private void Update()
 {
     if (npcController == null)
     {
         healthText.text   = "0";
         stateText.text    = "dead";
         stateText.color   = Color.red;
         positionText.text = "";
     }
     else
     {
         healthText.text   = npcController.GetHealth().ToString();
         stateText.text    = npcController.GetStateString();
         positionText.text = "x: " + (int)npcController.transform.position.x + ", y: " +
                             (int)npcController.transform.position.y;
     }
 }