objects disappear before time

Question

I created a little pool in order to better manage my enemies, to which, an enemySpawner object calls to retrieve a clone and show it on screen

public class ObjectPool : MonoBehaviour
{
    public static ObjectPool current;
    public GameObject objectForPool;
    public int poolAmmount = 20;
    public bool growth = true;

    List<GameObject> objectsForPool;

    void Awake()
    {
        current = this;    
    }

    // Use this for initialization
    void Start ()
    {
        objectsForPool = new List<GameObject>();

        for (int i = 0; i < poolAmmount; i++)
        {
            GameObject obj = Instantiate(objectForPool);
            obj.SetActive(false);
            objectsForPool.Add(obj);
        }
    }

    public GameObject GetPooledObject()
    {
        for (int i = 0; i < objectsForPool.Count; i++)
        {
            if (!objectsForPool[i].activeInHierarchy)
            {
                return objectsForPool[i];
            }
        }
        if (growth)
        {
            GameObject obj = Instantiate(objectForPool);            
            objectsForPool.Add(obj);
            return obj;
        }
        return null;
    }

    // Update is called once per frame
    void Update ()
    {

    }
}

The call(EnemySpawner update)

void Update ()
{
    transform.position = new Vector3(transform.position.x + (speed * Time.deltaTime), 0, transform.position.z);
    if (transform.position.x <= boundary.xMin || transform.position.x >= boundary.xMax)
        speed *= -1;

    if (Time.time > nextSpawn)
    {
        nextSpawn = Time.time + spawnRate;

        GameObject clone = GetComponent<ObjectPool>().GetPooledObject();
        if (clone == null || clone.activeInHierarchy) return;
        clone.GetComponent<EnemyMovement>().SetPlayerShip(playerShip);
        clone.transform.position = transform.position;
        clone.transform.rotation = transform.rotation;
        clone.GetComponent<Health>().RestoreHealth();
        clone.SetActive(true);
    }
}

The problem here is, that my enemies are being deactivated on mid trajectory

https://youtu.be/ZGHC6wwGX1E

I know my issue is in my pooling, but I can't figure out what I'm doing wrong

Answer 1

Well, finally realized my mistake

I followed Unity tutorial on object pooling

https://unity3d.com/es/learn/tutorials/topics/scripting/object-pooling

And, event though it works wonders on bullets, not so much on enemies.

I'm pooling the enemies, just, trying to keep a good memory management from the begginning, and every object pooled had this killScript

public class KillBox : MonoBehaviour
{    

    void OnEnable() => Invoke("Destroy", 2f);

    void Destroy() => gameObject.SetActive(false);

    private void OnDisable() => CancelInvoke();

}

This is the only place the SetActive(false) is ever called, so your mention of looking for this piece of code made me realize that, this is invoked 2 seconds after the object is pooled and activated. Changing this from 2 to 10 made that the enemies never dissapeared... like, never, and I had a kill box to set them innactive when reached, but the killbox logic wasn't ther, so I just needed to adjust this

public class KillBox : MonoBehaviour
{
    void OnTriggerExit(Collider other)
    {
        switch (other.gameObject.name)
        {
            case "Bullet":
                Debug.Log("A bullet reached the killbox");
                other.gameObject.transform.parent.gameObject.SetActive(false);
                break;
            case "Enemy(Clone)":
                Debug.Log("An Enemy reached the killbox");
                other.gameObject.SetActive(false);
                break;
            default:
                Debug.Log($"{other.gameObject.name} reached the killbox");
                break;
        }
    }
}

This way, enemies are respawned whenever they are inactive, either by the killBox, or when hit by a bullet

Answer 2

I could not read all your post, but I think just call SetActive(false) is not good idea. PooledObject have to be return to pool for reusing.

I love this site. I also recommend to read this. If you don't have time, see ObjectPool, PooledObject class only:)