.AddDynamic(this, &ASProjectileBase::OnActorHit);
	RootComponent = SphereComp;

	EffectComp = CreateDefaultSubobject("EffectComp");
	EffectComp->SetupAttachment(RootComponent);

	AudioComp = CreateDefaultSubobject("AudioComp");
	AudioComp->SetupAttachment(RootComponent);

	MoveComp = CreateDefaultSubobject("ProjectileMoveComp");
	MoveComp->bRotationFollowsVelocity = true;
	MoveComp->bInitialVelocityInLocalSpace = true;
	MoveComp->ProjectileGravityScale = 0.0f;
	MoveComp->InitialSpeed = 8000;

	ImpactShakeInnerRadius = 0.0f;
	ImpactShakeOuterRadius = 1500.0f;

}

胶囊碰撞体：USphereComponent* SphereComp;

• 设置名称
• 设置碰撞预设
• 设置碰撞触发事件
• 将RootComponent设为碰撞体

子弹移动组件：UProjectileMovementComponent* MoveComp;

• 初始化相关移动属性，比如速度

粒子系统组件（平A效果）：UParticleSystemComponent* EffectComp;

在cpp中构造函数进行初始化，只需要设置名称与挂载RootComponent。

因为子弹效果必然要跟随着子弹，故需要附着在RootComponent上。

粒子系统组件（爆炸效果）：UParticleSystem* ImpactVFX;

在编辑中设置。

因为爆炸效果只需要在碰撞点触发，故不需要附着在RootComponent上。

子弹爆炸音效组件：USoundCue* ImpactSound;

？子弹播放声音组件：UAudioComponent* AudioComp;

声音较小，在黑洞攻击时有体现

子弹击中画面震动效果：TSubclassOf ImpactShake;

	UPROPERTY(EditDefaultsOnly, Category = "Effects|Shake")
	TSubclassOf ImpactShake;

	UPROPERTY(EditDefaultsOnly, Category = "Effects|Shake")
	float ImpactShakeInnerRadius;

	UPROPERTY(EditDefaultsOnly, Category = "Effects|Shake")
	float ImpactShakeOuterRadius;

⭐碰撞事件&爆炸（虚函数）：void Explode();（BlueprintNativeEvent）

	// BlueprintNativeEvent = C++ base implementation, can be expanded in Blueprints
	// BlueprintCallable to allow child classes to trigger explosions
	// Not required for assignment, useful for expanding in Blueprint later on
	UFUNCTION(BlueprintCallable, BlueprintNativeEvent)
	void Explode();

在cpp中实现逻辑：

• 在爆炸处播放粒子特效ImpactVFX
• 在爆炸处播放爆炸音效ImpactSound
• 在爆炸处触发画面震动效果ImpactShake

void ASProjectileBase::OnActorHit(UPrimitiveComponent* HitComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, FVector NormalImpulse, const FHitResult& Hit)
{
	Explode();
}

// _Implementation from it being marked as BlueprintNativeEvent
void ASProjectileBase::Explode_Implementation()
{
	// Check to make sure we aren't already being 'destroyed'
	// Adding ensure to see if we encounter this situation at all
	if (ensure(!IsPendingKill()))
	{
		UGameplayStatics::SpawnEmitterAtLocation(this, ImpactVFX, GetActorLocation(), GetActorRotation());

		UGameplayStatics::PlaySoundAtLocation(this, ImpactSound, GetActorLocation());

		UGameplayStatics::PlayWorldCameraShake(this, ImpactShake, GetActorLocation(), ImpactShakeInnerRadius, ImpactShakeOuterRadius);

		Destroy();
	}
}

普通攻击：SMagicProjectile

依赖于USAtrributeComponent，人物属性组件，因为要影响人物的血量

设置并重写OnActorOverlap逻辑：

构造函数初始化并设置碰撞体触发事件：

ASMagicProjectile::ASMagicProjectile()
{
	SphereComp->SetSphereRadius(20.0f);
	SphereComp->OnComponentBeginOverlap.AddDynamic(this, &ASMagicProjectile::OnActorOverlap);

	DamageAmount = 20.0f;
}

重写事件逻辑：

• 更改属性组件AttributeComp（HP）数值
• 不能伤害自身：OtherActor != GetInstigator()

void ASMagicProjectile::OnActorOverlap(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult)
{
	if (OtherActor && OtherActor != GetInstigator())
	{
		USAttributeComponent* AttributeComp = Cast(OtherActor->GetComponentByClass(USAttributeComponent::StaticClass()));
		if (AttributeComp)
		{
			// minus in front of DamageAmount to apply the change as damage, not healing
			AttributeComp->ApplyHealthChange(GetInstigator(), -DamageAmount);
			
			// Only explode when we hit something valid
			Explode();
		}
	}
}

设置子弹伤害：DamageAmount

❗闪现：SDashProjectile

重写BeginPlay：设置子弹存活时间

void ASDashProjectile::BeginPlay()
{
	Super::BeginPlay();

	GetWorldTimerManager().SetTimer(TimerHandle_DelayedDetonate, this, &ASDashProjectile::Explode, DetonateDelay);
}

从Begin之后，DetonateDelay秒之后，调用一次ASDashProjectile。

虚幻引擎中的Gameplay定时器 | 虚幻引擎5.0文档 (unrealengine.com)

重写爆炸逻辑Explode_Implementation

• 清除计时器
• 爆炸依然播放粒子效果
• 爆炸后取消粒子效果
• 爆炸后子弹立即停止移动
• 爆炸后子弹立即取消碰撞
• 重新设置定时器，计时触发传送

void ASDashProjectile::Explode_Implementation()
{
	// Clear timer if the Explode was already called through another source like OnActorHit
	GetWorldTimerManager().ClearTimer(TimerHandle_DelayedDetonate);

	UGameplayStatics::SpawnEmitterAtLocation(this, ImpactVFX, GetActorLocation(), GetActorRotation());

	EffectComp->DeactivateSystem();

	MoveComp->StopMovementImmediately();
	SetActorEnableCollision(false);

	FTimerHandle TimerHandle_DelayedTeleport;
	GetWorldTimerManager().SetTimer(TimerHandle_DelayedTeleport, this, &ASDashProjectile::TeleportInstigator, TeleportDelay);

	// Skip base implementation as it will destroy actor (we need to stay alive a bit longer to finish the 2nd timer)
	//Super::Explode_Implementation();
}

实现闪现传送效果：TeleportInstigator

APawn* Instigator为人物本身，调用actor的TeleportTo函数实现传送AActor::TeleportTo | Unreal Engine Documentation

void ASDashProjectile::TeleportInstigator()
{
	AActor* ActorToTeleport = GetInstigator();
	if (ensure(ActorToTeleport))
	{
		// Keep instigator rotation or it may end up jarring
		ActorToTeleport->TeleportTo(GetActorLocation(), ActorToTeleport->GetActorRotation(), false, false);
	}
}

设置定时器：FTimerHandle

FTimerHandle TimerHandle_DelayedDetonate;

黑洞攻击（蓝图）：Proj_BlackHole

由SProjectileBase继承而来，为蓝图。

添加了RadialForce径向力，并设置为负数，因为要实现一种黑洞的吸附能力

径向力Force Strength

可影响物体Object Types to Affect

要排除自身

吸进黑洞后要杀掉物体：

❗接口类：USGameplayInterface

USInteractionComponent

利用射线检测实现交互 

void ASCharacter::PrimaryInteract()
{
	if (InteractionComp)
	{
		InteractionComp->PrimaryInteract();
	}
}

void USInteractionComponent::PrimaryInteract()
{
	//碰撞预设
	FCollisionObjectQueryParams ObjectQueryParams;
	ObjectQueryParams.AddObjectTypesToQuery(ECC_WorldDynamic);
	//获取自身
	AActor* MyOwner = GetOwner();

	//设置碰撞检测位置参数，从眼部开始
	FVector EyeLocation;
	FRotator EyeRotation;
	MyOwner->GetActorEyesViewPoint(EyeLocation, EyeRotation);
	
	FVector End = EyeLocation + (EyeRotation.Vector() * 1000);

	//FHitResult Hit;
	//bool bBlockingHit = GetWorld()->LineTraceSingleByObjectType(Hit, EyeLocation, End, ObjectQueryParams);

	TArray Hits;

	float Radius = 30.f;
	//射线检测形状
	FCollisionShape Shape;
	Shape.SetSphere(Radius);

	bool bBlockingHit = GetWorld()->SweepMultiByObjectType(Hits, EyeLocation, End, FQuat::Identity, ObjectQueryParams, Shape);
	//射线颜色
	FColor LineColor = bBlockingHit ? FColor::Green : FColor::Red;

	for (FHitResult &Hit : Hits)
	{
		AActor* HitActor = Hit.GetActor();
		if (HitActor)
		{
			//执行击中物体所实现的接口
			if (HitActor->Implements())
			{
				APawn* MyPawn = Cast(MyOwner);

				ISGameplayInterface::Execute_Interact(HitActor, MyPawn);
				break;
			}
		}

		DrawDebugSphere(GetWorld(), Hit.ImpactPoint, Radius, 32, LineColor, false, 2.0f);
	}

	DrawDebugLine(GetWorld(), EyeLocation, End, LineColor, false, 2.0f, 0, 2.0f);

}

世界中的物体

爆炸油桶：ASExplosiveBarrel

设置StaticMesh，径向力

ASExplosiveBarrel::ASExplosiveBarrel()
{
	MeshComp = CreateDefaultSubobject("MeshComp");
	MeshComp->SetSimulatePhysics(true);
	RootComponent = MeshComp;

	ForceComp = CreateDefaultSubobject("ForceComp");
	ForceComp->SetupAttachment(MeshComp);

	// Leaving this on applies small constant force via component 'tick' (Optional)
	ForceComp->SetAutoActivate(false);

	ForceComp->Radius = 750.0f;
	ForceComp->ImpulseStrength = 2500.0f; // Alternative: 200000.0 if bImpulseVelChange = false
	// Optional, ignores 'Mass' of other objects (if false, the impulse strength will be much higher to push most objects depending on Mass)
	ForceComp->bImpulseVelChange = true;

	// Optional, default constructor of component already adds 4 object types to affect, excluding WorldDynamic
	ForceComp->AddCollisionChannelToAffect(ECC_WorldDynamic);

	// Binding either in constructor or in PostInitializeComponents() below
	//MeshComp->OnComponentHit.AddDynamic(this, &ASExplosiveBarrel::OnActorHit);
}

初始化Actor组件（添加碰撞事件）

AActor::PostInitializeComponents | Unreal Engine Documentation

‎允许Actor在初始化所有组件后在C++端初始化自己，仅在游戏过程中调用‎ 

void ASExplosiveBarrel::PostInitializeComponents()
{
	// Don't forget to call parent function
	Super::PostInitializeComponents();

	MeshComp->OnComponentHit.AddDynamic(this, &ASExplosiveBarrel::OnActorHit);
}

 其实有效果的就是第一句：

void ASExplosiveBarrel::OnActorHit(UPrimitiveComponent* HitComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, FVector NormalImpulse, const FHitResult& Hit)
{
	ForceComp->FireImpulse();

	UE_LOG(LogTemp, Log, TEXT("OnActorHit in Explosive Barrel"));

	// %s = string
	// %f = float
	// logs: "OtherActor: MyActor_1, at gametime: 124.4" 
	UE_LOG(LogTemp, Warning, TEXT("OtherActor: %s, at game time: %f"), *GetNameSafe(OtherActor), GetWorld()->TimeSeconds);

	FString CombinedString = FString::Printf(TEXT("Hit at location: %s"), *Hit.ImpactPoint.ToString());
	DrawDebugString(GetWorld(), Hit.ImpactPoint, CombinedString, nullptr, FColor::Green, 2.0f, true);
	
	// Detailed info on logging in ue4
	// https://nerivec.github.io/old-ue4-wiki/pages/logs-printing-messages-to-yourself-during-runtime.html

}

宝箱（实现交互接口）：ASItemChest

 实现交互后，打开/关闭宝箱盖子 ，同时可以在蓝图中设置粒子效果

ASItemChest::ASItemChest()
{
	BaseMesh = CreateDefaultSubobject(TEXT("BaseMesh"));
	RootComponent = BaseMesh;

	LidMesh = CreateDefaultSubobject(TEXT("LidMesh"));
	LidMesh->SetupAttachment(BaseMesh);

	TargetPitch = 110;
}


void ASItemChest::Interact_Implementation(APawn* InstigatorPawn)
{
	LidMesh->SetRelativeRotation(FRotator(TargetPitch, 0, 0));
}

在蓝图中的Class Settings里可以看到继承了接口：

实现交互开关宝箱、设置粒子效果

血包（实现交互接口）：ASPowerupActor

老规矩，首先是简单的构造函数中的初始化

ASPowerupActor::ASPowerupActor()
{
	SphereComp = CreateDefaultSubobject("SphereComp");
	SphereComp->SetCollisionProfileName("Powerup");
	RootComponent = SphereComp;

	RespawnTime = 10.0f;
}

血包有很多种，因此接口实现逻辑由子类实现：

void ASPowerupActor::Interact_Implementation(APawn* InstigatorPawn)
{
	// logic in derived classes...
}

吃掉后隐藏血包（计时器）：

void ASPowerupActor::HideAndCooldownPowerup()
{
	SetPowerupState(false);

	GetWorldTimerManager().SetTimer(TimerHandle_RespawnTimer, this, &ASPowerupActor::ShowPowerup, RespawnTime);
}

void ASPowerupActor::SetPowerupState(bool bNewIsActive)
{
	SetActorEnableCollision(bNewIsActive);

	// Set visibility on root and all children
	RootComponent->SetVisibility(bNewIsActive, true);
}

血包子类：ASPowerup_HealthPotion

void ASPowerup_HealthPotion::Interact_Implementation(APawn* InstigatorPawn)
{
	if (!ensure(InstigatorPawn))
	{
		return;
	}

	USAttributeComponent* AttributeComp = USAttributeComponent::GetAttributes(InstigatorPawn);
	// Check if not already at max health
	if (ensure(AttributeComp) && !AttributeComp->IsFullHealth())
	{
		// Only activate if healed successfully
		if (AttributeComp->ApplyHealthChange(this, AttributeComp->GetHealthMax()))
		{
			HideAndCooldownPowerup();
		}
	}
}

UI：Widget

十字准星

创建Widget并设置：

游戏开始时添加到屏幕上

create widget：

人物血条、Credits、游戏进行时间：Main_HUD

血条

创建对应组件UI

为text绑定health事件

Credits：

游戏进行时间：

AI

UE中的AI系统

• Navigation Mesh：AI寻路，可达区域
• Behavior Tree：行为树，AI的大脑
• Blackboard：AI数据存储
• Environment Query System：空间查询
• PawnSensing&AIPerception：感知
• Debug相关

行为树：

设置黑板 

添加导航网格体：NavMeshBoundsVolume

游戏AI角色：SAICharacter

游戏AI控制器：SAIController

设置行为树

class UBehaviorTree;

/**
 * 
 */
UCLASS()
class ACTIONROGUELIKE_API ASAIController : public AAIController
{
	GENERATED_BODY()
	
protected:

	UPROPERTY(EditDefaultsOnly, Category = "AI")
	UBehaviorTree* BehaviorTree;

	virtual void BeginPlay() override;
};

void ASAIController::BeginPlay()
{
	Super::BeginPlay();

	if (ensureMsgf(BehaviorTree, TEXT("Behavior Tree is nullptr! Please assign BehaviorTree in your AI Controller.")))
	{
		RunBehaviorTree(BehaviorTree);
	}

// 	APawn* MyPawn = UGameplayStatics::GetPlayerPawn(this, 0);
// 	if (MyPawn)
// 	{
// 		GetBlackboardComponent()->SetValueAsVector("MoveToLocation", MyPawn->GetActorLocation());
// 
// 		GetBlackboardComponent()->SetValueAsObject("TargetActor", MyPawn);
// 	}
}

 

为SAICharacter设置控制器

游戏AI逻辑-范围内攻击：USBTService_CheckAttackRange（UBTService）

范围查询逻辑

• 检查AI与玩家的距离
• LineOfSightTo：true if controller's pawn can see Other actor
• 在黑板中添加对应key值，通过C++逻辑设置bool值：BlackBoardComp->SetValueAsBool(AttackRangeKey.SelectedKeyName, (bWithinRange && bHasLOS));

逻辑为：当且仅当：

• AI距离玩家小于MaxAttackRange时
• AI能够看见玩家时 

为真。 

void USBTService_CheckAttackRange::TickNode(UBehaviorTreeComponent& OwnerComp, uint8* NodeMemory, float DeltaSeconds)
{
	Super::TickNode(OwnerComp, NodeMemory, DeltaSeconds);

	// Check distance between ai pawn and target actor
	UBlackboardComponent* BlackBoardComp = OwnerComp.GetBlackboardComponent();
	if (ensure(BlackBoardComp))
	{
		AActor* TargetActor = Cast(BlackBoardComp->GetValueAsObject("TargetActor"));
		if (TargetActor)
		{
			AAIController* MyController = OwnerComp.GetAIOwner();

			APawn* AIPawn = MyController->GetPawn();
			if (ensure(AIPawn))
			{
				float DistanceTo = FVector::Distance(TargetActor->GetActorLocation(), AIPawn->GetActorLocation());

				bool bWithinRange = DistanceTo < MaxAttackRange;

				bool bHasLOS = false;
				if (bWithinRange)
				{
					bHasLOS = MyController->LineOfSightTo(TargetActor);
				}

				BlackBoardComp->SetValueAsBool(AttackRangeKey.SelectedKeyName, (bWithinRange && bHasLOS));
			}
		}
	}
}

在行为树添加此Service

CheckAttackRange后，会首先进入WithinAttackRange？，若条件为真，则AI执行攻击；若条件为假，则AI向玩家移动，直到到达攻击范围内；

游戏AI范围内攻击任务结点：USBTTask_RangedAttack

AI朝向玩家：Set default focus

环境查询系统：

创建EQS

图中蓝色球体为未选中移动目标，绿色球体为已被选择的目标，AI会对EQS所查询的目标进行移动 

随机选取一个位置让AI移动

在玩家周围半径内设置EQS生成移动目的地

AI死亡

void ASAICharacter::OnHealthChanged(AActor* InstigatorActor, USAttributeComponent* OwningComp, float NewHealth, float Delta)
{
	if (Delta < 0.0f)
	{
		if (InstigatorActor != this)
		{
			SetTargetActor(InstigatorActor);
		}

		if (ActiveHealthBar == nullptr)
		{
			ActiveHealthBar = CreateWidget(GetWorld(), HealthBarWidgetClass);
			if (ActiveHealthBar)
			{
				ActiveHealthBar->AttachedActor = this;
				ActiveHealthBar->AddToViewport();
			}
		}

		GetMesh()->SetScalarParameterValueOnMaterials(TimeToHitParamName, GetWorld()->TimeSeconds);

		if (NewHealth <= 0.0f)
		{
			// stop BT
			AAIController* AIC = Cast(GetController());
			if (AIC)
			{
				AIC->GetBrainComponent()->StopLogic("Killed");
			}

			// ragdoll
			GetMesh()->SetAllBodiesSimulatePhysics(true);
			GetMesh()->SetCollisionProfileName("Ragdoll");

			// set lifespan
			SetLifeSpan(10.0f);
		}
	}
}