2D线未与3D图上的表面清晰显示

Question

I am trying to plot a 1D line along with a 2D surface in matplotlib with Axes3D:

from mpl_toolkits.mplot3d import Axes3D
import numpy as np
import matplotlib.pyplot as plt


x = np.arange(-1., 1.1, 0.1)
y = x.copy()
X, Y = np.meshgrid(x, y)
Z = np.abs(X) + np.abs(Y)

plt.close('all')
fig = plt.figure()
ax = fig.gca(projection='3d')

ax.plot(np.zeros_like(y), y, 1, color='k')
ax.plot(x, np.zeros_like(x), 1, color='k')

surf = ax.plot_surface(X, Y, Z, color='w')

plt.show(block=False)

but the 2D plot somehow hides the lines:

If I comment the surf = plot_surface(...) code line, the 1D lines show correctly:

How can I have the lines showing correctly along with the surface?

Answer 1

Axes3D.plot_surface() apparently accepts a transparency ( alpha ) argument, which actually gets forwarded to a base class, Poly3DCollection.

And of course the line plot() calls accept a linewidth argument.

So if you render the line plots with thicker lines and you render the surface with some transparency, you should be able to find a combination of settings which let you see both the lines and the surface in a balanced way.

https://matplotlib.org/tutorials/toolkits/mplot3d.html#mpl_toolkits.mplot3d.Axes3D.plot_surface

https://matplotlib.org/api/_as_gen/mpl_toolkits.mplot3d.art3d.Poly3DCollection.html#mpl_toolkits.mplot3d.art3d.Poly3DCollection

Answer 2

You can also achieve this by using the zorder in the plot_surface and plot commands to make the lines sit on top of the surface. Eg

from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
import numpy as np

x = np.arange(-1., 1.1, 0.1)
y = x.copy()
X, Y = np.meshgrid(x, y)
Z = np.abs(X) + np.abs(Y)

plt.close('all')
fig = plt.figure()
ax = fig.gca(projection='3d')

surf = ax.plot_surface(X, Y, Z, color='w', zorder=1)

ax.plot(np.zeros_like(y), y, 1, color='k', zorder=10)
ax.plot(x, np.zeros_like(x), 1, color='k', zorder=11)


plt.show(block=False)