71

I was unsuccessful browsing web for a solution for the following simple question:

How to draw 3D polygon (say a filled rectangle or triangle) using vertices values? I have tried many ideas but all failed, see:

from mpl_toolkits.mplot3d import Axes3D
from matplotlib.collections import PolyCollection
import matplotlib.pyplot as plt
fig = plt.figure()
ax = Axes3D(fig)
x = [0,1,1,0]
y = [0,0,1,1]
z = [0,1,0,1]
verts = [zip(x, y,z)]
ax.add_collection3d(PolyCollection(verts),zs=z)
plt.show()

I appreciate in advance any idea/comment.

Updates based on the accepted answer:

import mpl_toolkits.mplot3d as a3
import matplotlib.colors as colors
import pylab as pl
import numpy as np

ax = a3.Axes3D(pl.figure())
for i in range(10000):
    vtx = np.random.rand(3,3)
    tri = a3.art3d.Poly3DCollection([vtx])
    tri.set_color(colors.rgb2hex(np.random.rand(3)))
    tri.set_edgecolor('k')
    ax.add_collection3d(tri)
pl.show()

Here is the result: enter image description here

Yulia V
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Developer
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    How can this solution be updated for Python 3.5? This version gives me the error that `TypeError: object of type 'zip' has no len()` – jlt199 Jun 21 '17 at 17:47
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    @jlt199 Simply use `[list(zip(...))]` or if using numpy > 1.10 `[np.stack([X, Y, Z], axis=1)]` or `[np.stack([X, Y, Z], axis=1)]` – tupui Nov 21 '17 at 08:59

2 Answers2

71

I think you've almost got it. Is this what you want?

from mpl_toolkits.mplot3d import Axes3D
from mpl_toolkits.mplot3d.art3d import Poly3DCollection
import matplotlib.pyplot as plt
fig = plt.figure()
ax = Axes3D(fig, auto_add_to_figure=False)
fig.add_axes(ax)
x = [0,1,1,0]
y = [0,0,1,1]
z = [0,1,0,1]
verts = [list(zip(x,y,z))]
ax.add_collection3d(Poly3DCollection(verts))
plt.show()

alt text You might also be interested in art3d.pathpatch_2d_to_3d.

Khalil Al Hooti
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DSM
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    I sincerely thank you very much. That's exactly my answer. Actually, I need to simulate fracture planes in 3D. So it was the basic form. It should be easy then to me to work with thousands realistic coordinates. I thank you again for your great help. Fristal – Developer Jan 07 '11 at 11:43
  • How to make it not closed? – Dims Aug 22 '17 at 12:17
8

The above solution is for Python 2, and gives an error 'TypeError: object of type 'zip' has no len()' when run with python 3.

See Plotting 3D Polygons in Python 3 for discussion on updating this to Python 3.

Here's some working code from there:

from mpl_toolkits.mplot3d import Axes3D
from mpl_toolkits.mplot3d.art3d import Poly3DCollection
import matplotlib.pyplot as plt

fig = plt.figure()
ax = Axes3D(fig)
x = [0, 1, 1, 0]
y = [0, 0, 1, 1]
z = [0, 1, 0, 1]
verts = [list(zip(x, y, z))]
print(verts)
ax.add_collection3d(Poly3DCollection(verts), zs='z')
plt.show()
Alex Kritchevsky
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