mplot3d更改默认（相反）着色

Question

我使用plot_surface创建了一个具有上下部分的三维锥形结构，参见下面的代码。在观察角度azim=90.时，底部圆锥体左侧较浅，右侧较暗。如果“光源”来自左侧，那么顶部圆锥体也会出现同样的情况。但是，上面的圆锥体有相反的阴影，所以对于我选择的其他视角，它仍然是如此。在

import matplotlib.pyplot as plt
import numpy as np

fig = plt.figure(figsize=(3,4));
ax = fig.add_subplot(111,projection='3d')

theta = np.linspace(0,2*np.pi,360)
r = np.linspace(0,1,100)
T, R = np.meshgrid(theta, r)

X = R * np.cos(T)
Y = R * np.sin(T)
Zup = np.sqrt(X**2 + Y**2)

ax.plot_surface(X, Y, Zup, rstride=1, cstride=1, linewidth=0, 
               antialiased=True,alpha=0.7,color='orange')
ax.plot_surface(X, Y, -Zup, rstride=1, cstride=1, linewidth=0, 
               antialiased=True,alpha=0.7,color='orange')

ax.set_axis_off()
ax.view_init(elev=4., azim=90.)
ax.dist=6

fig.tight_layout(pad=0.)

在一定的角度（例如，azim=45）两个锥体看起来是均匀的，但我希望它们有一些（一致的）照明。提前谢谢。在

Answer 1

有趣的是，我们必须将底部圆锥体参数改为X[::-1], Y[::-1], -Zup[::-1]以获得与顶部相同的着色效果。完整代码如下。在

import matplotlib.pyplot as plt
import numpy as np

fig = plt.figure(figsize=(2,2.6));
ax = fig.add_subplot(111,projection='3d')

theta = np.linspace(0,2*np.pi,360)
r = np.linspace(0,1,100)
T, R = np.meshgrid(theta, r)

X = R * np.cos(T)
Y = R * np.sin(T)
Zup = np.sqrt(X**2 + Y**2)

ax.plot_surface(X, Y, Zup, rstride=1, cstride=1, linewidth=0, 
antialiased=True,alpha=0.7,color='orange')
# fix here
# have to reverse the lists to get the same shading
ax.plot_surface(X[::-1], Y[::-1], -Zup[::-1], rstride=1, cstride=1, 
linewidth=0, antialiased=True,alpha=0.7,color='orange')

ax.set_axis_off()
ax.view_init(elev=4., azim=90.)
ax.dist=6

fig.tight_layout(pad=0.)