Object Not Dying When Approached

Hi! I'm trying to make an object die when the player approaches it. Any tips on what I'm doing wrong?

Script for the object (It patrols around)

Code (CSharp):

1. using System.Collections;
2. using System;
3. using System.Collections.Generic;
4. using UnityEngine;
5. using UnityEngine.AI;
6.  
7. public class NPCPatrol : MonoBehaviour
8. {
9.     //Determines whether NPC waits on a node
10.     [SerializeField]
11.     bool _patrolWaiting;
12.  
13.     //Sight distance
14.     [SerializeField]
15.     public float sightDistance = 10f;
16.  
17.     //Total time to wait on a node
18.     [SerializeField]
19.     float _totalWaitTime = 3f;
20.  
21.     //Probability to switch directions
22.     [SerializeField]
23.     float _switchProbability = 0.2f;
24.  
25.     //List of all patrol points to go to
26.     [SerializeField]
27.     List<PatrolPoint> _patrolPoints;
28.  
29.     //Private variables for behavior
30.     NavMeshAgent _navMeshAgent;
31.     int _currentPatrolIndex;
32.     bool _travelling;
33.     bool _waiting;
34.     bool _patrolForward;
35.     float _waitTimer;
36.  
37.     Transform target;
38.     Transform pad;
39.     // Start is called before the first frame update
40.     void Start()
41.     {
42.         target = PlayerTracker.instance.player.transform; //Calls on GameManager's PlayerTracker
43.         pad = PlayerTracker.instance.pad.transform;
44.         _navMeshAgent = this.GetComponent<NavMeshAgent>();
45.  
46.            if(_navMeshAgent == null) //If true no nav mesh attached
47.            {
48.                Debug.LogError("Nav mesh agent is not attached to " + gameObject.name);
49.            }
50.            else
51.            {
52.                if(_patrolPoints != null && _patrolPoints.Count >= 2) //Checks if patrol points exist and there are enough
53.                {
54.                    _currentPatrolIndex = 0;
55.                    SetDestination();
56.                }
57.                else
58.                {
59.                    Debug.Log("Insufficient patrol points for basic patrolling behaviour.");
60.                }
61.             }
62.  
63.     }
64.  
65.     // Update is called once per frame
66.     public void Update()
67.     {
68.         float distance = Vector3.Distance(target.position, transform.position);
69.         //Checks if close to the destination
70.         if (_travelling && _navMeshAgent.remainingDistance <= 1.0f)
71.         {
72.             _travelling = false;
73.  
74.             //If going to wait
75.             if (_patrolWaiting)
76.             {
77.                 _waiting = true;
78.                 _waitTimer = 0f;
79.             }
80.             else
81.             {
82.                 ChangePatrolPoint();
83.                 SetDestination();
84.             }
85.         }
86.         //Instead if we're waiting
87.         if (_waiting)
88.         {
89.             _waitTimer += Time.deltaTime;
90.             if(_waitTimer >= _totalWaitTime)
91.             {
92.                 _waiting = false;
93.  
94.                 ChangePatrolPoint();
95.                 SetDestination();
96.             }
97.         }
98.         if (distance <= sightDistance)
99.         {
100.             gameObject.SetActive(false);
101.         }
102.     }
103.  
104.     private void SetDestination() //Sets destination
105.     {
106.         if(_patrolPoints != null)
107.         {
108.             Vector3 targetVector = _patrolPoints[_currentPatrolIndex].transform.position; //Go to destination
109.             _navMeshAgent.SetDestination(targetVector);
110.             _travelling = true;
111.         }
112.     }
113.  
114.     private void ChangePatrolPoint()
115.     {
116.         if(UnityEngine.Random.Range(0f, 1f) <= _switchProbability)
117.         {
118.             _patrolForward = !_patrolForward;
119.         }
120.  
121.         if (_patrolForward)
122.         {
123.             _currentPatrolIndex = (_currentPatrolIndex + 1) % _patrolPoints.Count;
124.         }
125.  
126.         else
127.         {
128.             if(--_currentPatrolIndex < 0)
129.             {
130.                 _currentPatrolIndex = _patrolPoints.Count - 1;
131.             }
132.         }
133.     }
134.     void OnDrawGizmosSelected()
135.     {
136.         Gizmos.color = Color.blue; //Makes sight radius sphere blue
137.         Gizmos.DrawWireSphere(transform.position, sightDistance); //shows radius of sight
138.     }
139. }
140.  

Script for the GameManager that tracks the player

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class PlayerTracker : MonoBehaviour
6. {
7.      #region Singleton
8.  
9.     public static PlayerTracker instance;
10.  
11.     void Awake()
12.     {
13.         instance = this;
14.  
15.     }
16.  
17.     #endregion
18.  
19.     public GameObject player; //References player
20.     public GameObject pad;
21. }
22.  

If you need anything else to help solve the problem let me know

 

Multiple ways to approach this. One is to use a trigger around the object and check upon

OnTriggerEnter

from the player and then destroy the object. I recommend this variant.

Consider the following code placed on your player, and having your NPC having a collider with

isTrigger

enabled, and perhaps tagged with tag

NPC

:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class NPCDestroyer : MonoBehaviour {
6.     void OnTriggerEnter(Collider other) {
7.         if (other.CompareTag("NPC")) {
8.             Destroy(other.gameObject);
9.         }
10.     }
11. }

---

Alternative 2 is doing it via script. This can be done simply by checking the distance between the two positions of player and the NPC object, much like you're already doing in your patrol script for deciding when to start moving to the next patrol point.

Consider the following script placed on the NPC game object:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class PlayerTracker : MonoBehaviour {
6.     public Transform player;
7.     public float range = 10;
8.  
9.     void Update() {
10.         float distance = Vector3.Distance(player.position, transform.position);
11.  
12.         if (distance < range) {
13.             Destroy(gameObject);
14.         }
15.     }
16. }