RGB Mapping

Animation control:

Visualization	Frame Value
Surface geometry	sectioning parameter per frame
Surface position	fixed to the coordinate axis
Surface color	constant
Shading and highlighting	fixed to the coordinate axis
Axis coordinate	constant

import numpy as np
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation
import matplotlib.animation as animation
import s3dlib.surface as s3d

#.. RGB Color Space Animation

# 1. Define function to examine .....................................

def xyz2rgb(xyz) :
    # rgb color cube from -1 to 1
    x,y,z = xyz
    r = ( x + 1 ) /2.0
    g = ( y + 1 ) /2.0
    b = ( z + 1 ) /2.0  
    return r,g,b

def get_surface(Z1Z2) :
    z1, z2 = Z1Z2
    # z1 = f(1,1)    z2 = f(-1,-1)
    def topface(xyz, Z1, Z2) :
        x,y,z = xyz
        Z = ( Z2+Z1)/2.0 - (Z2-Z1)*(x+y)/4.0
        return x,y,Z
    def sideface(xyz, Z1, Z2, isX=True) :
        x,y,z = xyz
        Wmax = (Z2+Z1)/2
        Wmin = Z1
        X,Y = x,y
        if isX : 
            L,H,X = y, x, np.ones(len(x))
        else:
            L,H,Y = x,-y, np.ones(len(y))
        W = -(Wmax-Wmin)*L/2 + (Wmax+Wmin)/2
        Z = (W+1)*H/2 + (W-1)/2
        return X,Y,Z
    
    rez = 5
    ps = lambda : s3d.PlanarSurface(rez)
    top = ps().map_geom_from_op(lambda xyz : topface(xyz,z1,z2))
    front = ps().map_geom_from_op(lambda xyz : sideface(xyz,z1,z2))
    side = ps().map_geom_from_op(lambda xyz : sideface(xyz,z1,z2,False))
    surface = top+front+side
    surface.map_color_from_op( xyz2rgb )
    surface.shade(0.925, direction=[1,1,1])
    return surface

def get_frames(n) :
    negmin = -0.9999
    f2 = np.linspace(-1.0, 1.0, n)
    f1 = np.full(n,negmin)
    x = np.full(n,1.0)
    f2 = np.concatenate( ( f2, np.full(n,1.0) ) )
    f1 = np.concatenate( ( f1,np.linspace( negmin, 1.0, n) ) )
    f2 = np.concatenate( ( f2,np.linspace( 1.0, negmin, n) ) )
    f1 = np.concatenate( ( f1,np.linspace( 1.0, negmin, n) ) )
    return np.transpose([f1,f2])

# 2. Setup and map surfaces .........................................
framesize = 30
framearray = get_frames(framesize)

surface = get_surface( framearray[framesize] )

# 3. Construct figure, add surface, plot ............................

fig = plt.figure(figsize=plt.figaspect(1),facecolor='black')
ax = plt.axes(projection='3d')
ax.set(xlim=(-1,1), ylim=(-1,1), zlim=(-1,1) )
ax.set_facecolor('black')
ax.set_proj_type('ortho')
ax.set_axis_off()
ax.view_init(azim=25)

ax.add_collection3d(surface)

# 4. Animation ......................................................

def init_fig():
    return surface,

def update_fig(frame):
    global surface
    global framearray

    ax.collections.remove(surface)
    surface = get_surface( framearray[frame] )
    ax.add_collection3d(surface)

    return surface,

ani = FuncAnimation(fig, update_fig, frames = range(3*framesize),
                    init_func=init_fig, blit=False, repeat=True, interval=100)

print(">>>>>>>>>>>>>>> Animation completed, file save proceeds")
#ani.save('ZZZ.mp4')                                   # use for movie file.
ani.save(None,writer=animation.FFMpegFileWriter())    # use for temp files.
print(">>>>>>>>>>>>>>> Save completed, screen display proceeds")
#plt.show()
print(">>>>>>>>>>>>>>> process completed")