如何绘制轮廓虚线且没有表面颜色的双锥？

问题描述

我尝试了以下脚本，但是我不知道如何仅绘制轮廓。

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()

所需结果是带有轮廓的简单双锥。像这样，但只有黑线。

解决方法

要绘制您指定的几何图形：-2个圆和3条线，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,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]],color='green') #green line

m = nn//4
ax.plot([0,x[m]],[0,y[m]],[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：