How to draw triangels in 3D using matplotlib?

Question

Given a list looking like this:

triangels =  [

((1,1,1),(2,2,2),(1,3,4)),

((2,3,4),(9,9,9),(3,4,5)),

]

What is the fastest way to plot both triangles in 3D using pyplot? I do not find any way doing this, there is a 2D implementation.

Thank you!

This is not a duplicate since I asked how to convert the given list into triangles, I did not ask for a solution where the input is already manipulated.

Answer 1

Here is a solution that will give you exactly what you want:

from itertools import chain

import matplotlib.pyplot as plt

from mpl_toolkits.mplot3d import Axes3D

triangles =  [

    ((1, 1, 1), (2, 2, 2), (1, 3, 4)),

    ((2, 3, 4), (9, 9, 9), (3, 4, 5)),

]

# Convert the list of triangles into a "flat" list of points

tri_points = list(chain.from_iterable(triangles))

# Get the X, Y and Z coordinates of each point

x, y, z = zip(*tri_points)

# Make list of triangle indices ([(0, 1, 2), (3, 4, 5), ...])

tri_idx = [(3 * i, 3 * i + 1, 3 * i + 2) for i in range(len(triangles))]

# Make 3D axes

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

# Plot triangles

ax.plot_trisurf(x, y, z, triangles=tri_idx)

If you wish to learn more about Python visit this Python Tutorial.