Unity3d - 当玩家静止时炮塔停止射击

Question

I'm currently developing a 2D top down game and I have a problem with my Turret AI. Everything works perfectly except, when the player is stationary, the turret stops shooting. The bulletTimer stops increasing when player stops, instead of increasing over time. I'm guessing it has something to do with Time.deltaTime and frame refreshing but couldn't find a workaround. Do I need to write an attack function with IEnumerator and waitforseconds? It feels like it's a simple problem yet I'm unable to solve it. Thanks for the help. Here is my code :

TurretAI code

using UnityEngine;
using System.Collections;

public class TurretAI : MonoBehaviour 
{ 
     public float FireRate;
     public float bulletSpeed;
     public float bulletTimer;

     public GameObject Gun;
     public GameObject bullet;
     public Transform target;


     public void Attack()
     {    
         bulletTimer += Time.deltaTime;

         if (bulletTimer >= FireRate) 
         {
             Vector2 direction = target.transform.position - transform.position;
             direction.Normalize ();

             GameObject bulletClone;
             bulletClone = Instantiate (bullet, Gun.transform.position, Gun.transform.rotation) as GameObject;
             bulletClone.GetComponent<Rigidbody2D> ().velocity = direction * bulletSpeed;

             bulletTimer = 0;
         }
     }
 }

And this is the Turret Trigger code

using UnityEngine;
using System.Collections;

public class TurretTrigger : MonoBehaviour 
{ 
    public TurretAI turretAI;

    void Awake()
    { 
        turretAI = gameObject.GetComponentInParent<TurretAI> (); 
    }

     void OnTriggerStay2D(Collider2D Trigger)
     {
         if (Trigger.CompareTag ("Player")) 
         {
             turretAI.Attack ();
         }
     }
}

Answer 1

I think that your player's rigidBody2D is falling asleep when it's not moving (this is the engine optimizing performance, nothing that you have done). When rigidBody s sleep, the OnTriggerStay2D will stop detecting them. Calling rigidBody2D.WakeUp() on your player's rigidBody2D will force the rigidBody to wake up and be detected by the trigger box.

I can't find a more efficient way of making sure that the rigidBody stays awake just now. Try this to see if it what is causing your problem and then, if it is, try to find a more efficient way of stooping the ridgidBody sleeping!

Edit: Gunnar B has pointed out that this can be set in the inspector. Go to your player's RigidBody` component and set 'Sleeping Mode' to 'Never Sleep'.