module Bounding_sphere:General purpose bounding sphere class for enclosing nodes/objects/vertices.sig..end
    Bounds internal Osg.Nodes in the scene, assists in view frustum
    culling, etc. Similar in function to Osg.Bounding_box, it's quicker
    for evaluating culling but generally will not cull as aggressively
    because it encloses a greater volume.
type 
val create' : unit -> tval center : t -> Osg.Vec3.tval radius : t -> floatval radius2 : t -> float