code: def on_draw(self, event):
      gloo.clear()
      self.program.draw("points")
  
file_path: vispy/examples/demo/gloo/cloud.py
imports: import numpy
  from vispy import gloo
  from vispy import app
  from vispy.util.transforms import perspective, translate, rotate
label_desc: Use image node_id 6 for calling the Canvas obj's underlying member method code with example usage: obj.on_draw(event) without return types