如何绘制带有虚线轮廓且没有表面颜色的双锥体？
How to plot a double cone with dashed outline and no surface color?
我尝试了下面的脚本，但我不知道如何只画一个轮廓。
import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits import mplot3d
from matplotlib.tri import Triangulation
theta = np.linspace(0, 2*np.pi, 20)
rho = np.linspace(-2, 2, 20)
theta, rho = np.meshgrid(theta, rho)
x = np.ravel(rho*np.cos(theta))
y = np.ravel(rho*np.sin(theta))
z = np.ravel(rho)
fig, ax = plt.subplots()
plt.rcParams["figure.figsize"] = [10, 3]
ax = plt.axes(projection='3d')
tri = Triangulation(np.ravel(theta), np.ravel(rho))
ax.plot_trisurf(x, y, z, triangles=tri.triangles, antialiased=True)
plt.show()
所需的结果是一个带有轮廓的简单双锥体。像这样的东西，但只有黑线。
要绘制您指定的几何图形：- 2 个圆和 3 条线，您只需绘制它们中的每一个。我在下面给出的代码中提到了一些技巧。
import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits import mplot3d
nn = 400 #number of points along circle's perimeter
theta = np.linspace(0, 2*np.pi, nn)
rho = np.ones(nn)
# (x,y) represents points on circle's perimeter
x = np.ravel(rho*np.cos(theta))
y = np.ravel(rho*np.sin(theta))
fig, ax = plt.subplots()
plt.rcParams["figure.figsize"] = [10, 6]
ax = plt.axes(projection='3d') #set the axes for 3D plot
# low, high values of z for plotting 2 circles at different elev.
loz, hiz = -5, 5
ax.plot(x, y, hiz, color='red') #plot red circle
ax.plot(x, y, loz, color='blue') #plot blue circle
# set some indices to get proper (x,y) for line plotting
lo1,hi1 = 15, 15+nn//2
lo2,hi2 = lo1+nn//2-27, hi1-nn//2-27
# plot 3d lines using coordinates of selected points
ax.plot([x[lo1], x[hi1]], [y[lo1], y[hi1]], [loz, hiz], color='black') #black line
ax.plot([x[lo2], x[hi2]], [y[lo2], y[hi2]], [loz, hiz], color='green') #green line
m = nn//4
ax.plot([0, x[m]], [0, y[m]], [hiz, hiz], color='brown') #brown line
# must set proper viewing angles to get the plot as needed
ax.azim = 270.5 # y rotation (default=270)
ax.elev = 20 # x rotation (default=0)
ax.dist = 10 # zoom perspective
ax.axis("off") # hide frame
plt.show()
输出图：
我尝试了下面的脚本，但我不知道如何只画一个轮廓。
import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits import mplot3d
from matplotlib.tri import Triangulation
theta = np.linspace(0, 2*np.pi, 20)
rho = np.linspace(-2, 2, 20)
theta, rho = np.meshgrid(theta, rho)
x = np.ravel(rho*np.cos(theta))
y = np.ravel(rho*np.sin(theta))
z = np.ravel(rho)
fig, ax = plt.subplots()
plt.rcParams["figure.figsize"] = [10, 3]
ax = plt.axes(projection='3d')
tri = Triangulation(np.ravel(theta), np.ravel(rho))
ax.plot_trisurf(x, y, z, triangles=tri.triangles, antialiased=True)
plt.show()
所需的结果是一个带有轮廓的简单双锥体。像这样的东西，但只有黑线。
要绘制您指定的几何图形：- 2 个圆和 3 条线，您只需绘制它们中的每一个。我在下面给出的代码中提到了一些技巧。
import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits import mplot3d
nn = 400 #number of points along circle's perimeter
theta = np.linspace(0, 2*np.pi, nn)
rho = np.ones(nn)
# (x,y) represents points on circle's perimeter
x = np.ravel(rho*np.cos(theta))
y = np.ravel(rho*np.sin(theta))
fig, ax = plt.subplots()
plt.rcParams["figure.figsize"] = [10, 6]
ax = plt.axes(projection='3d') #set the axes for 3D plot
# low, high values of z for plotting 2 circles at different elev.
loz, hiz = -5, 5
ax.plot(x, y, hiz, color='red') #plot red circle
ax.plot(x, y, loz, color='blue') #plot blue circle
# set some indices to get proper (x,y) for line plotting
lo1,hi1 = 15, 15+nn//2
lo2,hi2 = lo1+nn//2-27, hi1-nn//2-27
# plot 3d lines using coordinates of selected points
ax.plot([x[lo1], x[hi1]], [y[lo1], y[hi1]], [loz, hiz], color='black') #black line
ax.plot([x[lo2], x[hi2]], [y[lo2], y[hi2]], [loz, hiz], color='green') #green line
m = nn//4
ax.plot([0, x[m]], [0, y[m]], [hiz, hiz], color='brown') #brown line
# must set proper viewing angles to get the plot as needed
ax.azim = 270.5 # y rotation (default=270)
ax.elev = 20 # x rotation (default=0)
ax.dist = 10 # zoom perspective
ax.axis("off") # hide frame
plt.show()
输出图：