public void setNewLod(int newLod) {
        this.newLod = newLod;
        if (this.newLod < 0)
            throw new IllegalArgumentException("newLod cannot be less than zero, was: "+newLod);
    }
Stores a terrain patch's details so the LOD background thread can update
the actual terrain patch back on the ogl thread.

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