void OnDisable()
{
if (handle != OpenVR.k_ulOverlayHandleInvalid)
{
var vr = SteamVR.instance;
if (vr != null && vr.overlay != null)
vr.overlay.DestroyOverlay(handle);
handle = OpenVR.k_ulOverlayHandleInvalid;
}
SteamVR_Overlay.instance = null;
}