LOD Example 

---

LOD {
    center 0 0 0
    range [ 11, 13 ]
    level [

        Inline {
            url "extrude.wrl"
        }
        ,
        Shape {
            appearance Appearance {material Material{}}
            geometry Cylinder{
                radius 2
                height 4
            }
        }
        ,
        Shape {
            appearance Appearance {material Material{}}
            geometry Box{
                size 4 2 2
            }
        }
    ]
}