Inner/Outer Surface Colormap 2

This example demonstrates the use of:

1. a binary colormap which has non-uniform colors within each binary section.
2. an optimal basetype, appropriate for the geometric mapping function. In this case, a split spherical grid basetype is used with rectangular faces that doesn’t have vertices at the poles.

import numpy as np
from matplotlib import pyplot as plt
import s3dlib.surface as s3d
import s3dlib.cmap_utilities as cmu

#.. Gradient Binary colormap used to visualize the inner/outer surfaces.

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

def shell_shape(rtp) :
    r,t,p = rtp
    N, Rmin, Zst, sqeez = 4, 0.25, 1.25, 0.65
    T = N*t
    zeta = np.power(Rmin,1/(1-N))
    n = (N/(1-N))/(2*np.pi)
    R = np.power(zeta,n*T)
    x,y,z = s3d.SphericalSurface.coor_convert([R,T,p],True)
    Z = (1+zeta)*R/zeta
    Z =  z - Zst*Z
    return x,y,sqeez*Z
 
# 2. Setup and map surfaces .........................................
mlt = 15

cmap1 = cmu.hsv_cmap_gradient('peru','bisque', name='peru_bisque')
cmap2 = cmu.hsv_cmap_gradient('+pink','plum',  name='+pink_plum' )
bcmap = cmu.stitch_cmap( cmap2, cmap1, name='piplm_|_pebsq' )

shell = s3d.SphericalSurface.grid(mlt*4,mlt*36, 'x')
shell.map_geom_from_op( shell_shape, True )

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

fig = plt.figure(figsize=plt.figaspect(1))
ax = plt.axes(projection='3d', aspect='equal')
ax.set_axis_off()
ax.view_init(elev=20,azim=-50)

s3d.auto_scale(ax,shell,uscale=0.7)
#shell.clip_plane(0,direction=[0,-1,0])
fig.text(0.02,0.02,str(shell), ha='left', va='bottom', fontsize='smaller')
shell.map_cmap_from_normals(direction=ax,cmap=bcmap)
ax.add_collection3d(shell.shade(ax=ax).hilite(ax=ax,focus=2,direction=[1,-.4,1]))

fig.tight_layout(pad=0)
plt.show()

By un-commenting the following line in the above script:

#shell.clip_plane(0,direction=[0,-1,0])

the inner surface is readily shown by planar clipping, as seen in the figure below: