Fw: Newbie's opening volley.

From: Innomation Systems & Technologies Pte. Ltd., (istpl@singnet.com.sg)
Date: Mon Jan 25 1999 - 14:14:28 EET


Dear Paul,

pardon me if i am wrong if you have only spline surfaces...then most of
your jewels look like straight cuts will it???

for reverse engineering, i still think that NURBS will still be the best
....if not...then most of your efforts to integrate Reverse Engineering
into your design will be lesser significant.

personally, i feel that Reverse Engineering requires more correction than
the accuracy.....if you are to use spline to define the accuracy of your
digitised workpiece than it will not give you the surface quality that you
wants....because every segment of straight lines does not constitute to a
well-defined curve.

i am not sure about the notations used in the IGES file(text based)....but
i do remember that for NURBS surface you are more likely to see non-uniform
length describing the surface equation parameters...while for splines or
lines you can notice a more uniform pattern.

well, don't try to understand the IGES text file...you can get crazy by
doing so....i will suggest that you use software like Surfacer or Rhino3D
to view the IGES surfaces.

Sincerely,
joseph sim

----------
> From: Paul Burr <tigerpb@ids.net>
> To: rapid proto. list <rp-ml@bart.lpt.fi>
> Subject: Newbie's opening volley.
> Date: Monday, January 25, 1999 10:21 AM
>
> Greetings fellow listers! As a first timer to this list I'm looking
> forward to the insights of this group.
> I'm currrently designing costume jewelry using JewelCad (any other users
> out there?) and building the parts on a Sanders MM2. I've also have used
> the Sanders MM6 Pro previously.
> Anyway my employer, Giovanni Jewelry (100 Nashua St, Providence, RI ) is
> looking to expand our capabilities with 3D scanning. This is a new area
> for us, and we'll need all the advice I can gather.
> I'd like to retain JewelCad as our design front end, at least for the
time
> being. It is capable if importing only igs files that are spline surface
> iges.
> So, my question is two fold: How does one tell the difference between
> spline and non spline iges files?
> and, are there any file translation packages that can tweek scanner
output
> into the "flavor" that I need?
>
>
>
>
> For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/

For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/



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