These are the predefined functions for the bands (as code in InitPage)
x_functions = "cos(p)*(1+q/(2*pi)*cos(a/2*p.v*t))";
y_functions = "sin(p)*(1+q/(2*pi)*cos(a/2*p-v*t))";
z_functions = "b*q/(pi)*sin(a/2*p-v*t)";
pi = π
a number of half twists
a = 1.0 common Moebius strip.
b defines height;
p and q range -π to +π