protected boolean calculateLod(List<Vector3f> location, HashMap<String,UpdatedTerrainPatch> updates, LodCalculator lodCalculator) {

        boolean lodChanged = false;

        if (children != null) {
            for (int i = children.size(); --i >= 0;) {
                Spatial child = children.get(i);
                if (child instanceof TerrainQuad) {
                    boolean b = ((TerrainQuad) child).calculateLod(location, updates, lodCalculator);
                    if (b)
                        lodChanged = true;
                } else if (child instanceof TerrainPatch) {
                    boolean b = lodCalculator.calculateLod((TerrainPatch) child, location, updates);
                    if (b)
                        lodChanged = true;
                }
            }
        }

        return lodChanged;
    }
Generate the entropy values for the terrain for the "perspective" LOD
calculator. This routine can take a long time to run!
@param progressMonitor optional
jme3-terrain/src/main/java/com/jme3/terrain/geomipmap/TerrainQuad.java