Radial Symmetries

        int reps = chi('reps');
float r = chf('radius');

float u = atan2(v@P.x, v@P.y);
u = fit(u, -PI, PI, 0.0, 1.0);
u = frac(u * float(reps));
float v = length(v@P * 2.0);

vector uvw = set(u, v, 0.0);

float d = xyzdist(1, uvw);

d *= chramp('shape', v);

v@rest = v@P;
v@P.y = d * v - r;