[X3D-Public] reason / benefits of homogeneous coordinates in NURBS?

[Philipp Serfling]

Hi, 
i´m sorry to bother you again with my problems, but if anyone know some
resources or reasons for my problem written underneath, i would be very
thankful.

thx 
.philipp


-----Ursprüngliche Nachricht-----
Von: Philipp Serfling [mailto:Philipp.Serfling at t-systems-mms.com] 
Gesendet: Mittwoch, 14. August 2013 15:09
An: 'x3d-public at web3d.org'
Betreff: reason / benefits of homogeneous coordinates in NURBS?

hello,

I´ve noticed that in x3d the control points of a nurbs surface are
represented in homogeneous coordinates 
see:
http://castle-engine.sourceforge.net/x3d_implementation_nurbs.php#section_ho
mogeneous_coordinates

Is there any benefit in doing it that way compared to the "normal /
intuitive way" (also explained in the link) ?

I´m asking for two reasons:

1. White_dune, Instant Reality & BSContact  Player are using the homogeneous
way.
    But Octaga Player uses the "normal" way.

2. I´m currently implementing NURBS Curves and PatchSurfaces in X3DOM and
i´m not sure if i should implement the homogeneous
  or the "normal way". Currently i´m developing both, but the homogeneous
way is unintuitive and more complex and i really don´t see any advance.

thx for your help
.philipp