sphere_project.m
sphere_project - project point X,Y,Z to the surface of sphere radius r
V = sphere_project(v,r,c)
Cartesian inputs:
v is the vertex matrix, Nx3 (XYZ)
r is the sphere radius, 1x1 (default 1)
c is the sphere centroid, 1x3 (default 0,0,0)
XYZ are converted to spherical coordinates and their radius is
adjusted according to r, from c toward XYZ (defined with theta,phi)
V is returned as Cartesian 3D coordinates