[cad-linux] Re: the parametric project
- From: Roland Krause <rokrau@xxxxxxxxx>
- To: cad-linux@xxxxxxxxxxxxx
- Date: Wed, 21 May 2003 15:57:30 -0700 (PDT)
--- Thomas Schmidt <thomas.schmidt@xxxxxxxxxx> wrote:
>
> Roland,
>
> It seems you actually want to setup a new parametric modeller. The
> brave =
> ones rule the world.
:-) That really hits the nail on the head - I am glad you said the
"brave ones" allthough I am sure you thought of 's/brave/crazy/' here.
Anyway, such a modelling kernel would be some really interesting
project, especially if it is backed up by a database as was discussed
earlier.
A CAD system that allows a user to specify dimensions by parameters is
probably built upon some form of a constraint solver. I assume that the
term "parametric" is used because what the user actually notices and
sees is, that an edge can have a length that can be changed at any time
and the endpoints will automagically move. Parametric is a term that
refers to the application of the solver not it's implementation.
The first and most succesful system that implemented this feature was
certainly Pro-E, they even named the company Parametric.
Roland
> I assume that you use the term "parametric" not to refer to the
> parametr=
> ic functions of curves and surfaces,
> but to a system, where objects interact by constraints. I have ever
> wonde=
> red why the term "parametric"
> is used to describe a constaint solving system. Does anybody know?
> Anyway, you might want to have a look here :
> http://www.cs.washington.edu=
> /research/constraints/
> The constaint solver they describe, are mostly based on local
> propagation=
> algorithms
> and therefor not very well suited for (complex) 3D modelling, but you
> get=
> a good introduction into the world of
> constaints and their solving algorithms. There is even some code for
> a fe=
> w solver.
> I also found many research papers about constaint solving algorithm
> on ht=
> tp://citeseer.nj.nec.com/cs.
> Search for constaints or solver. Mostly academic papers, but
> interesting =
> anyway.
>
__________________________________
Do you Yahoo!?
The New Yahoo! Search - Faster. Easier. Bingo.
http://search.yahoo.com
Other related posts:
