@Override
    public void setSpatial(Spatial spatial) {
        super.setSpatial(spatial);
        if (spatial instanceof Terrain) {
            this.terrain = (Terrain) spatial;
        }
    }
Back on the ogl thread: update the terrain patch geometries
jme3-terrain/src/main/java/com/jme3/terrain/geomipmap/TerrainLodControl.java