avg_distance /= springs.size ();
avg_distance = max (min_distance + 0.3, avg_distance);
Spring ret = Spring (avg_distance, min_distance);
ret.set_inverse_stretch_strength (avg_stretch);
avg_distance /= springs.size ();
avg_distance = max (min_distance + 0.3, avg_distance);
Spring ret = Spring (avg_distance, min_distance);
ret.set_inverse_stretch_strength (avg_stretch);