Multidirectional LineCastAll

Hello all.

I am making a 2D top down game where the player can set off bombs that transmit a virus to all robots that it has line of sight to. I am trying to use LineCastAll but am not having much success. Thus far I have this. The LOSLayerMask does contain the objects I'm looking for as well as the walls that block line of sight.

Code (CSharp):

1.     private GameObject[] EnemyReferences;
2.     private RaycastHit2D[] hits;
3.      
4.     void Start () {
5.  
6.         EnemyReferences = GameObject.FindGameObjectsWithTag("EnemyRobot");                      
7.     }
8.      
9.     void FixedUpdate () {
10.  
11.         for (int i = 0; i < EnemyReferences.GetLength(0); i++)
12.         {
13.             hits = Physics2D.LinecastAll(transform.position, EnemyReferences[i].transform.position, LOSLayerMask);
14.             if (hits[i].collider.tag == "EnemyRobot")
15.             {
16.                 print ("Hit");
17.             }
18.         }

When this code activates I sometimes get the debug line printing Hit, but most of the time I get this.

IndexOutOfRangeException: Array index is out of range.
SmallLightExplosion.FixedUpdate () (at Assets/Explosions/SmallLightExplosion.cs:61)

I'm not sure what I'm doing wrong. Can anyone please offer advice on how to fix this?

Thank you.

 

Nobody knows how to fix this at all?

 

I'm going to assume that you're populating the EnemyReferences in Start() but some are being destroyed and the array is not being updated to reflect this?

 

At the moment I'm testing the above code without any of the enemies being destroyed. When the error happens there are the same number of enemies as there were when the scene started.

 

Oh, your problem is likely:

Code (csharp):

1. if (hits[i].collider.tag == "EnemyRobot")
2. {
3.     print ("Hit");
4. }

the variable i has no meaning to hits[]..

Change that to:

Code (csharp):

1. for(int hitIndex = 0; hitIndex < hits.Length; ++hitIndex)
2. {
3.     if (hits[hitIndex].collider.tag == "EnemyRobot")
4.     {
5.         print ("Hit");
6.     }
7. }

to give:

Code (CSharp):

1.  
2.     private GameObject[] EnemyReferences;
3.     private RaycastHit2D[] hits;
4.  
5.     void Start()
6.     {
7.         EnemyReferences = GameObject.FindGameObjectsWithTag("EnemyRobot");
8.     }
9.  
10.     void FixedUpdate()
11.     {
12.         for (int i = 0; i < EnemyReferences.GetLength(0); i++)
13.         {
14.             hits = Physics2D.LinecastAll(transform.position, EnemyReferences[i].transform.position, LOSLayerMask);
15.  
16.             for (int hitIndex = 0; hitIndex < hits.Length; ++hitIndex)
17.             {
18.                 if (hits[hitIndex].collider.tag == "EnemyRobot")
19.                 {
20.                     print("Hit");
21.                 }
22.             }
23.         }
24.     }
25.  
26.  

 

Excellent! Thank you very much for your help!