Hi Author,
Take a look at the 2nd and the 3rd diagrams at my post here http://opencascade.blogspot.com/2009/02/topology-and-geometry-in-open-ca....
In fact, TShape returned by TopoDS_Vertex::TShape() *is* BRep_TVertex, so you can cast:
Handle(BRep_TVertex) aTVertex = Handle(BRep_TVertex)::DownCast (aVertex.TShape());
However normally you never need this (beware of doing this in places of extensive computations). If you simply need a point underlying a vertex, use BRep_Tool::Pnt().
Commenter-1
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