Unity: Enemy 로직 설계

[developerasun]

기존 3D 모델을 3가지로 분류

1. 쥐, 개구리 : easy 난이도, 플레이어 정면을 향해 천천히 다가옴
2. 뱀, 거미 : intermediate 난이도, 속도가 빨라짐
3. 벌, 외계인 : difficult 난이도, 하늘을 날아다님, 인공지능으로 플레이어를 따라옴

[developerasun]

진행 : enemies 브랜치 생성 후 작업 예정

디렉토리 구성

[developerasun]

enemy 인공지능 구현 1차 : NavMesh, NavMeshAgent

NavMesh와 NavMeshAgnet의 차이와 설정하는 법을 몰라 좀 헤맸네용

• NavMesh : Agent가 걸어다닐 수 있는(walkable field) 필드 설정, 장애물 설정 시 장애물은 walkable field에서 제외
• NavMeshAgent : Mesh에서 설정된 필드를 walk 함.

NavMesh and NavMeshAgent

set NavMesh and obstacle

1. set an object for wakability
2. make the object navigation-static and bake it.
3. add an obstacle with the same logic above(NavMesh will auto-sense it)

Agent setting in Navigation tab (Unity editor)

set NavMeshAgent with script

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.AI;

public class agent : MonoBehaviour
{
    [SerializeField] Transform target;

    private NavMeshAgent _agent;
    void Awake()
    {
        _agent = GetComponent<NavMeshAgent>();
    }

    // Update is called once per frame
    void Update()
    {
        if (Input.GetKeyDown(KeyCode.Space))
        {
        _agent.destination = target.position; 
        }
    }
}

[developerasun]

Enemy script 업데이트 공유

public class E_rat : MonoBehaviour, IEnemyBehavior
{
    private Player player; 
    
    public IEnemyBehavior.enemyState current; // enemy 상태
    public IEnemyBehavior.playerDistanceState isDetected; // enemy의 player 탐지  
    public NavMeshAgent _agent; // enemy 인공지능 인스턴스
    
    public float distance; // Player ~ enemy 사이 거리
    public float detectLimit = 200f; // enemy 감지 거리 한계

    // ============== Object initialization and update ============== // 
    void Awake()
    {
        current = IEnemyBehavior.enemyState.Idle; // awake시 상태는 idle
        player = FindObjectOfType<Player>();
        _agent = FindObjectOfType<NavMeshAgent>();
        print($"player is at : {player.transform.position}");
    }

    void Update()
    {
        updateState();
        updateBehavior();
        // Track();
    }
    // ============== Object initialization and update ============== // 

    // ============== Enemy state and behavior ============== // 
    public void updateBehavior()
    {
        switch(current) 
        {
            case IEnemyBehavior.enemyState.Idle : 
                Idle();
                break;
            case IEnemyBehavior.enemyState.Track : 
                // TO DO : enemy에 작은 신호등 붙이기(track state 표시용)
                GetComponent<Renderer>().material.color = Color.red;
                Track();
                break;
            case IEnemyBehavior.enemyState.Fire : 
                Fire();
                break;
            case IEnemyBehavior.enemyState.Die : 
                Die();
                break;
            default : 
                Idle();
                break;
        }
    }

    public void updateState()
    {
        switch (isDetected) {
            case IEnemyBehavior.playerDistanceState.TooFar :
                current = IEnemyBehavior.enemyState.Idle;
                break;
            case IEnemyBehavior.playerDistanceState.Within : 
                current = IEnemyBehavior.enemyState.Track;
                break;
            default : 
                current = IEnemyBehavior.enemyState.Idle;
                break;
        }
    }
    // ============== Enemy state and behavior ============== // 


    // ============== IEnemyBehavior implementation ============== // 
    public void Idle() 
    {
        // TO DO : 플레이어가 탐지 거리 바깥이면 주변 패트롤
        print("Enemy being idle");
        
    }

    public void Track() 
    {
        // 플레이어가 일정 거리 이상 좁혀지면 추적 시작
        distance = Vector3.Distance(player.transform.position, this.transform.position);

        if (current == IEnemyBehavior.enemyState.Track && distance < detectLimit) 
        {
            print("Enemy detected a player, starting tracking");
            _agent.destination = player.transform.position;

        }
    }

    public void Fire() 
    {
        print("Enemy found a player, starting to shoot");
    }

    public void Die() 
    {
        // TO DO : 플레이어가 밟고 지나가면 죽음
        print("Enemy died by a player");
        Destroy(this.gameObject);
    }
    // ============== IEnemyBehavior implementation ============== // 
}

@jshhhhh

[developerasun]

인공지능 적 구현 2차

Making an Agent Patrol Between a Set of Points

Many games feature NPCs that patrol automatically around the playing area. The navigation system can be used to implement this behaviour but it is slightly more involved than standard pathfinding - merely using the shortest path between two points makes for a limited and predictable patrol route. You can get a more convincing patrol pattern by keeping a set of key points that are “useful” for the NPC to pass through and visiting them in some kind of sequence. For example, in a maze, you might place the key patrol points at junctions and corners to ensure the agent checks every corridor. For an office building, the key points might be the individual offices and other rooms.

The ideal sequence of patrol points will depend on the way you want the NPCs to behave. For example, a robot would probably just visit the points in a methodical order while a human guard might try to catch the player out by using a more random pattern. The simple behaviour of the robot can be implemented using the code shown below.

The patrol points are supplied to the script using a public array of Transforms. This array can be assigned from the inspector using GameObjects to mark the points’ positions. The GotoNextPoint function sets the destination point for the agent (which also starts it moving) and then selects the new destination that will be used on the next call. As it stands, the code cycles through the points in the sequence they occur in the array but you can easily modify this, say by using Random.Range to choose an array index at random.

In the Update function, the script checks how close the agent is to the destination using the remainingDistance property. When this distance is very small, a call to GotoNextPoint is made to start the next leg of the patrol.

    // Patrol.cs
    using UnityEngine;
    using UnityEngine.AI;
    using System.Collections;


    public class Patrol : MonoBehaviour {

        public Transform[] points;
        private int destPoint = 0;
        private NavMeshAgent agent;


        void Start () {
            agent = GetComponent<NavMeshAgent>();

            // Disabling auto-braking allows for continuous movement
            // between points (ie, the agent doesn't slow down as it
            // approaches a destination point).
            agent.autoBraking = false;

            GotoNextPoint();
        }


        void GotoNextPoint() {
            // Returns if no points have been set up
            if (points.Length == 0)
                return;

            // Set the agent to go to the currently selected destination.
            agent.destination = points[destPoint].position;

            // Choose the next point in the array as the destination,
            // cycling to the start if necessary.
            destPoint = (destPoint + 1) % points.Length;
        }


        void Update () {
            // Choose the next destination point when the agent gets
            // close to the current one.
            if (!agent.pathPending && agent.remainingDistance < 0.5f)
                GotoNextPoint();
        }
    }

reference

• https://docs.unity3d.com/Manual/nav-AgentPatrol.html

[developerasun]

Enemy type : rat 2차 구현 끝

rat.mp4

[developerasun]

중간/어려움 난이도 Enemy 설계

플레이어를 추적하고 발사 가능 범위면 오브젝트를 발사.

Raycast와 Particle sytem을 활용한 Enemy fire 로직 설계 중. Raycast 발사 시 particle system 작동, raycast hit가 유효할 경우 오브젝트의 health를 감소시키고 파괴함.

raycastAndShoot.mp4

// Raycast 발사
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class shoot : MonoBehaviour
{
    public float damage = 10f; 
    public float range = 100f;
    private Rigidbody rb;
    public float speed = 4;
    // public Camera fpsCam;
    public ParticleSystem muzzleFlash;
    void Start()
    {
        rb = this.GetComponent<Rigidbody>();
    }

    void Move()
    {
        float h = Input.GetAxis("Horizontal");
        float v = Input.GetAxis("Vertical"); 
        // Rigidbody.velocity : change of Rigidbody position.
        rb.velocity = new Vector3(h * speed,0,v*speed);
    }
    // Update is called once per frame
    void Update()
    {
        Move();
        if (Input.GetKeyDown(KeyCode.Space))
        {
            Fire();
        }
    }

    void Fire() 
    {
        // ParticleSystem.Play : Starts the Particle System.
        muzzleFlash.Play();
        RaycastHit hit; // RaycastHit : struct type
        bool isHit = Physics.Raycast(
            this.transform.position,
            this.transform.forward, 
            out hit, // no explicit return but value is updated.
            range
        ); // Physics : class type, Raycast : 1) origin 2) direction

        if (isHit)
        {
            print($" target : {hit.transform.name}");
            gunTarget target = hit.transform.GetComponent<gunTarget>();
            if (target != null) 
            {
                target.TakeDamage(10f);
            }
            // print();
        } else { 
            print("no ray cast hit");
        }
    }
}

// Raycast 맞음
public class gunTarget : MonoBehaviour
{
    public float health = 50f;

    public void TakeDamage(float amount)
    {
        health -= amount;
        this.gameObject.GetComponent<MeshRenderer>().material.color = Color.black;
        if (health < 30)
        {
            this.gameObject.GetComponent<MeshRenderer>().material.color = Color.blue;
        }
        if (health < 0) {
            Destroy(gameObject);
        }
    }
}

[developerasun]

intermediate enemy 로직 구현 1차

구현 방법 : Raycast로 플레이어 체킹, instantiate로 오브젝트 생성, Coroutine
& Vector3.MoveTowards로 오브젝트 이동

E_intermediate.mp4

[developerasun]

Particle system 1차 구현

• enemy 오브젝트 슈팅 이펙트 구현

particleSys.mp4

[developerasun]

intermediate enemy 로직 구현 2차

• 플레이어 점프 시 이펙트와 함께 오브젝트 슈팅

동영상

intermediate.mp4

[developerasun]

difficult 난이도 enemy 구현 1차

• Vector3.MoveForwards 패트롤 구현
• 커스텀 Transform.LookAt 메소드 구현

void ShouldLookAtPlayer()
    {
        Vector3 playerPosWithLockedYAxis = new Vector3(
            player.transform.position.x, 
            transform.position.y, 
            player.transform.position.z
        ); 

        transform.LookAt(playerPosWithLockedYAxis); // fix y axis
        transform.Rotate( 0, 90, 0 ); // rotate enemy 90 degree in Y axis to correct direction
    }

• Trail renderer를 활용한 발사체 궤도 시각화
• Instantiate & coroutine 활용한 오브젝트 슈팅 구현

동영상

beeDone.mp4

[developerasun]

중간 점검 : 현재 남아있는 tasks

• enemy animation : 미정
• enemy health system : 미정
• enemy damage system : How to make Damage Popup Text (Unity Tutorial)

[developerasun]

애니메이션 구현 1차

자료 조사 및 애니메이션 튜토리얼

#131

3D 모델 애니메이션 확인 및 추출

beeAnim.mp4

애니메이션 컨트롤러 parameters/states 지정

[developerasun]

애니메이션 종류 지정

기존 enemy state에 맞춰

• attack
• idle
• track

기본 3종류로 지정, 적절한 애니메이션이 없을 경우 idle을 track으로 활용(idleTrack

)

애니메이션 파라미터 지정

enemy type에 맞춰 서로 다른 파라미터 지정 및 제네릭 함수 사용

• easy type : 개구리/쥐 idleOrTrack(0), shouldAttack(1), shouldJump(2)

    public void AnimationSetter<T>(string _name, T _condition)
    {
        if (_condition.GetType() == typeof(int))
        {
            animator.SetInteger(_name, (int.Parse(_condition.ToString())));
        }
    }

• intermediate type: 뱀/거미 shouldAttack(bool), idleOrTrack(bool)
• diffcult type: 벌/외계인 shouldAttack(bool), idleOrTrack(bool)

    public void AnimationSetter<T>(string _name, T _condition)
    {
        if (_condition.GetType() == typeof(bool))
        {
            animator.SetBool(_name, bool.Parse(_condition.ToString()));
        }
   }

[developerasun]

enemy 애니메이션 구현 2차

enemy-idle.mp4

[jshhhhh]

자체 애니메이션이 있다는 게 천만다행이네 ㅋㅋㅋ
enemy가 훨씬 생동감 있고 보기 좋다👍

[developerasun]

애초에 3D 모델 가지고 올 때 애니메이션 있는 걸로 가지고 오는 게 중요한 거 같아영 애니메이션 튜토리얼 진행해보니까 애니메이션 실제로 만드는 건 애니메이터라고 아예 따로 직종이 있는 거 같더라구