text: import matplotlib.pyplot as plt
  import scipy.ndimage
  
  
  def plot_voxels(varray, ax, title):
      ax.view_init(20, 200)
      ax.voxels(varray, edgecolor="k")
      ax.set_title(title, fontsize=30)
  
  
  fig = plt.figure(figsize=(16, 9))
  
  for i in [1, 2, 3]:
      ax = fig.add_subplot(1, 3, i, projection="3d")
      arrray = scipy.ndimage.generate_binary_structure(3, i)
      plot_voxels(arrray, ax, title=f"rank=3 \n connectivity={i}")
  
  plt.tight_layout()
  plt.show()
  