@Override
    public Ring clone() {
        try {
            Ring r = (Ring) super.clone();
            r.center = center.clone();
            r.up = up.clone();
            return r;
        } catch (CloneNotSupportedException e) {
            throw new AssertionError();
        }
    }
Create a copy of this ring.

@return a new instance, equivalent to this one
jme3-core/src/main/java/com/jme3/math/Ring.java