function LOD() {

		Object3D.call( this );

		this.type = 'LOD';

		Object.defineProperties( this, {
			levels: {
				enumerable: true,
				value: []
			}
		} );

	}
@author mikael emtinger / http://gomo.se/
@author alteredq / http://alteredqualia.com/
@author mrdoob / http://mrdoob.com/