UE4 C++ 实现敌人追逐与攻击

Posted 2021-09-01 Vincent_0000

效果展示

处在他的发现范围之外敌人是不会发现。

当走进他的发现范围之内的时候，他就会跑过来，

进行攻击。

现在还没有伤害。

C++ 文件

打开Built.cs文件，
找到：PublicDependencyModuleNames.AddRange
在之中添加"AIModule"，增加AI相关的模块，这样系统才能识别我们调用的函数。

Enemy

创建继承Character类的Enemy类，因为不是玩家控制敌人的状态，而是计算机控制状态，所以需要在文件中声明敌人的状态：

UENUM(BlueprintType)
enum class EMoveStatus : uint8 {
	MS_Idle				UMETA(DisplayName = "Idle"),
	MS_MoveToTarget		UMETA(DisplayName = "MoveToTarget"),
	MS_Attacking		UMETA(DisplayName = "Attacking"),
};

.h

• 添加球形组件，一个是表示检测角色的范围，一个是攻击敌人的范围

UPROPERTY(VisibleAnywhere, BlueprintReadOnly)
	class USphereComponent* DetectSphere;

UPROPERTY(VisibleAnywhere, BlueprintReadOnly)
	class USphereComponent* AttackSphere;

• 球形组件绑定的重叠函数

UFUNCTION()
	void OnDetectSphereOverlapBegin(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, 
		UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult);

UFUNCTION()
	void OnDetectSphereOverlapEnd(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor,
		UPrimitiveComponent* OtherComp, int32 OtherBodyIndex);

UFUNCTION()
	void OnAttackSphereOverlapBegin(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, 
		UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult);

UFUNCTION()
	void OnAttackSphereOverlapEnd(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor,
		UPrimitiveComponent* OtherComp, int32 OtherBodyIndex);

• 声明AI控制器

class AAIController* _AIController;

• 声明游戏状态

UPROPERTY(VisibleAnywhere, BlueprintReadWrite)
	EMoveStatus MoveStatus;

• 声明追击角色目标

UPROPERTY(VisibleAnywhere, BlueprintReadOnly)
	class ARole* TargetRole;

• 声明攻击角色目标

UPROPERTY(VisibleAnywhere, BlueprintReadOnly)
	class ARole* HittingRole;

• 声明移动到目标的函数

UFUNCTION(BlueprintCallable)
	void MoveToTarget();

.cpp文件

添加头文件：

#include "Components/SphereComponent.h"
#include "AIController.h"
#include "Kismet/KismetSystemLibrary.h"
#include "Role.h"

• 构造函数

加载球形组件和设置范围，初始化操作。

DetectSphere = CreateDefaultSubobject<USphereComponent>(TEXT("DetectSphere"));
DetectSphere->SetupAttachment(RootComponent);
DetectSphere->SetSphereRadius(300);

AttackSphere = CreateDefaultSubobject<USphereComponent>(TEXT("AttackSphere"));
AttackSphere->SetupAttachment(RootComponent);
AttackSphere->SetSphereRadius(100);

• BeginPlay()

绑定重叠函数，这个算是重叠的基本操作了。

DetectSphere->OnComponentBeginOverlap.AddDynamic(this, &AEnemy::OnDetectSphereOverlapBegin);
DetectSphere->OnComponentEndOverlap.AddDynamic(this, &AEnemy::OnDetectSphereOverlapEnd);

AttackSphere->OnComponentBeginOverlap.AddDynamic(this, &AEnemy::OnAttackSphereOverlapBegin);
AttackSphere->OnComponentEndOverlap.AddDynamic(this, &AEnemy::OnAttackSphereOverlapEnd);

获得AI控制器：

_AIController = Cast<AAIController>(GetController());

• OnDetectSphereOverlapBegin

触碰到检测球形组件的时候，设置我们的追击目标，然后移动到目标角色的位置。

• OnDetectSphereOverlapEnd

检测球形组件重叠结束的时候，敌人不在进行追逐，目标角色置为空，AI控制器控制敌人停止移动，人物处于呆滞状态。

if (OtherActor) {
	ARole* _Role = Cast<ARole>(OtherActor);
	if (_Role == TargetRole) {
		TargetRole = nullptr;
		if (MoveStatus != EMoveStatus::MS_Attacking) {
			MoveStatus = EMoveStatus::MS_Idle;
		}

		if (_AIController) {
			_AIController->StopMovement();
		}
	}
}

• OnAttackSphereOverlapBegin

在攻击范围之内的时候，敌人要进行攻击，设置攻击目标，敌人设置为攻击状态，如果敌人在移动状态就要停止移动。

if (!HittingRole) {
	if (OtherActor) {
		ARole* _Role = Cast<ARole>(OtherActor);
		if (_Role) {
			HittingRole = _Role;
			MoveStatus = EMoveStatus::MS_Attacking;
			if (_AIController) {
				_AIController->StopMovement();
			}
		}
	}
}

• OnAttackSphereOverlapEnd

在攻击范围之外的时候，敌人就变成了追击状态，设置追击目标，攻击目标置为空。

if (OtherActor) {
	ARole* _Role = Cast<ARole>(OtherActor);
	if (_Role == HittingRole) {
		TargetRole = HittingRole;
		HittingRole = nullptr;
	}
}

• MoveToTarget

让AI控制器控制敌人移动到角色的位置。

if (TargetRole) {
	if (_AIController) {
		FAIMoveRequest _MoveRequest;
		_MoveRequest.SetGoalActor(TargetRole);
		_MoveRequest.SetAcceptanceRadius(2);

		FNavPathSharedPtr NavPath;
		_AIController->MoveTo(_MoveRequest, &NavPath);
	}
}
else {
	MoveStatus = EMoveStatus::MS_Idle;
}

EnemyAnimInstance

创建继承AnimInstance的EnemyAnimInstance，这个就和之前的是一样的。

.h文件

初始化函数，更新函数，移动速度（便于我们区分人物状态）、敌人类、Pawn类。

virtual void NativeInitializeAnimation() override;

UFUNCTION(BlueprintCallable, Category = AnimationProperty)
	void UpdateAnimationProperties();

UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Movement)
	float MovementSpeed;

UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Movement)
	class AEnemy* _Enemy;

UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Movement)
	class APawn* _Pawn;

.cpp文件

添加头文件：

#include "Enemy.h"

void UEnemyAnimInstance::NativeInitializeAnimation()
{
	if (!_Pawn) {
		_Pawn = TryGetPawnOwner();
	}
	_Enemy = Cast<AEnemy>(_Pawn);
}

void UEnemyAnimInstance::UpdateAnimationProperties()
{
	if (!_Pawn) {
		_Pawn = TryGetPawnOwner();
	}

	if (_Pawn) {
		FVector Speed = _Pawn->GetVelocity();
		FVector LateralSpeed = FVector(Speed.X, Speed.Y, 0);
		MovementSpeed = LateralSpeed.Size();
	}
}

蓝图操作

创建动画蓝图，

设置角色状态机：

攻击动画中要添加一个注意：

蓝图中要更新状态：

和人物是差不多的。

根据动作传来的提醒，我们要对敌人的状态进行设置：