HDTenEightyP/NetNews huggingface dataset:
From: sjm@miles.com (Scott Mark)
Subject: Re: (04aug92) comp.graphics Frequently Asked Questions (FAQ)
Organization: Miles Inc., Diagnostics Division, Elkhart, IN
Date: Wed, 12 Aug 1992 13:04:58 GMT

In article <h72mr-f.jef@netcom.com> Jef Poskanzer <jef@netcom.com> writes:
>jk87377@cc.tut.fi (Juhana Kouhia):
>}In article <j6ymz8a.jef@netcom.com> Jef Poskanzer <jef@netcom.com> writes:
>}>Anyway, feel free to irk me all you want, if you can find a way.
>}>Juhana's recent posting should provide a good guide.
>}
>}Hmm.. I found this very insulting.
>}However, you're incorrect unless you prove your claim.

"...you're incorrect unless you prove your claim."


This is my favorite post of this whole discussion.
Brilliant debate technique.

At least "you're" and "your" were used correctly.  This time.

sjm
Newsgroups: comp.graphics
From: scollins@cs.tcd.ie (Steven Collins)
Subject: Re: SigGraph, Chicago, and Unions
Keywords: Coffee Break!
Organization: Trinity College, Dublin (Computer Science)
Date: Fri, 14 Aug 1992 17:43:54 GMT

In article <BsyK9q.18s.2@cs.cmu.edu> claude+@cs.cmu.edu (William Welch) writes:
>
>Though generally less polite. My favorite story involves a paper
>session which began to run overtime, and would thus have impacted a
>scheduled AV coffee-break. Supposedly, the crew began flashing a
>message on the speaker's monitor: "Stop Talking".
>

Not entirely true.  Its the AV crews responsibility to ensure that the
speakers are aware of time, and yes they do flick up messages to
speakers as they over-run, it's nothing to do with the AV crew, its
simply the staff of the McCormick Centre get over-time the instant time
runs over so things have to finish spot on or a little early otherwise
it gets very expensive.

Steven Collins
From: shielp@marcus.its.rpi.edu (Paul John Shields)
Newsgroups: comp.graphics
Subject: Sun raster file format
Summary: graphics conversions
Keywords: sun mac rasterfile conversion
Date: 22 Aug 92 03:03:06 GMT
Expires: Thu, 10 Sep 1992 04:00:00 GMT
Organization: Rensselaer Polytechnic Institute, Troy, NY

Is there a way to convert a sun rasterfile created using the
screendump command under sunview to a format that can be read
by a macintosh.

I'd really appreciate any help
Thanks
Paul Shields
shielp@rpi.edu
Newsgroups: comp.graphics
From: nyet@cco.caltech.edu (n liu)
Subject: Re: Is there a mathematical relationship RGB -> wavelength?
Organization: California Institute of Technology, Pasadena
Date: Thu, 13 Aug 1992 23:31:17 GMT

dangold1@iastate.edu (Daniel M Goldman) writes:

>In <92225.171906POLOWINJ@QUCDN.QueensU.CA> Joel Polowin <POLOWINJ@QUCDN.QueensU.CA> writes:

>> > For curiosity's sake, I was wondering if it is possible to take a set
>> > of RGB color fractions and come up with an approximate wavelength of
>> > the observed mixture.  I suppose this could be done by just
>> > interpolating between some known values in a table, but I would like
>> > to know if there is a way to actually calculate the wavelength.  Of
>> > course, I'd also be interested in a formula to compute the RGB
>> > fractions for a given wavelength.

>    In dealing with real light, we run into metamers, colors which look
>    the same under one light source, but look like different colors
>    under a different light source.  Colors expressed as wavelength,
>    I believe, are the most specific.  However, if memory serves, you
>    can have a hue-chroma-brightness specification which can be 
>    matched by more than one "wavelength" specified color, that is,
>    they might be metamers.  I don't really know if this has anything
>    to do with computer color graphics, but if it does, beware. -DmG

Basically, the three coordinate system was made up since we have 3 mostly
independent color receptors. RGB space manages to cover most (but not all)
of the color gamut we are able to see. Keep in mind that our color sense is
extremely crude, i.e. we can't tell the difference between pure magenta
and a spectrum that contains a spike at blue and a spike at red. This is because
our receptors are stimulated "identically" in both cases. CIE did a huge survey
with a bunch of subjects (does this look the same distance in blue to this 
sample as the distance in blue between these other samples? etc.) and came
up with an average cone response for each of the three cones. (foley and van
damn has some stuff on this i think). The CIE colorspaces are a very close
approximation to these responses. In any case, you can look up these response
curves and do a bit of math by superposing the responses to a particular
wavelength and then convert to RGB (i forget what the standard wavelengths
are for RGB... I have some notes on this somewhere, but this info and most of
the rest shouldn't be hard to find in CIE journals.)

Most Sci-Fi stories concern themselves with aliens that "see" EM radiation
in a different range, but not with a different system... Just imagine what
the world would "look" like if you could percieve real spectral lines!
-- 
nyet@cco.caltech.edu
nyet@aerospace.aero.org
Newsgroups: comp.graphics
From: tsines@magnus.acs.ohio-state.edu (Todd J Sines)
Subject: VR on a MAC? possible? i want to know!!
Organization: The Ohio State University
Date: Wed, 19 Aug 1992 16:45:21 GMT

is virtual reality on a macintosh even thinkable, let alone possible? i am 
interested, since i only have access to macs and more macs at work.

please tell me any info at all, or what might be the closest you can get, and 
what is the starting costs on other platforms?

sines
-- 
    respond>>
    **todd sines----email at: tsines@magnus.acs.ohio-state.edu---digitally.**
    **384 E.17th/Columbus, OH 43201 tel614.299.9529---the rest of the world**
Xref: sparky comp.graphics:8873 alt.graphics.pixutils:1947
From: rene@hardy.u.washington.edu (Rene Magritte)
Newsgroups: comp.graphics,alt.graphics.pixutils
Subject: POV
Summary: CTDS and WIndows with POV 1.0
Keywords: POVRAY
Date: 15 Aug 92 16:19:08 GMT
Article-I.D.: u.1992Aug15.161908.29923
Organization: University of Washington


        Has anyone managed to make POV v1.0 work under windows?  I
tried setting up a PIF with as much as four megs of XMS memory, and
compatible data.  I ran CTDS on the result.  Then, I put the file
through the dat2pov converter to get it to a usable format for POV
1.0.  It is at this point that I get stuck.  I don't know what I
should do next -- have the CTDS file as an "include" file as a part of
another file, or go ahead and put the lightsource/camera declarations
in the CTDS file.  In other words, what do you do once you have a good
CTDS conversion to make the raytracer "see" the object.  I am ending
up with lots of black even though I am pretty certain my manually
imput lightsource declaration is there.  My problem, I think, is that
I am not declaring the WHOLE CTDS object as an object or something.
What should I do?  Snippets of code or even whole .pov files
illustrating what procedure I should follow would be appreciated (I
did try looking at NTREAL and others, but it still didn't make sense.
)



        Thanks,
                rene@hardy.u.washington.edu
Newsgroups: comp.graphics
From: kaustine@nbrwh32.bnr.ca (Mathew Kaustinen)
Subject: Re: Where can I find GIF, PCX, PIC and BMP format spec and decoding files
Organization: Northern Telecom, Bramalea, Canada
Date: Wed, 19 Aug 92 15:05:36 GMT

The ISBN number for that book (Supercharged Bitmapped Graphics, by
Steve Rimmer) is: ISBN 0-8306-3788-5

The book contains all of the source for:
 GIF, PCX, PIC, BMP, and LBM graphics formats,
 Postscript output, and SVGA drivers for the Major GC manufacutures.
It is a _MUST_ for DOS graphics programmers

-- I am _NOT_ an official spokesperson for Northern Telecom --
-- 
Mathew A. Kaustinen          |      ESN:   (333) 2066
Field Service Engineering    |      PHONE: 416-452-2066
Northern Telecom, Bramalee   |      PAGER: 416-378-3246
From: wayne@schaefer.math.wisc.edu (Rick Wayne)
Newsgroups: comp.graphics
Subject: FLILIB library for Autodesk Animator available soon...
Date: 17 Aug 92 15:19:04 GMT
Organization: Univ. of Wisconsin Dept. of Mathematics

i have received several mail messages requesting the FLILIB 
library of Autodesk Animator file routines.  i will check out
the copyright issues, and if it's PD, i will post soon on 
where to get it.


rick
Newsgroups: comp.graphics
From: rodney@oslonews (Rodney Jensen)
Subject: Re: POV sample files
Reply-To: r_jensen@oslo.oslo.ingr.com
Organization: Intergraph Norway
Distribution: comp.graphics
Date: Thu, 13 Aug 92 11:22:45 GMT

In article <1992Aug11.034634.22922@wam.umd.edu> ara@wam.umd.edu (Ford Prefect) writes:
>Does anyone know where I can FTP sample files for POV raytracer
>also some utilities that have been updated for the POV 1.0 release?
>
Take a look at 134.117.1.1, thats where I ftpd the raytracer and sample files
from.
--
From: jr@speedy.cs.pitt.edu (Mr Jim Rosenblum)
Newsgroups: comp.graphics
Subject: Wanted graphics library for PC
Date: 12 Aug 92 19:40:19 GMT
Organization: Computer Science Dept., University of Pittsburgh

I'm looking for a graphics library, in C, for the PC. Free would be
nice, but I'll take what I can get. It will be used for an application
that may be marketed. I need to be able to do the standard 3D stuff -
rotate, scale, etc.

e-mail please.

Thanks
jim
jr@speedy.cs.pitt.edu


--
   //----------------------//------------------------------------------------//
  // Jim Rosenblum        //   Read my lips, 'Nothing new in Texas.'        //
 //  jr@cs.pitt.edu      //	                      - George Bush        //
//----------------------//------------------------------------------------//
From: checker@acf5.NYU.EDU (checker)
Newsgroups: comp.graphics
Subject: Re: SIGGRAPH conference history
Date: 17 Aug 92 01:11:07 GMT
Organization: New York University

capelli@VNET.IBM.COM ("Ron Capelli") writes:

>20.  1993   Anaheim
>21.  1994   Orlando
>22.  1995   Los Angeles

Now that's the kind of history I like to see!

Chris
From: kass@oasys.dt.navy.mil (Michael Kass)
Newsgroups: comp.graphics
Subject: Public Domain 2-D/3-D Plot Packages
Date: 19 Aug 92 15:12:47 GMT
Reply-To: kass@oasys.dt.navy.mil (Michael Kass)
Organization: Carderock Division, NSWC, Bethesda, MD

I'm looking for a public domain plotting package using X-windows that can
do a variety of plots, with an easy user interface, and can output to 
a Postscript format file.  Does anyone know where I could find one?

Thanks.
From: hayhurb@cards.com (Brett Hayhurst)
Newsgroups: comp.graphics
Subject: TEST
Date: 21 Aug 92 16:49:11 GMT

This is a test.
From: erich@eye.com (Eric Haines)
Newsgroups: comp.graphics
Subject: Re: The Best of SIGGRAPH 1992
Date: Wed, 12 Aug 92 19:12:14 GMT
Summary: or the worst...
Organization: 3D/EYE, Inc.  Ithaca, NY

In article <1992Aug11.170255.14445@nas.nasa.gov> uselton@wk207.nas.nasa.gov (Samuel P. Uselton) writes:

[some exceedingly good points about the Electronic Message System...]

>Most importantly,
>someone (everyone?) forgot the first rule of replacing an existing
>system with an automated version....  leave the old system in place
>'til the bugs are out of the new.

This is usually the first line in the first chapter of those "how to
computerize your office" books, and I was amazed that it wasn't done at
SIGGRAPH.

In hopes of improving the system for next year, here's my 1.722 cents (in 1980
inflation adjusted pennies):  One of the great advantages of email is that you
can send copies of a single note to many people, but this feature was not
available on the SIGGRAPH system.  I wanted to arrange a lunch meeting, but
cut down on invites after realizing I'd have to type in the same thing
repeatedly (in the past, I could make copies of a paper message I'd want to
send by photocopying them or copying them by hand while waiting for the bus).

A minor beef was that before SIGGRAPH I had arranged to meet someone at the
message board, and since there were now two of them it meant riding the
escalators up and down between them a fair bit.


Other than the message system, the crowded papers reception, and the hike
between the papers/panels and the exhibitions (and these last two couldn't be
helped), I thought this SIGGRAPH was the best planned and most organized I've
seen yet.  Also, Chicago beats Las Vegas any time (my apologies to all
cigar-smoking, gold-pinky-ring-wearing computer graphics programmers out
there who disagree (both of you)).

Eric Haines
From: M.CRAMER@qut.edu.au (Mark Cramer)
Newsgroups: comp.graphics
Subject: RayShade, Animator, TgaFli & AaPlay
Date: 13 Aug 92 17:03:11 GMT
X-Unparsable-Date: 13 Aug 92 13:55:16 GMT+1000



    I have been playing round with RayShade for a little while now, and
was going to produce some Fli files of the images I'm creating.  and I've
hit a little problem.  I have a copy of AutoDesk Animator,  AaPlay (an
fli player) and TgaFli (which converts a sequence of tga files to an fli)

    The files which TgaFli produces don't have a single palette, so the
image flickers from frame to frame.  The Docs for TGAFLI say to load the
Fli in Animator and force it to one palette, which I can do, but then
AaPlay no longer recognises the Fli file.  The docs also say save the
single palette in Animator, and use that to recreate the Fli using
TgaFli. I've tried that too, it just screws up the colours, so they look
nothing like the originals.

    Does anyone know what I'm doing wrong?  Or is there another way of
taking a sequence of TGA files and producing an Fli file, with a single
palette, that AaPlay can play?


    Any help greatly appreciated.


AaPlay.exe is the Autodesk Animator Public domain player version 1.0
AAPLAY   EXE     81904 bytes 05-12-90  12:23p

Autodesk Animator pro version 1.0

TgaFli is AutoDesk AutoFlix release 1.0s


            +-----------------------------------------------+
            | Mark Cramer.                           /\_|\  |
            | Operations Manager,     CBE Section   / QUT>\ |
            | Queensland University of Technology  (  __  | |
            | Australia.      M.Cramer@qut.edu.au   --  \/  |
            | Ph. 07 8642073.     Fax 07 8641525.        v  |
            +-----------------------------------------------+
Organization: Computing Technology Services, Michigan Technological Univ.
Date: Friday, 7 Aug 1992 20:52:31 EST
From: Steve Demlow <SCD@MTUS5.BITNET>
Newsgroups: comp.graphics
Subject:    Deciduous trees: how to ray trace?

I'm looking for advice on how to define deciduous trees for ray tracing.
I need to render a scene with about 260 trees, so I need something cheap!
Ideally, I'd like something that looks reasonably like a tree but is
composed of relatively few elements.  Some sort of definition that lends
itself to bounding volumes would also be nice.  I'm using POVray V1.0.

Branches aren't a problem - I'm using chopped cones generated by a
pseudo-fractal hack, and a bark-like texture wasn't too hard to cook up.
It's the foliage that seems to be the tricky part.  So far I've tried
bounding spheres of subtrees of the branches; to date, this has produced
only rather goofy-looking approximations of trees.  Of more concern to
me is the texture for the foliage.  POV has a "well-defined" noise
function for textures ("bozo"), so one can make a smoothly randomish,
partially transparent green 3D texture.  The problem here is that if you
use any sort of simple object (like a sphere), you get nice smooth clipped
edges.  What would be ideally suited for this problem would be a texture
that varied according to distance from a point (like an object's center).

Any suggestions are welcome.

Thanks,
Steve
--
Steve Demlow - Michigan Technological University, Houghton, MI
scd@mtu.edu
From: galanter@nyu.edu (Philip Galanter)
Newsgroups: comp.graphics
Subject: Re: SigGraph, Chicago, and Unions
Date: 14 Aug 92 18:18:46 GMT
Reply-To: galanter@nyu.edu (Philip Galanter)
Distribution: usa
Organization: New York University

In article <16gpbvINN375@sixgun.East.Sun.COM> nick@sunpix.East.Sun.COM  
(Nick England - Sun NC Development Center) writes:
(...)
|The Chicago unions are great examples of the very worst sort of union
|aroogance and abuse that make honest people sick. I have seen and been
|the victim of the "to hell with you and to hell with common sense" work
|rules that make co-operation a dirty word. Paying some rigger $50 (one
|hour minimum) to wheel a crate 40 ft, a carpenter $50 to open the crate,
|a decorator $50 to hang the sign that was in the crate, and an
|electrician $50 to plug in the sign is hardly distinguishable from any
|other form of extortion. If you are lucky, you can just pay them the
|money and they'll let you plug together your computer system yourself.
|
(...)

Unions are hardly unique in their applying old technology business  
practices to new technology businesses.  But this is no more extortion  
than the support fees computer companies charge to let you talk to them  
about failures in their product...the response usually being some  
combination of denial, your having to educate them, having them read to  
you from a document that you originally cited to them, and eventually  
being bumped up to someone who will tell you "fixed in the next release"
and maybe it is and maybe it isn't because all of their best people are  
working on new products, not supporting old ones.

The notion that the need for unions has passed, and that workers are no  
longer abused is of course nonsense.  Leaving aside ongoing problems  
related to racism, sexism, sexual harassment, etc...there are still places  
in this country straight out of Sinclair or Dickens.  I am reminded of a  
chicken processing plant where workers stand in water above their ankles,  
are locked in the factory ("to prevent theft"), are fired on the spot if  
they leave their post and so will sometimes urinate in place, and missing  
fingers are considered part of the job.  The conditions of migrant  
workers, who put food on all of our tables, are still a national shame.

The lesson of the 80's was that when unions (at the macro-level) cooperate  
and make concessions the resulting gains usually go into the pockets of  
the few at the top.  I have no doubt in my mind that if unions left cities  
like Chicago conditions for working people there would begin a steep  
downward decline.  So even where workers "have it good" there is an  
ongoing need for unions.

Phil

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Philip Galanter         New York University    phone:    212-998-3041
Research Associate      251 Mercer             fax:      212-995-4120
Academic Computing      New York, NY 10012     internet: galanter@nyu.edu
 
   O f f i c e   o f   A r t s   &   M e d i a   T e c h n o l o g i e s
From: hersh@expo.lcs.mit.edu (Jay Hersh)
Newsgroups: comp.graphics
Subject: Re: SigGraph, Chicago, and Unions
Date: 17 Aug 92 17:57:36 GMT
Organization: X Consortium, MIT Laboratory for Computer Science

galanter@nyu.edu (Philip Galanter) writes:


>Both at SigGraph and now here I have heard/read a number of anti-union  
>slams.  Yes, Chicago is a union town...it is also a town where working  
>class people have a chance to earn a decent living and maybe, if they are  
>careful and frugal, buy a home for their family someday.  

>Its time to stop laying the blame for a poor US economy at the feet of the  
>people who have the least power to influence the direction their given  
>industry takes, and are the first to suffer when things go bad.  After 12  
>years of Reagan/Bush/"right-to-work" union busting the economy is in worse  
>shape than ever, save for the few at the very top who enjoy the largest  
>gap between the executive and working class in the West.

>Yes, unions are _sometimes_ corrupt, wasteful, and/or counter-productive.
>So are the government, banks, Fortune 500 companies, and computer industry  
>standards committees.  Please allow working class people the only leverage  
>over their economic future that they have.  At the end of the day they are  
>just like you, tired and a little bit older...


Ahem.... Soapbox on

I know a few people who helped organize this year's SIGGRAPH.
According to them the reason that course attendees got box lunches instead
of the sit down lunch customary in past years was due to the costs 
involved in having a sit down lunch, which they indicated was mostly 
labor. 

Also the course breaks were rigidly scheduled with no flexibility
in time to accomodate the speakers. Again people involved with this
portion of the conference indicated this was due to Union work rules.

I don't know about other portions of the conference (though I've heard horror
stories of $700 slide projector rental costs since an Electrician was
required to plug it in, and an operator to run it), but it is clear from
these 2 examples alone that Union wages in Chicago are higher for comparable
services in other not-necessarily union towns as Boston or Las Vegas,
and that the work rules were substantially less flexible.

I would expect things will have to change substantially before SIGGRAPH 
goes back to Chicago as my hearsay understanding of the impression of those
involved was that people were generally unhappy with certain portions of the
conference (such as I mentioned above), and that much of this was a factor
of inflexible work rules and union costs.

Soapbox off.


My personal opinion is Chicago is a nice town, but in several instances
completely separate from SIGGRAPH I found the service dissapointing.
This could have been my bad luck, or it could be a deeper additudinal
thing among labor there.


	JaH






--
Hopfen und Malz, Gott erhalts
There is nothing open about OpenGL
From: bouma@cs.purdue.EDU (William J. Bouma)
Newsgroups: comp.graphics
Subject: Re: Quaternion questions
Date: 14 Aug 92 00:25:50 GMT
Organization: Department of Computer Science, Purdue University


In article <1992Aug13.201513.9123@meteor.wisc.edu>, brianp@meteor.wisc.edu (Brian Paul) writes:
 
|> Suppose I implement quaternions as a 4-element vector q[4] where:
|>    q[0] = i axis
|>    q[1] = j axis
|>    q[2] = k axis
|>    q[3] = rotation value

I am not sure what you mean here.  What is "i axis"?  When I use 
quaternions q[0] always has cos(X/2) in it.  Where X is my rotation
angle.

|> Is this the correct way to normalize a quaternion to unit length?
|>    double mag = sqrt( q[0]*q[0] + q[1]*q[1] + q[2]*q[2] + q[3]*q[3] );
|>    q[0] /= mag;
|>    q[1] /= mag;
|>    q[2] /= mag;
|>    q[3] /= mag;

Yes!

|> How does one scale a quaternion?  In Baraff's notes on the bottom of
|> page H23 there is the C++ expression:
|>    quaternion qdot = .5 * (rb->omega * rb->q);

Scaling a quaternion is pretty meaningless.  It should always remain unit
length.

This (rb->omega * rb->q) is not a quaternion multiplication.  omega (w)
must be the angular velocity of your object.  The * operation here must
form the matrix
                 [ 0.0 -w[0] -w[1] -w[2]]
                 [w[0]  0.0  -w[2]  w[1]]
                 [w[1]  w[2]  0.0  -w[0]]
                 [w[2] -w[1]  w[0]  0.0 ]

and then do a normal matrix multiplication on the left with q.

You don't have to normalize each time if you are using double precision,
since the normalization is a bit costly.
-- 
Bill <bouma@cs.purdue.edu>
From: frank@whare.cavebbs.welly.gen.nz (Frank van der Hulst)
Newsgroups: comp.graphics
Subject: Re: Autodesk Animator C library?
Date: Sat, 15 Aug 92 15:39:05 NZT
Organization: Tech-Soft Systems, Wellington NZ

murf@spike.comet.ucar.edu (John Murphy) writes:

> Does their exist any C library routines or code to allow a C-program
> to play an FLI animation in DOS?  I have the windows lib, but wish to
> playanimations from DOS also.  I wanted to get around calling the 
> player as a separate program.

I have used FLILIB, which is a PC-specific (TurboC) library to read,
write, and display .FLI files. You can get it from Simtel, I think.

Frank
Newsgroups: comp.graphics