Re: Digitizing / Laser Scanning

From: Alain BERNARD (alain.bernard@cran.u-nancy.fr)
Date: Thu Dec 03 1998 - 21:41:18 EET


Dear Alair,

what was the size of the figure ? like a human body ?

I have already made some laser scanning jobs in toys fields, for copy
(duplication at other sizes), 3D imaging for the first page of a journal,
3D modelling for CAD definition, or plastic injection mold definition for
milling.
The applications were for example masupilami figurine, zodiac fighters, or
jurassic parc animals.

These objects were toys, with real toy sizes. The use of laser scanning (it
was point laser scanning) allowed us to have a very fine replication. But
scanning was very time consuming, because we used a 4 axis machine.
Nowadays, it is possible to use some harm with laser sensors (like Faro for
example), and you manipulate the sensor. So scanning time is lower, but
precision is not so good, it depends on what you want to do with the point
cloud after scanning.

regarding mirror functions we made the same for jewelery (ear rings). We
scanned the left one, and obtained the right model using a mirror function.
This was in order to manufacture wax part, for fundry.

I think that time should be an intersting criterion for comparison, and
also the quality of the result. Do you have any idea about time comparison ?

A few weeks ago we scanned a figurine with objects and clothes. We also
used laser scanning (it was a line laser). We obtained a very good
restitution. The final objective is to define some die-lines and to obtain
the geometry of the surfaces of the different molds necessary for the
object injection. We are currently comparing different softwares, in order
for the future, the integrate all the different steps of the complete
process in the same information environment.

I hope this will help.

Best regards,

Prof. A. BERNARD

A 09:41 03/12/98 -0600, vous avez écrit :
>We recently bid out a large job that required "reverse engineering" of a
>life size, complicated figure (Star Wars kind of detail). This figure
>had clothes, earrings, head pieces, etc.
>
>We choose to digitize the figure rather than laser scan it but I am
>curious about what experiences others have had in this area and where the
>group as a whole feels the state-of-the-art is with respect to digitizing
>vs laser scanning is currently.
>
>Our requirements for the project were:
>
>1. Produce both NURBS and Polygon files.
>2. Create numerous small scale replicas using FDM and 3DP
>3. Create a 20 foot replica
>4. Produce CAD files suitable for ProE or I-DEAS
>5. Create billboard size renderings.
>6. Mirror features that could be mirrored (for example - half the face,
>the feet)
>7. Not include "blemishes" in the figure that were pointed out by the
>artists.
>8. Obtain maximum geometry details for all areas, including overhangs
>(such as in the ear areas).
>9. Realistic (meaning as small as possible) file sizes.
>
>We are very happy with the files that were generated via digitizing but
>I would like to hear discussions comparing the two technologies.
>
>Thanks in advance!!!
>
>Alair Griffin
>Engineer
>Javelin, a Lone Peak Company
>
>
>
>For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/
>
------------------------------------------------------------------------
Prof. Alain BERNARD Tel : + 33 (0)3 83 91 27 29
Professeur des Universites + 33 (0)3 83 91 20 09
CRAN ESA CNRS 7039 Fax : + 33 (0)3 83 91 23 90
UHP Nancy I - ESIAL
BP n° 239, 54506 - VANDOEUVRE Cedex - FRANCE
ATTENTION ! NEW E-MAIL !
e-mail : alain.bernard@cran.u-nancy.fr http://www.cran.u-nancy.fr
------------------------------------------------------------------------

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



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