```
 @Slot(bool)
    def showGrid(self, grid):
        print('show grid')
        if grid:
            self.machine_actor.DrawXGridlinesOn()
            self.machine_actor.DrawYGridlinesOn()
            self.machine_actor.DrawZGridlinesOn()
        else:
            self.machine_actor.DrawXGridlinesOff()
            self.machine_actor.DrawYGridlinesOff()
            self.machine_actor.DrawZGridlinesOff()
        self.update_render()