fish%gr.utah.edu@cs.utah.edu (Russ Fish) (03/28/91)
Archive-name: graphics/images/utah-nurbs/1991-03-27
Archive: cs.utah.edu:/graphics/nurbs-models.tar.Z [128.110.4.21]
Original-posting-by: fish%gr.utah.edu@cs.utah.edu (Russ Fish)
Original-subject: Re: NURBS data available
Reposted-by: emv@msen.com (Edward Vielmetti, MSEN)
Hi, folks. Seems we had a problem with missing data in the first rev of the
nurbs-models.tar.Z file, so I tracked it down and tried again.
The file is now 68537 bytes, instead of 28106 bytes, so you can see how much
got eaten! The new version is now on cs.utah.edu ~ftp/graphics, and I assume
the copy at uunet.uu.net will be updated soon as well. (Thanks, UUNET!)
The individual file sizes inside the .tar.Z file are now:
2881 README
58495 coke.txt
25079 dart.txt
6136 goblet.txt
74777 pencil.txt
30299 scissors.txt
9215 spoon.txt
206882 total
In case you're interested, here's an explanation of what happened: We pass
structures of C++ objects between programs inside Alpha_1 using a machine
independent binary object stream. There is a utility to dump that out in a
simple-minded temporary text form or read it back in, which is used primarily
for debugging since the text form will change as we evolve the object
structures. (The binary form provides type migration via polymorphism based
on interpreting object structure descriptions embedded in the stream.)
Rather than forcing the rest of the NURBS world to read our binary form, we
tried a hack: passing the text form through a script to strip out all of the
topology and attribute information, leaving just the surfaces in a slightly
prettified form. (Hence the somewhat curt statement in the README file:
The text format in which these models are distributed is intended to be
mashed into whatever form you want in order to read the data into your own
software. No parser or filters for this text form is (nor will be)
provided by the University of Utah.
Unfortunately, the attribute stripping was a bit too enthusiastic...
Further bugs, problems, queries, etc. to me via e-mail, please.
(somewhat) Chagrined,
-Russ Fish fish@cs.utah.edu (801) 581-5884