variant on mTesseracted's voxel script

fooneRotate.py

'''
=====================================
Rotating 3D voxel animation of PYTHON
=====================================

Demonstrates using ``ax.voxels`` with uneven coordinates
'''
import matplotlib.pyplot as plt
import numpy as np
from mpl_toolkits.mplot3d import Axes3D
import matplotlib.animation as manimation
from math import copysign



def explode(data):
		size = np.array(data.shape)*2
		data_e = np.zeros(size - 1, dtype=data.dtype)
		data_e[::2, ::2, ::2] = data
		return data_e

def voxel_face(corns, dm, nf):
		'''
		Grab the corner coordinates of one voxel face

		Parameters
		----------
		corns : np.indices array of corners for one voxel
		dm : (dimension), values can be  0(x), 1(y), 2(z)
		nf : (near/far face), values can be 0(near), 1(far)
		'''

		lc = corns.copy() #local copy so we don't swap original
		if dm == 1 : #swap y into x and correct ordering
				lc[0], lc[1] = corns[1].transpose(1,0,2), corns[0].transpose(1,0,2)
		if dm == 2 : #swap z into x and correct ordering
				lc[0], lc[2] = corns[2].transpose(2,1,0), corns[0].transpose(2,1,0)

		ret = np.zeros((3,2,2))
		xc1 = lc[0,nf,0,0] #hold x dim constant
		ret[0,:] = np.array([[xc1, xc1], [xc1, xc1]])
		yc1, yc2 = lc[1,0,0:2,0]
		ret[1,:] = np.array([[yc1, yc2], [yc1, yc2]])
		zc1, zc2 = lc[2,0,0,0:2]
		ret[2,:] = np.array([[zc1, zc1], [zc2, zc2]])

		if dm != 0 : #swap x back into desired dimension
				ret[0], ret[dm] = ret[dm].copy(), ret[0].copy()
		return ret

COLORS={
	'on':    '#FF55FF',
	'off':   '#55FFFF',
	'shade': '#000000',
	'bg':    '#000000'
}

plt.rcParams['axes.facecolor'] = COLORS['bg']

def create_face(voxels, side, facestr):
	if side == 'A':
		start=[0,0,4]
		for_x=[1,0,0]
		for_y=[0,0,-1]
	elif side == 'B':
		start=[-1,0,4]
		for_x=[0,1,0]
		for_y=[0,0,-1]
	elif side == 'C':
		start=[3,0,-1]
		for_x=[-1,0,0]
		for_y=[0,1,0]
	elif side == 'D':
		start=[0,3,4]
		for_x=[0,-1,0]
		for_y=[0,0,-1]
	elif side == 'E':
		start=[0,3,0]
		for_x=[0,-1,0]
		for_y=[1,0,0]
	elif side == 'F':
		start=[3,-1,4]
		for_x=[-1,0,0]
		for_y=[0,0,-1]
	x,y,z=start
	for out_y, line in enumerate(facestr.strip('\r\n').splitlines()):
			for out_x,char in enumerate(line.strip()):
				x=start[0]  + for_x[0]*out_x + for_y[0]*out_y
				y=start[1]  + for_x[1]*out_x + for_y[1]*out_y
				z=start[2]  + for_x[2]*out_x + for_y[2]*out_y
				#print out_x,out_y,x,y,z,char
				voxels[x,y,z] = (char == '#')



# build PYTHON letters
n_voxels = np.zeros((4, 4, 5), dtype=bool)
letters = [None]*6
letter_faces = np.zeros((6,2),dtype=int)

#First face

create_face(n_voxels,'A',"""
####
#___
###_
#___
#___
""")

letters[0] = np.array(np.where(n_voxels)).T
letter_faces[0] = [1, 0] #close y face
n_voxels[...] = False
#Y
create_face(n_voxels,'B',"""
____
_##_
#__#
#__#
_##_
""")

letters[1] = np.array(np.where(n_voxels)).T
letter_faces[1] = [0, 1] #far x face
n_voxels[...] = False
#T

create_face(n_voxels,'C',"""
_##_
#__#
#__#
_##_
""")


letters[2] = np.array(np.where(n_voxels)).T
letter_faces[2] = [2, 1] #far z face
n_voxels[...] = False
#H

create_face(n_voxels,'D',"""
____
##__
#_#_
#_#_
#_#_
""")

letters[3] = np.array(np.where(n_voxels)).T
letter_faces[3] = [0, 0] #close x face
n_voxels[...] = False
#O

create_face(n_voxels,'E',"""
_##_
#_#_
##__
_##_
""")

letters[4] = np.array(np.where(n_voxels)).T
letter_faces[4] = [2, 0] #close z face
n_voxels[...] = False
#N

create_face(n_voxels,'F',"""
____
____
____
____
____
""")

letters[5] = np.array(np.where(n_voxels)).T
letter_faces[5] = [1, 1] #far y face
n_voxels[...] = False

fcol = np.full(n_voxels.shape, COLORS['on'])
ecol = np.full(n_voxels.shape,  COLORS['shade'])
filled = np.ones(n_voxels.shape)

# upscale the above voxel image, leaving gaps
filled_2 = explode(filled)
fcolors_2 = explode(fcol)
ecolors_2 = explode(ecol)

# Shrink the gaps
corn = np.indices(np.array(filled_2.shape) + 1).astype(float) // 2
ccorn = 0.05 #close corner
fcorn = 1.0 - ccorn
corn[0,0::2, :, :] += ccorn
corn[1,:, 0::2, :] += ccorn
corn[2,:, :, 0::2] += ccorn
corn[0,1::2, :, :] += fcorn
corn[1,:, 1::2, :] += fcorn
corn[2,:, :, 1::2] += fcorn


fig = plt.figure(figsize=(2,2))
ax = fig.gca(projection='3d')
ax.axis("off")

#Plot the voxels
x, y, z = corn
ax.voxels(x, y, z, filled_2, facecolors=fcolors_2, edgecolors=ecolors_2)

#Plot the letter square faces
jj=0
for j in [x for x in letters if x is not None]:

		locf = np.empty((j.shape[0],3,2,2)) #local face

		ji = 0
		for i in j:
				i = i * 2 #skip empty voxels
				loc = corn[:,i[0]:i[0]+2,i[1]:i[1]+2,i[2]:i[2]+2] #local corners
				locf[ji] = voxel_face(loc, letter_faces[jj,0], letter_faces[jj,1])
				ax.plot_surface(locf[ji,0],locf[ji,1],locf[ji,2],color=COLORS['off'],
												shade=False)
				ji += 1

		jj += 1


#Views:        PY,  P, Y,  T,   H,   O,  N,  PY
view_elev = [  5,   0, 0, 90,   0, -90,  0,   5]
view_azim = [-60, -90, 0, 90, 180, 180, 90, -60]
#'''
FFMpegWriter = manimation.writers['ffmpeg']
metadata = dict(title='Movie Test', artist='Matplotlib',
								comment='Movie support!')
writer = FFMpegWriter(fps=15, metadata=metadata)

with writer.saving(fig, "pythonRot2.mp4", 100):

		for j in range(20):
				ax.view_init(view_elev[0], view_azim[0])
				plt.draw()
				writer.grab_frame()

		for i in range(1,len(view_elev)):

				de = (view_elev[i] - view_elev[i-1])
				da = (view_azim[i] - view_azim[i-1])

				if abs(da) >= 180 : #unecessary in this config
						da -= copysign(360, da)
				if abs(de) >= 180 :
						de -= copysign(360, de)

				if i != 1 :
						steps = 60
				else :
						steps = 10
				da = da / float(steps)
				de = de / float(steps)

				for j in range(10): #Pause on direct view of a letter
						ax.view_init(view_elev[i-1], view_azim[i-1])
						plt.draw()
						writer.grab_frame()
				for j in range(steps): #Rotate to next letter
						ax.view_init(view_elev[i-1] + j*de,
												 view_azim[i-1] + j*da)
						plt.draw()
						writer.grab_frame()
#'''