# 3D voxel / volumetric plot with rgb colorsΒΆ

Demonstrates using Axes3D.voxels to visualize parts of a color space.

import matplotlib.pyplot as plt
import numpy as np

# This import registers the 3D projection, but is otherwise unused.
from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import

def midpoints(x):
sl = ()
for i in range(x.ndim):
x = (x[sl + np.index_exp[:-1]] + x[sl + np.index_exp[1:]]) / 2.0
sl += np.index_exp[:]
return x

# prepare some coordinates, and attach rgb values to each
r, g, b = np.indices((17, 17, 17)) / 16.0
rc = midpoints(r)
gc = midpoints(g)
bc = midpoints(b)

# define a sphere about [0.5, 0.5, 0.5]
sphere = (rc - 0.5)**2 + (gc - 0.5)**2 + (bc - 0.5)**2 < 0.5**2

# combine the color components
colors = np.zeros(sphere.shape + (3,))
colors[..., 0] = rc
colors[..., 1] = gc
colors[..., 2] = bc

# and plot everything
fig = plt.figure()
ax = fig.gca(projection='3d')
ax.voxels(r, g, b, sphere,
facecolors=colors,
edgecolors=np.clip(2*colors - 0.5, 0, 1),  # brighter
linewidth=0.5)
ax.set(xlabel='r', ylabel='g', zlabel='b')

plt.show()


Total running time of the script: ( 0 minutes 1.091 seconds)

Keywords: matplotlib code example, codex, python plot, pyplot Gallery generated by Sphinx-Gallery