Why do I instantiate too many prefabs?

Questions & Answers
1

Hi, I have this initial block spawning script for a tetris clone.

When a new block instantiates after the very first, several blocks instantiate on top of each other at once.

Can anybody see an explanation in my script?

//Spawn.js

var Tetriminos : GameObject[];


function Start () {
	
		Create();

}


function Create (){
		Instantiate(Tetriminos[Random.Range(0,Tetriminos.Length)], transform.position, transform.rotation);
}

//NewBlockScript.js

var FallingRate : float = 0.5;

function Start () {
Falling();

}

function Falling(){
while(true){
	this.transform.position.y += -FallingRate;
	yield WaitForSeconds(0.2);
	}
}
function OnTriggerEnter (other : Collider) {
	if (other.gameObject.CompareTag ("Blue")) {
		var go = GameObject.Find("Spawner");
		go.GetComponent(Spawn).Create();
		Destroy(this);
}
}
2

var go = GameObject.Find(“Spawner”);
go.GetComponent(Spawn).Create();

that line is causing the extra instantiations, do a Debug.Log line so you can see when and how that create line is triggered. i think its colliding many times.

it is possible to make recursive instantiations so each instantiat object creates i.e. 2 more inside itself and so on.

3

I suspect its entering several triggers at once, firing multiple calls to Create();
I would suggest having a boolean to determine if the block has “landed” checked after each “falling” call, with the OnTriggerEnter function changing the bool to true if it fires.

For example:

    var Tetriminos : GameObject[];
    var landed : bool;
     
    function Start () {     
    Create();     
    }  
     
    function Create (){
    Instantiate(Tetriminos[Random.Range(0,Tetriminos.Length)], transform.position, transform.rotation);
    }
     
    //NewBlockScript.js
     
    var FallingRate : float = 0.5;
     
    function Start () {
    Falling();     
    }
    
    
     
    function Falling()
    {
    while(true){
    this.transform.position.y += -FallingRate;
    if(landed)
    {
    var go = GameObject.Find("Spawner");
    go.GetComponent(Spawn).Create();
    Destroy(this);
    }
    yield WaitForSeconds(0.2);
    }
    }
    function OnTriggerEnter (other : Collider) {
    if (other.gameObject.CompareTag ("Blue")) {
    landed = true;
    }
    }
4

make sure your clone object itself didn’t have a clone object attached.