def METHOD_NAME(self, bkgClr=[0.9,0.9,0.9], ptSize=1.0):
    self.vis = o3d.visualization.Visualizer()
    self.vis.METHOD_NAME()
    opt = self.vis.get_render_option()
    opt.background_color = np.asarray(bkgClr)
    opt.point_size = ptSize