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From: ad@txlad.dirksen.de (Axel Dirksen)
Newsgroups: comp.graphics
Subject: Re: curve represenation
Keywords: bezier or b-spline
Message-ID: <1990Nov16.100832.15408@txlad.dirksen.de>
Date: 16 Nov 90 10:08:32 GMT
References: <1990Nov14.160528.10333@progress.com>
Organization: Axel Dirksen, system & software consulting, Berlin, Germany
Lines: 34

In <1990Nov14.160528.10333@progress.com> as@progress.COM (Amitabh  Shukla) writes:


> I posted the following article in comp.graphics yesterday.
> 
..
..
>	and people complained and I was being to vague. I will be more clear
>now.

>What I want to know is what is the industry standard to store information about
>curves? The choices being bezier curve or uniform/non-uniform b-spline represenation.


>	Thanks 
>				amitabh

I think this question should not arise as bezier splines are only a
special case of bsplines, so why don't you just implement bsplines and
you'll get bezier's automatically by giving the right knot vector and
degree :-).

As far as industrial standards are concerned we have here the german
car manufacturer's norm VDA, ( Mercedes, Bmw, Vw use it) which so far
does not use splines at all but segmented polynominal representations
of arbitrary degree for surfaces as well as ( trimming ) curves, so
you would have to translate these back to bsplines in case you want to
get to e.g. Iges I guess.



-- 
axel	ad@txlad.uucp
	ad@txlad.dirksen.de