Problem with Coroutine

Hi guys! (and girls!)
I want to wait in my code at some point, it's a zombie spawner, and i want it to spawn a zombie every 3 second (for example). Here's the code:

Code (CSharp):

1. public class SpawnZombie : MonoBehaviour
2. {
3.     public Transform player;
4.     public int NumberOfZombies;
5.     public GameObject Zombie;
6.  
7.     private int range;
8.     // Use this for initialization
9.     void Start ()
10.     {
11.         range = 50;
12.     }
13.    
14.     // Update is called once per frame
15.     void Update ()
16.     {
17.         while (Vector3.Distance(transform.position, player.position) < range && NumberOfZombies > 0)
18.         {
19.             StartCoroutine(SpawnZombies());
20.         }
21.     }
22.  
23.     IEnumerator SpawnZombies()
24.     {
25.         GameObject instanceZombie = Instantiate(Zombie, transform.position, Quaternion.identity) as GameObject;
26.         instanceZombie.GetComponent<Zombie>().player = player;
27.         NumberOfZombies -= 1;
28.         yield return new WaitForSeconds(3.0f);
29.     }
30. }
31.  

I've read again and again the documentation, but i can't find my mistake, the script keep making all the zombies spawn at the same time.

Thanks for your help!

 

Hi there,

I can't really offer any advice as to why that isn't working, unfortunately, I'm not massively familiar with coroutines (even though I should be by now!). Though there's a good Unity tutorial explaining how to do a spawner via a script that doesn't use a coroutine, but instead just uses InvokeRepeating. It's here, if you're interested. If that's not what you're after, then I hope you find your answer!

 

You are calling the Coroutine every Update (when condition is met). so basically starting many coroutines. AND you are running a while loop in Update which is really scary.

You need a boolean to see if the coroutine is not running before calling it again in Update.(and fix the while in Update, as Update already runs once per frame) :

Code (csharp):

1.  
2. private bool isSpawning = false;
3.  
4. .... all your other code
5.  
6. void Update ()
7. {
8.    if ( isSpawning == false ) // check if spawning
9.    {
10.      if (Vector3.Distance(transform.position, player.position) < range && NumberOfZombies > 0) // check distance
11.      {
12.        StartCoroutine(SpawnZombies());
13.      }
14.    }
15. }
16.  
17. IEnumerator SpawnZombies()
18. {
19.    isSpawning = true; // NOW SPAWNING
20.    GameObject instanceZombie = Instantiate(Zombie, transform.position, Quaternion.identity) as GameObject;
21.    instanceZombie.GetComponent<Zombie>().player = player;
22.    NumberOfZombies -= 1;
23.    yield return new WaitForSeconds(3.0f);
24.    isSpawning = false; // ok, spawning delay has ffinished
25. }

 

Ok thank you alucard, indeed it was stupid ^^ i will try when i get home, thanks for the help