@Override
    public String toString() {
        return "SimpleLodThreshold "+size+", "+lodMultiplier;
    }
Just multiplies the terrain patch size by 2. So every two
patches away the camera is, the LOD changes.

Set it higher to have the LOD change less frequently.

@author bowens
jme3-terrain/src/main/java/com/jme3/terrain/geomipmap/lodcalc/SimpleLodThreshold.java