Why does this script spawn 13 ClickEffect prefabs instead of 1?

[Madswint]

private var targetPosition:Vector3;
var speed : float = 60;
var clickEffect : GameObject;

        function Update () {
 
            if(Input.GetKeyDown(KeyCode.Mouse0))
 
            {
 

           speed = 1;
 
                var playerPlane = new Plane(Vector3.up, transform.position);
 
                var ray = Camera.main.ScreenPointToRay (Input.mousePosition);
 
                var hitdist = 0.0;
 
               
 
                if (playerPlane.Raycast (ray, hitdist)) {
 
                    var targetPoint = ray.GetPoint(hitdist);
 
                    targetPosition = ray.GetPoint(hitdist);
 
                    var targetRotation = Quaternion.LookRotation(targetPoint - transform.position);
 
                    transform.rotation = targetRotation;
 
                   
 
                     
 
                }
 
             
 
            }
 
           
 
                var dir:Vector3 = targetPosition - transform.position;
 
    var dist:float = dir.magnitude;
 
    var move:float = speed * Time.deltaTime;
 
    if(dist > move){
 
    transform.position += dir.normalized * move;
    Instantiate(clickEffect,targetPosition,Quaternion.identity);
 
    } else {
 
    transform.position = targetPosition;
 
    }
 
           
 
           
 
            transform.position += (targetPosition - transform.position).normalized * speed * Time.deltaTime;
 
           
 
         
 
         
 
         
 
         }

Any ideas how to fix it? Thanks in advance.

[Fornoreason1000]

the problem
you’re instantiating for every frame that dist > move
try putting the code within.

  if(Input.GetKeyDown(KeyCode.Mouse0))     
{
//code goes here
}

that way it will only ever instantiate when you press the mouse button not for every frame that distance is more than move

private var targetPosition:Vector3; 
var speed : float = 60;      
var clickEffect : GameObject;
 
 
    function Update () {
 
            if(Input.GetKeyDown(KeyCode.Mouse0))
            {
				speed = 1;
                var playerPlane = new Plane(Vector3.up, transform.position);
                var ray = Camera.main.ScreenPointToRay (Input.mousePosition);
                var hitdist = 0.0;
 
                if (playerPlane.Raycast (ray, hitdist)) {
 
                    var targetPoint = ray.GetPoint(hitdist);
                    targetPosition = ray.GetPoint(hitdist);
                    var targetRotation = Quaternion.LookRotation(targetPoint - transform.position);
                    transform.rotation = targetRotation;
 
                }
				if(dist > move){
					Instantiate(clickEffect,targetPosition,Quaternion.identity);
				}

            }
 
 

    var dir:Vector3 = targetPosition - transform.position;
    var dist:float = dir.magnitude;
    var move:float = speed * Time.deltaTime;
 
    if(dist > move){
 
		transform.position += dir.normalized * move;
		//Instantiate(clickEffect,targetPosition,Quaternion.identity);
    } 
	else {
		transform.position = targetPosition;
    }
 
    transform.position += (targetPosition - transform.position).normalized * speed * Time.deltaTime;

     }

[Landern]

Input.GetKeyDown will return true each frame, meaning the duration of the mouse button held down might be 13+/- frames.

Input.GetMouseButtonDown will return true once and wait for the user to release the button and subsequently presses the button again.