Fixed `Academy` children `Brain` gathering. (#63)

unity-environment/Assets/ML-Agents/Scripts/Academy.cs

 
 
     [HideInInspector]
-    private Brain[] brains = new Brain[0];
+    private List<Brain> brains = new List<Brain>();
 
 
 
             resetParameters[kv.key] = kv.value;
         }
 
-        brains = gameObject.GetComponentsInChildren<Brain>();
+        GetBrains(gameObject, brains);
         InitializeAcademy();
 
         foreach (Brain brain in brains)
     public virtual void InitializeAcademy()
     {
 
-
     }
 
 
             Application.targetFrameRate = inferenceConfiguration.targetFrameRate;
         }
     }
-
 
     /// Environment specific step logic.
     /**
 
     }
 
+    private static void GetBrains(GameObject gameObject, List<Brain> brains)
+    {
+        var transform = gameObject.transform;
+        
+        for (var i = 0; i < transform.childCount; i++)
+        {
+            var child = transform.GetChild(i);
+            var brain = child.GetComponent<Brain>();
+
+            if (brain != null)
+                brains.Add(brain);
+        }
+    }
 }