Matplotlib - Wrong overlapping when plotting two 3D surfaces on the same axes

Question

I am trying to plot two 3D surfaces on the same axes in matplotlib with the plot_surface command.

fig = plt.figure() fig.figsize = fig_size ax = fig.gca(projection='3d')  surf = ax.plot_surface(X, Y, Exp_Fric_map, alpha = 1, rstride=1, cstride=1, cmap=cm.winter, linewidth=0.5, antialiased=True) surf = ax.plot_surface(X, Y, Fric_map, alpha = 1, rstride=1, cstride=1, cmap=cm.autumn,linewidth=0.5, antialiased=True) 

The problem I have is that when viewing the plot, not always the correct surface is 'on top', for instance in the plot:

in the back corner (200N, 2.5Hz on the axes) the blue-green surface is 'on top' when actually the yellow-red is closer to the viewer. If I rotate the plot:

then things look ok now, the blue-green surface is underneath the yellow-red one at 200N and 2.5Hz (now on the left side). I have tried searching stackoverflow and Google but cannot find any similar problems with a solution.

I am using Python 2.7.3, Numpy 1.6.1 and Matplotlib 1.1.1rc on Linux.

Answer 1

This behavior is documented in matplotlib FAQ here. The same page suggests to install Mayavi which works OK with 3D plots.

• Its interface is quite similar to matplotlib.
• Its main problem is that it's still tricky to install it on python 3. (got much easier now)

---

Here's a demo "matplotlib vs mayavi" comparison:

# generate data import numpy as np  x = np.arange(-2, 2, 0.1) y = np.arange(-2, 2, 0.1) mx, my = np.meshgrid(x, y, indexing='ij') mz1 = np.abs(mx) + np.abs(my) mz2 = mx ** 2 + my ** 2  # A fix for "API 'QString' has already been set to version 1" # see https://github.com/enthought/pyface/issues/286#issuecomment-335436808 from sys import version_info if version_info[0] < 3:     import pyface.qt   def v1_matplotlib():     from matplotlib import pyplot as plt     from mpl_toolkits.mplot3d import Axes3D      fig = plt.figure()     ax = fig.gca(projection='3d')     surf1 = ax.plot_surface(mx, my, mz1, cmap='winter')     surf2 = ax.plot_surface(mx, my, mz2, cmap='autumn')     ax.view_init(azim=60, elev=16)     fig.show()   def v2_mayavi(transparency):     from mayavi import mlab     fig = mlab.figure()      ax_ranges = [-2, 2, -2, 2, 0, 8]     ax_scale = [1.0, 1.0, 0.4]     ax_extent = ax_ranges * np.repeat(ax_scale, 2)      surf3 = mlab.surf(mx, my, mz1, colormap='Blues')     surf4 = mlab.surf(mx, my, mz2, colormap='Oranges')      surf3.actor.actor.scale = ax_scale     surf4.actor.actor.scale = ax_scale     mlab.view(60, 74, 17, [-2.5, -4.6, -0.3])     mlab.outline(surf3, color=(.7, .7, .7), extent=ax_extent)     mlab.axes(surf3, color=(.7, .7, .7), extent=ax_extent,               ranges=ax_ranges,               xlabel='x', ylabel='y', zlabel='z')      if transparency:         surf3.actor.property.opacity = 0.5         surf4.actor.property.opacity = 0.5         fig.scene.renderer.use_depth_peeling = 1   v1_matplotlib() v2_mayavi(False) v2_mayavi(True)  # To install mayavi, the following currently works for me (Windows 10): # #   conda create --name mayavi_test_py2 python=2.7 matplotlib mayavi=4.4.0 #    (installs pyqt=4.10.4 mayavi=4.4.0 vtk=5.10.1) #    * the `use_depth_peeling=1` got no effect. Transparency is not correct. #    * requires `import pyface.qt` or similar workaround # # or # #   conda create --name mayavi_test_py3 python=3.6 matplotlib #   conda activate mayavi_test_py3 #   pip install mayavi