Problem with finding instantinated GameObject - object

Question

this is my first post here. I'm doing pong game in Unity, and i have problem finding instantinated gameobject ball, which i want to gets it's position to program AI controlling second Paddle. Here how it looks like:
GameController.cs:
public class GameController : MonoBehaviour
{
public GameObject ballPrefab;
public Text score1Text;
public Text score2Text;
public float scoreCoordinates = 3.4f;
private Ball2 currentBall;
private int score1 = 0;
private int score2 = 0;
// Start is called before the first frame update
void Start()
{
SpawnBall();
}
void SpawnBall()
{
GameObject ballInstance = Instantiate(ballPrefab, transform);
currentBall = ballInstance.GetComponent<Ball2>();
currentBall.transform.position = Vector3.zero;
score1Text.text = score1.ToString();
score2Text.text = score2.ToString();
}
// Update is called once per frame
void Update()
{
if (currentBall != null)
{
if (currentBall.transform.position.x > scoreCoordinates)
{
score1++;
Destroy(currentBall.gameObject);
SpawnBall();
}
if (currentBall.transform.position.x < -scoreCoordinates)
{
score2++;
Destroy(currentBall.gameObject);
SpawnBall();
}
}
}
}
AI.cs:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class AI : MonoBehaviour
{
private Rigidbody2D AIrig;
private Ball2 ball;
public float speed = 1f;
// Start is called before the first frame update
void Start()
{
ball = GetComponent<Ball2>();
AIrig = GetComponent<Rigidbody2D>();
}
// Update is called once per frame
void Update()
{
ball.transform.position = Vector3.zero;
if (ball.transform.position.y > AIrig.transform.position.y)
{
AIrig.velocity = new Vector2(0, speed);
}
else if (ball.transform.position.y > AIrig.transform.position.y)
{
AIrig.velocity = new Vector2(0, -speed);
}
}
}
Ball2.cs:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Ball2 : MonoBehaviour
{
public float minXspeed = 0.8f;
public float maxXspeed = 1.2f;
public float minYspeed = 0.8f;
public float maxYspeed = 1.2f;
private Rigidbody2D ballRigidbody;
// Start is called before the first frame update
void Start()
{
ballRigidbody = GetComponent<Rigidbody2D>();
ballRigidbody.velocity = new Vector2(Random.Range(minXspeed, maxXspeed) * (Random.value > 0.5f ? -1 : 1), Random.Range(minYspeed, maxYspeed) * (Random.value > 0.5f ? -1 : 1));
}
// Update is called once per frame
void Update()
{
}
private void OnTriggerEnter2D(Collider2D otherCollider)
{
if (otherCollider.tag == "Limit")
{
if (otherCollider.transform.position.y > transform.position.y && ballRigidbody.velocity.y > 0)
{
ballRigidbody.velocity = new Vector2(ballRigidbody.velocity.x, -ballRigidbody.velocity.y);
}
if (otherCollider.transform.position.y < transform.position.y && ballRigidbody.velocity.y < 0)
{
ballRigidbody.velocity = new Vector2(ballRigidbody.velocity.x, -ballRigidbody.velocity.y);
}
}
else if (otherCollider.tag == "Paddle")
{
if (otherCollider.transform.position.x < transform.position.x && ballRigidbody.velocity.x < 0)
{
ballRigidbody.velocity = new Vector2(-ballRigidbody.velocity.x, ballRigidbody.velocity.y);
}
if (otherCollider.transform.position.x > transform.position.x && ballRigidbody.velocity.x > 0)
{
ballRigidbody.velocity = new Vector2(-ballRigidbody.velocity.x, ballRigidbody.velocity.y);
}
}
}
}
I can't get refference to instantinated object (ball). If anyone could help me i will be grateful.

Answer 1

All right, i get it, here is the solution:
I've modified AI.cs, now it looks like:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class AI : MonoBehaviour
{
private Rigidbody2D AIrig;
public GameObject ball;
public float speed = 1f;
// Start is called before the first frame update
void Start()
{
AIrig = GetComponent<Rigidbody2D>();
}
// Update is called once per frame
void Update()
{
ball = GameObject.Find("Ball(Clone)");
if (ball.transform.position.y > AIrig.transform.position.y)
{
AIrig.velocity = new Vector2(0, speed);
}
else if (ball.transform.position.y < AIrig.transform.position.y)
{
AIrig.velocity = new Vector2(0, -speed);
}
}
}

Answer 2

I am not exactly clear where are those scripts attached.
So, I don't know if your getComponent will work.
GetComponent will work if you have scripts attached to the same object
Otherwise, you have can consider options like FindObjectOfType(), FindGameObjectsWithTag(string tag), GameObject.Find("object name") and more...
But I think the best way to do it, is if you want one object reference then store the instantiated ball to a public variable, and access it through it.
And if you are instantiating multiple objects, then store them in the public list in GameController. Then in the start function take the reference of the game controller and you will have access to those public variables.