Unity - How to respawn a Gameobject after destroy

Question

I'm Using unity for developing my game. I've created a simple game just like football after scoring a goal the ball should be destroyed and then reappear at its original place.

I've attached this script to my goal object.

public GameObject ball;
Vector3 ballPosition = new Vector3 (4.51f,0.10f,-3.78f);

void OnTriggerEnter(Collider other)  
    {

        StartCoroutine ("RespwanBall");

    }

IEnumerator RespwanBall() {

    GameObject clone = (GameObject)Instantiate (ball, ballPosition, Quaternion.identity) as GameObject;

    Destroy (ball.gameObject);

    yield return null;

}

But it works only for the first time. and then After second destroy it gives an error saying that the object is already deleted and you are trying to access a deleted object or something like that. And if I use the destroy function in the OntriggerEnter function it gives the same error during the first collision.

How can I do it? Please Help.

ThankYou.

Lots of things wrong with this... 1. `ball.GameObject` should just be `ball` 2. You're casting the result from `Instantiate` twice 3. There's no reason for `RespwanBall` to be a coroutine 4. You never set `ball` to `clone` 5. You mispelled 'Respawn' :) — BlueRaja - Danny Pflughoeft, Feb 01 '14 at 23:48
@BlueRaja-DannyPflughoeft Thanx a lot for pointing out all those mistakes. I really should work on it. Thanx a lot. — Ashish Beuwria, Feb 02 '14 at 10:29
@BlueRaja-DannyPflughoeft Can you pls elaborate the correction for the 4th step. ThankYou — Ashish Beuwria, Feb 02 '14 at 14:44

score 2 · Accepted Answer · edited May 23 '17 at 10:30

2

You are trying to access the deleted object because you attached the script to the goal and you are always deleting the ball, and your clone never becomes the ball (so it's always the same ball).

Your script would work if it was attached to the ball, because in this case the ball would be itself, therefore the destruction method would always be activated in the active ball.

If you want to attach it to the goal, make sure to update your clone to be the active ball:

IEnumerator RespwanBall() {
    Destroy (ball.gameObject);
    ball = (GameObject)Instantiate (ball, ballPosition, Quaternion.identity);
    yield return null;
}

Also, BlueRaja's comments are important things that you could use to improve your code:

ball.GameObject could just be ball, since ball is a GameObject;
You're casting the result from Instantiate twice, check this question to know more about it;
At least with this piece of code, there's no reason for RespwanBall to be a coroutine;
You mispelled 'Respawn'.

edited May 23 '17 at 10:30

Community

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answered Feb 01 '14 at 23:22

Roberto

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@BlueRaja thanks for editing, I just copied his code and didn't notice! – Roberto Feb 02 '14 at 00:09
I have tried your code with the corrections suggested by BlueRaja. And now its not even destroying the object. – Ashish Beuwria Feb 02 '14 at 10:44
Sorry for the earlier comment. I have tried your code and now its giving me the same error after first respawn. Attached it to the goal object. – Ashish Beuwria Feb 02 '14 at 10:52
It worked when I attached it to the ball. Thanks, but still curious to know the methods if it is attached to the goal. – Ashish Beuwria Feb 02 '14 at 13:02
@AshishBeuwria If you want to attach it to the goal, make sure to update your clone to be the active ball, by doing ball = (GameObject) Instantiate... – Roberto Feb 02 '14 at 19:57
Where should i do it? In the onTriggerEnter() or Update() – Ashish Beuwria Feb 02 '14 at 20:43
Thats creating two instances of ball. One is ball(clone) and other is ball(clone)(clone) – Ashish Beuwria Feb 03 '14 at 10:23
let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/46666/discussion-between-ashish-beuwria-and-roberto) – Ashish Beuwria Feb 03 '14 at 10:33

score 0 · Answer 2 · answered Jun 18 '18 at 08:53

You can try respawning the object by using this script -




using UnityEngine;
using System.Collections;

public class copy : MonoBehaviour
{




     [SerializeField]
    private GameObject prefab = null; // assign Cube prefab to this in Editor
    void Start()
    {
        // no need for a local prefab variable, nor a call to Resources.Load();
        for (int i = 0; i < 4; ++i)
        {
            Instantiate(prefab, new Vector3(0, i * 10, 0), Quaternion.identity); // you can directly assign position in Instantiate
        }
    }

}

Unity - How to respawn a Gameobject after destroy

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