From ox-prg!uknet!mcsun!uunet!usc!zaphod.mps.ohio-state.edu!uwm.edu!linac!convex!constellation!unmvax!bbx!yenta!dt Sat Feb 22 18:58:32 GMT 1992
Article: 114 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!usc!zaphod.mps.ohio-state.edu!uwm.edu!linac!convex!constellation!unmvax!bbx!yenta!dt
From: dt@yenta.alb.nm.us (David B. Thomas)
Newsgroups: alt.3d
Subject: A genuine ASCII stereogram!
Message-ID: <1992Feb12.001639.849@yenta.alb.nm.us>
Date: 12 Feb 92 00:16:39 GMT
Organization: yenta unix pc, rio rancho, nm
Lines: 22
Status: RO

Here's an ASCII single image random dot stereogram for your enjoyment.
To get the 3d effect, you need to diverge (unfocus) your eyes
such that two adjacent letters in the same row come together.
To help you focus, try to make the two capital O's at the top
look like three.  Once you've done that, the rest of the image
should jump out of the screen at you!

                              O    O
n   n   n   n   n   n   n   n   n   n   n   n   n   n   n   n   n
f    f    f    f    f    f    f    f    f    f    f    f    f    f
e   e   e   e   e   e   e   e   e   e   e   e   e   e   e   e   e
a    a    a    a    a    a    a    a    a    a    a    a    a    a
a   a   a   a   a   a   a   a   a   a   a   a   a   a   a   a   a
r    r    r    r    r    r    r    r    r    r    r    r    r    r
r   r   r   r   r   r   r   r   r   r   r   r   r   r   r   r   r


Hope you enjoyed it!

						little david
-- 
Who *cares* if your child made the %&*#@! honor roll?


From ox-prg!bowen Sun Feb 23 15:36:21 GMT 1992
Article: 116 of alt.3d
Path: ox-prg!bowen
From: bowen@prg.ox.ac.uk (Jonathan Bowen)
Newsgroups: alt.3d,comlab.cracker
Subject: Re: A genuine ASCII stereogram!
Message-ID: <2971@culhua.prg.ox.ac.uk>
Date: 23 Feb 92 15:36:09 GMT
References: <1992Feb12.001639.849@yenta.alb.nm.us>
Sender: news@prg.ox.ac.uk
Reply-To: Jonathan.Bowen@prg.oxford.ac.uk (Jonathan Bowen)
Organization: Programming Research Group, Oxford University, UK
Lines: 49
Xref: ox-prg alt.3d:116 comlab.cracker:43
Status: RO

In article <1992Feb12.001639.849@yenta.alb.nm.us> dt@yenta.alb.nm.us
(David B. Thomas) writes:
>Hope you enjoyed it!

Yes I did, thank you very much. So much so, that I have created
one of my own. The instructions are as before:

>Here's an ASCII single image random dot stereogram for your enjoyment.
>To get the 3d effect, you need to diverge (unfocus) your eyes
>such that two adjacent letters in the same row come together.
>To help you focus, try to make the two capital O's at the top
>look like three.  Once you've done that, the rest of the image
>should jump out of the screen at you!

Try moving your head back from the screen and moving it about a bit
once you have focused on the image to increase the stereo effect even
more.  Have fun!  Perhaps we can have a whole series of these!


                            O         O
.  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
 .   .   .   .   .   .   .   .   .   .   .   .   .   .   .   .   .
   .    .    .    .    .    .    .    .    .    .    .    .    .
   .     .     .     .     .     .     .     .     .     .     .
     .      .      .      .      .      .      .      .      .
 .       .       .       .       .       .       .       .       .
      .        .        .        .        .        .        .
   .         .         .         .         .         .         .
.          .          .          .          .          .          .
|          |          |          |          |          |          |
|          |          |          |          |          |          |
|          |          |          |          |          |          |
|          |          |          |          |          |          |
|          |          |          |          |          |          |
|          |          |          |          |          |          |
   .         .         .         .         .         .         .
      .        .        .        .        .        .        .
 .       .       .       .       .       .       .       .       .
     .      .      .      .      .      .      .      .      .
   .     .     .     .     .     .     .     .     .     .     .
   .    .    .    .    .    .    .    .    .    .    .    .    .
 .   .   .   .   .   .   .   .   .   .   .   .   .   .   .   .   .
.  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .



--
Jonathan Bowen, <Jonathan.Bowen@comlab.ox.ac.uk>
Oxford University Computing Laboratory.


From ox-prg!uknet!mcsun!uunet!think.com!unixland!scott Mon Feb 24 20:04:36 GMT 1992
Article: 117 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!think.com!unixland!scott
From: scott@unixland.natick.ma.us (Scott Evernden)
Newsgroups: alt.3d
Subject: Re: A genuine ASCII stereogram!
Message-ID: <1992Feb13.185730.620@unixland.natick.ma.us>
Date: 13 Feb 92 18:57:30 GMT
References: <1992Feb12.001639.849@yenta.alb.nm.us> <1992Feb12.232132.14292@monu6.cc.monash.edu.au>
Organization: Unixland Public Access Unix & Think_Tank BBS
Lines: 17
Status: RO

In article <1992Feb12.232132.14292@monu6.cc.monash.edu.au> steve@monu6.cc.monash.edu.au (Steve Balogh (+61 3 565 4747)) writes:
>In article <1992Feb12.001639.849@yenta.alb.nm.us> dt@yenta.alb.nm.us (David B. Thomas) writes:
>>Here's an ASCII single image random dot stereogram for your enjoyment.
>>
>>                              O    O
>>n   n   n   n   n   n   n   n   n   n   n   n   n   n   n   n   n
>>f    f    f    f    f    f    f    f    f    f    f    f    f    f

>Yes I did. But I also noticed that I could make 'near' appear behind 'far'
>depending on how I focused my eyes. 

Well, in fact, I can't see it any other way- near *is* farther away than
far.  Just look a the codes- the "far"s are widely separated meaning
they're up close, while the "near"s are closer together meaning they're
farther away...

-scott


From ox-prg!uknet!mcsun!uunet!spool.mu.edu!sol.ctr.columbia.edu!chmsun1!jhsiung Tue Feb 25 12:53:34 GMT 1992
Article: 118 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!spool.mu.edu!sol.ctr.columbia.edu!chmsun1!jhsiung
From: jhsiung@chmsun1.csupomona.edu (Jack Hsiung)
Newsgroups: alt.3d
Subject: Re: A genuine ASCII stereogram!
Message-ID: <1992Feb13.190419.18066@ctr.columbia.edu>
Date: 13 Feb 92 19:04:19 GMT
References: <1992Feb12.001639.849@yenta.alb.nm.us> <1992Feb12.232132.14292@monu6.cc.monash.edu.au>
Sender: news@ctr.columbia.edu (The Daily Lose)
Organization: California State Polytechnic University, Pomona
Lines: 14
Status: RO

In article <1992Feb12.232132.14292@monu6.cc.monash.edu.au> steve@monu6.cc.monash.edu.au (Steve Balogh (+61 3 565 4747)) writes:
>
>Yes I did. But I also noticed that I could make 'near' appear behind 'far'
>depending on how I focused my eyes. 
>
>Steve

I found that the odd rows appear closer if I fuse two adjacent letters.
If I fuse 2 letters 2 columns apart, then the even rows appear closer.
So fusing letters at odd or even distances give the opposite illusion.
-- 
Jack Hsiung
cvetp035@csupomona.edu
jhsiung@isis.cs.du.edu


From ox-prg!uknet!mcsun!uunet!zaphod.mps.ohio-state.edu!uwm.edu!fps.mcw.edu!brodie Tue Feb 25 12:58:32 GMT 1992
Article: 119 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!zaphod.mps.ohio-state.edu!uwm.edu!fps.mcw.edu!brodie
From: brodie@fps.mcw.edu
Newsgroups: alt.3d
Subject: Re: A genuine ASCII stereogram!
Message-ID: <1992Feb13.134334.523@fps.mcw.edu>
Date: 13 Feb 92 19:43:34 GMT
References: <1992Feb12.001639.849@yenta.alb.nm.us> <1992Feb12.232132.14292@monu6.cc.monash.edu.au>
Organization: Medical College of Wisconsin,  Milwaukee, WI
Lines: 74
Status: RO

In article <1992Feb12.232132.14292@monu6.cc.monash.edu.au>, steve@monu6.cc.monash.edu.au (Steve Balogh (+61 3 565 4747)) writes:
> In article <1992Feb12.001639.849@yenta.alb.nm.us> dt@yenta.alb.nm.us (David B. Thomas) writes:
>>Here's an ASCII single image random dot stereogram for your enjoyment.

nice, but I found a nice *REAL* random-letter stereogram, a while
ago.  It was posted by charles durst to the "3d" mailing list
(see mail headers below for info).   There is talk that this list
and this newsgroup will be gatewayed sometime soon.   anyway, enjoy
the following.  --kcb
----------------------------------------------
From: cdurst@aecmail.Prime.COM (Charles Durst {x6163})
Subject: Random LETTER Stereograms
To: 3d@bfmny0.BFM.COM (Stereo Photography)
Reply-To: 3d@bfmny0.BFM.COM
Sender: 3d-request@bfmny0.BFM.COM
Errors-To: 3d-error@bfmny0.BFM.COM


With all the talk on this list about "random dot stereograms", I have
been toying with the idea of writing a program to generate random LETTER
stereograms.  The only problem is that I don't have enough spare time to
write such a program.

Anyway, I just created (manually) a sort of "proof of concept" sample of
what I'm talking about.

It is intended for cross-eyed free viewing.  Cross your eyes until the
V's and X's at the top and bottom overlap with the adjacent ones.

V              V              V              V              V
OIWEQPOISDFBKJFOIWEQPOISDFBKJFOIWEQPOISDFBKJFOIWEQPOISDFBKJF
EDGHOUIEROUIYWEVDGHOXUIEROIYWEVDGHEOXUIEOIYWEVDGHEOXUIEOIYWE
KJBSVDBOIWERTBAKJBSVEDBOIWRTBAKJBSOVEDBOWRTBAKJBSOVEDBOWRTBA
SFDHNWECTBYUVRGSFDHNYWECTBUVRGSFDHCNYWECBUVRGSFDHCNYWECBUVRG
HNOWFHLSFDGWVRGHNOWFGHLSFDWVRGHNOWSFGHLSDWVRGHNLOWSFGLSDWVRG
YPOWVXTNWFECHRGYPOWVEXTNWFCHRGYPOWNVEXTNFCHRGYPWOWNVETNFCHRG
SVYUWXRGTWVETUISVYUWVXRGTWVETUISVYUWVXRGWVETUISVYUWVXRGWVETU
WVERBYOIAWEYUIVWVERBEYOIAWEYUIVWVERBEYOIWEYUIVWLVERBEOIWEYUI
EUIOETOUINWEBYOEUIOEWTOUINWEBYOEUIOEWTOUNWEBYOETUIOEWOUNWEBY
WFVEWVETN9PUW4TWFVEWPVETN9UW4TWFVETWPVET9UW4TWFBVETWPET9UW4T
NOUWQERFECHIBYWNOUWQXERFECIBYWNOUWFQXERFCIBYWNOFUWFQXRFCIBYW
VEHWETUQECRFVE[VEHWERTUQECFVE[VEHWQERTUQCFVE[VEOHWQERUQCFVE[
UIWTUIRTWUYWQCRUIWTUYIRTWUWQCRUIWTXUYIRTUWQCRUIBWTXUYRTUWQCR
IYPOWOXNPWTHIECIYPOWTOXNPWHIECIYPONWTOXNWHIECIYLPONWTXNWHIEC
R9UHWVETPUNRQYBR9UHWVETPUNRQYBR9UHWVETPUNRQYBR9UHWVETPUNRQYB
X              X              X              X              X

The letters are not really random, I just got them by pounding on the
keyboard with CAPS LOCK on.  Since there are far fewer letters than there
are dot patterns, it seems to be very important to avoid repeated letters.


Charles Durst				cdurst@aecmail.prime.com
Computervision/Prime Computer		decvax!cvbnet!cdurst

Remember: NOT playing the Lottery only slightly reduces your chances
of winning.

==
3D -- Stereo Photography                  Tom Neff, moderator

To contribute, mail to ...... 3d@bfmny0.BFM.COM
To join or leave, mail to ... 3d-request@bfmny0.BFM.COM

Please include a Subject, and keep line lengths under 80 characters.

-- 
Kent C. Brodie - Sr. Systems Manager		InterNet:  brodie@fps.mcw.edu
Faculty Physicians & Surgeons			uucpNet:   fps.mcw.edu!brodie
Medical College of Wisconsin			MaBellNet: +1 414 266 5080

"Researchers have shown that people who drink four or more cups of
 coffee a day are 40% more prone to heart attacks.... I guess we all
 now know what happened to *MISTER* Olson...."  -Jay Leno


From ox-prg!uknet!mcsun!uunet!orca!scratchy!galt Wed Feb 26 12:41:12 GMT 1992
Article: 123 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!orca!scratchy!galt
From: galt@scratchy.dsd.es.com (Greg Alt - Perp)
Newsgroups: alt.3d
Subject: Re: A genuine ASCII stereogram!
Message-ID: <1992Feb13.230124.5142@dsd.es.com>
Date: 13 Feb 92 23:01:24 GMT
References: <1992Feb12.001639.849@yenta.alb.nm.us> <1992Feb12.232132.14292@monu6.cc.monash.edu.au> <1992Feb13.134334.523@fps.mcw.edu>
Sender: galt@scratchy (Greg Alt - Perp)
Followup-To: alt.3d
Organization: Evans & Sutherland Computer Corp., Salt Lake City, UT
Lines: 28
Nntp-Posting-Host: 130.187.85.107
Status: RO

Can anyone explain the algorithm for this?  I know the basic idea, but
I couldn't figure out how to a random one...  I know that you have to shift
things by one to make it appear at a different depth, but could someone
give a simple algrithm to do this:
 
Given:  a mask:

                      #####    #####
return a row:
               v              v              v   
ABGHDPLOQMENERUABGHDPLOQMENERUABGHDPLOQMENERUABGHDPLOQMENERU
(only shifted correctly...)

I would think you would do a row something like this:
               v              v              v   
ABGHDPLOQMENERUABGHDPLQMENEORUAGHDPLBOQMENERUABGHDPLOQMENERU 
                      ^^^^^    ^^^^^
Note the two places where I shifted...

Is this correct?  This seems to be different way from the random stereogram
that was posted just recently.
-- 
/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)
 "I speak only for myself" -me ) "But if someone came for you one night
 _     _  _     _    ___       )  and dragged you away, do you really 
( ` D  L ( `   /_\ |  |        )  think your neighbors would even care?"
 \7 |\ L  \7   | | L_ |        )    --Jello Biafra, 
      (galt@dsd.es.com)        )  _Last Scream of the Missing Neighbors_


From ox-prg!uknet!mcsun!uunet!cs.utexas.edu!rice!news.rice.edu!kendall Mon Mar  2 11:11:05 GMT 1992
Article: 137 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!cs.utexas.edu!rice!news.rice.edu!kendall
From: kendall@screech.rice.edu (Kendall Helmstetter Gelner)
Newsgroups: alt.3d
Subject: Where to find random dot sterogram ppm generator?
Message-ID: <KENDALL.92Feb16030045@screech.rice.edu>
Date: 16 Feb 92 09:00:45 GMT
Sender: news@rice.edu (News)
Organization: Rice University, Houston, Texas
Lines: 12
Status: RO


A while ago, someone in this group posted something about a program that
could take in a (greyscale?) ppm picture, and output a ppm format random
dot sterogram... could anyone tell me where I might find this program?  I
had it for a while but then accidently deleted it. :-(

Thanks in advance,
--
I am a .signature anti-virus.  If I am obscured, you have a .signature virus!
I am a .signature antKendall Gelner (kendall@rice.edu)ave a .signature virus!
I am a .signature anti-virus.  If I am obscured, you have a .signature virus!
I am a .signature anti-virus.  If I am obscured, you have a .signature virus!


From ox-prg!uknet!mcsun!uunet!europa.asd.contel.com!darwin.sura.net!udel!rochester!cornell!uw-beaver!news.u.washington.edu!milton.u.washington.edu!wiml Mon Mar  2 11:12:04 GMT 1992
Article: 130 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!europa.asd.contel.com!darwin.sura.net!udel!rochester!cornell!uw-beaver!news.u.washington.edu!milton.u.washington.edu!wiml
From: wiml@milton.u.washington.edu (William Lewis)
Newsgroups: alt.3d
Subject: Random-letter stereograms
Message-ID: <1992Feb14.055803.23473@u.washington.edu>
Date: 14 Feb 92 05:58:03 GMT
Sender: news@u.washington.edu (USENET News System)
Organization: The Seattle Group
Lines: 10
Status: RO

A while ago there was posted in one of the sources groups, probably
comp.sources.misc, a program named "rl3d" that can generate arbitrary
random-letter stereograms. These are different from the ones
posted here in that they contsin a separate block of text for
EACH eye, but still I'm able to get good effects. 

-- 
      wiml@u.washington.edu       Seattle, Washington   
     (William Lewis)   |  47 41' 15" N   122 42' 58" W  
       (NeXTmail to wiml@ingalls.cs.washington.edu)


From ox-prg!uknet!mcsun!uunet!munnari.oz.au!uniwa!cujo!marsh!puchm Mon Mar  2 11:12:16 GMT 1992
Article: 131 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!munnari.oz.au!uniwa!cujo!marsh!puchm
From: puchm@marsh.cs.curtin.edu.au (RichardPuchmayer)
Newsgroups: alt.3d
Subject: Re: A genuine ASCII stereogram!
Message-ID: <puchm.698041246@marsh>
Date: 14 Feb 92 04:20:46 GMT
References: <1992Feb12.001639.849@yenta.alb.nm.us> <1992Feb12.232132.14292@monu6.cc.monash.edu.au> <1992Feb13.185730.620@unixland.natick.ma.us>
Sender: news@cujo.curtin.edu.au (News Manager)
Organization: Curtin University of Technology
Lines: 31
Status: RO

scott@unixland.natick.ma.us (Scott Evernden) writes:

>In article <1992Feb12.232132.14292@monu6.cc.monash.edu.au> steve@monu6.cc.monash.edu.au (Steve Balogh (+61 3 565 4747)) writes:
>>In article <1992Feb12.001639.849@yenta.alb.nm.us> dt@yenta.alb.nm.us (David B. Thomas) writes:
>>>Here's an ASCII single image random dot stereogram for your enjoyment.
>>>
>>>                              O    O
>>>n   n   n   n   n   n   n   n   n   n   n   n   n   n   n   n   n
>>>f    f    f    f    f    f    f    f    f    f    f    f    f    f

>>Yes I did. But I also noticed that I could make 'near' appear behind 'far'
>>depending on how I focused my eyes. 

>Well, in fact, I can't see it any other way- near *is* farther away than
>far.  Just look a the codes- the "far"s are widely separated meaning
>they're up close, while the "near"s are closer together meaning they're
>farther away...


I found that if I crossed my eyes I get a different effect from when
I unfocused my eyes.

    My 2 cents,
        Richard.

>-scott
--
Richard Puchmayer == puchm@cutmcvax.cs.curtin.edu.au   | Some of us are poets,
Masters Student at Curtin University of Technology, WA.|  some of us are not!
-------------------------------------------------------+------------------------
I know nothing, so can hold no opinions for myself or others...


From ox-prg!uknet!mcsun!uunet!spool.mu.edu!umn.edu!cs.umn.edu!lynx!unmvax!bbx!yenta!dt Mon Mar  2 11:13:30 GMT 1992
Article: 132 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!spool.mu.edu!umn.edu!cs.umn.edu!lynx!unmvax!bbx!yenta!dt
From: dt@yenta.alb.nm.us (David B. Thomas)
Newsgroups: alt.3d
Subject: another ASCII stereogram!
Message-ID: <1992Feb13.215843.19014@yenta.alb.nm.us>
Date: 13 Feb 92 21:58:43 GMT
Organization: yenta unix pc, rio rancho, nm
Lines: 26
Status: RO

Thanks for all the positive reaction.  A few of you have sent me your
ASCII stereograms, most of which were variants on the same theme.
Here is my rendition of a particularly good idea sent to me by
Matthew Elvey:

   
   g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g
   r   r   r   r   r   r   r   r   r   r   r   r   r   r   r   r   r   r   r
    e    e    e    e    e    e    e    e    e    e    e    e    e    e    e
   a     a     a     a     a     a     a     a     a     a     a     a     a
    t      t      t      t      t      t      t      t      t      t      t
   <<<<>>>><<<<>>>><<<<>>>><<<<>>>><<<<>>>><<<<>>>><<<<>>>><<<<>>>><<<<>>>>
    d      d      d      d      d      d      d      d      d      d      d
   e     e     e     e     e     e     e     e     e     e     e     e     e
    p    p    p    p    p    p    p    p    p    p    p    p    p    p    p
   t   t   t   t   t   t   t   t   t   t   t   t   t   t   t   t   t   t   t
   h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h


To view, try and make a pair of the letter e's (from the lower row of e's)
come together.  This one is not as easy on the eyes as my earlier "near/far"
one, but it has much more depth to it.  Enjoy!

						little david
-- 
Who *cares* if your child made the %&*#@! honor roll?


From ox-prg!uknet!mcsun!uunet!elroy.jpl.nasa.gov!news.claremont.edu!nntp-server.caltech.edu!lakata Mon Mar  2 11:16:51 GMT 1992
Article: 135 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!elroy.jpl.nasa.gov!news.claremont.edu!nntp-server.caltech.edu!lakata
From: lakata@cco.caltech.edu (Mark T. Lakata)
Newsgroups: alt.3d
Subject: Re: another ASCII stereogram!
Message-ID: <1992Feb14.204237.21120@cco.caltech.edu>
Date: 14 Feb 92 20:42:37 GMT
References: <1992Feb13.215843.19014@yenta.alb.nm.us>
Organization: California Institute of Technology, Pasadena
Lines: 24
Status: RO

dt@yenta.alb.nm.us (David B. Thomas) writes:

>   
>   g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g  g
>   r   r   r   r   r   r   r   r   r   r   r   r   r   r   r   r   r   r   r
>    e    e    e    e    e    e    e    e    e    e    e    e    e    e    e
>   a     a     a     a     a     a     a     a     a     a     a     a     a
>    t      t      t      t      t      t      t      t      t      t      t
>   <<<<>>>><<<<>>>><<<<>>>><<<<>>>><<<<>>>><<<<>>>><<<<>>>><<<<>>>><<<<>>>>
>    d      d      d      d      d      d      d      d      d      d      d
>   e     e     e     e     e     e     e     e     e     e     e     e     e
>    p    p    p    p    p    p    p    p    p    p    p    p    p    p    p
>   t   t   t   t   t   t   t   t   t   t   t   t   t   t   t   t   t   t   t
>   h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h  h

you can make almost any row appear in any plane.  It depends on how
many times over you cross your eyes.  for instance, the e and a rows
become periodic if you cross your eyes over 6 e's and 5 a's.  since
they have the same period, they appear on the same plane.  There are
lots of other weird things you can do.

If you diverge your eyes to infinity, the image pops out in the opposite
direction.  It's much harder to diverge your eyes a lot, than to cross them
a lot however.


From ox-prg!uknet!mucs!mcc.ac.uk!M.Whidby Mon Mar  2 11:17:18 GMT 1992
Article: 139 of alt.3d
Path: ox-prg!uknet!mucs!mcc.ac.uk!M.Whidby
From: M.Whidby@mcc.ac.uk (Mark Whidby)
Newsgroups: alt.3d
Subject: random dot stereogram GIFs
Message-ID: <M.Whidby.47@mcc.ac.uk>
Date: 17 Feb 92 09:31:16 GMT
Sender: news@cs.man.ac.uk
Organization: Manchester Computing Center
Lines: 8
Status: RO

If anyone is interested there are a couple of random dot sterogram GIFs 
at wuarchive.wustl.edu. They are called 'stereo' and 'stereo1'. The latter
is in colour and is particularly effective. The first time I saw these I
didn't know what I had to do with them - I thought they were pictures of
raked sand :-)

-------------------------------------------------------------------------
Mark Whidby, Distributed Systems, Manchester Computing Centre


From ox-prg!uknet!mcsun!uunet!haven.umd.edu!wam.umd.edu!dododge Wed Mar  4 18:16:45 GMT 1992
Article: 142 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!haven.umd.edu!wam.umd.edu!dododge
From: dododge@wam.umd.edu (David O. Dodge)
Newsgroups: alt.3d
Subject: Re: Random-letter stereograms
Summary: about rl3d
Message-ID: <1992Feb16.054633.16487@wam.umd.edu>
Date: 16 Feb 92 05:46:33 GMT
References: <1992Feb14.055803.23473@u.washington.edu>
Sender: usenet@wam.umd.edu (USENET News system)
Organization: Workstations at Maryland, University of Maryland, College Park
Lines: 117
Nntp-Posting-Host: rac2.wam.umd.edu
Status: RO

In article <1992Feb14.055803.23473@u.washington.edu>, wiml@milton.u.washington.edu (William Lewis) writes:
> A while ago there was posted in one of the sources groups, probably
> comp.sources.misc, a program named "rl3d" that can generate arbitrary
> random-letter stereograms. These are different from the ones
> posted here in that they contsin a separate block of text for
> EACH eye, but still I'm able to get good effects. 

I wrote rl3d, and posted it a few months back (and someone else announced it
on alt.3d when the group was started). It came from an idea someone had on
the 3d mailing list, where they gave a simple demonstration of a random-
letter stereogram (using two panels). I got bored back in December and wrote
up a program which could generate such stereograms.

Rl3d takes a "program" written in a language similar to LISP and generates
stereo pairs from the pictures described in the program. For example, here's
a little rl3d program I wrote last month as a demonstration for someone:

---------------------------------------------------------------------

;; canadian flag, with maple leaf and bars in front

(setq `mapleleaf (CreateStringPicture
"         1"
"        111"
"      1 111 1"
"      1111111"
"      1111111"
"      1111111"
"    1  11111  1"
" 11 11 11111 11 11"
" 11111111111111111"
"  111111111111111"
"1111111111111111111"
" 11111111111111111"
"  111111111111111"
"   1111111111111"
"    11111111111"
"     111111111"
"    11111111111"
"    111  1  111"
"         1"
"         1"
))

(setq `flagborder1 (CreateStringPicture
"11111 " "11111 " "11111 " "11111 " "11111 " "11111 " "11111 "
"11111 " "11111 " "11111 " "11111 "))
(setq `flagborder1 (ComposePictures flagborder1 (OriginAdd flagborder1 0 11)))

(setq `flagborder2 (CreateStringPicture
" 11111" " 11111" " 11111" " 11111" " 11111" " 11111" " 11111"
" 11111" " 11111" " 11111" " 11111"))
(setq `flagborder2 (ComposePictures flagborder2 (OriginAdd flagborder2 0 11)))
(setq `flagborder2 (OriginAdd flagborder2 29 0))

(setq `bigpicture
    (ComposePictures
        (CreateEmptyPicture 35 22 0)
        flagborder1
        flagborder2
        (OriginCenterInside mapleleaf 35 22)
    )
)

(setq `CharSet
    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
)
(setq `ViewFormat "cross")
(DrawPicture bigpicture)

;; that's all, folks...

-------------------------------------------------------------------------

When I run this through the rl3d interpreter, I get this:

ha741olOR0LgZCxKXCpQP2J8NklubStYHur  Gha741lOR0LgZCxKXCpQP2J8NklubSctYHu
9WRK7qD4JkjERihMX4bkjGFkve161ghcjCN  g9WRK7D4JkjERihMXp4kjGFkve161gMhcjC
zibKTohgvQfI7g1ovEB0vMVarAZStSLg7ST  OzibKThgvQfI7g1o2vEBvMVarAZStSkLg7S
T8VcTA1GvyxOvg1YzWR8tIHId2tuPy1oLsv  WT8VcT1GvyxOvgs1yzWRitHId2tuPyI1oLs
xgDiBKrCr8h47qpw1Y34VuHYx8F6xOtIJUv  gxgDiBrCr8h47qWpw1Y34VHYx8F6xOItIJU
HcVwLODw363Glc7KFcLQZE5En8JSfA5kxy3  cHcVwLDw363Glci7KFcLQZ5En8JSfAe5kxy
Tkn2t0PwTct6dQPI1mL6fs3CN4pwLK78HKz  ITkn2tPwTct6dQaPI1mL6f3CN4pwLKS78HK
7ujgPQjQLmrA1MDA7wpedSNsrI7qbktiv8Z  E7ujgPjQLmrAA1DLA7wpeSoNrI7qbkwtiv8
3CVgFytSJKP4zIpoPA92pCzcxETitQ3Qlex  U3CVgFtSJHKPSzI3oPA92fCzoxEitQo3Qle
XYrmtkvIPkDmPCTubM3gpYvWVq7YpkDEbEv  sXYrmtvIP7kDmPCTubM3gpYvWVqYpk2DEbE
HUtc9sbAVuLuTMNgB0HKbkz6da7kxoXOZsd  cHUtc9bAVuILuTMNgB0HKbkz6d7kxoCXOZs
Foxifmt61gZUD4pChGNq9WtUxi5qJSlqhSD  mFoxift6o1gZUD4pChGNq9WtUxi5JS8lqhS
ZGBcXEjizSrutORunQJcjaRIJujgzITSrk5  4ZGBcXjizZSrutORunQJcjaRIJugzIYTSrk
hSlYlM14LoHmL2J6nsXmfO36tUVwlwNaLSR  ehSlYl14LoMHmL2J6nsXmfO36tVwlweNaLS
9IfWTIJOByZCXOFgdGvmnunMHSrE92nm5y5  G9IfWTJOByZPCXOFgdGvmnunMSrE92unm5y
1e9EZon6dAXyraDInIRyp4RmpOtWpYJ6V2R  u1e9EZn6dAXySraDInIRyp4RpOtWpYqJ6V2
NoZ0z0Jcl8vYz4NMFiPyVYry3YvKX4H47ez  CNoZ0zJcl8vYzN4NMFiPyVYy3YvKX4GH47e
T6r2pQhA5yzcbYZgBkRuNQbWtURydgFAj4v  YT6r2phA5yzcmbYZgBkRuNQbtURydguFAj4
lC5OZozeB2NyJgrWlsNs1aPYb4NQrqFKt8Z  UlC5OZzeB2NyyJgrlvssS1aPb4NQrqkFKt8
fE1EXG1otMXwFa7eJW1i1svIzEry36H8Jm9  KfE1EX1otMXwFa7eJ3Wi1svIzEry36aH8Jm
RkV410VKbqpWVY5qpeLEz6xEzcdgJal4JOV  cRkV41VKbqpWVY5qpjeEz6xEzcdgJaql4JO
bQhGrsXaXKnGlMjifOpcL8Z0byxaDqPivWJ  sbQhGrXaXKnGlMjifOpcL8Z0byxaDqSPivW

To view this cross your eyes until the panels line up, and the maple leaf
and bars on the flag should appear "in front".

Rl3d is a bit rough, since I did almost no design work and hacked it out
in two days, but it does seem to work. If I get around to it, I plan to
add some more commands that will make picture description easier, and
I will probably try to add commands for generating single-panel stereograms
and maybe even pbm-format bitmaps.

You can get pretty good random-*dot* stereo pairs with rl3d by using a
single pixel on/off font and fooling with the picture parameters to make
really BIG panels.

If you want the source, check out the alt.sources archives for the two
shar files or you can send me mail and I'll send you a
uuencoded-compressed-tar file.

                                      -Dave Dodge/dododge@wam.umd.edu


From ox-prg!uknet!mcsun!news.funet.fi!sunic!psinntp!psinntp!rpi!usc!elroy.jpl.nasa.gov!jato!csi!sam Thu Mar  5 10:45:41 GMT 1992
Article: 149 of alt.3d
Path: ox-prg!uknet!mcsun!news.funet.fi!sunic!psinntp!psinntp!rpi!usc!elroy.jpl.nasa.gov!jato!csi!sam
From: sam@csi.jpl.nasa.gov (Sam Sirlin)
Newsgroups: alt.3d
Subject: Re: 4D matrix equation?
Message-ID: <1992Feb20.011343.18825@csi.jpl.nasa.gov>
Date: 20 Feb 92 01:13:43 GMT
References: <1992Feb19.105401.1@happy.colorado.edu>
Sender: usenet@csi.jpl.nasa.gov (Network Noise Transfer Service)
Organization: Jet Propulsion Laboratory, Pasadena, CA
Lines: 17
Originator: sam@kalessin
Nntp-Posting-Host: kalessin
Status: RO


In article <1992Feb19.105401.1@happy.colorado.edu>, kskelm@happy.colorado.edu writes:
|> 	Could someone direct me to a matrix capable of rotating a 4D object on
|> its 4 axes?  Every time I sit down and try to derive such a beast I end up
|> blowing my cerebral cortex :).

Just think of a planar rotation, embedded in 4 space. Recall from 3d
rotations you have a 3x3 matrix with 1 axis invariant - 3 different
ways to do this (e.g. Euler angles). In four space, you have the same
planar rotation (sin etc among 2 axes), but now you'll have 2 ones on
the diagonal in the matrix. Think of choosing 2 axes to form the plane
to do the rotation. You now have 4 chose 2 or 6 ways of doing this.
Hence a general 4 space rotation has 6 degrees of freedom. 6d is just
as easy!
-- 
Sam Sirlin
Jet Propulsion Laboratory         sam@kalessin.jpl.nasa.gov


From ox-prg!uknet!mcsun!uunet!orca!scratchy!galt Fri Mar 13 10:05:53 GMT 1992
Article: 153 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!orca!scratchy!galt
From: galt@scratchy.dsd.es.com (Greg Alt - Perp)
Newsgroups: alt.3d
Subject: Code for random letter stereograms....
Message-ID: <1992Feb21.203030.22364@dsd.es.com>
Date: 21 Feb 92 20:30:30 GMT
Sender: galt@scratchy (Greg Alt - Perp)
Followup-To: alt.3d
Organization: Evans & Sutherland Computer Corp., Salt Lake City, UT
Lines: 26
Nntp-Posting-Host: 130.187.85.107
Status: RO

#include <stdlib.h>
main()
{
char m[100],s[80];
int j,i,e;
 
for(e=0;e<5;printf("X%15s",""),e++);
for(puts(""),scanf("%d\n",&j);gets(m),j>=0;puts(s),j--)
 for(e=s[79]=i=0;i<79;s[i++]=(e||i<16)?'!'+random(92):s[i-16])
  for(e=0;m[i-16]=='#'&&i<79&&i>15;e=1,s[i]=s[i++-15]);
}



First it takes a number that is the number of lines, then it takes
a mask that is made up of lines that are 64 characters long.  In the
mask, #'s represent characters that stick out, while everything else
is background...

-- 
/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)
 "I speak only for myself" -me ) "But if someone came for you one night
 _     _  _     _    ___       )  and dragged you away, do you really 
( ` D  L ( `   /_\ |  |        )  think your neighbors would even care?"
 \7 |\ L  \7   | | L_ |        )    --Jello Biafra, 
      (galt@dsd.es.com)        )  _Last Scream of the Missing Neighbors_


From ox-prg!uknet!mcsun!uunet!orca!scratchy!galt Fri Mar 13 10:06:52 GMT 1992
Article: 158 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!orca!scratchy!galt
From: galt@scratchy.dsd.es.com (Greg Alt - Perp)
Newsgroups: alt.3d
Subject: oops...  (random letter stereogram...)
Message-ID: <1992Feb21.223851.25024@dsd.es.com>
Date: 21 Feb 92 22:38:51 GMT
Sender: galt@scratchy (Greg Alt - Perp)
Followup-To: alt.3d
Organization: Evans & Sutherland Computer Corp., Salt Lake City, UT
Lines: 60
Nntp-Posting-Host: 130.187.85.107
Status: RO

The code I posted works with Turbo C, but to get it to work with unix,
change the "random(92)" to something that gives a random number between
0 and 92...  I changed mine to "random()%92" and it works...
 
Here's the fixed code:
 
#include <stdlib.h>
main()
{
char m[100],s[80];
int j,i,e;
 
for(e=0;e<5;printf("X%15s",""),e++);
for(puts(""),scanf("%d\n",&j);gets(m),j>=0;puts(s),j--)
for(e=s[79]=i=0;i<79;s[i++]=(e||i<16)?'!'+random()%92:s[i-16])
for(e=0;m[i-16]=='#'&&i<79&&i>15;e=1,s[i]=s[i++-15]);
}

and here's some sample output...
 
X               X               X               X               X               
NCHgXng4<#\xfy@DNCHgXng4<#\xfy@DNCHgXng4<#\xfy@DNCHgXng4<#\xfy@DNCHgXng4<#\xfy@
@cQguJ/-@"",{0%t@cQguJ/-@"",{0%t@cQguJ/-@"",{0%t@cQguJ/-@"",{0%t@cQguJ/-@"",{0%
RM_.fqAMsHH(lgLXRM_.fqAMsHH(lgLXRM_.fqAMsHH(lgLXRM_.fqAMsHH(lgLXRM_.fqAMsHH(lgL
MHBm=yE\zG4x"8pTMHB=yE\zG4x"8pT0MHB=yE\zG4"8pT0zMHB=yE\z4"8p-T0zMHB=yE\4"8pu-T0
:uFYi9`$$/[x"!5?:uFi9`$$/[x"!5?E:uFi9`$/[x"!5?E:uFYi9`$/x"!5z?E:uFYi9`$x"!5Bz?E
K1fMq%$$JXycxjgdK1fq%$$JXycxjgd&K1fq%$JXycxjgd&K1fq%K$JXcxjghd&K1fq%K$JcxjgQhd&
%Fu'n-E6ej$4{5,o%Fun-E69ej$4{5,o%FunE69ejW$4{5,o%unE6>9ej$4{5.,o%unE6>ej$42{5.,
b<-O'=!Q(y!uq'3!b<-'=!QK(y!uq'3!b<-'!QK(Hy!uq'3!b-'!Q2K(H!uq'93!b-'!Q2(H!usq'93
m_+Dykz:D/|`cvf#m_+ykz:BD/|`cvf#m_+kz:BbD/|`cvf#m_+kz:BbD|`cvRf#m_+kz:bD|`?cvRf
bK[i]\_P9CoQMEtqbK[]\_P49CoQMEtqbK[\_P4q9CoQMEtqbK[\_P4q9CQMEt/qbK[\_4q9C#QMEt/
KVbYws\=XY'fOazWKVbws\=hXY'fOazWKVbs\=h\XY'fOazWKVbs\=h\XYfOaz+WKVbs\h\XY$fOaz+
KE|wi?8H[nK)G0biKE|i?8HO[nK)G0biKE|i8HO[niK)G0biKE|i8HO[ni)G0bQiKE|i8O[niR)G0bQ
EW;@<8v'@LSjpR0]EW;<8v'q@LSjpR0]EW;<8'q@LSjpRG0]EW;<8'q@LSjRG0](EW;<'q@LwSjRG0]
`R$R.1?(EoY5JtTe`R$.1?(EoY5Jt/Te`R$.1?(oY5Jt/Te`NR$.1?(oY5J/Te`kNR$.?(oYN5J/Te`
yicm??M[1|Uqz$FSyic??M[1|Uqz$\FSyic??M[1|Uz$\FSyicd??M[1|Uz\FSyZicd?M[1|$Uz\FSy
#6aL-8\der]._DzI#6a-8\der]._D.zI#6a-8\der]._D.I#6a-r8\der]._.I#6Oa-8\de>r]._.I#
=OZ:{$lZ3I*]+jT7=OZ{$lZM3I*]+jT7=OZ{$lZM3I*]+jT7OZ{$3lZM3I*]jT7OFZ{3lZM^3I*]jT7
Q'k[r4'#Q!h9OFSMQ'kr4'#qQ!h9OFSMQ'kr4'#qQ!h9OFSMQkr4'j#qQ!h9FSMQSkr'j#qOQ!h9FSM
_(0i=cKiBqrrw,xl_(0=cKigBqrrw,xl_(0=cKigBqrrw,xl_0=cKJigBqrrwxl_0:cKJi;gBqrrwxl
J%TxrRqfgo9Ivp]6J%TrRqfVgo9Ivp]6J%TrRqfVgo9Ivp]6JTrRq,fVgo9Iv]6JTJRq,fCVgo9Iv]6
Hh`Bs[Y^(rDQvCulHh`s[Y^@(rDQvCulHh`s[Y^@(rDQvCulH`s[Y5^@(rDQvulH`![Y5^+@(rDQvul
'9SHT4).gzx2e\{('9ST4).:gzx2e\{('9T4).W:gzx2e\{(9T4)e.W:gzx2e\(9T4)e.jW:gzx2e\(
LTfmw*(:>)DliC_ALTfw*(:">)DliC_ALTw*(:3">)DliCALTw*v(:3">)DliCLTw*v(:h3">)DliCL
1qEAPCH6yX#p04`*1qEPCH6yX#p04`*>1qECH6yX#p04`*>1qhECH6yX#p04`*1qhECH6kyX#p04`*1
[p3s(UUH"4AiD61d[p3(UUH"4AiD61d1[p3(UH"4AiD61d1S[p3(UH"4AiD61d1[p3(UXH"4AiD61d1
Fw3pjB(uKE`:K{tAFw3jB(uKE`:K{tA'Fw3jB(uK`:K{ttA'Fw3jB(uK`:K{ttA'Fw3jB(uK`:K{ttA
BNuU;-DP=S,;.R]ABNuU;-DP=S,;.R]ABNuU;-DP=S,;.R]ABNuU;-DP=S,;.R]ABNuU;-DP=S,;.R]
mJbtBYdN>3t]{zThmJbtBYdN>3t]{zThmJbtBYdN>3t]{zThmJbtBYdN>3t]{zThmJbtBYdN>3t]{zT
tth2$W-h.8N;5.'Ntth2$W-h.8N;5.'Ntth2$W-h.8N;5.'Ntth2$W-h.8N;5.'Ntth2$W-h.8N;5.'
#imlmUeV3]6YZ5my#imlmUeV3]6YZ5my#imlmUeV3]6YZ5my#imlmUeV3]6YZ5my#imlmUeV3]6YZ5m


-- 
/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)/)
 "I speak only for myself" -me ) "But if someone came for you one night
 _     _  _     _    ___       )  and dragged you away, do you really 
( ` D  L ( `   /_\ |  |        )  think your neighbors would even care?"
 \7 |\ L  \7   | | L_ |        )    --Jello Biafra, 
      (galt@dsd.es.com)        )  _Last Scream of the Missing Neighbors_


From ox-prg!uknet!mcsun!news.funet.fi!sunic!psinntp!psinntp!uunet!zaphod.mps.ohio-state.edu!uwm.edu!rutgers!bach.rutgers.edu!caip.rutgers.edu!froncio Fri Mar 13 10:08:12 GMT 1992
Article: 169 of alt.3d
Path: ox-prg!uknet!mcsun!news.funet.fi!sunic!psinntp!psinntp!uunet!zaphod.mps.ohio-state.edu!uwm.edu!rutgers!bach.rutgers.edu!caip.rutgers.edu!froncio
From: froncio@caip.rutgers.edu (Andy Froncioni)
Newsgroups: alt.3d
Subject: Stereograms...
Keywords: 3d, graphics
Message-ID: <Feb.26.12.45.45.1992.9146@caip.rutgers.edu>
Date: 26 Feb 92 17:45:46 GMT
Organization: Rutgers Univ., New Brunswick, N.J.
Lines: 17
Status: RO

OK, I'm sure this will qualify me for the "Worst Listener of
the Year" award, but I just let all those nice postings about
stereograms go by without really understanding how to do it.

I'd like to display 3d CAD wireframe images using stereograms.

Can anyone tell me how to do that?

Please e-mail me if you think everyone else is already sick of
hearing about this stuff...

Thanx,

Andy
-- 
Andy Froncioni			CAIP Center Parallel Computing Lab
froncio@caip.rutgers.edu	Rutgers University, Piscataway, NJ


From ox-prg!uknet!mcsun!fuug!news.funet.fi!sunic!psinntp!psinntp!rpi!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!bronze!jbaron@silver.ucs.indiana.edu Fri Mar 13 10:09:33 GMT 1992
Article: 170 of alt.3d
Path: ox-prg!uknet!mcsun!fuug!news.funet.fi!sunic!psinntp!psinntp!rpi!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!bronze!jbaron@silver.ucs.indiana.edu
From: jbaron@silver.ucs.indiana.edu (Jeffrey Baron)
Newsgroups: alt.3d
Subject: Re: 3d gifs
Message-ID: <1992Feb26.161155.8393@bronze.ucs.indiana.edu>
Date: 26 Feb 92 21:11:27 GMT
References: <880188s.699132738@aucs>
Organization: Indiana University
Lines: 13
Status: RO

There are three GIFs available I know of that are 3d at wuarchive.wustl.edu:
graphics/gif/s/stereo
graphics/gif/s/stereo1 (color)
grapcics/gif/s/st0092s (color)
The first two are scattergrams, the last is a dual perspective picture.
All in all, if you can stand the head aches, you'll enjoy them.

(.X.X.X.X.X.X.X.X.X.X.X.X.X.X.)/ I heard two claps of thunder         \ 
Jeffrey Sittenfield Baron  (_  | this afternoon.                      |
b.k.a. Phaedrus            -__-| Well, we hear - sometimes we see.    |
Indiana University Psychology  | which doesn't say                    |
jbaron@silver.ucs.indiana.edu  | there is a world, or we are.         |
('X'X'X'X'X'X'X'X'X'X'X'X'X'X')\ But something is.    - William Bronk /


From ox-prg!uknet!mcsun!uunet!zaphod.mps.ohio-state.edu!qt.cs.utexas.edu!yale.edu!cmcl2!sbcs.sunysb.edu!engws10.ic.sunysb.edu!ggregori Fri Mar 13 10:09:53 GMT 1992
Article: 171 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!zaphod.mps.ohio-state.edu!qt.cs.utexas.edu!yale.edu!cmcl2!sbcs.sunysb.edu!engws10.ic.sunysb.edu!ggregori
From: ggregori@engws10.ic.sunysb.edu (Greg "Killing Fingers" Gregorio)
Newsgroups: alt.3d
Subject: Re: 3d gifs
Message-ID: <1992Feb27.204812.26109@sbcs.sunysb.edu>
Date: 27 Feb 92 20:48:12 GMT
References: <880188s.699132738@aucs>
Sender: usenet@sbcs.sunysb.edu (Usenet poster)
Organization: Slaughterhouse at Stony Brook
Lines: 32
Nntp-Posting-Host: engws10.ic.sunysb.edu
Status: RO

In article <880188s.699132738@aucs> 880188s@aucs.acadiau.ca (Craig Stephen) writes:
>
>    Could someone send or tell me where I could get some 3-d gifs or for
>that matter any other format.  I got a 3d fern and a gif of stonehenge off
>of here a while ago and would like some more graphics for my pc.


	If possible, e-mail me where I could get the 3d gifs as well.
Thanx.
-- 
                          ___====-_  _-====___
                    _--^^^#####//      \\#####^^^--_
                 _-^##########// (    ) \\##########^-_
                -############//  |\^^/|  \\############-
              _/############//   (@::@)   \\############\_
             /#############((     \\//     ))#############\
            -###############\\    (oo)    //###############-
           -#################\\  / ** \  //#################-
          -###################\\/      \//###################-
         _#/|##########/\######(   /\   )######/\##########|\#_
         |/ |#/\#/\#/\/  \#/\##\  |  |  /##/\#/  \/\#/\#/\#| \|
         '  |/  V  V  '   V  \#\| |  | |/#/  V   '  V  V  \|  '
            '   '  '      '   / | |  | | \   '      '  '   '
                             (  | |  | |  )
                            __\ | |  | | /__
                           (vvv(VVV)(VVV)vvv)

   	         IF IT'S TOO LOUD, THEN YOU ARE TOO OLD.
							-The Metal Duck

	- ggregori@csws9.ic.sunysb.edu
	- ggregori@ccmail.sunysb.edu


From ox-prg!uknet!mcsun!uunet!spool.mu.edu!tulane!ukma!hsdndev!rutgers!mcnc!borg!news_server!martinc Mon Mar 16 17:23:28 GMT 1992
Article: 190 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!spool.mu.edu!tulane!ukma!hsdndev!rutgers!mcnc!borg!news_server!martinc
From: martinc@hatteras.cs.unc.edu (Charles R. Martin)
Newsgroups: alt.3d
Subject: Beginners code for 3D stuff
Message-ID: <MARTINC.92Mar4191023@hatteras.cs.unc.edu>
Date: 5 Mar 92 00:10:23 GMT
Sender: news@cs.unc.edu
Distribution: alt
Organization: /theta/theta5/unc/martinc/.organization
Lines: 20
Status: RO

I don't know if there is an FAQ for this group, so I'll just take my
life in my hands here --

I've just recently discovered the "scattergram" stereoimaging trick.  Is
there any code lying about for doing this?  Or can someone recommend
some references for the way that a stereopair is transformed into such a
picture? 

Just in case I've not got the terminology right, I mean the particular
approach whereby both parts of the image are stored in one scattergram
that is merged by cross-eyed viewing.

Thanks for any references.

--
Charles R. Martin/(Charlie)/martinc@cs.unc.edu/(nee crm@cs.duke.edu) 
O/Department of Computer Science/Sitterson Hall/UNC/Chapel Hill, NC 27599
H/3611 University Dr #9N/Durham, NC 27707/(919) 419 1754
The universe is full of magical things patiently waiting for our wits to
grow sharper.  -- Eden Phillpot, I'm told.  Anyone have a better reference?


From ox-prg!uknet!mcsun!uunet!haven.umd.edu!darwin.sura.net!jhunix.hcf.jhu.edu!incubus Mon Mar 16 17:23:59 GMT 1992
Article: 191 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!haven.umd.edu!darwin.sura.net!jhunix.hcf.jhu.edu!incubus
From: incubus@jhunix.hcf.jhu.edu (Alexander Swietlicki)
Newsgroups: alt.3d
Subject: Re: Beginners code for 3D stuff
Message-ID: <1992Mar5.040505.26615@jhunix.hcf.jhu.edu>
Date: 5 Mar 92 04:05:05 GMT
References: <MARTINC.92Mar4191023@hatteras.cs.unc.edu>
Distribution: alt
Organization: HAC - Johns Hopkins University, Baltimore
Lines: 19
Status: RO

In article <MARTINC.92Mar4191023@hatteras.cs.unc.edu> martinc@hatteras.cs.unc.edu (Charles R. Martin) writes:
>I don't know if there is an FAQ for this group, so I'll just take my
>life in my hands here --
>
>I've just recently discovered the "scattergram" stereoimaging trick.  Is
>there any code lying about for doing this?  Or can someone recommend
>some references for the way that a stereopair is transformed into such a
>picture? 
>
>Just in case I've not got the terminology right, I mean the particular
>approach whereby both parts of the image are stored in one scattergram
>that is merged by cross-eyed viewing.

	Oh, THAT's what you're supposed to do.  If I look at it that
way, it pops out of the screen.  If I focus my eyes behind the screen,
I still see it in 3d, but all the parts which pop up are inverted and
appear to dip inward.  However, I don't get a headache this way... :-)

					Alex Swietlicki


From ox-prg!uknet!mcsun!uunet!haleiki!haleiki.nyc.ny.us Mon Mar 23 12:02:01 GMT 1992
Article: 207 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!haleiki!haleiki.nyc.ny.us
From: tneff@haleiki.nyc.ny.us (Tom Neff)
Newsgroups: alt.3d
Subject: Re: Is this group for 3-D stuff ???
Message-ID: <719045@haleiki.NYC.NY.US>
Date: 13 Mar 92 05:27:05 GMT
References: <901430w.700355447@aucs> <719042@haleiki.NYC.NY.US> <i6esv0s@fido.asd.sgi.com>
Reply-To: tneff@haleiki.nyc.ny.us (Tom Neff)
Lines: 42
Status: RO

In article <i6esv0s@fido.asd.sgi.com> gavin@krypton.asd.sgi.com (Gavin Bell) writes:
>In <719042@haleiki.NYC.NY.US> tneff@haleiki.nyc.ny.us (Tom Neff) writes:
>>I originally created it to discussion stereoscopy and holography, but it
>>quickly got co-opted by the wireframe crowd and others who think a flat
>>picture of a solid object qualifies as "3D".  So, I'm not sure what it's
>>for anymore.
>
>If you can put up a series of 'flat' pictures of solid objects
>fast enough that you can interact with them, does that count as 3D?

In that case, _Gone With The Wind_ must be a 3D movie.  Far out!

>I've heard the phrase "If it dont move it ain't 3D" here at Silicon
>Graphics.  

Presumably because they've figured out how to make stuff move.  If they
had figured out how to attach odors to pictures instead, you'd probably
be hearing the phrase "If it dont smell it ain't 3D" at Silicon Graphics.
This is called making a virtue of convenience.

>          Stereoscopy, which is really just two flat pictures,
>wouldn't count.  

Stereoscopy is not "two flat pictures."  Stereoscopy is the PROCESS by
which showing separate image information -- still images, moving images,
odor attached or what have you -- to the right and left eye causes the
human brain to re-create the experience of DEPTH, otherwise known as the
"third dimension" or 3D.  (Aha!)

>So, I think it is appropriate that this newsgroup be a place for
>discussing the more general problems of interacting with 3D solid
>objects (instead of just exploring ways of looking at them).

So it appears after a few weeks of the newsgroup.  I am powerless to
change this perception, I can only point it out.  It was my error to
forget that "3D" has become a term of art for programmers whose code
simply knows about solid objects, and for whom actual human perception
of depth in the image is just a special case of the display problem.
It is evident from subsequent postings that y'all needed a place to chat,
and more power to you.  I will continue with the mailing list
(3D-REQUEST@BFMNY0.BFM.COM) for now, and we'll try a new alt or rec group
in a bit.  Bon appetit.


From ox-prg!uknet!mcsun!uunet!wupost!uwm.edu!rutgers!rochester!kodak!ispd-newsserver!psinntp!newstand.syr.edu!rodan.acs.syr.edu!dbarberi Mon Mar 23 12:05:38 GMT 1992
Article: 225 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!wupost!uwm.edu!rutgers!rochester!kodak!ispd-newsserver!psinntp!newstand.syr.edu!rodan.acs.syr.edu!dbarberi
From: dbarberi@rodan.acs.syr.edu (London W11)
Newsgroups: alt.3d
Subject: FTP site for 3d
Message-ID: <1992Mar18.020401.18316@newstand.syr.edu>
Date: 18 Mar 92 07:04:01 GMT
Organization: Syracuse University, Syracuse, NY
Lines: 23
Status: RO


     Hello Net.world!

	   There's been a lot of people asking about ftp sites, so I 
	   thought I would mention the VR archive here at Syracuse.  
	   I've set up a directory with files related to 3d viewing.
	   It's available to anyone by ftp'ing to:
	       sugrfx.acs.syr.edu (that's 128.230.24.1)

           The 3d files are located in /pub/vr/3d.  If you would
	   like to (please!) put any files up please place them
	   in /pub/incoming.

		       
                             --=--------------------------------------------.
  _          _    _____                        David Barberi                |
  \\        //   ||---\\                       -------------                |
   \\      //    ||    ||               dbarberi@sugrfx.acs.syr.edu         |
    \\    //     ||___//                                                    |
     \\  //      ||---\\          Syracuse University Virtual Reality Lab   |
      \\//       ||    \\                 Syracuse, New York, USA           |
       \/        ||     \\            "Bringing Cyberspace to the masses"   |
                             --=--------------------------------------------'


From ox-prg!uknet!mcsun!uunet!haven.umd.edu!darwin.sura.net!jvnc.net!yale.edu!think.com!spdcc!dirtydog.ima.isc.com!newsserver.pixel.kodak.com!kinsman Tue Jun 16 10:36:41 BST 1992
Article: 485 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!haven.umd.edu!darwin.sura.net!jvnc.net!yale.edu!think.com!spdcc!dirtydog.ima.isc.com!newsserver.pixel.kodak.com!kinsman
From: kinsman@ssd.kodak.com (Andy Kinsman 253-7794)
Newsgroups: alt.3d,comp.lang.postscript
Subject: Random dot Stereogram -> torus.ps
Message-ID: <1992Jun12.155811.21317@pixel.kodak.com>
Date: 12 Jun 92 15:58:11 GMT
Sender: news@pixel.kodak.com
Organization: Eastman Kodak
Lines: 2585
Xref: ox-prg alt.3d:485 comp.lang.postscript:7420
Originator: kinsman@massive
Status: RO

I hope this keeps you random dot stereogram people happy.
It plots a torus on postscript printer, in landscape mode.

to view on a sun box at least...

  1. cut out the file below
  2. uudecode file               -> yields torus.ps.Z
  3. uncompress torus.ps.Z       -> yields torus.ps
  4. ship it to a printer...     -> try "lpr torus.ps"

If you show it to a group of people, and more than 15%
can see it, tell me how you displayed it so that they could.

I have about twenty others, including fractals.  Now the
focus is on scanning really interesting subjects:-) But I
don't know what groups to post those to.  The first 4-5
off the press were shipped to the Stereo World magazine.

Look for my name in the bottom border. -AAK

kinsman@ssd.kodak.com

CUT-HERE-CUT-HERE-CUT-HERE-CUT-HERE
begin 666 torus.ps.Z
[ omitted ]
 
end


From ox-prg!uknet!mcsun!uunet!haven.umd.edu!ncifcrf!fcs260c2!toms Mon Jun 22 11:19:54 BST 1992
Article: 521 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!haven.umd.edu!ncifcrf!fcs260c2!toms
From: toms@fcs260c2.ncifcrf.gov (Tom Schneider)
Newsgroups: alt.3d,comp.lang.postscript
Subject: Re: Random dot Stereogram -> torus.ps
Message-ID: <3415@fcs280s.ncifcrf.gov>
Date: 18 Jun 92 21:18:55 GMT
References: <1992Jun12.155811.21317@pixel.kodak.com> <1992Jun16.210842.4007@ucsu.Colorado.EDU> <1992Jun17.025430.13948@primerd.prime.com>
Sender: news@ncifcrf.gov
Followup-To: alt.3d
Organization: Frederick Cancer and Research Devlopment Center
Lines: 56
Xref: ox-prg alt.3d:521 comp.lang.postscript:7496
Status: RO

In article <1992Jun17.025430.13948@primerd.prime.com> hnguyen@hob1.prime.com
(Hien Huu Nguyen) writes:
|In article <1992Jun16.210842.4007@ucsu.Colorado.EDU>, knapp@spot.Colorado.EDU
| (David Knapp) writes:
|> In article <1992Jun12.155811.21317@pixel.kodak.com> kinsman@ssd.kodak.com
|> (Andy Kinsman 253-7794) writes:
|> >I hope this keeps you random dot stereogram people happy.
|> >It plots a torus on postscript printer, in landscape mode.
|> 
|> *Please* post more of these! These are TOO COOL!
|> 
|> Can you expound on the process used to create these?  This was really quite
|> striking.
|> 
|How about expounding on the process to SEE these?  Try as I might, I couln't
|see anything. What am I missing?
|Hien Nguyen hnguyen@cal3.prime.com (also try hnguyen@s34.prime.com)

Unfortunately these, although beautiful, are not good to learn the method
with.  I suggest pulling out a few issures of the Journal of Molecular Biology
where there are often good stick figure sterio pictures of molecules.  The
sterio pairs are usually presented on the page so that the left one should be
seen by your left eye and the right one should be seen by your right eye.
Don't cross your eyes.  When you look at something in the far distance your
eyes are like this: || (parallel).  When you look at something close, they will
be like this:  /\ (focused to a point).  The idea is to have the eyes parallel
so that each sees the right image, but in focus on the page.  Start by looking
at something far away.  On David Knapp's image there are two triangles.  If you
have the paper near your eyes as you look far away, there will probably be 4
triangle images, and they will be fuzzy.  The trick will be to get what looks
like 3 triangles.  The middle one is the fused image.  You are to ignore the
outer two.  Ok, here's what to do.  Put those triangles on the top of the page,
and put the page just under your line of sight.  Look to the far distance.
RELAX!  Allow your eyes to drift down onto the page where the triangles are,
but don't focus.  Allow the triangles to overlap.  You may have to rotate the
page a little to get them to overlap (they have to line up with your eyes,
right?)  Concentrate on getting them to overlap, and don't worry that they are
fuzzy.  Once they overlap, slowly allow them to come into focus.  As you
succeed in doing this the torus will begin to appear further down on the page.
You can carefully move your eyes down and explore it.  The center is pretty
neat.  You can see the layers on it also.

It is really better to do this while the page is lying flat and still, since
the stereo effect will be destroyed if you move too much relative to the
paper.  Also, before you start, make sure that the lighting is the same on both
stereo parts (or across the image in the case of the random dot ones), to avoid
distracting highlights.

Don't worry.  It takes some practice to do it, but the images can be
spectacular.  Often they feel more three dimensional than real objects!

  Tom Schneider
  National Cancer Institute
  Laboratory of Mathematical Biology
  Frederick, Maryland  21702-1201
  toms@ncifcrf.gov


From ox-prg!uknet!mcsun!uunet!munnari.oz.au!uniwa!watson Mon Jun 22 11:20:11 BST 1992
Article: 523 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!munnari.oz.au!uniwa!watson
From: watson@maths.uwa.oz.au (David Watson)
Newsgroups: alt.3d
Subject: Re: Random dot Stereogram -> torus.ps
Message-ID: <1992Jun19.011212.17107@uniwa.uwa.edu.au>
Date: 19 Jun 92 01:12:12 GMT
References: <1992Jun12.155811.21317@pixel.kodak.com> <1992Jun16.210842.4007@ucsu.Colorado.EDU> <1992Jun17.025430.13948@primerd.prime.com> <3415@fcs280s.ncifcrf.gov>
Sender: news@uniwa.uwa.edu.au (USENET News System)
Organization: University of Western Australia
Lines: 18
Nntp-Posting-Host: madvax.maths.uwa.oz.au
Status: RO

toms@fcs260c2.ncifcrf.gov (Tom Schneider) writes:

>I suggest pulling out a few issures of the Journal of Molecular Biology
>where there are often good stick figure sterio pictures of molecules.  The
>sterio pairs are usually presented on the page so that the left one should be
>seen by your left eye and the right one should be seen by your right eye.

See the article

Speakman, J.C., 1978, Visualising molecules without really trying your eyes,
New Scientist, vol. 78, p. 827.


--
Dave Watson                           Internet: watson@maths.uwa.oz.au
Department of Mathematics            
The University of Western Australia               Tel: (61 9) 380 3359
Nedlands, WA 6009  Australia.                     FAX: (61 9) 380 1028


From ox-prg!uknet!mcsun!corton!chorus!opera.chorus.fr!mir Mon Jun 22 11:21:54 BST 1992
Article: 531 of alt.3d
Path: ox-prg!uknet!mcsun!corton!chorus!opera.chorus.fr!mir
From: mir@opera.chorus.fr (Adam Mirowski)
Newsgroups: alt.3d
Subject: Re: Random dot Stereogram -> torus.ps
Message-ID: <13753@chorus.fr>
Date: 19 Jun 92 13:48:41 GMT
References: <1992Jun12.155811.21317@pixel.kodak.com> <NELSON.92Jun18114812@cheetah.clarkson.edu>
Sender: mir@chorus.fr
Reply-To: mir@opera.chorus.fr (Adam Mirowski)
Organization: Chorus systemes, Saint Quentin en Yvelines, France
Lines: 19
Status: RO

In article <NELSON.92Jun18114812@cheetah.clarkson.edu>, nelson@sun.soe.clarkson.edu (Russ Nelson) writes:
%% In article <1992Jun12.155811.21317@pixel.kodak.com> kinsman@ssd.kodak.com (Andy Kinsman 253-7794) writes:
%% 
%%    I hope this keeps you random dot stereogram people happy.
%%    It plots a torus on postscript printer, in landscape mode.
%% 
%% Hey!  That's not a torus!  That's a stacked pile of flattened cylanders,
%% each with a smaller ID and OD than the one below it.  Look carefully
%% and you'll see what I mean...

More seriously, I can see 2 images on this picture: either a big torus
or a 2-hole smaller torus on the top of a hill (:-)).
In the first case, I see 3 triangles on the top of the figure.
In the second case, I see 4 equally spaced triangles, so my eyes
are probably even more diverging.

-- 
Adam Mirowski,  mir@chorus.fr (FRANCE),  tel. +33 (1) 30-64-82-00 or 74
Chorus systemes, 6, av.Gustave Eiffel, 78182 Saint-Quentin-en-Yvelines CEDEX


From ox-prg!uknet!mcsun!uunet!gatech!ncar!ico!newsserver.pixel.kodak.com!kinsman Mon Jun 22 11:22:54 BST 1992
Article: 514 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!gatech!ncar!ico!newsserver.pixel.kodak.com!kinsman
From: kinsman@ssd.kodak.com (Andy Kinsman 253-7794)
Newsgroups: comp.lang.postscript,alt.3d
Subject: Making high resolution random dot stereograms
Message-ID: <1992Jun17.150721.25165@pixel.kodak.com>
Date: 17 Jun 92 15:07:21 GMT
Sender: news@pixel.kodak.com
Organization: Eastman Kodak
Lines: 200
Xref: ox-prg comp.lang.postscript:7459 alt.3d:514
Originator: kinsman@massive
Status: RO

I have received many of your letters raving about the torus.ps
I posted on this news group last week.  Here is a letter that
has almost all of your questions enclosed.  I will attempt to answer
them in one response.  Wish me luck:-)

>From spotter@darwin.bio.uci.edu Wed Jun 17 03:55:14 1992
>
>I got your random-dot torus from alt.3d--its really neato!!
>
>I have always been into vision, optical illusions, stereo
>photography, etc. and first heard of Julez stereograms when I took
>a perception class from V. S. Ramachandran.  They seemed to
>be limited in several respects, but I see you have dealt with some
>of those limitations admirably. For instance, I had only seen ones that
>were two or three layers.  The donut has so many, it's hard to tell
>it's made of layers. 

	I too thought that only several layers were possible, until
	I saw the Pentica ad in EDN several months back.  I went
	madly through my files for past examples and came up with
	about 4, all in two layers.  After some quick calculations
	it appeared that almost a hundred layers could be made if
	the resolution of the printing device was good and the cell	
	size was kept small. The torus uses about 60 if memory 
	serves me right.  With 2400 DPI lithography machines available
	to some, the results could be spectacular, but un-NET-able,
	which is one reason the elevation maps of mine are only 800x800
	pixels.  Adjusting the Postscript code to print it smaller will
	even make the object seem smoother in texture, allowing even
	more levels to be used for output.

>I did find your name, a nice touch to the creation.  

	I can compose a view of many separations at this time.  Each
	crafted with postscript or from any other bitmap.  The bitmaps
	are then summed to obtain the final elevations in the stereogram.
	One in my collection, "Old Glory" is an increasing frequency
	sine wave superimposed on the American flag.  It is a bit of
	failure as the relatively small stars appear as holes.
	
>
>Hey, is the background really flat? It seems kind of lumpy and uneven to
>me, and I can't tell whether that is the nature of the pattern of dots,
>or some depth effect, perhaps caused by throwing a little randomness into
>the exact position of each dot, relative to its corresponding dot.

	Strange you should spot this... The image is manufactured on a
	line by line basis with the first field that is outside (left)of the
	viewing square generated by a random number generator.
	The perturbations you are detecting are inherent in my random()
	function on this computer.  This first field is repeated over
	and over from left to right, inserting and removing pixels
	as a function of elevation of the image.
>
>
>And yet another idea, inspired by your donut:  It would be nice to have
>some shading.  Sure, the original reason for making these random-dot
>stereograms was to prove that we don't need things like shading to 
>perceive depth.  But hey, we're here to make neato pictures, not prove
>theories, right?  Could the density of dots be reduced or increased in
>portions of the figure to imply a directional light source?
>I think this wouldn't work with the panorama mode, but who knows?

	My experiments with attempts at shading have all failed.  Any
	loss of randomness in the overall texture seems to add clues
	that distract the viewer into hunting for other depth information.
	The end result is the image is not viewable.  Try this with
	a photo copy of the torus, and shade it with a pencil.  You
	will probably get results similar to mine.  

>
>I am intrigued by the region where pixels on the very edge of the
>donut are horizontal streaks.  Was this a glitch in the algorithm?
>The top, bottom, and other side get the same shart depth ledge without
> any such streaks.  One of the really cool things about these images
>is that, until you do the fusing, you have no idea what is on the 
>page.  The streaks give it away a little bit.

	Now the algorithm, for the truly curious, others may pass over
	this....  

	Each line is built by on a line by line basis.  Each line consists
	of "offset" pixels of random noise, where "offset" is the number of pixels 
	between the sighting triangles.  Then the noise if followed with the 
	pixels of our elevation map.
	
	For each successive point on the line after the random noise:
 
	pixel[j] = pixel[j - (offset - pixel_elevation)];

	
>
>Finally, I heard someone in the stereo photog mailing list say
>that Scripps Institute of oceanography was using this technique
>to portray viruses whose structure they are working on.  Have
>you seen or heard of this or other such applications?

	Any 3d object can be rendered this way.  You have to
	accept the resolution available though.  I'd love to get
	my hands on some cartography data, if anybody would care
	to ship me some.
>
>Finally #2, can I download your other stereograms? I am dying
>to see what else you have.

	I will let a few at a time out to alt.3d, as it is the
	best newsgroup to post them at.  They cannot endure the
	jpeg or GIF compression.  So alt.binaries.pictures seems
	not the place.  Look there now for another!
>
>Steve Potter
>spotter@darwin.bio.uci.edu


>
>Is Stereo World magazine specifically for stereo-grams? If so, what's the 
>address for a subscription?
>                                                                Todd


	Stereo World
	National Stereoscopic Association
	P.O. Box 14801
	Columbus, OH 43214

	Is a magazine that caters to stereoscopic image enthusiasts.
	Almost every picture in the thing is done 2-up for a stereo
	view.  NOT x-eyed, so you need a viewer, or at least most
	do:-)  They have often published articles on random dot
	stereograms.

	They cost $32 first class postage, and $22 third class, higher
	for other countries.  Write them and ask for details.  They
	were news to me, till a friend pointed them out.


>	Oddly enough, we had one person who could NOT make out the image, but
>could only make out your name at the bottom.
>
>Leonard Schmidt
>n13@krypton.mankato.msus.edu

	Surely they were pulling your leg... ?

>I downloaded and successfully (?) extracted torus.ps, but when I
>print it, I get something that I can't make anything of.  How are
>these supposed to be viewed?
>
>Thanks in advance.

	This was the most polite version of this question.  It
	was asked by several:-)

ANS-
Stare into this at a depth that makes the two black triangles
become three.  Four means you are looking too deep, or not
deep enough.  If you are lucky you will see a toroid, or 
donut that fills most of the entire image.  Cut below at the 
line making the first line in the file the one that starts
with the %! and ship to a postscript laser printer.  Wait
about 5 minutes, it will finish printing.  If you can't fuse
the image show it to others and see if they can.  Some are
aided by photocopying it to a piece of mylar, and holding
it at arms length while staring through it at a white wall.
Do this while adjusting the distance of the mylar to the
viewer's eye.  Make sure the wall is about 50 or more
feet away. 

Others find they can view it by looking at their finger
when held between the drawing and their nose.  The finger
is moved slowly back and forth between the viewer and
the drawing until the four fuzzy triangles over the finger
become three fuzzy triangles, and then they concentrate on
the center triangle.  It eventually focuses, and so does
the object in the picture.  In this form the object will
be pressed into the plane, not standing out.  For some
images, my fractal plots, this viewing technique seems to
produce an almost different image. -AAK


>I've never heard about this kind of thing before, and would
>be interested in the history behind it.  Could you post some
>info. about it?  If you can divulge any info. about how these
>were created, I'd be interested in that too.
>
>Thanks much,
>Stan Tazuma
>skt@sundry.boeing.com

	Sorry, can't help much on the history, or even with
	those who have worked with it before.  The EDN ad
	inspired me.  Perhaps others on the net know more of
	the history of the technique.  I must plead ignorant.


See alt.3d for all future posts on the net.  TNX.

-AAK
kinsman@ssd.kodak.com
	


From ox-prg!uknet!stl!bnrgate!corpgate!news.utdallas.edu!wupost!zaphod.mps.ohio-state.edu!rpi!newsserver.pixel.kodak.com!kinsman Mon Jun 22 11:23:46 BST 1992
Article: 515 of alt.3d
Path: ox-prg!uknet!stl!bnrgate!corpgate!news.utdallas.edu!wupost!zaphod.mps.ohio-state.edu!rpi!newsserver.pixel.kodak.com!kinsman
From: kinsman@ssd.kodak.com (Andy Kinsman 253-7794)
Newsgroups: alt.3d
Subject: Hi-res random dot stereogram of fractal -AAK
Message-ID: <1992Jun17.151625.25742@pixel.kodak.com>
Date: 17 Jun 92 15:16:25 GMT
Sender: news@pixel.kodak.com
Organization: Eastman Kodak
Lines: 859
Originator: kinsman@massive
Status: RO



Here is a random dot stereogram of a chunk of the mendlebrot fractal
set.  After viewing with far-eyed techniques, try cross-eyed.  You
may like the results better.

Next week a post of a human face, probably should find somebody better
looking than yours truly:-)    -AAK



------------cut here cut here
[ PostScript omitted ]

From ox-prg!uknet!stl!bnrgate!corpgate!news.utdallas.edu!wupost!zaphod.mps.ohio-state.edu!rpi!newsserver.pixel.kodak.com!kinsman Mon Jun 22 11:25:23 BST 1992
Article: 516 of alt.3d
Path: ox-prg!uknet!stl!bnrgate!corpgate!news.utdallas.edu!wupost!zaphod.mps.ohio-state.edu!rpi!newsserver.pixel.kodak.com!kinsman
From: kinsman@ssd.kodak.com (Andy Kinsman 253-7794)
Newsgroups: alt.3d
Subject: High res random dot stereogram  Hyperbolic paraboloid -AAK
Message-ID: <1992Jun17.152026.25917@pixel.kodak.com>
Date: 17 Jun 92 15:20:26 GMT
Sender: news@pixel.kodak.com
Organization: Eastman Kodak
Lines: 855
Originator: kinsman@massive
Status: RO



This is a hyperbolic paraboloid.  It should stretch out your eyes
a bit:-)



-----------------------cut here-------------------------------
[ PostScript omitted ]

From ox-prg!uknet!stl!bnrgate!corpgate!news.utdallas.edu!wupost!uunet!elroy.jpl.nasa.gov!ucla-cs!ucla-mic!ucla-physics!msimon Mon Jun 22 11:26:48 BST 1992
Article: 518 of alt.3d
Path: ox-prg!uknet!stl!bnrgate!corpgate!news.utdallas.edu!wupost!uunet!elroy.jpl.nasa.gov!ucla-cs!ucla-mic!ucla-physics!msimon
From: msimon@physics.ucla.edu (Simon)
Newsgroups: alt.3d
Subject: Viewing random dot stereograms
Message-ID: <1992Jun18.003207.23498@physics.ucla.edu>
Date: 18 Jun 92 00:32:07 GMT
Organization: UCLA Department of Physics
Lines: 8
Status: RO

One technique that works for people having difficulty viewing random
dot stereograms is the following.  Hold the page close to your face
and you will see three triangles or arrows at the top.  Move the
page away from your face in small steps, keeping the middle marker
together.  If you go too fast it will separate into two markers (there
will then be four total) and you have to move the page closer again.
When you get the page about 1 foot away, look down into the body of
the picture.  It gets easier and easier with practice. 


From ox-prg!uknet!mcsun!uunet!newsserver.pixel.kodak.com!kinsman Mon Jun 22 11:27:06 BST 1992
Article: 522 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!newsserver.pixel.kodak.com!kinsman
From: kinsman@ssd.kodak.com (Andy Kinsman 253-7794)
Newsgroups: alt.3d
Subject: Hi-res random dot stereogram of face.  -AAK
Message-ID: <1992Jun18.201743.25129@pixel.kodak.com>
Date: 18 Jun 92 20:17:43 GMT
Sender: news@pixel.kodak.com
Organization: Eastman Kodak
Lines: 868
Originator: kinsman@massive
Status: RO

Here is a stereogram of yours truly.  I was too concerned about
the laser to open my eyes, and too frightened of the device
that held my head to smile:-)     What do they say... fools
names and fools faces...  Frozen in "carbonite" for all time.

for even higher resolution try changing the lines...

% scale appropriately
10.0 inch 7.5 inch scale

   to

% scale appropriately
 7.5 inch 5.6 inch scale

Enjoy.  -AAK   

Andrew A. Kinsman, kinsman@ssd.kodak.com

---------------cut here cut here -------------------------
[ PostScript omitted ]

From ox-prg!uknet!mcsun!uunet!spool.mu.edu!mips!sdd.hp.com!cs.utexas.edu!ut-emx!ccwf.cc.utexas.edu!aubrey Mon Jun 22 11:28:52 BST 1992
Article: 535 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!spool.mu.edu!mips!sdd.hp.com!cs.utexas.edu!ut-emx!ccwf.cc.utexas.edu!aubrey
From: aubrey@ccwf.cc.utexas.edu (Aubrey McIntosh)
Newsgroups: alt.3d
Subject: Re: Hi-res random dot stereogram
Message-ID: <74303@ut-emx.uucp>
Date: 20 Jun 92 21:46:31 GMT
References: <1992Jun17.151625.25742@pixel.kodak.com>
Sender: news@ut-emx.uucp
Reply-To: aubrey@ccwf.cc.utexas.edu (Aubrey McIntosh)
Lines: 27
Status: RO

In my informal survey, approximately 5 people could achieve stereo without
requiring artificial aids.  The field was about 30.  Surprisingly, the
chemists were poorly represented in the lot, and the department generally
thinks I'm daft.

Clearly, artists were the best represented, all three saw the image within
a minute of instruction.


So.  My friend and I devised the characteristics of a self-instructing image:

1)  An easily recognizable portion of the image, e.g. the tip of the nose,
should be so elevated in the image that the shift corresponds to 1 random
dot period.  e.g. they overlap, and you see an image on the paper without
special focusing.

2)  A more strongly attended object should be a short distance deeper in the
image.  Probably the most strongly attended object would be a pair of eyes.
Fortunately, they are typically deeper in the image :-)

3)  The other characteristics, which may cause ghost images in the flat
printing, should not be so strongly perceived.  Again, a face and perhaps other
background would satisfy this.


Aubrey McIntosh  /  Chemistry  /  University of Texas  /  Austin, TX 78712
...another Gaelic learner...


From ox-prg!uknet!mcsun!uunet!munnari.oz.au!trlluna!bruce.cs.monash.edu.au!monu6!minyos.xx.rmit.oz.au!smt Tue Jun 23 10:25:59 BST 1992
Article: 539 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!munnari.oz.au!trlluna!bruce.cs.monash.edu.au!monu6!minyos.xx.rmit.oz.au!smt
From: smt@cgl.rmit.oz.au (Stephen Taylor)
Newsgroups: alt.3d
Subject: Re: Viewing random dot stereograms
Message-ID: <smt.709185825@godzilla>
Date: 22 Jun 92 04:03:45 GMT
References: <1992Jun18.003207.23498@physics.ucla.edu>
Sender: usenet@minyos.xx.rmit.oz.au (Njuiz noveles nova newes)
Organization: Royal Melbourne Institute of Technology
Lines: 18
Status: RO

msimon@physics.ucla.edu (Simon) writes:

>One technique that works for people having difficulty viewing random
>dot stereograms is the following.  Hold the page close to your face
>and you will see three triangles or arrows at the top.  Move the
>page away from your face in small steps, keeping the middle marker
>together.  If you go too fast it will separate into two markers (there
>will then be four total) and you have to move the page closer again.
>When you get the page about 1 foot away, look down into the body of
>the picture.  It gets easier and easier with practice. 

The technique that finally worked for me (and I had a *lot* of trouble) was
to use a ruler to mark two fat black dots in the middle of the picture, in
line with the arrows, and get these to merge. This solved the problem I'd
had of my eyes refocusing every time I looked down.


							Steve


From ox-prg!uknet!mcsun!uunet!think.com!spdcc!dirtydog.ima.isc.com!newsserver.pixel.kodak.com!kinsman Mon Jun 29 16:34:19 BST 1992
Article: 547 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!think.com!spdcc!dirtydog.ima.isc.com!newsserver.pixel.kodak.com!kinsman
From: kinsman@ssd.kodak.com (Andy Kinsman 253-7794)
Newsgroups: alt.binaries.pictures.misc,alt.3d
Subject: Update on making random dot stereograms w/reference
Message-ID: <1992Jun24.145258.7257@pixel.kodak.com>
Date: 24 Jun 92 14:52:58 GMT
Sender: news@pixel.kodak.com
Organization: Eastman Kodak
Lines: 224
Xref: ox-prg alt.binaries.pictures.misc:6838 alt.3d:547
Originator: kinsman@massive
Status: RO

I have received many of your letters raving about the torus.ps
I posted on this news group last week.  Here is a letter that
has almost all of your questions enclosed.  I will attempt to answer
them in one response.  Wish me luck:-)

>From spotter@darwin.bio.uci.edu Wed Jun 17 03:55:14 1992
>
>I got your random-dot torus from alt.3d--its really neato!!
>
>I have always been into vision, optical illusions, stereo
>photography, etc. and first heard of Julez stereograms when I took
>a perception class from V. S. Ramachandran.  They seemed to
>be limited in several respects, but I see you have dealt with some
>of those limitations admirably. For instance, I had only seen ones that
>were two or three layers.  The donut has so many, it's hard to tell
>it's made of layers. 

	I too thought that only several layers were possible, until
	I saw the Pentica ad in EDN several months back.  I went
	madly through my files for past examples and came up with
	about 4, all in two layers.  After some quick calculations
	it appeared that almost a hundred layers could be made if
	the resolution of the printing device was good and the cell	
	size was kept small. The torus uses about 60 if memory 
	serves me right.  With 2400 DPI lithography machines available
	to some, the results could be spectacular, but un-NET-able,
	which is one reason the elevation maps of mine are only 800x800
	pixels.  Adjusting the Postscript code to print it smaller will
	even make the object seem smoother in texture, allowing even
	more levels to be used for output.

>I did find your name, a nice touch to the creation.  

	I can compose a view of many separations at this time.  Each
	crafted with postscript or from any other bitmap.  The bitmaps
	are then summed to obtain the final elevations in the stereogram.
	One in my collection, "Old Glory" is an increasing frequency
	sine wave superimposed on the American flag.  It is a bit of
	failure as the relatively small stars appear as holes.
	
>
>Hey, is the background really flat? It seems kind of lumpy and uneven to
>me, and I can't tell whether that is the nature of the pattern of dots,
>or some depth effect, perhaps caused by throwing a little randomness into
>the exact position of each dot, relative to its corresponding dot.

	Strange you should spot this... The image is manufactured on a
	line by line basis with the first field that is outside (left)of the
	viewing square generated by a random number generator.
	The perturbations you are detecting are inherent in my random()
	function on this computer.  This first field is repeated over
	and over from left to right, inserting and removing pixels
	as a function of elevation of the image.
>
>
>And yet another idea, inspired by your donut:  It would be nice to have
>some shading.  Sure, the original reason for making these random-dot
>stereograms was to prove that we don't need things like shading to 
>perceive depth.  But hey, we're here to make neato pictures, not prove
>theories, right?  Could the density of dots be reduced or increased in
>portions of the figure to imply a directional light source?
>I think this wouldn't work with the panorama mode, but who knows?

	My experiments with attempts at shading have all failed.  Any
	loss of randomness in the overall texture seems to add clues
	that distract the viewer into hunting for other depth information.
	The end result is the image is not viewable.  Try this with
	a photo copy of the torus, and shade it with a pencil.  You
	will probably get results similar to mine.  

>
>I am intrigued by the region where pixels on the very edge of the
>donut are horizontal streaks.  Was this a glitch in the algorithm?
>The top, bottom, and other side get the same shart depth ledge without
> any such streaks.  One of the really cool things about these images
>is that, until you do the fusing, you have no idea what is on the 
>page.  The streaks give it away a little bit.

	Now the algorithm, for the truly curious, others may pass over
	this....  

	Each line is built by on a line by line basis.  Each line consists
	of "offset" pixels of random noise, where "offset" is the number of pixels 
	between the sighting triangles.  Then the noise if followed with the 
	pixels of our elevation map.
	
	For each successive point on the line after the random noise:
 
	pixel[j] = pixel[j - (offset - pixel_elevation)];

	
>
>Finally, I heard someone in the stereo photog mailing list say
>that Scripps Institute of oceanography was using this technique
>to portray viruses whose structure they are working on.  Have
>you seen or heard of this or other such applications?

	Any 3d object can be rendered this way.  You have to
	accept the resolution available though.  I'd love to get
	my hands on some cartography data, if anybody would care
	to ship me some.
>
>Finally #2, can I download your other stereograms? I am dying
>to see what else you have.

	I will let a few at a time out to alt.3d, as it is the
	best newsgroup to post them at.  They cannot endure the
	jpeg or GIF compression.  So alt.binaries.pictures seems
	not the place.  Look there now for another!

	UPDATE... I'm told that GIF is loss-less and I should use
	this method.  Now to look for a conversion tool.  
>
>Steve Potter
>spotter@darwin.bio.uci.edu


>
>Is Stereo World magazine specifically for stereo-grams? If so, what's the 
>address for a subscription?
>                                                                Todd


	Stereo World
	National Stereoscopic Association
	P.O. Box 14801
	Columbus, OH 43214

	Is a magazine that caters to stereoscopic image enthusiasts.
	Almost every picture in the thing is done 2-up for a stereo
	view.  NOT x-eyed, so you need a viewer, or at least most
	do:-)  They have often published articles on random dot
	stereograms.

	They cost $32 first class postage, and $22 third class, higher
	for other countries.  Write them and ask for details.  They
	were news to me, till a friend pointed them out.


>	Oddly enough, we had one person who could NOT make out the image, but
>could only make out your name at the bottom.
>
>Leonard Schmidt
>n13@krypton.mankato.msus.edu

	Surely they were pulling your leg?..., ask them what my first
	name is, then catch them by telling them only my first initial
	is in the picture!!!

>I downloaded and successfully (?) extracted torus.ps, but when I
>print it, I get something that I can't make anything of.  How are
>these supposed to be viewed?
>
>Thanks in advance.

	This was the most polite version of this question.  It
	was asked by several:-)

ANS-

Orient so the two black triangles are at the top of the page.

Stare into this at a depth that makes the two black triangles
become three.  Four means you are looking too deep, or not
deep enough.  If you are lucky you will see a toroid, or
donut that fills most of the entire image.  Cut below at the
line making the first line in the file the one that starts
with the %! and ship to a postscript laser printer.  Wait
about 5 minutes, it will finish printing.  If you can't fuse
the image show it to others and see if they can.  Some are
aided by photocopying it to a piece of mylar, and holding
it at arms length while staring through it at a white wall.
Do this while adjusting the distance of the mylar to the
viewer's eye.  Make sure the wall is about 50 or more
feet away.
 
Others find they can view it by looking at their finger
when held between the drawing and their nose.  The finger
is moved slowly back and forth between the viewer and
the drawing until the four fuzzy triangles over the finger
become three fuzzy triangles, and then they concentrate on
the center triangle.  It eventually focuses, and so does
the object in the picture.  In this form the object will
be pressed into the plane, not standing out.  For some
images, my fractal plots, this viewing technique seems to
produce an almost different image. -AAK
 

>I've never heard about this kind of thing before, and would
>be interested in the history behind it.  Could you post some
>info. about it?  If you can divulge any info. about how these
>were created, I'd be interested in that too.
>
>Thanks much,
>Stan Tazuma
>skt@sundry.boeing.com

	Sorry, can't help much on the history, or even with
	those who have worked with it before.  The EDN ad
	inspired me.  Perhaps others on the net know more of
	the history of the technique.  I must plead ignorant.


	UPDATE.... I was just given a copy of the article in
	the May/June 1992 issue of Journal of Imaging Science
	and Technology.  Vol 36, number 3, Pages 260-267 gives
	a little history and a complete description of the
	algorithm in Pascal.  Sadly no spectacular RDAs are
	included in the article.


Animations....  
        Motion is possible, but as I wrote somebody else
this morning the concept of a "lip server" to generate the correct 
lips for a talking face left me laughing on the floor:-)   I've 
never truly recovered. 


Who does these?
	I do.

-AAK
kinsman@ssd.kodak.com
	


From ox-prg!uknet!mcsun!uunet!zaphod.mps.ohio-state.edu!rpi!newsserver.pixel.kodak.com!kinsman Mon Jun 29 16:36:12 BST 1992
Article: 563 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!zaphod.mps.ohio-state.edu!rpi!newsserver.pixel.kodak.com!kinsman
From: kinsman@ssd.kodak.com (Andy Kinsman 253-7794)
Newsgroups: alt.3d,alt.binaries.pictures.misc
Subject: Russian Random Dot Stereogram puzzle (as promised) -AAK
Message-ID: <1992Jun26.132924.15509@pixel.kodak.com>
Date: 26 Jun 92 13:29:24 GMT
Sender: news@pixel.kodak.com
Organization: Eastman Kodak
Lines: 11935
Xref: ox-prg alt.3d:563 alt.binaries.pictures.misc:6903
Originator: kinsman@massive
Status: RO

%!  russian puzzle stereogram that hurt the eyes.
%   scanned at 125 DPI  -A. Kinsman
%
%   credit where credit is due...
%   scanned from Vision research without permission
%   Vol 26 No 3 pp517-519 1986
%   "An ambiguous random-dot stereogram which permits
%    continuous change of interpretation"  by 
%    L.L.Kontsevich - Institute for Problems of Information
%    Transmission, Acad of Sciences of the U.S.S.R., 
%    Ermolovoy 19, 101447 Moscow, U.S.S.R. 
%
%    Please view with x-eyed techniques as the separation
%    is great.  Put the square on the left and the rectangle
%    to the right, and the stairway should appear to 
%    proceed clockwise in steps towards the viewer.
%
%    It appears to have survived the scanning process, but
%    a small portion of the square's left edge was clipped.
%   

[ rest omitted ]

From ox-prg!uknet!warwick!slxsys!pipex!ibmpcug!eff!iWarp.intel.com|uunet!elroy.jpl.nasa.gov!ucla-cs!ucla-mic!ucla-physics!msimon Tue Jul  7 11:35:24 BST 1992
Article: 591 of alt.3d
Path: ox-prg!uknet!warwick!slxsys!pipex!ibmpcug!eff!iWarp.intel.com|uunet!elroy.jpl.nasa.gov!ucla-cs!ucla-mic!ucla-physics!msimon
From: msimon@physics.ucla.edu (Simon)
Newsgroups: alt.3d
Subject: Random Dot Stereogram
Message-ID: <1992Jul6.182054.10533@physics.ucla.edu>
Date: 6 Jul 92 18:20:54 GMT
Organization: UCLA Department of Physics
Lines: 809
Status: RO


I was inspired by A. Kinsman's post of a toroid to try to make a
translucent toroid.  Unfortunately, it is not as easy to see as
a solid figure, but you can see the outer and inner surface if you
look.  I also made a large translucent bubble which has the same
properties and difficulties for viewing.  
    The following is a postscript file of a random dot stereogram.
----------------------CUT HERE------------------------------------
%!
%% Martin Simon 7-92 Translucent Torus

[ rest omitted ]

From ox-prg!uknet!mcsun!uunet!elroy.jpl.nasa.gov!ucla-cs!ucla-mic!ucla-physics!msimon Wed Jul  8 12:24:35 BST 1992
Article: 593 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!elroy.jpl.nasa.gov!ucla-cs!ucla-mic!ucla-physics!msimon
From: msimon@physics.ucla.edu (Simon)
Newsgroups: alt.3d
Subject: Even More Random Dots
Message-ID: <1992Jul7.210930.13448@physics.ucla.edu>
Date: 7 Jul 92 21:09:30 GMT
References: <1992Jul7.210512.13348@physics.ucla.edu>
Organization: UCLA Department of Physics
Lines: 804
Status: RO


The following is a random dot landscape.  It is a postscript file.
---------------------CUT HERE------------------------------------
%!
%%Martin Simon Rwave 7-92

[ rest omitted ]

From ox-prg!uknet!mcsun!uunet!elroy.jpl.nasa.gov!ucla-cs!ucla-mic!ucla-physics!msimon Wed Jul  8 12:25:58 BST 1992
Article: 594 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!elroy.jpl.nasa.gov!ucla-cs!ucla-mic!ucla-physics!msimon
From: msimon@physics.ucla.edu (Simon)
Newsgroups: alt.3d
Subject: More Random Dots
Message-ID: <1992Jul7.210512.13348@physics.ucla.edu>
Date: 7 Jul 92 21:05:12 GMT
Organization: UCLA Department of Physics
Lines: 807
Status: RO


The following is a random dot stereogram of a translucent bubble.
The translucent property makes it harder to see than solid shapes
but, if you look, you can see the inside and outside surface of the
bubble.  This is a postscript file.
------------------------CUT HERE----------------------------------------
%!
%% Martin Simon 7-92 Translucent Bubble

[ rest omitted ]

From ox-prg!uknet!newcastle.ac.uk!tuda!ngjf Sat Jul 11 14:05:18 BST 1992
Article: 605 of alt.3d
Path: ox-prg!uknet!newcastle.ac.uk!tuda!ngjf
From: G.J.Flanagan@newcastle.ac.uk (G.J. Flanagan)
Newsgroups: alt.3d
Subject: 3d randomdot stereogram
Message-ID: <Br6HyK.CDE@newcastle.ac.uk>
Date: 10 Jul 92 15:06:20 GMT
Organization: University of Newcastle upon Tyne, UK NE1 7RU
Lines: 1248
Nntp-Posting-Host: tuda
Status: RO

Following the recent random dot pictures, here is the first
from a different source. This was produced on an ACORN A5000
in much the same time it will take to send the file to a 
parallel printer. I used a simple BASIC program, to scan a
screen which shows the original image, where colour is used
to show height. This is a picture of an ascending spiral.
Enjoy it. 

             Robert.Scott@eata.ncl.ac.uk
             
-----------------------cut here---------------------------

%!PS-Adobe-1.0
%(C)opyright R.Scott July 1992

[ rest omitted ]

From ox-prg!msc9.comlab!imc Thu Jul 16 12:28:33 BST 1992
Article: 621 of alt.3d
Path: ox-prg!msc9.comlab!imc
From: imc@prg.ox.ac.uk (Ian Collier)
Newsgroups: alt.3d
Subject: cube_sphere.ps (random dot stereogram)
Message-ID: <2361.imc@uk.ac.ox.prg>
Date: 15 Jul 92 14:30:04 GMT
References: <Br6HyK.CDE@newcastle.ac.uk>
Sender: news@comlab.ox.ac.uk
Organization: Oxford University Computing Laboratory, UK
Lines: 559
X-Local-Date: Wednesday, 15th July 1992 at 3:28pm BST
Status: RO

Is this a private forum, or can anyone join in? :-)

My offering is a cube and a sphere sitting in front of a flat background
(yes, boring) - or if you are cross-eyed a square and a circular pit :-)

It was made from a raster produced by a C program on a Sun workstation.
I'm posting it in PostScript format, but I would probably prefer to post
gifs or compressed PBM files.  Would that be unacceptable to anyone?

Ian Collier
Ian.Collier@prg.ox.ac.uk | imc@ecs.ox.ac.uk

---------------------CUT HERE--Cut Here--cut here-------------------------
%!PS-Adobe-1.0
%%Creator: booth8.ecs:imc (Ian Collier)
%%Title: cube_sphere.ras
%%CreationDate: Wed Jul 15 15:04:15 1992
% lib/pssun.pro -- prolog for pssun (raster screen dump) files
% Copyright (C) 1985 Adobe Systems, Inc.

[ rest omitted ]

From ox-prg!uknet!mcsun!uunet!munnari.oz.au!spool.mu.edu!wupost!usc!elroy.jpl.nasa.gov!ucla-cs!ucla-mic!ucla-physics!msimon Thu Jul 16 12:30:19 BST 1992
Article: 624 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!munnari.oz.au!spool.mu.edu!wupost!usc!elroy.jpl.nasa.gov!ucla-cs!ucla-mic!ucla-physics!msimon
From: msimon@physics.ucla.edu (Simon)
Newsgroups: alt.3d
Subject: Random Dot Sinewave Carpet
Message-ID: <1992Jul15.210211.16909@physics.ucla.edu>
Date: 15 Jul 92 21:02:11 GMT
Organization: UCLA Department of Physics
Lines: 838
Status: RO


What follows was the first RDS that I made.  After I posted
some later RDS's, I got many questions about how to make
these, so I thought that I would explain a simple one by
showing the generic code that produced it.  (More complete C
code for a torus was recently posted to this newsgroup by someone
else.)  I hope this shows the principle involved in generating
RDSs.  The following is not in an actual language, it's just
heuristic.

    C Code to generate a Sinewave Carpet
    C First lay down a random patch 100 pixels wide
    C Assume the screen size is 600 x 400

    for i 1 100
      for j 1 400
          point(i,j)=Round(Rand)  C Rand generates a random number
      endfor                      C between 0 and 1 and Round makes
    endfor                        C it 0 or 1

    C Now generate the rest of the patern and introduce a sine
    C wave modulation.  

    for i 101 600
      for j 1 400
          point(i,j)=point(i-100+B*sin(i/A),j) 
      endfor
    endfor

    C If point(i,j) is zero, don't put a point, if it's one, do.

It's that simple.  Have fun.


The following is a large amplitude sinewave in a random dot
stereogram.  It is a postscript file.
---------------------------CUT HERE--------------------------------
%!
%% Martin Simon 7-92 Sinewave

[ rest omitted ]

From ox-prg!uknet!stl!bnrgate!corpgate!news.utdallas.edu!wupost!darwin.sura.net!mips!swrinde!network.ucsd.edu!sdcrsi!equalizer!timbuk.cray.com!shamash!mpe Thu Jul 16 12:32:11 BST 1992
Article: 625 of alt.3d
Path: ox-prg!uknet!stl!bnrgate!corpgate!news.utdallas.edu!wupost!darwin.sura.net!mips!swrinde!network.ucsd.edu!sdcrsi!equalizer!timbuk.cray.com!shamash!mpe
From: mpe@shamash.cdc.com
Newsgroups: alt.3d
Subject: Random dot 3d stereo generators
Message-ID: <45141@shamash.cdc.com>
Date: 15 Jul 92 21:10:47 GMT
Lines: 12
Status: RO

Hello,

  I'm looking for a program that can produce the 3d stereo dot
images previously posted within this news group.  I've seen
several references to a commercial package availavle for ~$50
but I am hoping that a public shareware version might exist.
 
  I believe the basic algorithm parallels the code used to 
generate computer holograms.  Basicly, a 2d convolution of 
sampled datapoints.  Please help.
 
mpe@shamash.cdc.com


From ox-prg!uknet!mcsun!uunet!sun-barr!cs.utexas.edu!tamsun.tamu.edu!venus.tamu.edu!jew5001 Fri Jul 24 11:02:30 BST 1992
Article: 649 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!sun-barr!cs.utexas.edu!tamsun.tamu.edu!venus.tamu.edu!jew5001
From: jew5001@venus.tamu.edu (WILLIAMSON, JOHN EDWARD)
Newsgroups: alt.3d
Subject: Random Dot Stereograms
Message-ID: <17JUL199201013827@venus.tamu.edu>
Date: 17 Jul 92 06:01:00 GMT
Sender: news@tamsun.tamu.edu (Read News)
Organization: Texas A&M University, Academic Computing Services
Lines: 18
News-Software: VAX/VMS VNEWS 1.41
Status: RO

The BEST source of information on random dot stereograms is from the
man who "invented" them, Bela Julesz.  Go to you library and look
for a copy of his book _Foundations of Cyclopean Vision_ (1971) University
of chicago press.  It has hundreds of random dot stereograms (both side 
by side pairs and anaglyph) along with a very detailed description of the
theoretical and psychological aspects of how random dot stereograms work.

Also look at Introductory, perctual, or experimental psychology
textbooks published after 1975.  Nearly everyone of these books will
have at least a very short section on random dot stereograms.

You can create your own very crude random dot stereograms with most
paint programs or write your own 10 line basic program.  Take the
spray can tool and randomly fill in a section, copy this section
and place it to the right, exactly parallel with the original.  Then
copy a square (or other shape) from one side and slide it over about
1/4" and past it down.  You will have to play with the size of the images
but it will work.


From ox-prg!uknet!mcsun!uunet!dtix!mimsy!afterlife!glreno Fri Jul 24 11:02:53 BST 1992
Article: 659 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!dtix!mimsy!afterlife!glreno
From: glreno@afterlife.ncsc.mil (Gerald Reno)
Newsgroups: alt.3d
Subject: Stereogram References (was: Re: Guitars)
Message-ID: <1992Jul20.020716.26973@afterlife.ncsc.mil>
Date: 20 Jul 92 02:07:16 GMT
References: <1992Jul9.043420.12416@panix.com> <1992Jul16.184302.6476@porthos.cc.bellcore.com>
Organization: The Great Beyond
Lines: 19
Status: RO

In article <1992Jul16.184302.6476@porthos.cc.bellcore.com> afd@bellcore.com writes:
>
>Besides the _Games_ magazine article, what else has been
>published about the random dot stereograms?  I would like
>to look into this further (so to speak).
>
>-A Dietz
>Bellcore, Morristown

As it happens, I wrote a paper on this last Winter for my
Cognitive Science class; unfortunately, I have neither it nor my
references with me. What I did, tho, was to take every name in
the _Games_ article and look them upeverywhere I could. I got a
couple articles that way, and they pointed elsewhere. Sorry I
couldn't help more, but I can't seem to telnet back to my school
tonight. I'll try again later.

Jerry Reno (Cmdr. Steve C Loser) glreno@afterlife.ncsc.mil
reno@cps.msu.edu, when I can get there.


From ox-prg!uknet!mcsun!uunet!dtix!mimsy!afterlife!glreno Fri Jul 24 11:03:07 BST 1992
Article: 665 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!dtix!mimsy!afterlife!glreno
From: glreno@afterlife.ncsc.mil (Gerald Reno)
Newsgroups: alt.3d
Subject: Re: Stereogram References (was: Re: Guitars)
Message-ID: <1992Jul20.195635.20216@afterlife.ncsc.mil>
Date: 20 Jul 92 19:56:35 GMT
References: <1992Jul9.043420.12416@panix.com> <1992Jul16.184302.6476@porthos.cc.bellcore.com> <1992Jul20.020716.26973@afterlife.ncsc.mil>
Organization: The Great Beyond
Lines: 80
Status: RO

In article <1992Jul20.020716.26973@afterlife.ncsc.mil> I wrote:
>In article <1992Jul16.184302.6476@porthos.cc.bellcore.com> afd@bellcore.com writes:
>>
>>Besides the _Games_ magazine article, what else has been
>>published about the random dot stereograms?  I would like
>>to look into this further (so to speak).
>>
>>-A Dietz
>>Bellcore, Morristown
>
>As it happens, I wrote a paper on this last Winter for my
>Cognitive Science class;

and here is the bibliography, in handy bibTeX form.

hope it helps...

Jerry Reno (Cmdr. Steve C Loser) glreno@afterlife.ncsc.mil
reno@cps.msu.edu, when I can get there.



@BOOK{Julesz,
	AUTHOR = "Bela Julesz",
	TITLE = "Foundations of Cyclopean Perception",
	PUBLISHER = "The University of Chicago Press",
	ADDRESS = "Chicago and London",
	YEAR = 1971
}

@BOOK{Frisby,
	AUTHOR="John P. Frisby",
	TITLE="Seeing",
	PUBLISHER="Oxford University Press",
	ADDRESS="Oxford",
	YEAR=1979
}

% This next one isn't about stereograms, but it has some
% neat stereograms of biochemicals...
@BOOK{Rawn,
	AUTHOR="J. David Rawn",
	TITLE="Biochemistry",
	PUBLISHER="Neil Patterson Publisers",
	ADDRESS="Burlington, NC",
	YEAR=1989
}

@INCOLLECTION{Tyler,
	AUTHOR="Christopher W. Tyler",
	TITLE="Cyclopean Vision",
	BOOKTITLE="Binocular Vision",
	PUBLISHER="The Macmillan Press Ltd",
	ADDRESS="Boca Raton, FL",
	YEAR=1991,
	EDITOR="David Regan",
	CHAPTER=3
}

@ARTICLE{Poggio,
	AUTHOR="Tomaso Poggio",
	TITLE="Vision by Man and Machine",
	JOURNAL="Scientific American",
	YEAR=1984,
	VOLUME=250,
	NUMBER=4,
	PAGES="106--116",
	MONTH="April"
}

@ARTICLE{Games,
	AUTHOR="John Grossman",
	TITLE="Look, Ma, No Glasses!",
	JOURNAL="Games",
	YEAR=1992,
	VOLUME=16,
	NUMBER=2,
	PAGES="12--15",
	MONTH="APRIL"
}


From ox-prg!uknet!stl!bnrgate!nrcnet0!cunews!torn!csd.unb.ca!morgan.ucs.mun.ca!nstn.ns.ca!cs.dal.ca!ug.cs.dal.ca!franck Fri Jul 24 11:03:48 BST 1992
Article: 678 of alt.3d
Path: ox-prg!uknet!stl!bnrgate!nrcnet0!cunews!torn!csd.unb.ca!morgan.ucs.mun.ca!nstn.ns.ca!cs.dal.ca!ug.cs.dal.ca!franck
From: franck@ug.cs.dal.ca (Glenn Franck)
Newsgroups: alt.3d
Subject: Random dot stereograms WANTED
Message-ID: <BrszH3.8zG@cs.dal.ca>
Date: 22 Jul 92 18:31:51 GMT
Sender: usenet@cs.dal.ca (USENET News)
Organization: Math, Stats & CS, Dalhousie University, Halifax, NS, Canada
Lines: 21
Nntp-Posting-Host: ug.cs.dal.ca
Status: RO

I have only two of the RDS's posted over the last little while (the
cube-sphere and the disc), and I would like to get more.

PLEASE, anyone who has the other ones (I remember a torus, and a face,
among others) or any others, can you mail them to me? Actually, if you're
willing to send me any, can you send me short note first and tell me
which ones you have, then I'll ask you for the ones I need? Or better yet
(I know this question was asked before) - is there an FTP site for these?

Any and all replies _greatly_ appreciated! 

-Glenn


 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  Glenn Franck        |      "Everybody's got to deviate from the norm."      
  franck@ug.cs.dal.ca |                            - N. Peart, RUSH           
  gfranck@ac.dal.ca   |=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  Don't take life too seriously. After all, you'll never get out of it alive! 
 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=


From ox-prg!uknet!mcsun!uunet!news.larc.nasa.gov!icase.edu!avik Fri Jul 24 11:11:01 BST 1992
Article: 686 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!news.larc.nasa.gov!icase.edu!avik
From: avik@icase.edu (Avik Banerjee)
Newsgroups: alt.3d
Subject: sampler stereogram
Message-ID: <Brt4CJ.5y8@news.larc.nasa.gov>
Date: 22 Jul 92 20:17:06 GMT
Sender: news@news.larc.nasa.gov (USENET Network News)
Organization: ICASE/NASA Langley
Lines: 657
Status: RO

%!PS
%%BoundingBox: 54 72 566 712
%%Creator: Micro Synectic, Inc.
%%Title: Stare-E-O Sampler

[ rest omitted ]

From ox-prg!uknet!mcsun!uunet!news.larc.nasa.gov!icase.edu!avik Fri Jul 24 11:12:51 BST 1992
Article: 690 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!news.larc.nasa.gov!icase.edu!avik
From: avik@icase.edu (Avik Banerjee)
Newsgroups: alt.3d
Subject: ftp sites with stereograms
Message-ID: <BruBDv.6p@news.larc.nasa.gov>
Date: 23 Jul 92 11:46:43 GMT
Sender: news@news.larc.nasa.gov (USENET Network News)
Organization: ICASE/NASA Langley
Lines: 16
Status: RO

greetings,
	well, i still think it would be quicker if we posted what we
	had here but two anonymous ftp sites (the only ones i know of)
	are sugrfx.acs.syr.edu under /pub/vr/3d/stereograms/ and
	cs.tut.fi under /pub/src/GameDev/graphics/stereogram/. later.

            ___ __    _ ______  __
           /   || |  / /| || | / /
          / /| || | / / | || |/ /
         / / | || |/ /  | || |\ \
        /_/  |_||___/   |_||_| \_\
  		@icase.edu
-----------------------------------------------
|"Only the insane have strength to prosper.   |
| Only those that prosper judge what is sane."|
-----------------------------------------------


From ox-prg!uknet!newcastle.ac.uk!tuda!ngjf Mon Jul 27 10:32:06 BST 1992
Article: 692 of alt.3d
Path: ox-prg!uknet!newcastle.ac.uk!tuda!ngjf
From: G.J.Flanagan@newcastle.ac.uk (G.J. Flanagan)
Newsgroups: alt.3d
Subject: Random dot Stereogram
Message-ID: <BrwAGJ.DLG@newcastle.ac.uk>
Date: 24 Jul 92 13:21:55 GMT
Organization: University of Newcastle upon Tyne, UK NE1 7RU
Lines: 564
Nntp-Posting-Host: tuda
Status: RO

Here's another Stereogram to enjoy. Note the decreased y resolution
as a compromise to less information to transmit on the net.

-------------------------cut here---------------------------------
%!PS-Adobe-1.0
%(C) Rob Scott+Gordon Flanagan
%Ramshorn July 1992 R.Scott & G.Flanagan
%Fri,24 Jul 1992

[ rest omitted ]

From ox-prg!uknet!mcsun!uunet!decwrl!access.usask.ca!ccu.umanitoba.ca!rao Mon Jul 27 10:33:59 BST 1992
Article: 700 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!decwrl!access.usask.ca!ccu.umanitoba.ca!rao
From: rao@ccu.umanitoba.ca (Govindaraju Rao)
Newsgroups: alt.3d
Subject: Re: PS stereograms
Message-ID: <1992Jul25.232800.26343@ccu.umanitoba.ca>
Date: 25 Jul 92 23:28:00 GMT
References: <12948@chalmers.se>
Sender: news@ccu.umanitoba.ca
Organization: University of Manitoba, Winnipeg, Manitoba, Canada
Lines: 41
Nntp-Posting-Host: pollux.cc.umanitoba.ca
Status: RO


   Johan writes:
   >> When I print them (RDS) on our standard laserwriter 
   >> (Apple type 300 dpi ?) it doesn't seem to produce 
   >> the wanted effect.
  
I printed them on a HP LaserJet III (300 dpi) and they seem to
be fine. However, I have encountered the following problems.
  
   1) In the bubble stereoram I see an "inverted" bubble. It
      appears bowl-shaped (concave away from observer). Is this
      correct or should it appear convex towards the observer, like
      a blister, or hemispherical soap bubble. I viewed it in
      both orientations i.e. arrow marks away from me and towards
      me; still the same result. 
  
   2) In the Ram's Horn sterogram I see two "objects" shaped like
      a comma (,), one larger than the other. Both these are at the
      same elevation, between and close to the upper tips of 
      the horns. When I try to "lock" onto them they disappear.
      Are they really there or is my eyesight going downhill ??
      If they exist, are they intentional, or artifacts of the
      generating algorithm? 
 
  3) I am having great difficulty with the Toroid stereogram.
     I am unable to keep the image formed even fleetingly. 
     What exactly am I supposed to see in this one? I see
     "ridges" on the left and right side and a large circular
     depression in the center, with another conical (?) projection
     in the dead center of the depression. Sometimes the conical
     projection appears as a floating disk. Is anyone else having
     trouble with this one ? I think my technique is correct since
     I see all the others easily. 
 
Please e-mail replies to <rao@ccm.umanitoba.ca>. Will post summary
if warranted. (Preferably please do not reply to e-mail address
in the header of this posting.)
  
Thank you.
 
G.S.K. Rao <rao@ccm.umanitoba.ca> 


From ox-prg!uknet!mcsun!uunet!wupost!uwm.edu!rutgers!rochester!cornell!uw-beaver!news.u.washington.edu!raven.alaska.edu!raven.alaska.edu!ejo Mon Jul 27 10:34:53 BST 1992
Article: 702 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!wupost!uwm.edu!rutgers!rochester!cornell!uw-beaver!news.u.washington.edu!raven.alaska.edu!raven.alaska.edu!ejo
From: ejo@kaja.gi.alaska.edu (Eric J. Olson)
Newsgroups: alt.3d
Subject: Re: PS stereograms
Message-ID: <1992Jul26.012844.23784@raven.alaska.edu>
Date: 26 Jul 92 02:28:37 GMT
References: <12948@chalmers.se> <1992Jul25.232800.26343@ccu.umanitoba.ca>
Sender: news@raven.alaska.edu (USENET News System)
Organization: Citizens for Boysenberry Jam Fans
Lines: 21
In-Reply-To: rao@ccu.umanitoba.ca's message of Sat, 25 Jul 1992 23: 28:00 GMT
Nntp-Posting-Host: kaja.gi.alaska.edu
Status: RO

In article <1992Jul25.232800.26343@ccu.umanitoba.ca> rao@ccu.umanitoba.ca (Govindaraju Rao) writes:

>   1) In the bubble stereoram I see an "inverted" bubble. It
>      appears bowl-shaped (concave away from observer). Is this
>      correct or should it appear convex towards the observer, like
>      a blister, or hemispherical soap bubble. I viewed it in
>      both orientations i.e. arrow marks away from me and towards
>      me; still the same result. 

It's "correct" in that you see something, but you're viewing the
opposite of what was intended.  If you allow your eyes to relax and
focus on infinity, the bubble will be convex.  When you view the
images crosseyed, the depth information is inverted, and it becomes a
bowl.  You're having the same problem with the toroid; look for a
half-donut embedded in the page, inside view.

Your view isn't incorrect because different people view stereograms
different ways; for example, I can't view them crosseyed, and my
father can't view them at infinity.  Just go with what you can do.

Eric Olson <ejo@kaja.gi.alaska.edu>


From ox-prg!msc2.comlab!imc Thu Jul 30 15:04:16 BST 1992
Article: 707 of alt.3d
Path: ox-prg!msc2.comlab!imc
From: imc@prg.ox.ac.uk (Ian Collier)
Newsgroups: alt.3d
Subject: Re: PS stereograms
Message-ID: <2397.imc@uk.ac.ox.prg>
Date: 28 Jul 92 17:38:09 GMT
References: <12948@chalmers.se> <1992Jul25.232800.26343@ccu.umanitoba.ca> <1992Jul26.012844.23784@raven.alaska.edu>
Sender: news@comlab.ox.ac.uk
Organization: Oxford University Computing Laboratory, UK
Lines: 29
X-Local-Date: Tuesday, 28th July 1992 at 6:37pm BST
Status: RO

In article <1992Jul26.012844.23784@raven.alaska.edu>, ejo@kaja.gi.alaska.edu (Eric J. Olson) wrote:
>In article <1992Jul25.232800.26343@ccu.umanitoba.ca> rao@ccu.umanitoba.ca (Govindaraju Rao) writes:

>>   1) In the bubble stereoram I see an "inverted" bubble. It
>>      appears bowl-shaped (concave away from observer). Is this
>>      correct or should it appear convex towards the observer, like
>>      a blister, or hemispherical soap bubble.

>It's "correct" in that you see something, but you're viewing the
>opposite of what was intended.  If you allow your eyes to relax and
>focus on infinity, the bubble will be convex.  When you view the
>images crosseyed, the depth information is inverted, and it becomes a
>bowl.

I viewed the bubble and the torus in wide-eyes mode, and I saw the same.  I
was unable to see anything except an amorphous circular blob for some time,
mind you.

What I saw was a hemispherical bowl sitting on top of the background
surface, similar to the first poster above.  Similarly, when viewing the
torus I saw half a torus sitting on the background with the hollow face
towards me - though I was only able to see anything while by looking at the
upper half of the picture.

So, if these apparitions are incorrect, then something strange is happening
- not just that we are viewing them "inside out" in cross-eye mode.

Ian Collier
Ian.Collier@prg.ox.ac.uk | imc@ecs.ox.ac.uk


From ox-prg!uknet!mcsun!uunet!zephyr.ens.tek.com!tekig7!tekig1!rick Thu Jul 30 15:04:36 BST 1992
Article: 708 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!zephyr.ens.tek.com!tekig7!tekig1!rick
From: rick@tekig1.PEN.TEK.COM (Fredrick Wilson)
Newsgroups: alt.3d
Subject: Re: PS stereograms
Message-ID: <6338@tekig7.PEN.TEK.COM>
Date: 28 Jul 92 23:06:35 GMT
References: <1992Jul25.232800.26343@ccu.umanitoba.ca> <1992Jul26.012844.23784@raven.alaska.edu> <2397.imc@uk.ac.ox.prg>
Sender: news@tekig7.PEN.TEK.COM
Organization: Tektronix, Inc., Beaverton,  OR.
Lines: 32
Status: RO

In article <2397.imc@uk.ac.ox.prg> imc@prg.ox.ac.uk (Ian Collier) writes:
>In article <1992Jul26.012844.23784@raven.alaska.edu>, ejo@kaja.gi.alaska.edu (Eric J. Olson) wrote:
>>In article <1992Jul25.232800.26343@ccu.umanitoba.ca> rao@ccu.umanitoba.ca (Govindaraju Rao) writes:
>
>>>   1) In the bubble stereoram I see an "inverted" bubble. It
>>
>>opposite of what was intended.  If you allow your eyes to relax and
>>focus on infinity, the bubble will be convex.  When you view the
>>images crosseyed, the depth information is inverted, and it becomes a
>>bowl.
>
>I viewed the bubble and the torus in wide-eyes mode, and I saw the same.  I
>was unable to see anything except an amorphous circular blob for some time,
>mind you.
>

Are you guys perhaps looking at the TRANSPARENT bubble and TRANSPARENT
torus?  They have been posted here too, and are more advanced viewing
subjects.  You would likely see the inside of the bottom surface first
since they are closest to the back plane.



      Rick   Wilson             Rick Wilson       Cross-eyed STEREO
      --------------           --------------
     |       O      |         |      O       |
     |    O         |         |     O        |    rick@sable.pen.tek.com
     |              |         |              |    Tektronix
     \    _     O   |         |\    _  O     |    Beaverton, Orygun
     |\  /      _   |         | \  /   _     |
     | \/   \  /    |         |  \/\  /      | 
      --------------           --------------      


From ox-prg!uknet!mcsun!uunet!darwin.sura.net!mips!sdd.hp.com!usc!elroy.jpl.nasa.gov!ucla-cs!ucla-mic!ucla-physics!msimon Thu Jul 30 15:05:33 BST 1992
Article: 709 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!darwin.sura.net!mips!sdd.hp.com!usc!elroy.jpl.nasa.gov!ucla-cs!ucla-mic!ucla-physics!msimon
From: msimon@physics.ucla.edu (Simon)
Newsgroups: alt.3d
Subject: Re: PS stereograms
Message-ID: <1992Jul28.230122.2065@physics.ucla.edu>
Date: 28 Jul 92 23:01:22 GMT
References: <1992Jul25.232800.26343@ccu.umanitoba.ca> <1992Jul26.012844.23784@raven.alaska.edu> <2397.imc@uk.ac.ox.prg>
Organization: UCLA Department of Physics
Lines: 60
Status: RO

In article <2397.imc@uk.ac.ox.prg> imc@prg.ox.ac.uk (Ian Collier) writes:
>In article <1992Jul26.012844.23784@raven.alaska.edu>, ejo@kaja.gi.alaska.edu (Eric J. Olson) wrote:
>>In article <1992Jul25.232800.26343@ccu.umanitoba.ca> rao@ccu.umanitoba.ca (Govindaraju Rao) writes:
>
>>>   1) In the bubble stereoram I see an "inverted" bubble. It
>>>      appears bowl-shaped (concave away from observer). Is this
>>>      correct or should it appear convex towards the observer, like
>>>      a blister, or hemispherical soap bubble.
>
>>It's "correct" in that you see something, but you're viewing the
>>opposite of what was intended.  If you allow your eyes to relax and
>>focus on infinity, the bubble will be convex.  When you view the
>>images crosseyed, the depth information is inverted, and it becomes a
>>bowl.
>
>I viewed the bubble and the torus in wide-eyes mode, and I saw the same.  I
>was unable to see anything except an amorphous circular blob for some time,
>mind you.
>
>What I saw was a hemispherical bowl sitting on top of the background
>surface, similar to the first poster above.  Similarly, when viewing the
>torus I saw half a torus sitting on the background with the hollow face
>towards me - though I was only able to see anything while by looking at the
>upper half of the picture.
>
>So, if these apparitions are incorrect, then something strange is happening
>- not just that we are viewing them "inside out" in cross-eye mode.
>
>Ian Collier
>Ian.Collier@prg.ox.ac.uk | imc@ecs.ox.ac.uk


As I said when I first posted these, translucent surfaces are "harder
to see" than  solid surfaces.  This was an experiment to see whether
translucent surfaces would work all.  Most people can see them with
little trouble, especially if they know what they are looking for.
Because these RDSs have objects in front of other surfaces, they are
not good candidates for pseudoscopic viewing (cross-eyed in this case).
    Because the top and bottom surfaces of the bubble and toroid are
at different heights, it requires some work on the part of the viewer
to see both surfaces.  You must "look around" at different heights.
It sounds like you are only seeing the inner surfaces.  If you "look"
at the region further from the paper towards you, or follow the surface
that you see upward, slightly changing the convergence of your eyes as
you go, you will see the top surface of the toroid or bubble.  There is
some intermediate point where you can see both surfaces at the same time.
    What you "should" see is the following:
    Bubble--A very large bubble in front of a flat background.  With one
           convergence you should be able to see the outer surface
           (convex) of the bubble.  Looking further back, or following
           the surface downward you should see through the outer surface
           to the inner concave surface.
    Translucent Toroid--A toroid floating above a wavy surface.  Both
           the inner and outer surfaces should be apparent at different
           depths.  The lower wavy surface can be seen through the
           donut hole.

Good Luck and have fun!

Martin Simon


From ox-prg!prg.ox.ac.uk!imc Thu Jul 30 19:19:29 BST 1992
Article: 717 of alt.3d
Path: ox-prg!prg.ox.ac.uk!imc
From: imc@prg.ox.ac.uk (Ian Collier)
Newsgroups: alt.3d
Subject: mandelbrot.gif (1/1)  [800x564x1]
Message-ID: <2404.imc@uk.ac.ox.prg>
Date: 30 Jul 92 14:42:51 GMT
Sender: news@comlab.ox.ac.uk
Distribution: world
Organization: Oxford University Computing Laboratory, UK
Lines: 1487
X-Local-Date: Thursday, 30th July 1992 at 3:40pm BST
Status: RO

This is a random dot stereogram containing a relief map of the
Mandelbrot set: instead of colouring the points differently, I
placed them at different heights.

It is an 800x564 GIF file (with 2 colours), uuencoded in one
part.  To extract it, simply pipe this article through uudecode,
and "mandelbrot.gif" will appear in your News directory.  For more
information (such as what to do if you can't find a uudecode
utility), find the pictures FAQ posting in news.answers.

It is best viewed with the wide-eyes method; that is, stare at the
picture as if at a distant object, so that you see doubly.  Attempt
to merge the inner two of the four (i.e. two doubled) arrows at the
top of the page, and gradually try to focus the picture with the
eyes in this position.

Ian Collier
Ian.Collier@prg.ox.ac.uk | imc@ecs.ox.ac.uk

begin 644 mandelbrot.gif

[ omitted ] 

end


From ox-prg!uknet!mcsun!Germany.EU.net!news.netmbx.de!zrz.tu-berlin.de!math.fu-berlin.de!Sirius.dfn.de!ira.uka.de!yale.edu!qt.cs.utexas.edu!cs.utexas.edu!sdd.hp.com!mips!darwin.sura.net!news.duc.auburn.edu!lab12!long1 Tue Aug  4 17:16:18 BST 1992
Article: 725 of alt.3d
Path: ox-prg!uknet!mcsun!Germany.EU.net!news.netmbx.de!zrz.tu-berlin.de!math.fu-berlin.de!Sirius.dfn.de!ira.uka.de!yale.edu!qt.cs.utexas.edu!cs.utexas.edu!sdd.hp.com!mips!darwin.sura.net!news.duc.auburn.edu!lab12!long1
From: long1@eng.auburn.edu (Matthew Long)
Newsgroups: alt.3d
Subject: SteroGram Animation
Keywords: SIRDS
Message-ID: <1992Aug2.153945.2772@news.duc.auburn.edu>
Date: 2 Aug 92 15:39:45 GMT
Sender: usenet@news.duc.auburn.edu (News Account)
Reply-To: long1@eng.auburn.edu
Organization: Auburn University Engineering
Lines: 15
Nntp-Posting-Host: lab12.eng.auburn.edu
Status: RO

Hello All,
	Back in March I posted the source for a program to make SIRDS (single image
random dot sterograms)  I have been very busy lately and have not done much 
with it.  Until now.  I created an animation.  It is not very impressive but
then again I did it in 1 hour.  If you have the ImageMagic package with the
animate program, and you can free view well then you should ftp the animation
from:

ftp.eng.auburn.edu		/pub/3d/animation.tar.Z

Have Fun and let me know if anybody does some more.  The source code is in the
same directory.

Matthew Long
Matthew.Long@eng.auburn.edu


From ox-prg!uknet!mcsun!news.funet.fi!ajk.tele.fi!funic!nntp.hut.fi!vipunen.hut.fi!jone Tue Aug  4 17:16:29 BST 1992
Article: 726 of alt.3d
Path: ox-prg!uknet!mcsun!news.funet.fi!ajk.tele.fi!funic!nntp.hut.fi!vipunen.hut.fi!jone
From: jone@vipunen.hut.fi (Jouni Pekkanen)
Newsgroups: alt.3d
Subject: Randomdot stereogram paint program for Amiga
Keywords: SIRDS paint Amiga
Message-ID: <jone.712786680@vipunen.hut.fi>
Date: 2 Aug 92 20:18:00 GMT
Sender: usenet@nntp.hut.fi (Usenet pseudouser id)
Organization: Helsinki University of Technology, Finland
Lines: 6
Nntp-Posting-Host: vipunen.hut.fi
Status: RO

I just uploaded a randomdot stereogram paint program for Amiga to
ftp.eng.auburn.edu. It's in /incoming/rpaint.lha until someone moves it to
/pub/3d.

Jouni Pekkanen
jone@vipunen.hut.fi


From ox-prg!uknet!mcsun!news.funet.fi!ajk.tele.fi!funic!nntp.hut.fi!nntp!kartano Tue Aug  4 17:18:42 BST 1992
Article: 730 of alt.3d
Path: ox-prg!uknet!mcsun!news.funet.fi!ajk.tele.fi!funic!nntp.hut.fi!nntp!kartano
From: kartano@vipunen.hut.fi (Mikko Kartano)
Newsgroups: alt.3d
Subject: Re: 3d sigs
Message-ID: <KARTANO.92Aug3203547@vipunen.hut.fi>
Date: 3 Aug 92 19:35:47 GMT
References: <1992Aug2.234240.14076@news.acns.nwu.edu>
Sender: usenet@nntp.hut.fi (Usenet pseudouser id)
Reply-To: Mikko.Kartano@hut.fi
Organization: Helsinki University of Technology, Finland
Lines: 15
In-Reply-To: jlh@casbah.acns.nwu.edu's message of Sun, 2 Aug 1992 23:42:40 GMT
Nntp-Posting-Host: vipunen.hut.fi
Status: RO

In article <1992Aug2.234240.14076@news.acns.nwu.edu> jlh@casbah.acns.nwu.edu (John Hoebing) writes:

   Several weeks ago, someone posted a message with a "3D .sig".  At first
   :
   the message, but I'd like to see it again.  I'd appreciate if someone could
   repost the effect, or email it to me.  Thanks ...

I wonder if it was this. (are there others?)

Kartano
--
The worlds first 3-D .sig!  +               .   .   .   .   .   .   .
Look at the picture on the  +            :    :    :    :    :    :    :
right cross-eyed and really +         3     3     3     3     3     3     3
_really_ close.             +      D      D      D      D      D      D      D


From ox-prg!uknet!mcsun!uunet!autodesk!m31!danielg Tue Aug  4 17:19:37 BST 1992
Article: 731 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!autodesk!m31!danielg
From: danielg@autodesk.com (Daniel Green)
Newsgroups: alt.3d
Subject: Re: 3d sigs
Message-ID: <17375@autodesk.COM>
Date: 3 Aug 92 19:19:17 GMT
References: <1992Aug2.234240.14076@news.acns.nwu.edu>
Sender: news@Autodesk.COM
Reply-To: danielg@autodesk.com
Organization: Autodesk, Inc.
Lines: 24
Status: RO

In article 14076@news.acns.nwu.edu, jlh@casbah.acns.nwu.edu (John Hoebing) writes:
> Several weeks ago, someone posted a message with a "3D .sig".  At first
> glance, it looked to be four rows of differently spaced letters, but if you
> looked close-up and crossed your eyes you got a distinct stereo effect,
> with the letters in each row disposed at different distances.  I've lost
> the message, but I'd like to see it again.  I'd appreciate if someone could
> repost the effect, or email it to me.  Thanks ...

Actually the effect only works well when looked at wall-eyed though you could
just as easily make cross-eyed versions.

---
Daniel Green
danielg@autodesk.com
      ___________          ___________
      |         |          |         |
      |  _________         | _________
      |  |       |         | |       |
      |  |  _______        | | _______
      |  |  |     |        | | |     |
      ---|  |  _____       --| | _____
	 ---|  | D |         --| | D |
	    ---|  G|           --|  G|
	       -----             -----


From ox-prg!uknet!mcsun!uunet!haven.umd.edu!darwin.sura.net!zaphod.mps.ohio-state.edu!uwm.edu!rutgers!network.ucsd.edu!sdchemw2!reg Tue Aug  4 17:20:48 BST 1992
Article: 733 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!haven.umd.edu!darwin.sura.net!zaphod.mps.ohio-state.edu!uwm.edu!rutgers!network.ucsd.edu!sdchemw2!reg
From: reg@sdchemw2.ucsd.edu (Richard E. Gillilan)
Newsgroups: alt.3d
Subject: Re: 3d sigs
Message-ID: <15khhcINNfn1@network.ucsd.edu>
Date: 4 Aug 92 00:03:56 GMT
References: <1992Aug2.234240.14076@news.acns.nwu.edu> <17375@autodesk.COM> <1992Aug3.230930.17239@raven.alaska.edu>
Sender: Richard E. Gillilan
Organization: UC San Diego Chemistry
Lines: 27
NNTP-Posting-Host: sdchemw2.ucsd.edu
Status: RO

This is the last one I saw:

      IIIIIIIIIIIIIII   IIIIIIIIIIIIIII      Marty Hewes
      H ( )  \|/    H   H   ( )   \|/ H      Tellabs Inc.
      H(   ) -O-    H   H  (   )  -O- H      System and Applications Test
      H     )/|\    H   H (     ) /|\ H      Lisle, Il
      H======^======H   H======^======H      nitram@tellabs.com
      H- |----@-----H   H----| ---@---H      uunet!tellab1.TELLABS.COM!nitram
      H /|\ @\|/ @  H   H   /|\@ \|/@ H 
      H    \|/  \|/ H   H     \|/  \|/H      W (708) 955-3038
      III^IIIIIII^III   III^IIIIIII^III      H (708) 665-6671
     Wide eyed stereo  Wide  eyed  stereo    

Is there a program to create these things, or does one simply
edit cleverly?



Richard





-----
test
-----


From ox-prg!uknet!mcsun!uunet!caen!malgudi.oar.net!chemabs!jdh64 Thu Aug  6 11:13:45 BST 1992
Article: 740 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!caen!malgudi.oar.net!chemabs!jdh64
From: jdh64@cas.org (Dave Huddle)
Newsgroups: alt.3d
Subject: National Stereoscopic Association Convention
Keywords: 3D photography
Message-ID: <1992Aug5.204239.6396@cas.org>
Date: 5 Aug 92 20:42:39 GMT
Sender: usenet@cas.org
Organization: What, me organized?
Lines: 53
Status: RO


The 1992 NSA national convention will be held August 13-16 in The Grand Wayne
Center, 120 West Jefferson Boulevard, Fort Wayne, Indiana.

Tentative Schedule:

	Thursday, August 13     Pre-Convention Check-in
				Room hopping

	Friday, August 14       Stereo Projection Theater (9 AM - 4 PM)
				NSA Spotlight Auction (8 PM)

	Saturday, August 15     Trade Fair (9;30 am - 4:30 PM)
				Stereo Projection Theater (times TBA)
				Banquet/Awards Dinner (7 PM)
					Guest Speaker: Gary Evans
					Director of Product Development
					View-Master Ideal Inc.

	Sunday, August 16       President's Breakfast (8:30 AM)
				Trade Fair (10 AM - 4 PM)
				Stereo Projection Theater (times TBA)



For more info write to:         NSA 1992 Convention
				P. O. Box 398
				Sycamore Oh. 44882




FROM THE NSA BROCHURE:

The National Stereoscopic Association is an incorporated, non-profit.
tax-exempt organization founded in 1974.  Its purposes are to promote the
study and collection of stereographs, stereo cameras, and related materials;
to provide a forum for collectors and students of stereoscopic history; to
promote the practice of stereo photography; to encourage the use of
stereoscopy in the visual arts and technology; to foster the appreciation of
the stereograph as a visual historical record; and to provide for the
Stereoscopic Research Library.

STEREO WORLD magazine is published bimonthly with 40 or more pages per issue.
Stereo images from a variety of eras and formats are printed as high-quality
side-by-side pairs, lavishly illustrating every article.......


To receive a membership application send your POSTAL address to jww64@cas.org
or to NSA   PO Box 14801, Columbus OH 43214.

---
Dave Huddle     jdh64@cas.org


From ox-prg!uknet!mcsun!uunet!think.com!spdcc!dirtydog.ima.isc.com!laidbak!tellab5!nitram Thu Aug  6 11:14:47 BST 1992
Article: 741 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!think.com!spdcc!dirtydog.ima.isc.com!laidbak!tellab5!nitram
From: nitram@tellabs.com (Marty Hewes)
Newsgroups: alt.3d
Subject: Re: 3d sigs
Summary: By hand
Message-ID: <1992Aug5.135006.1239@tellab5.tellabs.com>
Date: 5 Aug 92 13:50:06 GMT
References: <1992Aug2.234240.14076@news.acns.nwu.edu> <17375@autodesk.COM> <15khhcINNfn1@network.ucsd.edu>
Sender: news@tellab5.tellabs.com (News)
Organization: Tellabs, Inc.
Lines: 41
Nntp-Posting-Host: tellab1
Status: RO

In article <15khhcINNfn1@network.ucsd.edu>, reg@sdchemw2.ucsd.edu (Richard E. Gillilan) writes:
> This is the last one I saw:
> 
>       IIIIIIIIIIIIIII   IIIIIIIIIIIIIII      Marty Hewes
>       H ( )  \|/    H   H   ( )   \|/ H      Tellabs Inc.
>       H(   ) -O-    H   H  (   )  -O- H      System and Applications Test
>       H     )/|\    H   H (     ) /|\ H      Lisle, Il
>       H======^======H   H======^======H      nitram@tellabs.com
>       H- |----@-----H   H----| ---@---H      uunet!tellab1.TELLABS.COM!nitram
>       H /|\ @\|/ @  H   H   /|\@ \|/@ H 
>       H    \|/  \|/ H   H     \|/  \|/H      W (708) 955-3038
>       III^IIIIIII^III   III^IIIIIII^III      H (708) 665-6671
>      Wide eyed stereo  Wide  eyed  stereo    
> 
> Is there a program to create these things, or does one simply
> edit cleverly?
> 
> Richard
> 
> -----
> test
> -----

That particular one was the product of a boring afternoon gone to distraction.
Done by hand.  I had just read Jack Ferwerda's (spelling?) chapter on stereo
slide mounting and decided to do a little visual play on the "stereo window"
terminology used so often in stereo slide mounting.

It's also possible to do cross-eyed or wide-eyed 3d drawings on P.C. drawing
programs, once you get the hang of it.

      IIIIIIIIIIIIIII   IIIIIIIIIIIIIII      Marty Hewes
      H ( )  \|/    H   H   ( )   \|/ H      Tellabs Inc.
      H(   ) -O-    H   H  (   )  -O- H      System and Applications Test
      H     )/|\    H   H (     ) /|\ H      Lisle, Il
      H======^======H   H======^======H      nitram@tellabs.com
      H- |----@-----H   H----| ---@---H      uunet!tellab1.TELLABS.COM!nitram
      H /|\ @\|/ @  H   H   /|\@ \|/@ H 
      H    \|/  \|/ H   H     \|/  \|/H      W (708) 955-3038
      III^IIIIIII^III   III^IIIIIII^III      H (708) 665-6671
     Wide eyed stereo  Wide  eyed  stereo    


From ox-prg!uknet!mcsun!uunet!hoptoad!decwrl!sdd.hp.com!swrinde!network.ucsd.edu!sdchemw2!reg Fri Aug  7 10:17:36 BST 1992
Article: 748 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!hoptoad!decwrl!sdd.hp.com!swrinde!network.ucsd.edu!sdchemw2!reg
From: reg@sdchemw2.ucsd.edu (Richard E. Gillilan)
Newsgroups: alt.3d
Subject: Re: 3d sigs
Keywords: gullible joke
Message-ID: <15rl0sINNshb@network.ucsd.edu>
Date: 6 Aug 92 16:46:20 GMT
References: <KARTANO.92Aug3203547@vipunen.hut.fi> <bsisd9.i1v@wang.com> <1992Aug6.054551.26376@u.washington.edu>
Sender: Richard E. Gillilan
Organization: UC San Diego Chemistry
Lines: 23
NNTP-Posting-Host: sdchemw2.ucsd.edu
Status: RO

In article <1992Aug6.054551.26376@u.washington.edu> lectro@milton.u.washington.edu (Jonathan E. Maier) writes:
>In article <bsisd9.i1v@wang.com> smayo@wang.com (Scott Mayo) writes:
>>kartano@vipunen.hut.fi (Mikko Kartano) writes:
>>
>>>The worlds first 3-D .sig!  +               .   .   .   .   .   .   .
>>>Look at the picture on the  +            :    :    :    :    :    :    :
>>>right cross-eyed and really +         3     3     3     3     3     3     3
>>>_really_ close.             +      D      D      D      D      D      D      D
>>
>>Is it just me? I've never gotten any image of this type to look 3D no matter
>>how I cross my eyes or how close I get to the screen. All I get is double
>>images shifting before my eyes, and no sense of depth. Is there a *trick* to
>>this?
>
>   I may be paranoid, but ...

Gee, it works fine for me. Cross eyed, the D's are in front and the view
is from above, and wide eyed, the dots are in front and the view is from
below. This particular image does seem more difficult than simple stereo
pairs, however.


Richard


From ox-prg!uknet!stl!bnrgate!nrcnet0!cunews!torn!cs.utexas.edu!uunet!munnari.oz.au!uniwa!swanee.ee.uwa.oz.au!phillips Tue Aug 11 10:46:04 BST 1992
Article: 763 of alt.3d
Path: ox-prg!uknet!stl!bnrgate!nrcnet0!cunews!torn!cs.utexas.edu!uunet!munnari.oz.au!uniwa!swanee.ee.uwa.oz.au!phillips
From: phillips@uwa.oz.au (Christopher Phillips)
Newsgroups: alt.3d
Subject: Re: 3d sigs
Message-ID: <phillips.713338860@s13>
Date: 9 Aug 92 05:41:00 GMT
References: <1992Aug2.234240.14076@news.acns.nwu.edu> <KARTANO.92Aug3203547@vipunen.hut.fi> 	<bsisd9.i1v@wang.com> <1992Aug5.182806.21019@raven.alaska.edu>
Sender: news@swanee.ee.uwa.oz.au
Organization: Elec Eng, Univ of Western Australia
Lines: 29
Status: RO


>In article <bsisd9.i1v@wang.com> smayo@wang.com (Scott Mayo) writes:

>>kartano@vipunen.hut.fi (Mikko Kartano) writes:

>>>The worlds first 3-D .sig!  +               .   .   .   .   .   .   .
>>>Look at the picture on the  +            :    :    :    :    :    :    :
>>>right cross-eyed and really +         3     3     3     3     3     3     3
>>>_really_ close.             +      D      D      D      D      D      D      D

>>Is it just me? I've never gotten any image of this type to look 3D no matter
>>how I cross my eyes or how close I get to the screen. All I get is double
>>images shifting before my eyes, and no sense of depth. Is there a *trick* to
>>this?

Well I find it a lot easier to view from a distance of about 40cm from the
screen  (thats with a 12" 80column terminal, green text on black).
You need to get adjacent '3's to coincide.  Try this and see if it helps;
Place you finger on the screen, somewhere in the .sig
Slowly move your finger towards your eyes, watching your finger
not the screen.  About 1/3 of the way toward your eyes, the .sig
should leap into perspective behind your finger.  Good luck!


--
Christopher Jam	__________________________________________________
'Another day, another try.  But remember, SHOOT OR DIE!' -turrican
phillips@swanee.ee.uwa.oz.au		c64 forever!!!!
------------------------------------------------------------------


From ox-prg!uknet!mcsun!uunet!cs.utexas.edu!usc!rpi!newsserver.pixel.kodak.com!kinsman Tue Aug 11 10:46:47 BST 1992
Article: 766 of alt.3d
Path: ox-prg!uknet!mcsun!uunet!cs.utexas.edu!usc!rpi!newsserver.pixel.kodak.com!kinsman
From: kinsman@ssd.kodak.com (Andy Kinsman 253-7794)
Newsgroups: alt.3d
Subject: Who wrote this program?  (stereogram.c)
Message-ID: <1992Aug9.040152.18258@pixel.kodak.com>
Date: 9 Aug 92 04:01:52 GMT
Sender: news@pixel.kodak.com
Organization: Eastman Kodak
Lines: 29
Originator: kinsman@crestone
Status: RO

If anybody can steer me to the author of this program please
do so.  Perhaps somebody saved it with a header that identifies
its place of origin.  Thank you. 

-AAK       kinsman@ssd.kodak.com



/*

 stereogram.c

Input is of the form: (any number of 64 char lines)

----------------------------------------------------------------
---------####-----####------------------------------------------
---------####-----####-------------##########-------------------
---------####-----####------------------------------------------
----------------------------------------------------------------

/*
                 /*/                               /*/
#include <math.h>/*STEREOGRAMSX/**#include <math.h>/*XSTEREOGRAMS/**/
#include <stdio.h>/*IN ASCII!$%/**#include <stdio.h>/*$IN ASCII!@/**/
main(){char m[80],a[80],e,j;for/**main(){char m[80],a[80],e,j;for/**/
(;gets(m)!=NULL;puts(a))for(a[ /**(;ges(m)!=NULL;puts(a))fork(a[ /**/
80]=e=j=0;j<80;j++)a[j]=e&&m[j-/**80]==j=0;<80;j++)a[j#]=e&&rm[j-/**/
16]!='#'||j<16?e=0,random()%26+/**16]!'#'||j<16?e=0,random()z%26+/**/
'A':a[j-16+(e=m[j-16]=='#')];} /**'A':a[j-16+(e=m[j-16]=='#')];} /**/


From ox-prg!bowen Tue Aug 11 12:13:07 BST 1992
Article: 767 of alt.3d
Path: ox-prg!bowen
From: bowen@prg.ox.ac.uk (Jonathan Bowen)
Newsgroups: alt.3d
Subject: FTP archive of alt.3d stereogram material
Message-ID: <4249@inca.comlab.ox.ac.uk>
Date: 11 Aug 92 11:02:32 GMT
Sender: news@comlab.ox.ac.uk
Reply-To: Jonathan.Bowen@prg.oxford.ac.uk (Jonathan Bowen)
Organization: Programming Research Group, Oxford University, UK
Lines: 42
Status: RO

I have installed most of the random dot stereograms issued on
alt.3d on the FTP server here.

Type the command "ftp ftp.comlab.ox.ac.uk" (or alternatively "ftp
192.76.25.2" if this does not work) and use "anonymous" as the login id
and your e-mail address as the password when prompted.  The FTP command
"cd Documents/3d" will get you into the 3-D stereogram archive
directory.  The file "README" gives some general information and
"00index" gives a list of the files. (Retrieve these using the FTP
command "get README", for example.) Note that the large files are
compressed and have an extra ".Z" suffix (e.g., "torus.ps.Z").  "get
torus.ps" should retrieve an uncompressed version; "get torus.ps.Z"
will get the file in compressed form. Remember to use the "binary"
command first when retrieving compressed files.

See below for the current contents of the "00index" file.

--
Jonathan Bowen, Oxford University



Random dot and ASCII stereogram archive
---------------------------------------

This is mostly derived from the alt.3d newsgroup that is
recommended reading for stereogram addicts.

Alt.3d          Relevant messages on alt.3d newsgroup
ascii-3d.ps     Short article on ASCII stereograms
stereogram.c    Short program to generate ASCII stereograms
*.ps            PostScript random dot stereograms from alt.3d
*.gif           GIF random dot stereograms from alt.3d

Collected by Jonathan Bowen, Oxford University Computing Laboratory
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