/* create HeightfieldTree, it automatically downloads the root node */
htree = new HeightfieldTree(new URL(source, url).toString(), gSphere, 6378140. / Global.heightfieldmultiplier);
htree.addHeightfieldTreeChangeListener(this);
newCore = new HeightfieldTreeNodeCore(gSphere, (float) (6378140. / Global.heightfieldmultiplier), htree);;
newCore.setRequestID(new URL(source, url).toString());
rootNode.setCore(1, newCore);
} catch (MalformedURLException e2) {
// TODO Auto-generated catch block