restriction of the window

[Serge Zouev <Serge.Zouev at sophia.inria.fr>]

Dear experienced geomview and qhull-users,
While constructing (with the help of the program 'qhull') 
the Voronoi tesselation for a big number of points distributed
uniformly in a square [-1/2,1/2]^2 I've got a picture of a star-like object
comprising tesselation of the plane itself. 
I guess there must be some means to restrict the observation window to desired 
limits, say to the very square. Could anybody tell me that - up to now I have
to use camera scale to see what's going on in [-1/2,1/2]^2.
Cheers,
        Serguei Zouev