HDTenEightyP/NetNews huggingface dataset:
From: mal11@po.CWRU.Edu (Matthew A. Lewis)
Newsgroups: comp.graphics
Subject: rayshade on SGI Personal IRIS
Date: 6 Nov 1992 01:36:18 GMT
Organization: Case Western Reserve University, Cleveland, OH (USA)
Reply-To: mal11@po.CWRU.Edu (Matthew A. Lewis)
NNTP-Posting-Host: slc5.ins.cwru.edu


Subject: compiling rayshade on SGI Personal IRIS

hello.....
i am attempting to compile rayshade on a SGI Personal Iris. I don't
know most of the answers to the questions so I just hit return. After I
do a make depend, I do a make which eventually fails as follows:

cc -I.. -I../.. -DLANGUAGE_C -O -c fog.c
accom: Error: fog.c, line 31: static function declaration in inner block is illegal (ANSI C 3.5.1)
	static void ComputeFog();
        ------------------------^
*** Error code 1
Stop.
*** Error code 1
Stop.
*** Error code 1
Stop.


perhaps would you understand this type of error or know where I could
find out more about a config file for this type oif machine? I have
seen reference to the SGI 4D, but I am not familiar with that machine.

I appreciate any help you can offer.
Thank you

Mathieu Lewis
Physics Dept.
Case Western Reservce Univ.

-- 
maThiEu a. LeWis     "I'll see you again/when the stars fall from 
cyber-mercenary       the sky/and the moon has turned red/over one 
Thieves Like Us       tree hill."
mal11@Po.cwru.edu                              This sentnce has threee errors.
From: bmh1@soc10.acpub.duke.edu (Benjamin Mark Holzman)
Newsgroups: comp.graphics
Subject: Re: Graphic File Formats
Date: 11 Nov 92 22:33:10 GMT

Does anyone know where I can get information of GIF file
specifications and other information?

Please email me at bmh1@raphael.acpub.duke.edu.  

Thanx!
From: akin@tuolumne.asd.sgi.com (Allen Akin)
Newsgroups: comp.graphics
Subject: Re: Duplicate Vertices in a Vertex Table
Date: 12 Nov 1992 17:45:23 GMT
Organization: Silicon Graphics, Inc.  Mountain View, CA
NNTP-Posting-Host: tuolumne.asd.sgi.com


In article <1992Nov12.154448.27917@cs.wm.edu>, tracey@ri.cs.wm.edu writes:
> Can anyone give me any pointers to algorithm for removing
> duplicate vertices in a polygon mesh vertex table?

The OFF code from Digital includes routines to do this.
It's archived at many sites, including the new anonymous FTP
site for 3D objects at avalon.chinalake.navy.mil (129.131.31.11).

I believe the relevant routines are OFFPackObj() and OFFPackProperty().

Allen
Newsgroups: comp.graphics
From: pvowles@hawk.adied.oz.au (Paul Vowles)
Subject: ISO standards [Re: (26oct92) comp.graphics FAQ]
Organization: Australian Defence Industries
Date: Wed, 11 Nov 1992 06:23:54 GMT

John.T..Grieggs@freudsys.nl.mugnet.org (John T. Grieggs) writes:

>12) How to order standards documents.

>The American National Standards Institute sells ANSI standards, and also
>ISO (international) standards.  Their sales office is at 1-212-642-4900,
>mailing address is 1430 Broadway, NY NY 10018.  It helps if you have the
>complete name and number.
>
>Some useful numbers to know:
>
>CGM (Computer Graphics Metafile) is ISO 8632-4 (1987).  GKS (Graphical
>Kernel System) is ANSI X3.124-1985.  PHIGS (Programmer's Hierarchical
>Interactive Graphics System) is ANSI X3.144-1988.  IGES is ASME/ANSI
>Y14.26M-1987.  Language bindings are often separate but related numbers;
>for example, the GKS FORTRAN binding is X3.124.1-1985.

	Are any of the above ISO standards ??? If so, does anybody have the
	relavent ISO standards numbers ... thanks ....

	Paul

-- 
Paul Vowles                   ,-_|\               Australian Defence Industries
Software Engineer            /     \            
                             X_,-._/          
Phone: +61 9 333 8826             v                  Email: pvowles@adied.oz.au
Xref: sparky comp.graphics:11550 rec.arts.animation:5250 sci.geo.meteorology:3345 sci.image.processing:1108 sci.med.physics:445
From: honig@dixie.ICS.UCI.EDU ("David A. Honig")
Subject: simple X animator, with digital subtraction and monochrome support
Newsgroups: comp.graphics,rec.arts.animation,sci.geo.meteorology,sci.image.processing,sci.med.physics
Date: 6 Nov 92 01:04:34 GMT


I've updated the "mov.c" source that I've posted before.  "mov"
animates a movie on an X display.  Previously it only handled 8-bit
displays; now it manages on mono displays too.  Also, if you use
the -q option, it will display your movies using digital subtraction.

The source, "mov.c" is in the honig directory on ics.uci.edu.  A compiled
version for sun4s in called mov.sun4.

If you need a movie to try it with, you could ftp the file coffee.128.Z
which is a 128 x 128 x 8-bit x 30 frame file.  Or ftp the iclouds or clouds
scripts and run them, after building mov.  Those scripts get the past day's
weather satellite images (a dozen 600 x 300 x 8 frames).  Subtraction mode
with clouds is pretty cool.

dh
From: ernie@tartarus.uwa.edu.au (Ernest Ong)
Newsgroups: comp.graphics
Subject: OCR sources.
Date: 6 Nov 1992 15:40:52 GMT
Organization: The University of Western Australia
NNTP-Posting-Host: tartarus.uwa.edu.au
X-Newsreader: Tin 1.1 PL5


Does anybody know of an ftp site that contains OCR sources???

Or a good book on the subject.

Regards

Alfred Tascon at ernie@tartarus.uwa.edu.au

Newsgroups: comp.graphics
From: rky57514@uxa.cso.uiuc.edu (Tall Cool One )
Subject: Where can I find graphtal 1.0???
Organization: University of Illinois at Urbana
Date: Fri, 6 Nov 1992 17:44:18 GMT

Maybe I missed the announcement earlier, but where can I find graphtal 1.0?
FTP site??                


 _I_______________________________________________________________________I_
(_@_)                                                                   (_@_)
|   |   Raymond Yeung               Internet: Nimbus@uiuc.edu           |   |
|   |                                         rky57514@uxa.cso.uiuc.edu |   |
|   |   EE student at the                                               |   |
|   |   University of Illinois    CompuServe: 70700,1011                |   |
|   |   at Urbana-Champaign                                             |   |
(___)-------------------------------------------------------------------(___)
  I                                                                       I
Newsgroups: comp.graphics,comp.sys.ibm.pc.misc
From: srlncnc@gopher.dosli.govt.nz (Chris Crook)
Subject: Generic CADD 6 macros - help/information please
Organization: Department of Survey and Land Information, New Zealand
Date: Wed, 11 Nov 1992 00:08:36 GMT

I am trying to write macros for Generic CADD version 6.  The documentation
that comes with it is not very helpful, and, as far as I can tell, not
very complete.

For example the macros that AutoDesk provide include a function
  /SYS,C,...
which is not referenced at all in the documentation.

Do you know of a more comprehensive list of commands, or a useful
quick reference guide, or any 3rd party books which give more detailed
information about macro programming.

If so could you let me know either by email (I will summarise if there
is enough interest) or by posting to comp.sys.ibm.pc.misc.

Many thanks in advance for your help
Chris Crook

Newsgroups: comp.graphics
From: faraghec@cognos.com (Chad Faragher)
Subject: Re: Is POV optically accurate ?
Organization: Cognos Incorporated, Ottawa CANADA
Date: Fri, 13 Nov 1992 15:27:34 GMT

In article <1992Nov12.133317.5833@genes.icgeb.trieste.it> oberto@genes.icgeb.trieste.it (Jacques Oberto) writes:
>I am trying to reproduce one of Newton's experiments with POV.
>Would a simulated white light beam hitting a glass prism with the 
>right angle be scattered into a rainbow spectrum ? 
>Are POV and other ray-tracers optically accurate in that respect ?
>Has anybody tested the properties of 'raytraced' light other than
>reflection and refraction ?

NO, POV is not accurate.  (I can't speak for other ray tracers)

In POV, white light is composed of a RED source a GREEN source and a BLUE
source, as opposed to true "White" light which is composed of light of all
visible frequencies.

Also, POV's refraction does not depend on the frequency of the light.  In 
fact at no point in the program does POV convert RGB to frequency.  The
Red, Green, and Blue light intensities are bundled up into an abstraction
called "colour".  All three beams of move together not as a wave of light,
but throught a single mathematical abstraction called a "Ray".  The ray
is geometrically projected as a single entity, then a "colour" is assigned
to it when it hits something.

Also don't try anything with interference patterns, that's not implemented
either.  Forget about Newton's Rings, and don't look for colour fringing
on a fish in a fishbowl.

If you want to do Newtonian Optics with a ray tracer, the "colour" abstraction
must be more true to life.  Keep in mind that the RGB representation of colour
was chosen because the eye perceives all colours as combinations of these.
It can let you see any colour, but it does not represent the colour properties
of light (frequency properties).  A more suitable representation would
require colour to be a spectrogram, clearly indicating which frequencies of
light are present.  Perhaps a list of hi,lo ranges would be a good data
structure for this becuase one ray would have to be traced for each frequency.

If someone writes a raytracer to do this, lemme know.  Some algorithms to 
convert between Frequency and RGB may be of interest here too.

Chad Faragher -- faraghec@cognos.com
Newsgroups: comp.graphics
From: idpt249@tpts1.seed.net.tw
Subject: Problems with 3D studio
Organization: Seednet Information Service Center
Date: Wed, 4 Nov 1992 06:48:38 GMT

Hello, folks:
I met a problem when doing animations with 3D studio R2. The fact is that
my PC reboots automatically without any error message when rendering is in
progress and almost done.  I tried to use different Pcs,  but problem 
remains.  Here's my environment:
486-66 PC with 32Mb Ram
ET4000 VGA driven by RCPADI
Shading: Phong
Anti-alias: High
Atmosphere: D-Cue
The problem might be in the spot lights.  I have 14 spot lights casting      
shadows and 35000 faces.  If I turned off 4 shadows of these 14 lights, 
it works.  Can anyone tell me ehy is that?  Is there any limitation to 
this package.  Thanks in adv.
Please reply to idpt249@tpts1.seed.net.tw
Neil Chou
Sinotech Engineering Consultants, Inc. TAIWAN
From: seitz@cs.wisc.edu (Steve Seitz)
Newsgroups: comp.graphics
Subject: Re: polyhedron/polyhedron intersection
Keywords: 3d graphics, intersection
Date: 12 Nov 92 16:11:17 GMT
Organization: U of Wisconsin CS Dept

In article <1992Nov12.091352.5323@leland.Stanford.EDU>, ledwards@leland.Stanford.EDU (Laurence James Edwards) writes:
|> In article <1992Nov12.011952.1154@cis.uab.edu>, sloan@cis.uab.edu (Kenneth Sloan) writes:
|> |> [......]
|> |> 
|> |> Here's a nice simple question to keep everyone occupied (sit down Joe -
|> |> this one's not for you).  
|> |> 
|> |> GIVEN an arbitrary, simple polyhedron, P.
|> |> 
|> |> FIND the largest (greatest volume) convex polyhedron completely
|> |> contained in P.
|> 
|> Interesting question ... well it would seem that you'd have to split the
|> polyhedra with planes containing each concave edge. It would also seem that
|> to maximize the volume the splitting plane would have to contain a face.
|> So split the polyhedra up into convex pieces with two splitting planes
|> at each concave edge, then find the combination of convex pieces that
|> maximizes the volume and is convex. Not very efficient (and maybe not even
|> correct) but, as usual, this is just off the top of my head.
|> 

I don't think this will work in general (if I understand you correctly).
Try it with this example:

                                ____________________
                                |                   |
                                |                   |
 minute sharp indentation -->   >                   |  
                                |                   |
                                |___________________|
 
Imagine this in 3D by sweeping along the Z axis (through the screen).
If I understand your suggestion, you'll get something like:

                                ____________________
                                |  /                |
                                | /                 |
                                \/                  |
                                /\                  |
                                | \                 |
                                |__\________________|

which is obviously suboptimal.  The problem gets worse as the corner gets
sharper, in the limit dividing the box in half.

-Steve Seitz
From: sloan@cis.uab.edu (Kenneth Sloan)
Newsgroups: comp.graphics
Subject: Re: polyhedron/polyhedron intersection
Keywords: 3d graphics, intersection
Date: 11 Nov 92 04:01:42 GMT
Article-I.D.: cis.1992Nov11.040142.9570
Organization: CIS, University of Alabama at Birmingham

In article <1992Nov10.221943.18792@sophia.smith.edu> orourke@sophia.smith.edu (Joseph O'Rourke) writes:
>In article <1992Nov10.192804.13981@zip.eecs.umich.edu> katkere@engin.umich.edu writes:
>>I am looking for code/ideas for finding if two polyhedrons intersect.
>
>@article{CD
>, author =	"B. Chazelle and D. P. Dobkin"
>, title =	"Intersection of convex objects in two and three dimensions"
>, journal =	"J. ACM"
>, volume =	34
>, year =	1987
>, pages =	"1--27"
>}

But Joe...what if the polyhedra aren't convex?  



-- 
Kenneth Sloan                   Computer and Information Sciences
sloan@cis.uab.edu               University of Alabama at Birmingham
(205) 934-2213                  115A Campbell Hall, UAB Station 
(205) 934-5473 FAX              Birmingham, AL 35294-1170
From: donc@phred.UUCP (Don Carlson)
Newsgroups: comp.graphics
Subject: Tips for beginner using CGA...
Date: 10 Nov 92 21:12:35 GMT
Article-I.D.: phred.4022
Reply-To: donc@phred.UUCP
Distribution: usa
Organization: Physio-Control

Hello,

Believe it or not, I am fairly new to the PC realm, and I am investigating
a project that will be using CGA (320x200) screen.

I have not worked much with the PC, and would appreciate any pointers for
good reference books on CGA animation/graphics, along with some possible
sites I may obtain some good example code.

If you can, please E-Mail your response directly to me.

					Thanx in advance,
					Don ...

-----------------------------------------------------------------------------
Don L. Carlson                     | Reply: donc@phred.UUCP                  
Physio Control Corp.               |   or : phred!donc@data-io.com           
11811 Willows Rd NE                |   or : ...uunet!pilchuck!phred!donc     
Redmond WA  98073   (206)-867-4376 |   or : pilchuck!phred!donc@uunet.uu.net 
-----------------------------------------------------------------------------
Newsgroups: comp.graphics,comp.graphics.visualization,comp.graphics.animation
From: chrisw@fciad2.bsd.uchicago.edu (chris williams)
Subject: Re: FOLLOW-UP: FTP SITE FOR 3D MODELS/UTILS
Organization: FCIA Univ. of Chicago
Distribution: na
Date: Tue, 10 Nov 1992 04:40:03 GMT

In article <xkj1_fj@rpi.edu> kyriazis@mistral.rdrc.rpi.edu (George Kyriazis) writes:
>In article <1992Nov5.142035.20498@alias.com> Reid Ellis <rae@Alias.com> writes:
>>
>>Does IGES handle NURBS?  I can't recall offhand..
>>
>Yes, it does.. I am not sure, but I think it also handles connectivity
>(ie., topological information) which is always a plus..

   IGES is a fairly bloated format, and a good example of
design-by-commitee. It contains _everyones_ favorite entities
and lacks limits that would encourage a designer to convert his/her
design elements to a common denominator. For example; IGES contains
Autocad's "polyline" entity, bezier splines _and_ NURBSs, with nothing
to encourage one over the other. Thus a given "IGES translator" will,
likely as not, be missing some vital conversion due to the programmer's
lack of familierity with some elements. It's the proverbial "mouse to
government specs."

>It's pretty difficult not to write such software without having money in 
>his mind, so I predict that this discussion about what is the "right" format
>could go on for a LONG time..

    My two cents worth: go with the least common denominator - triangle
polygons, vertex list, face list, surface list, ascii. Hey, you want
free geometry? Beggers can't be choosers, and the greatest quantities
of freely distributable objects are being built by folks using Amigas 
with Sculpt-4D, Imagine, Lightwave, etc. These user have learned to
cope with using triangles as an exchange medium very well. (Really,
its _unbelievable_ how much geometry is out there on Amiga boards.)

                                       Chris Williams
                                          chrisw@fciad2.bsd.uchicago.edu
Newsgroups: comp.graphics
From: orourke@sophia.smith.edu (Joseph O'Rourke)
Subject: Re: polyhedron/polyhedron intersection
Keywords: 3d graphics, intersection
Organization: Smith College, Northampton, MA, US
Date: Wed, 11 Nov 1992 13:57:12 GMT

In article <1992Nov11.041237.9669@cis.uab.edu> sloan@cis.uab.edu (Kenneth Sloan) writes:

>I believe that
>you must also test all edges for intersection with all faces of the
>other polyhedron ...

Exactly.

>Testing vertices works for polygons - ...

Nope:
                        +--+
                        |  |
                        |  |
                +------------------+
                |       |  |       |
                +------------------+
                        |  |
                        |  |
                        +--+
Newsgroups: comp.graphics,comp.org.ieee
From: lwang@eecs.nwu.edu (Liwa Wang)
Subject: range images wanted
Organization: EECS Department, Northwestern University
Distribution: na
Date: Sun, 8 Nov 1992 03:12:12 GMT

I need some range images of simple objects. If anybody has information
on where and how I can access to such images (such as some image
libraries), please e-mail me at lwang@eecs.nwu.edu  Thanks in advance. 


	
Newsgroups: comp.graphics
From: thumper@cs.montana.edu (Wade Hasbrouck)
Subject: Fractint and POV
Organization: Dept. of Computer Science, MSU, Bozeman Mt 59717
Date: Mon, 9 Nov 1992 21:31:00 GMT


I have just gotten POV-Ray 1.0 and have compiled on a DEC Station 5000, and I
have played with Fractint 17.2 a little, but haven't had much time to do much.
I know that Fractint will output a plasma fractal to a file in which DKBtrace
can trace, but will POV be able to trace this file.  One other quick question
regarding this, is where would a good place be to put the light source and the
view point.  I haven't had much luck with the ones I have chose like, I am 
looking at nothing or nothing is illuninated (I tried this with DKBtrace about
a month ago). Just want some quick suggestions.  Please respond via e-mail or
NEWS



Thanks for the time, and thanks in advance,





-- 
Wade A. Hasbrouck
thumper@fubar.cs.montana.edu

Newsgroups: comp.graphics,comp.multimedia,alt.graphics
From: Torbjorn Lindgren <Torbjorn.Lindgren@infolog.se>
Subject: Real Time Encoders for MPEG?
X-Xxmessage-Id: <A7257A6DCF018315@tobbe.lindgren.gbg.infolog.se>
X-Xxdate: Tue, 10 Nov 92 13:40:45 GMT
Organization: Infologics AB-SWEDEN
X-Useragent: Nuntius v1.1.1d9
Date: Tue, 10 Nov 1992 13:45:01 GMT

This article is cross-posted on comp.graphics, comp.multimedia and
alt.graphics.

I'm involved in a project that deals with MPEG coded videos. I want to
know if there are any MPEG-coders that automatically encodes analog video
into a digital stream, prefferebly in real time?

Email answers would be appreciated.

Thanks in advance,

Torbjorn

PS. It would also be very interesting to know if you have any experience
in  this area. DS
From: capelli@vnet.ibm.com (Ron Capelli)
Date: Thu, 12 Nov 92 19:10:56 EST
Newsgroups: comp.graphics
Subject: Re: Is POV optically accurate ?
Disclaimer: This posting represents the poster's views, not those of IBM
News-Software: UReply 3.0

In article <1992Nov12.133317.5833@genes.icgeb.trieste.it>
oberto@genes.icgeb.trieste.it (Jacques Oberto) writes:
>I am trying to reproduce one of Newton's experiments with POV.
>Would a simulated white light beam hitting a glass prism with the
>right angle be scattered into a rainbow spectrum ?
>Are POV and other ray-tracers optically accurate in that respect ?
>Has anybody tested the properties of 'raytraced' light other than
>reflection and refraction ?

Can't say about POV, but here are some references that may be of
interest:

   Spencer W. Thomas,
   "Dispersive refraction in ray tracing",
   The Visual Computer (1986) Vol.2, pp.3-8

   Yokoi, Kurashige, and Toriwaki,
   "Rendering gems with asterism and chatoyancy",
   The Visual Computer (1986) Vol.2, pp.307-312

   Yuan, Kunii, Inamoto, and Sun,
   "GemstoneFire: adaptive dispersive ray tracing of polyhedrons",
   The Visual Computer (1988) Vol.4, pp.259-270

"The Visual Computer" is published by Springer-Verlag.
_______________________________________________________________________

...Ron Capelli                 IBM Corp.  Dept. C13,  Bldg. 703-2
   capelli@vnet.ibm.com        PO Box 950
   (914) 435-1673              Poughkeepsie, NY  12602

"Cold hearted orb, rules the night; removes the colors from our sight.
 Red is Grey, and Yellow White.  But we decide which is right.
 And which is an illusion?"  --  Moody Blues
Newsgroups: comp.graphics
From: tomw@stephanie.megatek.com (Tom Wright)
Subject: "Scientific American Frountiers" rips off SIGGRAPH
Keywords: SIGGRAPH
Organization: Megatek Corporation, San Diego, California
Date: Fri, 13 Nov 1992 19:33:53 GMT

Wednesday night on PBS, "Scientific American Frountiers" presented during
their hour long show a roughly 5 minute segment on SIGGRAPH '92. They showed
the exhibit hall, featured "The Cave", and showed examples of scientific
visualization. Yet they NEVER MANAGED TO SAY THE WORD "SIGGRAPH"! And just 
in case you saw the clip and would give your right arm to attend the next 
conference, they never said the next one would be in Anaheim or that it 
would be next summer.

These are the same jerks who showed the great thunderstorm clip Donna Cox has
popularized WITH THE NARRATION TURNED OFF AND MUSIC SUBSTITUTED so as to
be absolutely sure no one could accidently learn anything.

Prof. Woodie Flowers of MIT is the host. I e-mailed him about the storm tape
last spring. From his answer, I guess they suscribe to the idea that no one 
ever got poor by underestimating the American public. I consider this to be 
another example of the drift in "scientific" programming on PBS to be "content
free" so as to not in any way challange the viewer. 

One wonders if ACM should support PBS activities if this is their attitude.

You can, if you agree with me, send flames to flowers@athena.mit.edu .

Tom Wright
(While I am the SIGGRAPH Treasurer, these opinions are purely my own.)
From: ganter@carson.u.washington.edu (Mark Ganter)
Newsgroups: comp.graphics
Subject: Re: Meta Balls
Keywords: meta balls, blob, implicit surface, soft object
Date: 9 Nov 92 17:57:54 GMT
Article-I.D.: u.1992Nov9.175754.27151
Organization: University of Washington

>Bloomenthal has discussed techniques for modeling organic forms (trees,
>leaves, arms) using blobby techniques [Bloomenthal 1991]
>(though he prefers the term "implicit modeling")...

>Meanwhile, in Canada and New Zealand, the Wyvill brothers, and grad
>students, were doing investigating many of the same ideas...

My colleage (Duane Storti) and I have recently been active in what we call
"Implicit Solid Modeling (ISM)."  Basicly, this is implicit modeling with
various forms of boolean or psuedo-boolean operators.  We find the symbolic
math systems (ala Mma, Maple, Reduce, etc) are a great platform for development
in ISM.  A very simple version of an ISM package was presented in: 

D.W. Storti, M.A. Ganter,and C. Nevrinceanu, "A Tutorial on Implicit Solid
Modeling", _The Mathematica Journal_, Vol. 2, No. 3, 1992

We believe that ISM is a very nature and teachable system for solid modeling.
Our current work focuses on ISM object extent determination, ISM collision
detection and ISM swept solids.  ....Mark

Mark Ganter/Univ of Washington/Seattle, WA 98195/ganter@u.washington.edu
Xref: sparky comp.graphics:11654 comp.multimedia:3303 comp.compression:3782