HDTenEightyP/NetNews huggingface dataset:
From: js@cophos.co.at (Jodok Schaeffler)
Subject: Polygon with holes
Organization: COPHOS Development Team, ZUMtOBEL Licht GmbH, Dornbirn, AUSTRIA
Distribution: comp.graphics
Date: Wed, 6 Jan 1993 13:58:08 GMT

I have a problem with polygons, specifically with the holes
within a polygon. 

There are (at least) two ways to specify such a polygon:
 - as a structure of polygons, holes beeing represented
   as polygons within polygons
 - as a closed line, following the edges of the polygon
   and the holes. To connect all holes to the actual polygon,
   the closed line needs to cross the interior of the polygon.
   The closed line comes back to the point where it left the edge 
   at the same position, but with opposite direction.

What I am looking for: 
   An algorithm to find a line connecting all
   holes within a polygon.

My idea: to construct something like a Voronoi diagramm to find
         the 'minimal spanning tree' of all holes within the 
         polygon.

The problem seems similar to the traveling salesman problem, as
I have to find any (not even an 'optimal') connection between
the holes. My problem is to construct a Voronoi diagram from
polygons, not from points.

If someone can help me, point me to a direction to go, or
even knows a source for code, I would appreciate this.


Jodok Schaeffler
Newsgroups: comp.graphics
From: willis@evax0.eng.fsu.edu
Subject: NCAR plotting package for Cyber 850.
Organization: Famu/Fsu College of Engineering
Date: 10 Jan 93 00:25:49 EST

Hello,

    I need some information regarding the NCAR plotting package.  I recently
    received a question from someone using a Cyber 850 running the NCAR 
    plotting package to plot a contour map using the CONREC subroutine.  
    The question has to do specifically with the common blocks associated 
    with the CONREC subroutine, namely:

         CONRE1,CONRE2,CONRE3, etc..

    The user wants to print out a contour plot containing the contour lines
    without the numeric values appearing on each line - including the zero- 
    value lines.  We adjusted a few internal parameters including NULBLL, 
    which was the obvious choice, but we couldn't acheive the desired 
    results.  

    If there is someone out there who uses the NCAR plotting package and 
    knows which CONRE# common blocks to look through and which internal 
    parameters to adjust, please respond as soon as possible. The fortran 
    code for this beast would be a definite plus.  Thanks in advance.


-- 
============================================================================
Russell E. Willis
Academic Computing & Networking Services
Innovation Park
Tallahassee, FL 32310

e-mail:      willis@evax0.eng.fsu.edu
             russell willis@rai.acns.fsu.edu
             willis@garnet.acns.fsu.edu
             willis@fsu1.acns.fsu.edu
=============================================================================
Newsgroups: comp.graphics
From: gln@iti.org (Glen Niebur)
Subject: Area of a parametric patch
Summary: How do i calculate the area of a parametric patch
Organization: Mayo Foundation, Rochester MN. Campus
Date:  6 Jan 93 19:11:44 GMT

I have an application where i need to find the area of a bicubic Coons
patch.  Is there a straight forward method to do this, or is it better
to approximate it by subdividing the batch into rectangles, and finding
the area of the rectangles?

Any references to equations or algorithms would be appreciated.

Thanks in advance

--
Glen Niebur     | By the force of will, my lungs are filled, and so i breath
Mayo Clinic     |
Biomechanics Lab|
gln@mayo.edu    |            ~Natalie Merchant
Newsgroups: comp.graphics
From: mark@ocsmd.ocs.com (Mark Wilson)
Subject: Re: Memory-searcher
Organization: Online Computer Systems, Inc.
X-Newsreader: Tin 1.1 PL5
Date: Mon, 4 Jan 1993 18:45:20 GMT

--
SORRY!  Posted to wrong group by mistake!  Feel free to flame at will!
--
-------------------------------------------------------------------------------
Mark Wilson, Online Computer Systems.  1-800-922-9204 or 1-301-601-2215
(Try email address mark@wilson.ocs.com....)
This file .disclaims everything signed with my .signature, I .mean it!
-------------------------------------------------------------------------------
From: twb@tivoli.com (Tom Bereiter)
Newsgroups: comp.graphics
Subject: Polygon-polygon intersection
Date: 4 Jan 93 19:22:03 GMT
Reply-To: twb@tivoli.com (Tom Bereiter)
Organization: TIVOLI Systems Inc., Austin, TX

I'm looking for an efficient test for whether two 2D polygons intersect.
The brute force approach seems to be: do a point-in-polygon test for each
point of polyA in polyB, but if that says false you still have to check for
line intersections.  This feels like the sort of problem, like area of
a polygon, which has a non-obvious trivial answer.

Thanks

---
Tom Bereiter                                   TIVOLI Systems, Inc.
twb@tivoli.com                                 6034 West Courtyard, Suite 210
(512) 794-9070 [794-0623 fax]                  Austin, TX   78730
Newsgroups: comp.graphics
From: M16302@mwvm.mitre.org
Subject: Experience importing .cgm files into Aster*x.
Organization: The MITRE Corporation, McLean VA 22102
Date: Mon, 11 Jan 1993 18:47:49 GMT

Does anyone have any experience importing .cgm files into Aster*x draw.  When
I import from McDraw using Graph Porter I lose the font type information.
 
Robert B. Shain                               EMAIL: RSHAIN @MITRE.ORG
The MITRE Corporation                         Voice: (703)883-5592
Center for Intellignence & Special Programs   FAX: (703)883-6991
Mailstop W955
7525 Colshire Drive                           "My other computer is a Cray"
McLean, VA. 22102                             "My other car is a bike"
                                              "My other sport is ping pong"
 
Newsgroups: comp.graphics
From: julian@sun-1.cs.uct.ac.za (Julian Hansen)
Subject: Gl files/ viewer
Summary: GL files and viewer request and FAQ
Keywords: GL files, viewer, FAQ
Organization: Computer Science Department, University of Cape Town
Date: Wed, 6 Jan 1993 07:57:24 GMT


Hi world

I have a programme called grasprt.exe that I believe is supposed to
display something called a GL file. I also have 2 GL files. The problem
is all the programme displays is a blank screen (for one) and an error
message (missing file something.txt). I do not know if I have a bad
viewer or a bad data file.

So what I need is another viewer that works and a GL file (does not
matter what - anything) so I can test which of the two (programme or
data file) is corrupted.

Any other info on GL files would be nice too.8-). If there is a FAQ
then that would be nice.

Thanks

julian


----------------------------------------------------------------------------
                                                   VVVVVVV
                                                  /       \
Julian Hansen                                    / _     _ \   I'm Back
University of Cape Town                          |/_\   /_\|  /
South Africa                              ____   ||o|   |o|| / ____
email: julian@sun-3.cs.uct.ac.za   -------VVVV---|---\ /---|---VVVV------
                                                      U 
----------------------------------------------------------------------------
From: ez006683@othello.ucdavis.edu (Daniel D. Todd)
Newsgroups: comp.graphics
Subject: 3d scanning?
Date: 9 Jan 93 02:23:34 GMT
X-Newsreader: Tin 1.1 PL3


Hello net.wisdom,
	I tried to post a similar message but it was refused by my server
I hope it didn't lie to me and actually post it.  If so, sorry for the 
double post.  
	I'm tryingto build a database of 3d images but I don't have any 
idea how to input the data. The largest items should be no more than 1 m
in length and less than .5 m in width and depth.  I haven't any need for
internal scans such as an MRI or Cat provides, I only want the shells.
	I will also need some software which can make comparisons based
upon the data. The comparisons would be size and shape (eg. is face a
more or less flat than face b?).
	Please e-mail responses I don't read the group regularly yet, I
may have to start. If there are a lot of responses I will condense and post.


	THANK YOU for any and all responses
Dan Todd
From: sngattan@venture.ksu.ksu.edu (Down and Under)
Newsgroups: comp.graphics
Subject: 2D Plotting using GnuC?
Date: 5 Jan 1993 06:06:18 -0600
Organization: Kansas State University
NNTP-Posting-Host: venture.ksu.ksu.edu
Keywords: Histogram, line plot

Hello:

	I am using GnuC to develop a few basic routines for image
enhancement.  I have not been able to comprehend GnuC fully though.
Can someone guide me what commands I can use in order to make an
X-Y plot.  The commands that I am looking for should do the following:

	1.  Move to (x,y)
	2.  Be able to draw a line from (x1,y1) to (x2,y2)
	3.  Write out text at (x,y) location

I found a command GrLine (x1,y1,x2,y2,color) but when I use it, the
compiler gives me an error. Thanks in advance. 

						sanjay
						sngattan@matt.ksu.ksu.edu
From: nige@werple.apana.org.au (Nigel Senior)
Newsgroups: comp.graphics
Subject: Quantization or Colour Reduction Information required
Date: 5 Jan 1993 22:43:56 +1100
Organization: werple public-access unix, Melbourne
NNTP-Posting-Host: werple.apana.org.au
Summary: Can anybody help me with routines for colour reduction
Keywords: Quantization Colour color

: I am doing some work which involves reducing the number of colours in PCX
: images from 256 down to around 25. Currently I am reducing colours by
: merging similar colours, removing colours with small quantities, using
: Heckbert's median cut technique and using Fletcher's box and merge
: technique. While these techniques are good, reducing the number of colours
: in an image to 25 is a bit hit and miss, hence any extra techniques would
: be most appreciated. I am also generally after information related to
: color comparison and transformation specifically related to perceptual
: spaces such as CIE LUV etc. Any suggestions would be most gratefully
: accepted.
: 
: Thank you in advance
: Cheers
: Nigel Senior
From: csyew@ecst.csuchico.edu (YewSim Cheah)
Newsgroups: comp.graphics
Subject: Sorting RGB Palette in Intensity Order.  Please Help !
Date: 6 Jan 93 07:34:48 GMT
Organization: California State University, Chico
NNTP-Posting-Host: cscihp.ecst.csuchico.edu

Dear Fellow Netters:

I would like to sort an array of RGB Palette in intensity order,
but do not know how.  Does anybody please help ?

Thankyou

-- 
   __     *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
  / __\  /_           name: YewSim Cheah.  alias: Xie Yaosen.
 / /__`\//_//   / campus: California State University, Chico. 
/_,__/_//_, \/\/           internet: csyew@ecst.csuchico.edu.
Newsgroups: comp.graphics,comp.sys.sun.apps,comp.windows.x.apps
From: scott@ryptyde.cts.com (Scott McClure)
Subject: XWD-->GIF conversion
Organization: Ryptyde TimeSharing, San Diego, CA
Date: Wed, 13 Jan 1993 01:01:28 GMT

Thanks to all who responded.  The overwhelming majority of recommendations
were for PBMPLUS.  I got it, installed it, and it worked on the first try!

Scott

-- 
INTERNET:  scott@ryptyde.cts.com                     | "Nuke the homeless gay
ARPANET:   ryptyde!scott@nosc.mil                    |  baby whales for Jesus!"
UUCP:      {crash, nosc}!ryptyde!scott               |    - bumper sticker
Newsgroups: comp.graphics
From: goza@norm.JSC.NASA.GOV (Mike Goza)
Subject: Re: Winged-edge data structure 
Organization: IGOAL
Date: Thu, 7 Jan 1993 19:09:52 GMT

I believe graphics gems II has some info on that type of
data structure and possibly C code as well.

Mike Goza
goza@cheers.jsc.nasa.gov
Xref: sparky comp.graphics:13590 alt.cad.autocad:1820
From: prestonm@cs.man.ac.uk (Martin Preston)
Newsgroups: comp.graphics,alt.cad.autocad
Subject: Re: Reconstructing 3D solid from planar cross sections
Keywords: reconstruction 3D solid autocad
Date: 8 Jan 93 11:34:19 GMT
Followup-To: comp.graphics

In <martin.726422303@marsh> martin@cs.curtin.edu.au (Martin Dougiamas) writes:

>I envisage some sort of wireframe "skin" placed over the 
>sections, defining the final 3D solid.

You might want to look at 
Wayne Tiller, "Rational B-Splines for Curve and Surface Representation"
IEEE CG&A 1983, September pp 61-69

which covers the creation of NURBS surfaces by 'skinning'.

I have no experience of AutoCAD, and so i don't know how easy it would be
to convert a NURBS into whatever it can handle. If you are interested a C
library for the manipulation of NURBS can be obtained from unix.hensa.ac.uk
(129.12.21.7) in /pub/misc/unix/nurbs, and i have some C which will perform
a basic skinning operation using that library which i'll email you if you
want.

The basic library includes routines to convert sequences of points into
NURBS curves, which are then skinned, so getting data in from other sources
isn't too painful.

You also mention that it might be necessary to handle non-connected solids,
which this algorithm ~won't~ perform.

Hope thats of some interest!

Martin
--
---------------------------------------------------------------------------
|Martin Preston,        (preston@uk.ac.mcc.cgu)       | Computer Graphics |
|Computer Graphics Unit, Manchester Computing Centre, |    is just        |
|University of Manchester,                            |  a load of balls. |
|Manchester, U.K., M13 9PL     Phone : 061 275 6095   |                   |
---------------------------------------------------------------------------
Newsgroups: comp.graphics
From: umarsa00@ctrvx1.vanderbilt.edu (PROF. A.S. UMAR, (615)322-2459)
Subject: NEED POINT_AND_CLICK UNIX GRAPHICS PACKAGES
News-Software: VAX/VMS VNEWS 1.41    
Organization: Vanderbilt University
Date: Tue, 5 Jan 1993 00:00:00 GMT


I am looking for commercial or shareware point-and-click
packages that are able to do contours and surfaces with
capabilities to manipulate axis and labels. Fancy postscript
labels with symbols is a must.

This is a challenge I never faced before. I am willing to
find something but cannot find anything. I do not want a 
command line package like IDL or PV-Wave, Mathematica,
Speakeasy, gnuplot,....

Why is this kind of graphics gui for unix is so far behind?

PS: My system is ibm/rs6000.

umar@compsci.cas.vanderbilt.edu         Prof.A.S. Umar
umarsa00@vuctrvax.bitnet                Department of Physics & Astronomy
Tel: (615) 322-2459                     Vanderbilt University
Fax: (615) 343-7263                     Nashville, TN 37235
Newsgroups: comp.graphics
From: rebuck@blue.crayola.cs.psu.edu (Mark A Rebuck)
Subject: Re: Quantization or Colour Reduction Information required
Keywords: Quantization Colour color
Organization: Penn State Computer Science
Date: Wed, 6 Jan 1993 12:58:53 GMT

In article <1ibs9sINNn7@werple.apana.org.au> nige@werple.apana.org.au (Nigel Senior) writes:
>:
>:   (about Color Quantization....)
>: 
>: Nigel Senior

Good timing, I just went searching for a few references the other day
on this very subject.  So far, I've been able to find the following
references:

%A Foley and VanDam
%T Computer Graphics, principles and practice
%P 1175
%I addison-westly publishing company

%A Heckbert, P.
%T Color Image Quantization for Frame Buffer Display
%J SIGGRAPH 82
%P 297-307

Foley and VanDam do little more then give the Heckbert article as
a reference.

The Heckbert article is *very* good.  It describes two good methods for
reducing colormaps.    

Hope this helps,

====================================================================
| Mark Rebuck           |  Some people say that daydreams are      |
| rebuck@cs.psu.edu     |  for all the lazy minded fools           |
|                       |  with nothing better to do...            |
|                       |  So let them laugh, laugh at me...       |
| 6502 forever!!        |              Jimmy Hendrix               |
====================================================================
From: danny.hawrysio@canrem.com (danny hawrysio)
Newsgroups: comp.graphics
Subject: explaining how jpeg works
Date: 11 Jan 93 22:47:29 GMT
Reply-To: "danny hawrysio" <danny.hawrysio@canrem.com>
Distribution: comp
Organization: Canada Remote Systems



 On a graphic BBS I'm often asked how JPEG works in technical terms (and
yet they want it a fashion they can understand), I find any
explanation I come with is too long and hard to understand for the
average computer graphics user.  Has anybody come up with a brief but
yet all covering description of JPEG?
 The JPEG frequent question list is really no help since they avoid the
questions by recommending periodicals.

 Thanks in advance.
--
Canada Remote Systems  - Toronto, Ontario
World's Largest PCBOARD System - 416-629-7000/629-7044
Newsgroups: comp.graphics
From: dejesus@pluto.nwc.navy.mil (Francisco X DeJesus)
Subject: Re: REQUEST: StarTrek 3D Objects and others to avalon
Organization: Science Applications International Corp.
Date: Thu, 7 Jan 1993 16:29:24 GMT

In article <C0FuCt.Bv@news.iastate.edu> niko@iastate.edu (Nikolaus E Schuessler) writes:
>>
>>Send mail to file-server@graphics.rent.com with the word "HELP" in the
>>body of the text and a help file telling you how to use the server will
>>be sent to your mailbox.
>
> I'm looking into this and if I can manage to down load them I will post
>them to china.lake

I'm sure everyone will appreciate it!

>p.s. what is the .3D2 format? what program? specs.. anyone anyone?

It is the object format for the old CAD-3D program on Atari ST machines. This
program was written by Tom Hudson who then went on to co-write 3D-Studio. I
know there is a 3d2-to-DKB converter that came with the DKB raytracer. If
anyone can find the format spec please upload it to avalon!
-- 
      Francisco X DeJesus  ----- S A I C -----  dejesus@chinalake.navy.mil
 ------------------------------------------------------------------------------
  * disclaimer: Opinions expressed here are mine. Typos and errors are yours *
 "Duck Season!" "Rabbit Season!" "...rabbit season." "It's Duck Season! SHOOT!"
Newsgroups: comp.graphics
From: vostveen@prl.philips.nl (Gerrit van Oostveen)
Subject: Re: PC ray-tracing
Organization: Philips Research Laboratories Eindhoven, Netherlands
Date: Mon, 11 Jan 1993 14:21:54 GMT

In <871.132.uupcb@tfd.coplex.com> eric.vitiello@tfd.coplex.com (Eric Vitiello)  writes:

>TO: 1628726ps485@vaxr.sscl.uwo.ca

>>Hi! I'm interested in ray-tracing on the PC.  I wondered if anyone could help
>>me compile a list of software I should investigate.  I know 3d Studio 2.0 is
>>probably the be-all and end-all of modellers on the PC, but I cannot justify
>>spending over $500.  I have no preferance for Windows over Dos, but I would

>   Sorry... It's going to be very hard to find a ray tracer for an IBM
>   compatible comuter for under $500.... If you do find one, it may not
>   do all that you want.  The only one I can think of that is half good
>   is from Brown-Wagh Publishing can't quite remember the name of it,
>   but thier number is: 1-800-451-0900

>....r.c V.t.ell. .r...
>---
> . DeLuxe./386 1.25 #959sa . My Address: eric.vitiello@tfd.coplex.com
>                                                                                                                              

How about POVRay, Rayshade and VORT ? These are all public domain (cheaper
than $500) available on many sites (simtel-20, nic.funet.fi and wuarchive)
and do real raytracing. 3D-Studio does rendering only (other principle).

I used POVRay and Rayshade myself and I'm impressed with their output.
VORT gave somewhat less quality.


G.v.Oostveen
vostveen@prl.philips.nl
Xref: sparky comp.graphics:13520 comp.graphics.visualization:1978 comp.multimedia:4007 comp.org.acm:1040 alt.graphics.pixutils:2854 comp.graphics.animation:1509
From: rsc@altair.csustan.edu (Steve Cunningham)
Newsgroups: comp.graphics,comp.graphics.visualization,comp.multimedia,comp.org.acm,alt.graphics.pixutils,comp.graphics.animation
Subject: SIGGRAPH to do online electronic publication
Summary: Call for Submissions
Keywords: SIGGRAPH, electronic publication, online, experimental
Date: 7 Jan 93 19:56:26 GMT
Organization: CSU Stanislaus


   ACM SIGGRAPH to Publish Non-Print Special Issue of Computer Graphics

       Focus to be on non-print publishing; articles are solicited

In the spring of 1993, SIGGRAPH plans to publish a non-print special issue 
of Computer Graphics as an experiment in electronic publishing. This will 
not be a numbered issue of the newsletter and so will not contain many of 
the normal SIGGRAPH news items, but we plan to include some information of 
timely interest and a set of articles on non-print publishing. The issue 
will be available by ftp or e-mail from siggraph.org.

   Following the successful pattern of the SIGGRAPH '91 panels transcripts, 
we plan to make the contents available in several formats.  Articles may 
include text, monochrome or color figures, or additional material if it can 
be used on a wide range of platforms).  In the ftp area, text will be 
provided in plain ASCII, rtf (rich text format), and PostScript formats, 
and images will be provided in tiff format and possibly other formats.  
Versions for e-mail will be in a subset of these formats, with images 
converted to ASCII formats as far as possible to allow e-mail access.

   We invite anyone with experience in non-print publishing of text and/or 
images, or with an understanding of the issues involved in such publishing, 
to send us articles for this publication. Please contact Steve Cunningham 
(cunningham@siggraph.org) or Susan Mair (mair@siggraph.org) if you are 
interested in providing an article.  You are encouraged to contact us early 
to discuss your ideas, and the deadline for completed articles is April 6, 
1993.  We will not ask for copyright transfer for articles in this 
publication and will state clearly with each article that the copyright is 
retained by the author.

   We are very interested in how the graphics community will react to this 
publication.  We expect publication to be on on siggraph.org by early May , 
1993. After that date, to check if the publication is there, you should do 
an anonymous ftp to siggraph.org and download the files
      /publications/May_93_online/README
      /publications/May_93_online/contents
or send e-mail to archive-server@siggraph.org with the Subject line
      send May_93_online index
We will also include a reader survey in this publication because we want 
your feedback on how to use this additional channel to communicate with 
you.

-- Steve Cunningham
   SIGGRAPH director for publications
Newsgroups: comp.graphics
From: kennehra@craft.camp.clarkson.edu (Rich"TheMan"Kennehan)
Subject: 320x200x16 is not what it seems...(???)
Organization: Clarkson University
Date: Tue, 12 Jan 1993 23:48:13 GMT



HI.  I have a VGA card and I wrote a program that initialized 320x200
x16 color mode, and whenever I wrote a byte to memory location
A000:0000, it would write 8 bits instead of 2.  How do I specify
colors in this mode?  Thanks in advance!!!

- Rich
  kennehra@logic.camp.clarkson.edu

Newsgroups: comp.graphics
From: booth@ccad.uiowa.edu (Michael Booth)
Subject: Need a .3D2 converter
Followup-To: booth@ccad.uiowa.edu
Organization: CAD-Research, University of Iowa, Iowa City
Date: Tue, 5 Jan 1993 17:33:47 GMT

Sorry if this is in a FAQ, but I couldnt find the FAQ for this
newsgroup (perhaps someone could tell me where it is).

I have some models in .3d2 format (I found them on an ftp site under
a directory for Atari uploads) and I need to be able to parse the
polygonal data using my own software. So if anyone can tell me the
format spec, or if there are converters to other simple ASCII formats,
please drop me some e-mail to 'booth@ccad.uiowa.edu'.

Thanks in advance.

Mike

-- 
---------- ---------- ---------- ---------- ---------- ---------- ----------
  Michael S. Booth (booth@ccad.uiowa.edu)
  Iowa Driving Simulator Scenario Control Subsystem Developer
  Center for Computer Aided Design, the University of Iowa
Newsgroups: comp.graphics