uniform curvature with respect to number of sides

// decrease curvature as number of sides increases
// behavior is somewhat more orderly but not as interesting either
double  s = 1.0f / float(Ring.Sides - 2);
Ring.EvenCurve = float(m_Parms.EvenCurve * s);
Ring.OddCurve = float(m_Parms.OddCurve * s);