/// <summary>
    /// Called when the virtual button has just been released:
    /// </summary>
    public void OnButtonReleased(VirtualButtonBehaviour vb)
    {
        Debug.Log("OnButtonReleased: " + vb.VirtualButtonName);

        SetVirtualButtonMaterial(m_VirtualButtonMaterial);

        switch (vb.VirtualButtonName)
        {
        case "wave":
            // Stop Astronaut waving animation
            GetComponentInChildren <Animator>().SetBool("IsWaving", true);
            break;

        case "scan":
            // Stop Drone scanning animation
            Drone drone = GetComponentInChildren <Drone>();
            drone.AnimEvt_StopScanning();
            break;

        case "oxygen":
            // Hide Oxygen Tank display
            GetComponentInChildren <Animator>().SetBool("IsDetailOn", false);
            break;

        case "fissure":
            // Revert Fissure color
            var fissureGradient = GetComponentInChildren <ParticleSystem>().colorOverLifetime;
            fissureGradient.enabled = false;
            break;
        }
    }