minmax  optimal spherical tesselations
Usage: minmax [options] [input_file]
Read a file in OFF format containing a graph of a polyhedron, with or
without vertex coordinates, and try to create a spherical or ellipsoidal
tesselation where the maximum edge is a minimum length, or try to make
into a regular polyhedron. If input_file is not given the program reads
from standard input.
Options
h,help this help message (run 'off_util H help' for general help)
version version information
n <itrs> number of iterations (default 1000)
s <perc> percentage to shorten longest edges on iteration (default: 1)
l <perc> percentage to lengthen shortest edges (a a/v) on iteration
(default: 0.0)
k <perc> percentage to reduce polygon radius (a u) on iteration
(default: value of s)
f <perc> percentage to reduce distance of vertex from face plane (a u)
on iteration (default: value of s)
a <alg> length changing algorithm
v  shortest and longest edges attached to a vertex (default)
a  shortest and longest of all edges
u  make faces into unitedged regular polygons (l controls
planarity, ignore p, E)
p <mthd> method of placement onto a unit sphere:
n  project onto the sphere (default)
r  random placement
u  unscramble: place a small polygon on one side and the
rest of the vertices at a point on the other side
E <prms> use ellipsoid, three numbers separated by commas are the
axis lengths (for a superellipsoid an optional fourth number
gives the power)
L <lim> minimum change of distance/width_of_model to terminate, as
negative exponent (default: 16 giving 1e16)
z <n> status checking and reporting every n iterations, 1 for no
status (default: 1000)
q quiet, do not print status messages
o <file> write output to file (default: write to standard output)
Turn an icosahedron 3fold axis into a sixfold axis, and make the
resulting faces regular
off_trans y D3v ico  to_nfold 6  minmax a u s 20 n 10000  antiview
Make a geometric representation of a polyhedron having only face data,
in this case a geodesic sphere has all its coordinates set to the origin
and is then laid out again on a sphere
off_trans geo_3 S 0 > scrambled.off
minmax p u n 100000 scrambled.off > unscrambled.off
Run for a bit longer, don't need p u this time
minmax n 100000 unscrambled.off > unscrambled2.off
Doesn't always succeed. Experiment with option s, l,
k and f to improve convergence, but setting them too
high may cause the model to scramble. Run the program for longer by
increasing option n. The program shows the progress every
1000 iterations (change with option z) by printing the
longest and shortest edge lengths (a v/a) or the maximum
distance a vertex moved (a u).
Next:
col_util  colour utilities including plots and blends
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Programs and Documentation
