private void OnJoystickAppears(int joystickID)
        {
            Debug.Log("new joystick connected:");

            if (nHumanoids > maxJoysticks)
            {
                return;
            }

            HumanoidControl humanoid = SpawnHumanoid();

            if (humanoid == null)
            {
                return;
            }

            humanoid.gameControllerEnabled = true;
            HumanoidControl.SetControllerID(humanoid, joystickID);

            spawnedHumanoids[joystickID]   = humanoid;
            joystickAssignment[joystickID] = joystickID;
            nHumanoids++;
        }