code: protected void propagateOnNoPick(GVRPicker picker)
      {
          if (mEventOptions.contains(EventOptions.SEND_PICK_EVENTS))
          {
              if (mEventOptions.contains(EventOptions.SEND_TO_LISTENERS))
              {
                  getGVRContext().getEventManager().sendEvent(this, IPickEvents.class, "onNoPick", picker);
              }
              if (mEventOptions.contains(EventOptions.SEND_TO_SCENE) && (mScene != null))
              {
                  getGVRContext().getEventManager().sendEvent(mScene, IPickEvents.class, "onNoPick", picker);
              }
          }
      }
docs: Propagate onNoPick events to listeners
  @param picker GVRPicker which generated the event