# Animate the midpoints of a 3d "Rhombic dodecahedron"

I need help in animating a Rhombic dodecahedron. I want to enlarge and to shrink the midpoints (center points) with FuncAnimation from Matplotlib. I wanted to use the δ for this (make smaller/bigger) and for this an animation. But just don’t know how. I successfully created a 3d Rhombic dodecahedron but now I’m stuck… .

This is the code:

``````%matplotlib notebook
fig = plt.figure()
ax = Axes3D(fig)
δ = symbols('δ')
δ = 0.3

points = [
(0.5, 0.5, 0.5),
(0.5, 0.5, -0.5),
(0.5, -0.5, 0.5),
(0.5, -0.5, -0.5),
(-0.5, 0.5, 0.5),
(-0.5, 0.5, -0.5),
(-0.5, -0.5, 0.5),
(-0.5, -0.5, -0.5),
(0, 0,(0.5 + δ)),
(0, 0, -(0.5 + δ)),
(0,(0.5 + δ), 0),
(0, -(0.5 + δ), 0),
((0.5 + δ), 0, 0),
(-(0.5 + δ), 0, 0)
]

surfaces = [
[points[0], points[1], points[12]], #front
[points[1], points[3], points[12]],
[points[3], points[2], points[12]],
[points[2], points[0], points[12]],

[points[6], points[4], points[13]], #behind
[points[4], points[5], points[13]],
[points[5], points[7], points[13]],
[points[7], points[6], points[13]],

[points[6], points[4], points[8]], #top
[points[4], points[0], points[8]],
[points[0], points[2], points[8]],
[points[2], points[6], points[8]],

[points[3], points[1], points[9]], #below
[points[1], points[5], points[9]],
[points[5], points[7], points[9]],
[points[7], points[3], points[9]],

[points[0], points[4], points[10]], #right
[points[4], points[5], points[10]],
[points[5], points[1], points[10]],
[points[1], points[0], points[10]],

[points[2], points[6], points[11]], #left
[points[6], points[7], points[11]],
[points[7], points[3], points[11]],
[points[3], points[2], points[11]]
]

ax.set_xlim3d(-1,1)
ax.set_ylim3d(-1,1)
ax.set_zlim3d(-1,1)

ax.add_collection3d(Poly3DCollection(surfaces, edgecolors = "k"))

fig.show()
``````

I tried to animate it with older code which I used to animate a 2d graph but I couldn’t really figure it out because I’m new to this stuff.

This is the old 2d animation code for the graph which I tried to reuse with some adjustments:

``````fig, ax = plt.subplots()
xdata, ydata = [], []
ln, = plt.plot([], [], '-')

xdata = np.linspace(1, 5, 2000)

def afunc(frame):
result = []
for i in xdata:
result.append(np.sin(3*i+frame))
return result

def init():
ax.set_xlim(1, 5)
ax.set_ylim(-1, 1)
ax.spines['left'].set_position('center')
ax.spines['bottom'].set_position('center')
ax.spines['right'].set_color('none')
ax.spines['top'].set_color('none')
return ln

def update(frame):
ydata = afunc(frame)
ln.set_data(xdata, ydata)
return ln

step = 100
frames = np.arange(0, 1001, step)

ani = FuncAnimation(fig, update, frames,init_func=init, interval=30)

plt.show()
``````

The imports are:

``````from mpmath import *
from sympy import *
from sympy.interactive import printing
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.animation import FuncAnimation
from sympy.plotting import plot3d
from mpl_toolkits.mplot3d import Axes3D
from mpl_toolkits.mplot3d.art3d import Poly3DCollection
``````

Could someone help with code examples/working 3d animations for the midpoints of the 3d “Rhombic dodecahedron”? I’m stuck for some hours now… .

(I tried to reuse the old code for a 2d graph animation, then I tried some adjustments to it to make it 3d and fitting for the “Rhombic dodecahedron” but I couldn’t really get it to work at all. English is not my native language and I’m beginner with python so it would be nice if you could be considerate about it.)

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