@Override
    public int compareTo(Object o) {
        if (o instanceof TerrainPickData) {
            TerrainPickData tpd = (TerrainPickData) o;
            if (this.cr.getDistance() < tpd.cr.getDistance())
                return -1;
            else if (this.cr.getDistance() == tpd.cr.getDistance())
                return 0;
            else
                return 1;
        }

        return 0;
    }
Pick result on a terrain patch with the intersection on the bounding box
of that terrain patch.

@author Brent Owens
jme3-terrain/src/main/java/com/jme3/terrain/geomipmap/picking/TerrainPickData.java