Destroying an object after its out of sight !

Questions & Answers
1

I have a project which I load two road planes one after another to create endless road.I also have a script attached to camera which creates tree’s.All of the code works perfectly fine the tree’s are perfectly created but I want to destroy them after they are out of the camera’s sight.I tried to destroy them by using destroy(gameobject) but I destroy myself.

So can you help me in this guys ?

My code:

void generateSideTress( )
	{
		GameObject treeObj = GameObject.Instantiate( sideTres[ Random.Range(0,sideTres.Length-1 ) ] ) as GameObject;
		treeObj.transform.position = new Vector3( Random.Range(-80,-60 ) ,0 , playerObj.transform.position.z + 780  ) ;
		treeObj.transform.Rotate (0, Random.Range (0, 36) * 10, 0);
}

My code to destroy them I thought that maybe if I destroy them after a second it may work but it doesnt. (not works)

Destroy (treeObj, 1);
2

Check function OnBecomeInvisible. You can set it in your trees code with a Destroy call to themselves. Although as @HarshadK suggest, better use pooling.

3

Add this code to your Tree Object…

void Update ()
{
  Vector3 position=Camera.main.ScreenToWorldPoint(new Vector3(Screen.width,Screen.height,0f));
  if(transform.position.x > position.x)
  {
      Destroy(gameObject);
  }
}