title: Python matplotlib : plot3D with a color for 4D
body: <p>I am trying to make a 3D plot from x, y, z points list, and I want to plot color depending on the values of a fourth variable rho.</p>
  
  <p>Currently I have ; </p>
  
  <pre><code>fig = plt.figure()
  ax = fig.add_subplot(111, projection='3d')
  ax.plot3D(cell_x, cell_y, cell_z, linestyle='None', marker='o', markersize = 5, antialiased=True)
  ax.set_xlim3d(0.45, 0.55)
  ax.set_ylim3d(0.45, 0.55)
  ax.set_zlim3d(0.45, 0.55)
  </code></pre>
  
  <p>How to add cell_rho (my fourth array) as the color of my x, y, z points ? (for example for a jet colormap).</p>
  
  <p>Thank you very much.</p>
  
  <p>EDIT : I can't use scatter plots because for my 18000 points scatter plots are very slow compared to plot3d with markers only.</p>