title: Python 3D scatter/surf plot
body: <p>I have a 3D surf plot, where I plot a scatter cloud.
  You are then supposed to be able to see whether the scatter cloud is inside or outside the surface envelope. However, it's as if the scatter cloud is printed outside the surface plot depending on which angle I'm looking at?</p>
  
  <p>As I've tried to show on the figure below, the red dots are my scatter plots and even though I know they are inside the blue surface "barrel" I can see them through the surface plot. If I then rotate the picture a little bit, it shows as it's supposed to.</p>
  
  <p><a href="https://i.stack.imgur.com/LuaRU.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/LuaRU.jpg" alt="Wrong and correct"></a></p>
  
  <p>My plotting sequence looks like this:</p>
  
  <pre><code>fig = plt.figure()
      ax = fig.gca(projection='3d') 
      for ii in range(0,numspan):
          for j in range(0,numpoints+1):
              for i in range(0,4):
                  Nx[i,j,ii] = MMN_Diagram[Myplt[i]+j,Mzplt[i]+ii*3]
                  My[i,j,ii] = MMN_Diagram[Myplt[i]+j,Mzplt[i]+ii*3+1]*scale
                  Mz[i,j,ii] = MMN_Diagram[Myplt[i]+j,Mzplt[i]+ii*3+2]*scale
          surf = ax.plot_surface(My[:,:,ii], Mz[:,:,ii], Nx[:,:,ii], color='blue', rstride=1, cstride=1, linewidth=0.25, antialiased=True)
  
      plt.ylabel('MY [kNm]')
      plt.xlabel('MZ [kNm]')
  
      ax.plot([-10000,10000],[0,0],[0,0], color='black', linewidth=1.5) # X-axis
      ax.plot([0,0],[-10000,10000],[0,0], color='black', linewidth=1.5) # Y-axis
      ax.plot([0,0],[0,0],[-10000,10000], color='black', linewidth=1.5) # Z-axis
  
      ax.scatter(xl.iloc[:,2], xl.iloc[:,1], xl.iloc[:,0], color='red', s=1)
  
      plt.show(fig)
  </code></pre>