1

I have an automatic turret I would like to aim at specific enemies and prioritize shooting the closest enemy in its OverlapSphere. I got it to aim at the enemies just fine but it doesn’t seem to be picking them up in the Inspector. Did I get everything right in my script?

using UnityEngine;
using System.Collections;

public class Cannon : MonoBehaviour {
	
	private GameObject target;
    public float Range = 5;
    private Quaternion targetRotation;
	public bool Aiming = false;
	public Collider[] Targets;

	
	
	// Update is called once per frame
	void Start () {
		
		 target = GameObject.FindWithTag("Enemy");
    }
	
	Transform FindTargets(){
		Transform nearest = null;
		Collider[] Targets = Physics.OverlapSphere(transform.position, Range);
		foreach (Collider hit in Targets){
			if(hit && hit.tag == "Enemy"){
				float dist = Vector3.Distance(transform.position, hit.transform.position);
				if(dist < Range){
					Range = dist;
					nearest = hit.transform;
				}
			}
		}
		return nearest;
		
	}
 
    void Update(){
		
		if(Aiming){
    
       Vector3 look = target.transform.position - transform.position;
	   look.z = 0;
       targetRotation = Quaternion.LookRotation (look);
       transform.rotation = Quaternion.Slerp(transform.rotation, targetRotation, Time.deltaTime * 2.0f);
    
		Transform enemy = FindTargets ();
		if(enemy){
			Debug.Log("BANG");
		}
  }
	
	}
	
}
2

I see three problems with your code.

  1. You declare ‘public Collider Targets’ on line 10, then on line 22, you declare ‘Collider Targets’. The second one is local to FindTargets() and therefore overrides the one on line 10. This mean the one on line 10 is never accessed. That is why you don’t seen any values in the inspector. You need to remove the ‘Colider’ from the one on line 22 in order for the one on line 10 to be assigned.
  2. On line 27, you write, ‘Range = dist’. This code means that you are overwriting the value of ‘Range’ set in the inspector. The first time through the value gets dropped to the distance to the nearest object. After that, Physics.OverlapSphere() will only change if other objects are nearer the the nearest object. That is, it will not find targets that are within the original range but further than the last nearest target even if previous nearest target no longer exists or has moved out of range.
  3. In Update() you never assign the results of ‘FindTargets()’ to ‘targtet’, therefore the code never finds any target but the first one.

Here is a bit of a rewrite:

Transform FindTargets(){
	   float maxDist = Range;
   Transform nearest = null;
   Targets = Physics.OverlapSphere(transform.position, Range);
		Debug.Log (Targets.Length+","+Range);
   foreach (Collider hit in Targets){
     if(hit && hit.tag == "Enemy"){
      float dist = Vector3.Distance(transform.position, hit.transform.position);
      if(dist < maxDist){
          maxDist = dist;
          nearest = hit.transform;
      }
     }
   }
   return nearest;
}

Note when you rewrite Update(), make sure you assign null values returned by FindTargets() to be assigned to ‘target’. If you don’t, your gun will continue to track the last target even if it is out of range, and it will also attempt to track the last target even when all the enemies are destoryed. Of course if you allow null values for ‘target’, you will need to avoid accessing target when it is null.