问题描述
我正在尝试使用 matplotlib 绘制不同大小的长方体,这样:旋转后,长方体不会以非物理方式在视觉上重叠,立方体具有不同的颜色并在它们周围绘制一个框.
我已经阅读了几篇引用类似问题的博客文章和 stackoverflow 页面,但总是略有不同;没有一个对我有用.克服重叠问题的最简单方法是使用体素(如
A.使用 Poly3DCollection
一个选项是创建一个长方体面的Poly3DCollection
.由于同一收藏的艺术家不存在重叠问题,因此这可能最适合这里的目的.
from mpl_toolkits.mplot3d 导入 Axes3D从 mpl_toolkits.mplot3d.art3d 导入 Poly3DCollection将 numpy 导入为 np导入 matplotlib.pyplot 作为 pltdef cuboid_data2(o, size=(1,1,1)):X = [[[0, 1, 0], [0, 0, 0], [1, 0, 0], [1, 1, 0]],[[0, 0, 0], [0, 0, 1], [1, 0, 1], [1, 0, 0]],[[1, 0, 1], [1, 0, 0], [1, 1, 0], [1, 1, 1]],[[0, 0, 1], [0, 0, 0], [0, 1, 0], [0, 1, 1]],[[0, 1, 0], [0, 1, 1], [1, 1, 1], [1, 1, 0]],[[0, 1, 1], [0, 0, 1], [1, 0, 1], [1, 1, 1]]]X = np.array(X).astype(float)对于范围内的 i (3):X[:,:,i] *= 大小[i]X += np.array(o)返回 Xdef plotCubeAt2(positions,sizes=None,colors=None, **kwargs):如果不是 isinstance(colors,(list,np.ndarray)):colors=[C0"]*len(positions)如果不是 isinstance(sizes,(list,np.ndarray)):sizes=[(1,1,1)]*len(positions)克 = []对于 zip 中的 p、s、c(位置、大小、颜色):g.append( cuboid_data2(p, size=s) )返回 Poly3DCollection(np.concatenate(g),facecolors=np.repeat(colors,6), **kwargs)位置 = [(-3,5,-2),(1,7,1)]尺寸 = [(4,5,3), (3,3,7)]颜色 = [深红色",柠檬绿"]fig = plt.figure()ax = fig.gca(projection='3d')ax.set_aspect('相等')pc = plotCubeAt2(位置,大小,颜色=颜色,边缘颜色=k")ax.add_collection3d(pc)ax.set_xlim([-4,6])ax.set_ylim([4,13])ax.set_zlim([-3,9])plt.show()
B.使用 plot_surface
采用
I'm trying to plot cuboids of different sizes using matplotlib, such that: after rotation the cuboids do not overlap visually in a non-physical way, the cubes have different colors and a box drawn around them.
I've read several blog posts and stackoverflow pages referencing similar problems, but always with a slight difference; none which have worked for me. The easiest way to overcome the overlapping problem was to use voxels (as in https://matplotlib.org/api/_as_gen/mpl_toolkits.mplot3d.axes3d.Axes3D.html?highlight=voxel#mpl_toolkits.mplot3d.axes3d.Axes3D.voxels), but these do not allow me to draw boxes around them. What's the easiest way to do this in matplotlib?
The image below shows what I have on the left, and what I want on the right.
EDIT:I've looked into several approaches that can give the desired effect, of which the main ones are:
- using voxels, but somehow scaling them such that a single voxel represents a single item.
- using surface plots, but then adjusting the drawing order dynamically to avoid non-physical overlapping.
The former seemed easier to execute, but I'm still stumped.
A. Using Poly3DCollection
An option is to create a Poly3DCollection
of the faces of the cuboids. As the overlapping issue is not present for artists of the same collection, this might best serve the purpose here.
from mpl_toolkits.mplot3d import Axes3D
from mpl_toolkits.mplot3d.art3d import Poly3DCollection
import numpy as np
import matplotlib.pyplot as plt
def cuboid_data2(o, size=(1,1,1)):
X = [[[0, 1, 0], [0, 0, 0], [1, 0, 0], [1, 1, 0]],
[[0, 0, 0], [0, 0, 1], [1, 0, 1], [1, 0, 0]],
[[1, 0, 1], [1, 0, 0], [1, 1, 0], [1, 1, 1]],
[[0, 0, 1], [0, 0, 0], [0, 1, 0], [0, 1, 1]],
[[0, 1, 0], [0, 1, 1], [1, 1, 1], [1, 1, 0]],
[[0, 1, 1], [0, 0, 1], [1, 0, 1], [1, 1, 1]]]
X = np.array(X).astype(float)
for i in range(3):
X[:,:,i] *= size[i]
X += np.array(o)
return X
def plotCubeAt2(positions,sizes=None,colors=None, **kwargs):
if not isinstance(colors,(list,np.ndarray)): colors=["C0"]*len(positions)
if not isinstance(sizes,(list,np.ndarray)): sizes=[(1,1,1)]*len(positions)
g = []
for p,s,c in zip(positions,sizes,colors):
g.append( cuboid_data2(p, size=s) )
return Poly3DCollection(np.concatenate(g),
facecolors=np.repeat(colors,6), **kwargs)
positions = [(-3,5,-2),(1,7,1)]
sizes = [(4,5,3), (3,3,7)]
colors = ["crimson","limegreen"]
fig = plt.figure()
ax = fig.gca(projection='3d')
ax.set_aspect('equal')
pc = plotCubeAt2(positions,sizes,colors=colors, edgecolor="k")
ax.add_collection3d(pc)
ax.set_xlim([-4,6])
ax.set_ylim([4,13])
ax.set_zlim([-3,9])
plt.show()
B. Using plot_surface
Adapting the solution from this question, which uses plot_surface
, and allow for different sizes as desired here seems to work just fine for most cases:
from mpl_toolkits.mplot3d import Axes3D
import numpy as np
import matplotlib.pyplot as plt
def cuboid_data(o, size=(1,1,1)):
# code taken from
# https://stackoverflow.com/a/35978146/4124317
# suppose axis direction: x: to left; y: to inside; z: to upper
# get the length, width, and height
l, w, h = size
x = [[o[0], o[0] + l, o[0] + l, o[0], o[0]],
[o[0], o[0] + l, o[0] + l, o[0], o[0]],
[o[0], o[0] + l, o[0] + l, o[0], o[0]],
[o[0], o[0] + l, o[0] + l, o[0], o[0]]]
y = [[o[1], o[1], o[1] + w, o[1] + w, o[1]],
[o[1], o[1], o[1] + w, o[1] + w, o[1]],
[o[1], o[1], o[1], o[1], o[1]],
[o[1] + w, o[1] + w, o[1] + w, o[1] + w, o[1] + w]]
z = [[o[2], o[2], o[2], o[2], o[2]],
[o[2] + h, o[2] + h, o[2] + h, o[2] + h, o[2] + h],
[o[2], o[2], o[2] + h, o[2] + h, o[2]],
[o[2], o[2], o[2] + h, o[2] + h, o[2]]]
return np.array(x), np.array(y), np.array(z)
def plotCubeAt(pos=(0,0,0), size=(1,1,1), ax=None,**kwargs):
# Plotting a cube element at position pos
if ax !=None:
X, Y, Z = cuboid_data( pos, size )
ax.plot_surface(X, Y, Z, rstride=1, cstride=1, **kwargs)
positions = [(-3,5,-2),(1,7,1)]
sizes = [(4,5,3), (3,3,7)]
colors = ["crimson","limegreen"]
fig = plt.figure()
ax = fig.gca(projection='3d')
ax.set_aspect('equal')
for p,s,c in zip(positions,sizes,colors):
plotCubeAt(pos=p, size=s, ax=ax, color=c)
plt.show()
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