This is what @JohanC suggestion looks like. IMO, it looks much better than my attempt with Bezier curves. However, there appears to be a small problem with the RoundedPolygon
class, as there are sometimes small defects at the corners (e.g. between blue and purple in the image below).
编辑:我修复了 RoundedPolygon 类。
#!/usr/bin/env python
# coding: utf-8
"""
https://stackoverflow.com/questions/72061965/create-voronoi-art-with-rounded-region-edges
"""
import numpy as np
import matplotlib.pyplot as plt
from matplotlib import patches, path
from scipy.spatial import Voronoi, voronoi_plot_2d
def shrink(polygon, pad):
center = np.mean(polygon, axis=0)
resized = np.zeros_like(polygon)
for ii, point in enumerate(polygon):
vector = point - center
unit_vector = vector / np.linalg.norm(vector)
resized[ii] = point - pad * unit_vector
return resized
class RoundedPolygon(patches.PathPatch):
# https://stackoverflow.com/a/66279687/2912349
def __init__(self, xy, pad, **kwargs):
p = path.Path(*self.__round(xy=xy, pad=pad))
super().__init__(path=p, **kwargs)
def __round(self, xy, pad):
n = len(xy)
for i in range(0, n):
x0, x1, x2 = np.atleast_1d(xy[i - 1], xy[i], xy[(i + 1) % n])
d01, d12 = x1 - x0, x2 - x1
l01, l12 = np.linalg.norm(d01), np.linalg.norm(d12)
u01, u12 = d01 / l01, d12 / l12
x00 = x0 + min(pad, 0.5 * l01) * u01
x01 = x1 - min(pad, 0.5 * l01) * u01
x10 = x1 + min(pad, 0.5 * l12) * u12
x11 = x2 - min(pad, 0.5 * l12) * u12
if i == 0:
verts = [x00, x01, x1, x10]
else:
verts += [x01, x1, x10]
codes = [path.Path.MOVETO] + n*[path.Path.LINETO, path.Path.CURVE3, path.Path.CURVE3]
verts[0] = verts[-1]
return np.atleast_1d(verts, codes)
if __name__ == '__main__':
# make up data points
n = 100
max_x = 20
max_y = 10
points = np.c_[np.random.uniform(0, max_x, size=n),
np.random.uniform(0, max_y, size=n)]
# add 4 distant dummy points
points = np.append(points, [[2 * max_x, 2 * max_y],
[ -max_x, 2 * max_y],
[2 * max_x, -max_y],
[ -max_x, -max_y]], axis = 0)
# compute Voronoi tesselation
vor = Voronoi(points)
fig, ax = plt.subplots(figsize=(max_x, max_y))
for region in vor.regions:
if region and (not -1 in region):
polygon = np.array([vor.vertices[i] for i in region])
resized = shrink(polygon, 0.15)
ax.add_patch(RoundedPolygon(resized, 0.2, color=plt.cm.Reds(0.5 + 0.5*np.random.rand())))
ax.axis([0, max_x, 0, max_y])
ax.axis('off')
ax.set_facecolor('black')
ax.add_artist(ax.patch)
ax.patch.set_zorder(-1)
plt.show()