Resolved Gameobject script freezes unity upon play

I created this script to let the object roam freely when it doesn't detect the player and will engage combat when it does. I also included the codes for it's animations.
The thing is, I have 2 scenes,TestingScene and GameScene. On TestingScene, I encountered no problem other than the model stuttering when the player's within a certain distance. On the other hand, the GameScene freezes when I hit the play button. Disabling the script from the problem prefab somehow lets Unity runs normally.
Here's the script :

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class EnemyController : MonoBehaviour
6. {
7.     public Animator myAnimator;
8.     private Collider myCollider;
9.     private Rigidbody rb;
10.     private Vector3 startPosition;
11.     private Vector3 randomDirection;
12.     private Coroutine combatCor;
13.     private Coroutine idleCor;
14.  
15.     public GameObject pointer;
16.     public GameObject deathModel;
17.     private GameObject player;
18.     public GameObject firePoint;
19.     public GameObject projectile;
20.     public float minFireRate = 2.0f;
21.     public float maxFireRate = 5.0f;
22.     private float nextFire;
23.     public float combatMovementSpeed = 10.0f;
24.     private bool fired = false;
25.     private bool combat = false;
26.     private bool freeRoam = false;
27.  
28.     public float awareRadius = 10.0f;
29.  
30.     private Vector3 newPos;
31.     private bool newPosIsSet;
32.  
33.     public float roamRadius;
34.     public float walkingSpeed = 2.0f;
35.     public float minIdleTime = 3.0f;
36.     public float maxIdleTime = 6.0f;
37.     private bool nextDestinationSet;
38.  
39.  
40.     // Start is called before the first frame update
41.     void Start()
42.     {
43.         myCollider = GetComponent<CapsuleCollider>();
44.         rb = GetComponent<Rigidbody>();
45.  
46.         player = GameObject.FindWithTag("Player");
47.         startPosition = transform.position;
48.         FreeRoam();
49.     }
50.  
51.     // Update is called once per frame
52.     void Update()
53.     {
54.         float checkPlayerDistance = Vector3.Distance(player.transform.position, transform.position);
55.         float roundedDistance = Mathf.Round(checkPlayerDistance);
56.         if (checkPlayerDistance <= awareRadius)
57.         {
58.             combat = true;
59.             freeRoam = false;
60.         }
61.         else if (roundedDistance >= awareRadius + 5.0f && freeRoam == false)
62.         {
63.             Debug.Log("Enemy disengage !");
64.             combat = false;
65.             freeRoam = true;
66.             FreeRoam();
67.         }
68.  
69.         //--------------------------------------------------------------------------------------------------
70.         //Combat Mode
71.         //--------------------------------------------------------------------------------------------------
72.  
73.         if (combat == true)
74.         {
75.             pointer.SetActive(true);
76.             nextDestinationSet = false;
77.             transform.LookAt(player.transform.position);
78.             if (roundedDistance > 5f)
79.             {
80.                 transform.position = Vector3.MoveTowards(transform.position, player.transform.position, Time.deltaTime * combatMovementSpeed);
81.                 myAnimator.SetTrigger("isIdle");
82.                 myAnimator.ResetTrigger("isWalking");
83.             }
84.             else
85.             {
86.                 transform.position += -transform.forward * Time.deltaTime * combatMovementSpeed;
87.                 myAnimator.SetTrigger("isIdle");
88.                 myAnimator.ResetTrigger("isWalking");
89.             }
90.  
91.             if (Time.time > nextFire)
92.             {
93.                 nextFire = Time.time + Random.Range(minFireRate,maxFireRate);
94.                 Fire();
95.             }
96.         }
97.  
98.         //--------------------------------------------------------------------------------------------------
99.         //Roaming Mode
100.         //--------------------------------------------------------------------------------------------------
101.  
102.         if (nextDestinationSet == true)
103.         {
104.             myAnimator.SetTrigger("isIdle");
105.             myAnimator.ResetTrigger("isWalking");
106.             transform.position = Vector3.MoveTowards(transform.position, randomDirection, Time.deltaTime * walkingSpeed);
107.             if (transform.position == randomDirection)
108.             {
109.                 nextDestinationSet = false;
110.                 Debug.Log("IdleTime");
111.                 myAnimator.SetTrigger("isWalking");
112.                 myAnimator.ResetTrigger("isIdle");
113.                 idleCor = StartCoroutine(IdleTime());
114.             }
115.         }
116.     }
117.  
118.     void FreeRoam()
119.     {
120.         Debug.Log("FreeRoam");
121.         pointer.SetActive(false);
122.         freeRoam = true;
123.         randomDirection = Random.insideUnitSphere * roamRadius;
124.         randomDirection.y = 0;
125.         float checkDistance = Vector3.Distance(startPosition, randomDirection);
126.         float distance = Vector3.Distance(transform.position, randomDirection);
127.         Debug.Log(randomDirection);
128.         if (checkDistance <= roamRadius)
129.         {
130.             Debug.Log("Next destination is set");
131.             Vector3 currentPosition = transform.position;
132.             transform.LookAt(randomDirection);
133.             nextDestinationSet = true;
134.         }
135.         else if (distance <= 2)
136.         {
137.             FreeRoam();
138.         }
139.         else
140.         {
141.             FreeRoam();
142.         }
143.     }
144.  
145.     IEnumerator IdleTime()
146.     {
147.         yield return new WaitForSeconds(Random.Range(minIdleTime, maxIdleTime));
148.         if(combat == false)
149.         FreeRoam();
150.     }
151.  
152.     void OnCollisionEnter(Collision other)
153.     {
154.         if (other.gameObject.tag == "PlayerProjectile")
155.         {
156.             Instantiate(deathModel, transform.position, transform.rotation);
157.             Destroy(gameObject);
158.         }
159.     }
160.  
161.     void Fire()
162.     {
163.         Instantiate(projectile, firePoint.transform.position, transform.rotation);
164.     }
165. }
166.  

 

Looks like a potential path to a stack overflow. Lines 137 and 141 could call FreeRoam recursively.

 

I removed line 135 ~ 139, and unity still freezes. By the way, what does stack overflow means? I'm not really experienced in coding.

 

Basically, it means FreeRoam calls FreeRoam which calls FreeRoam which calls FreeRoam.....
Each time you call a function it gets put on the "stack" until it finishes; the stack has a limited (though very large) capacity, so if you call the same function within itself repeatedly, it overflows.

Calling a function from inside itself is called "recursion", and if you're not explicitly trying to use recursion for a specific reason (and know how to avoid situations like this), you should not really ever try to call a function from inside itself.

If you deleted 135 - 139, you still have the "else" at the end that will still call itself recursively.

 

The "stack" is where your program stores local variables. Also, when you call a function, it adds some information to the stack to remember where you were, so it can go back there once the other function finishes.

A "stack overflow" is when the stack runs out of space and your program can't continue because it doesn't have any more room for that stuff.

A stack overflow is usually the result of infinite recursion, where you keep calling new functions but not finishing them and so you have to keep adding more and more information onto the stack to keep track of where you need to go back to when you're done. (It can happen for other reasons, but this is the main one.)



When one of your scripts freezes Unity, that usually means you are stuck in some sort of infinite loop or infinite recursion so that your program never finishes what it's trying to do.

 

WOAH THANKS ! I changed that part to ...

Code (CSharp):

1.     void FreeRoam()
2.     {
3.         Debug.Log("FreeRoam");
4.         pointer.SetActive(false);
5.         freeRoam = true;
6.         randomDirection = Random.insideUnitSphere * roamRadius;
7.         randomDirection.y = 0;
8.         float checkDistance = Vector3.Distance(startPosition, randomDirection);
9.         float distance = Vector3.Distance(transform.position, randomDirection);
10.         Debug.Log(randomDirection);
11.         if (checkDistance <= roamRadius)
12.         {
13.             Debug.Log("Next destination is set");
14.             Vector3 currentPosition = transform.position;
15.             transform.LookAt(randomDirection);
16.             nextDestinationSet = true;
17.         }
18.         else
19.         {
20.             nextDestinationSet = false;
21.         }
22.     }

... and it worked ! Oh gosh I'm so happy. Thank you for all your support guys !