Detect Enemies in spherecast

[Fetdressing]

Hey! I am working on a towerdefence kind of game and I want my towers to be able to detect enemies at a certain range. It is working fine untill I build one more tower. The second tower just won’t shoot while the first tower is going on like normal.
Here is my code:

private var target;
private var posTarget : Vector3;
public var projectile : Rigidbody;
private var cloneProjectile;
public var projectileSpeed : float = 900;
public var skottEld : GameObject;
private var cloneSkottEld;
private var center : Vector3;



private var nextShot = 0.0;
var reloadTime = 0.5;




function Update () { //ändra så att det är function Update() ist

	if(Time.time > nextShot && target != null){
		nextShot = Time.time + reloadTime;
	
		
		
		//target = GameObject.FindGameObjectWithTag("Enemy");
		
		
		posTarget = Vector3(target.transform.position.x,target.transform.position.y,target.transform.position.z);
		this.transform.LookAt(posTarget);
		
		cloneProjectile = Instantiate(projectile, transform.position, transform.rotation);
		Destroy(cloneProjectile.gameObject, 6);
		cloneProjectile.rigidbody.AddForce(cloneProjectile.transform.forward * projectileSpeed);
		
		
		//cloneSkottEld = Instantiate(skottEld, transform.position, transform.rotation);
		//Destroy(cloneSkottEld, 3);
		
		
	}

		
}

function OnTriggerStay(hitTarget : Collider){

	if(hitTarget.gameObject.tag == "Enemy" && target == null){
		target = hitTarget.gameObject;
		
		
	}
}

I would really appreciate some help! Thanks in advance

[TonyLi]

Okay, so a summary of the issues were:

1. The sphere collider trigger was on the moving gun barrel (cylinder). As it tracked the enemy using LookAt(), the collider moved out of range of the target. To fix this, I believe you moved the sphere collider to an empty, stationary parent game object. Using Scene View helped you identify the issue because you could see the collider gizmos.

2. You were getting a null reference error when trying to get the Detector script on the parent game object. You fixed that by referencing the transform component like this:

   target = transform.root.GetComponent(Detector).target;

Note that transform.root will return the top-most game object in the hierarchy, which might not be the one you want. If you only want to go up one level to the parent, use transform.parent. Otherwise, say you were to group several towers together under a single game object, maybe if they represented a row or collection of towers that you want to keep together. Then transform.root would return this game object instead of the cylinder’s parent, and it wouldn’t find the Detector script.