在 matplotlib 中为旋转的 3D 图形制作动画

Question

我设置了散点图并按照我想要的方式绘制，我想创建一个在空间中旋转的图形的 .mp4 视频，就好像我使用了plt.show() 并拖动视点一样。

This answer 几乎正是我想要的，除了保存电影，我必须手动调用带有图像文件夹的 FFMpeg。我宁愿使用 Matplotlib 内置的动画支持，而不是保存单个帧。代码转载如下：

from mpl_toolkits.mplot3d import Axes3D
ax = Axes3D(fig)
ax.scatter(xx,yy,zz, marker='o', s=20, c="goldenrod", alpha=0.6)
for ii in xrange(0,360,1):
    ax.view_init(elev=10., azim=ii)
    savefig("movie"%ii+".png")

Answer 1

如果你想了解更多关于 matplotlib 动画的信息，你真的应该关注 this tutorial。它详细解释了如何创建动画情节。

注意：创建动画情节需要安装ffmpeg 或mencoder。

这是他的第一个示例的一个版本，已更改为与您的散点图一起使用。

# First import everthing you need
import numpy as np
from matplotlib import pyplot as plt
from matplotlib import animation
from mpl_toolkits.mplot3d import Axes3D

# Create some random data, I took this piece from here:
# http://matplotlib.org/mpl_examples/mplot3d/scatter3d_demo.py
def randrange(n, vmin, vmax):
    return (vmax - vmin) * np.random.rand(n) + vmin
n = 100
xx = randrange(n, 23, 32)
yy = randrange(n, 0, 100)
zz = randrange(n, -50, -25)

# Create a figure and a 3D Axes
fig = plt.figure()
ax = Axes3D(fig)

# Create an init function and the animate functions.
# Both are explained in the tutorial. Since we are changing
# the the elevation and azimuth and no objects are really
# changed on the plot we don't have to return anything from
# the init and animate function. (return value is explained
# in the tutorial.
def init():
    ax.scatter(xx, yy, zz, marker='o', s=20, c="goldenrod", alpha=0.6)
    return fig,

def animate(i):
    ax.view_init(elev=10., azim=i)
    return fig,

# Animate
anim = animation.FuncAnimation(fig, animate, init_func=init,
                               frames=360, interval=20, blit=True)
# Save
anim.save('basic_animation.mp4', fps=30, extra_args=['-vcodec', 'libx264'])

Answer 2

当我偶然发现这个时，我正在研究用 matplotlib 为我的情节制作动画： http://zulko.wordpress.com/2012/09/29/animate-your-3d-plots-with-pythons-matplotlib/

它提供了简单的功能来围绕绘图制作动画并以多种格式输出。

Answer 3

这有点小技巧，但如果您使用的是 Jupyter 笔记本，您可以使用单元魔法直接从笔记本本身运行命令行版本的 ffmpeg。在一个单元格中运行您的脚本以生成原始帧

from mpl_toolkits.mplot3d import Axes3D
ax = Axes3D(fig)
ax.scatter(xx,yy,zz, marker='o', s=20, c="goldenrod", alpha=0.6)
for ii in xrange(0,360,1):
    ax.view_init(elev=10., azim=ii)
    savefig("movie%d.png" % ii)

现在，在一个新的笔记本单元格中，输入以下内容，然后运行该单元格

%%bash 
ffmpeg -r 30 -i movie%d.png -c:v libx264 -vf fps=25 -pix_fmt yuv420p out.mp4

Answer 4

Viktor Kerkez 提供的解决方案对我不起作用（matplotlib 版本 3.4.2）。我收到与user3015729 报告的相同错误。下面是一个修改后的版本，它产生相同的结果，但适用于 matplotlib 3.4.2。

# First import everthing you need
import numpy as np
from matplotlib import pyplot as plt
from matplotlib import animation
from mpl_toolkits.mplot3d import Axes3D

# Create some random data, I took this piece from here:
# http://matplotlib.org/mpl_examples/mplot3d/scatter3d_demo.py


def randrange(n, vmin, vmax):
    return (vmax - vmin) * np.random.rand(n) + vmin


n = 100
xx = randrange(n, 23, 32)
yy = randrange(n, 0, 100)
zz = randrange(n, -50, -25)

# Create a figure and a 3D Axes
fig = plt.figure()
ax = Axes3D(fig)
scat = ax.scatter(xx, yy, zz, marker='o', s=20, c="goldenrod", alpha=0.6)

# Create an init function and the animate functions.
# Both are explained in the tutorial. Since we are changing
# the the elevation and azimuth and no objects are really
# changed on the plot we don't have to return anything from
# the init and animate function. (return value is explained
# in the tutorial.


def init():
    ax.view_init(elev=10., azim=0)
    return [scat]


def animate(i):
    ax.view_init(elev=10., azim=i)
    return [scat]


# Animate
anim = animation.FuncAnimation(fig, animate, init_func=init,
                               frames=360, interval=20, blit=True)
# Save
anim.save('basic_animation.mp4', fps=30, extra_args=['-vcodec', 'libx264'])