三维图

matplotlib 中的三维绘图在历史上有点像 kludge，因为渲染引擎本质上是 2d。通过在另一个之后绘制一个 2d 块来渲染 3d 设置这一事实意味着通常存在与对象的表观深度相关的渲染问题 。问题的核心是两个未连接的对象可以完全在后面，或者完全在彼此的前面，这会导致伪像，如下图所示的两个互锁环（点击动画 gif）：

然而，这可以修复。只有在同一绘图上绘制多个曲面时才会出现这种假象 - 每个曲面都呈现为平面 2D 形状，其中一个参数决定了视距。你会注意到单个复杂的表面不会遇到同样的问题。

解决这个问题的方法是使用透明桥将绘图对象连接在一起：

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

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

X = np.arange(0, 6, 0.25)
Y = np.arange(0, 6, 0.25)
X, Y = np.meshgrid(X, Y)

Z1 = np.empty_like(X)
Z2 = np.empty_like(X)
C1 = np.empty_like(X, dtype=object)
C2 = np.empty_like(X, dtype=object)

for i in range(len(X)):
  for j in range(len(X[0])):
    z1 = 0.5*(erf((X[i,j]+Y[i,j]-4.5)*0.5)+1)
    z2 = 0.5*(erf((-X[i,j]-Y[i,j]+4.5)*0.5)+1)
    Z1[i,j] = z1
    Z2[i,j] = z2

    # If you want to grab a colour from a matplotlib cmap function, 
    # you need to give it a number between 0 and 1. z1 and z2 are 
    # already in this range, so it just works as is.
    C1[i,j] = plt.get_cmap("Oranges")(z1)
    C2[i,j] = plt.get_cmap("Blues")(z2)

# Create a transparent bridge region
X_bridge = np.vstack([X[-1,:],X[-1,:]])
Y_bridge = np.vstack([Y[-1,:],Y[-1,:]])
Z_bridge = np.vstack([Z1[-1,:],Z2[-1,:]])
color_bridge = np.empty_like(Z_bridge, dtype=object)

color_bridge.fill((1,1,1,0)) # RGBA colour, onlt the last component matters - it represents the alpha / opacity.

# Join the two surfaces flipping one of them (using also the bridge)
X_full = np.vstack([X, X_bridge, np.flipud(X)])
Y_full = np.vstack([Y, Y_bridge, np.flipud(Y)])
Z_full = np.vstack([Z1, Z_bridge, np.flipud(Z2)])
color_full = np.vstack([C1, color_bridge, np.flipud(C2)])

surf_full = ax.plot_surface(X_full, Y_full, Z_full, rstride=1, cstride=1,
                            facecolors=color_full, linewidth=0,
                            antialiased=False)

plt.show()