private void TrackerVelocityChanged(object sender, TrackerVelocityChangeEventArgs e)
 {
     if (e.Sensor == HMDTrackerID)
     {
         _hmd.Velocity = ToXNA(e.Velocity);
         _hmd.Time     = e.Time;
     }
 }
 private void TrackerVelocityChanged(object sender, TrackerVelocityChangeEventArgs e)
 {
     if (e.Sensor == HMDTrackerID)
     {
         _hmd.Velocity = ToXNA(e.Velocity);
         _hmd.Time = e.Time;
     }
 }