code: def on_mouse_move(event):
      if event.button == 1 and event.is_dragging:
          update_axis_visual()
  
file_path: vispy/examples/scene/volume_plane.py
imports: import sys
  import numpy
  from vispy import app, scene, io
  from vispy.visuals.transforms import STTransform
label_desc: Use image node_id 2 for calling a global function with example usage: on_mouse_move(event) without return types