POV-Ray : Newsgroups : povray.general : Colograms Server Time
31 Jul 2024 18:20:04 EDT (-0400)
  Colograms (Message 1 to 8 of 8)  
From: Gilles Tran
Subject: Colograms
Date: 21 Sep 2006 17:14:35
Message: <451300bb@news.povray.org>
http://george.ph.utexas.edu/~schreck/schreck/cologram/ (link courtesy of 
Brian McConnell)

This guy uses POV-Ray to create some sort of stereoscopic images. He calls 
them "colograms" but there's probably a more common term for this technique 
(it looks like lenticular prints without the lens).
The cool thing is that it can be done at home using a regular printer.

G.


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From: Rene Bui
Subject: Re: Colograms
Date: 21 Sep 2006 19:20:01
Message: <web.45131d3ab2c58e1295c7aa230@news.povray.org>
"Gilles Tran" <gitran_nospam_@wanadoo.fr> wrote:
> This guy uses POV-Ray to create some sort of stereoscopic images. He calls
> them "colograms" but there's probably a more common term for this technique

It's seems to be the polarized light technique or something


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From: Warp
Subject: Re: Colograms
Date: 21 Sep 2006 19:55:43
Message: <4513267f@news.povray.org>
Rene Bui <ren### [at] freefr> wrote:
> It's seems to be the polarized light technique or something

  Polarized light? Isn't it just a simple occlusion technique where
you see just part of the image at a certain angle?

-- 
                                                          - Warp


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From: Trevor G Quayle
Subject: Re: Colograms
Date: 21 Sep 2006 22:15:00
Message: <web.4513463bb2c58e128fb5a6f0@news.povray.org>
Warp <war### [at] tagpovrayorg> wrote:
> Rene Bui <ren### [at] freefr> wrote:
> > It's seems to be the polarized light technique or something
>
>   Polarized light? Isn't it just a simple occlusion technique where
> you see just part of the image at a certain angle?
>
> --
>                                                           - Warp

It seems so.  Sort of like a poor man's version of the little hologram cards
that you could get in cereal boxes and such with the ridged plastic front.
I may have to try it some time...

-tgq


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From: Kenneth
Subject: Re: Colograms
Date: 22 Sep 2006 00:10:00
Message: <web.451360cbb2c58e12b0d7b10e0@news.povray.org>
"Trevor G Quayle" <Tin### [at] hotmailcom> wrote:
> Warp <war### [at] tagpovrayorg> wrote:
> > Rene Bui <ren### [at] freefr> wrote:
> > > It's seems to be the polarized light technique or something
> >
> >   Polarized light? Isn't it just a simple occlusion technique where
> > you see just part of the image at a certain angle?
> >
> > --
> >                                                           - Warp
>
> It seems so.  Sort of like a poor man's version of the little hologram cards
> that you could get in cereal boxes and such with the ridged plastic front.
>

Yes, a sort of lenticular-like image/effect without the need for a plastic
lenticular screen in front.  Didn't know that was possible. Thanks for
posting the link!

I assume there's a somewhat low limit to the number of images that can be
combined (less than with a lenticular print, which uses a kind of lens-like
refraction to pick out each individual image, I believe.)

Ken W.


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From: Rene Bui
Subject: Re: Colograms
Date: 22 Sep 2006 03:30:00
Message: <web.45138fafb2c58e1295c7aa230@news.povray.org>
Warp <war### [at] tagpovrayorg> wrote:
>   Polarized light? Isn't it just a simple occlusion technique where
> you see just part of the image at a certain angle?
>

ooops! I forgot to put some irony in my post...
yeeees indeed, it is a simple lenticular technique without lens but light
from back (ingenious imo)
sorry it was so late and I was tired ;-)


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From: Chris B
Subject: Re: Colograms
Date: 22 Sep 2006 08:10:00
Message: <4513d298$1@news.povray.org>
"Trevor G Quayle" <Tin### [at] hotmailcom> wrote in message 
news:web.4513463bb2c58e128fb5a6f0@news.povray.org...
> Warp <war### [at] tagpovrayorg> wrote:
>> Rene Bui <ren### [at] freefr> wrote:
>> > It's seems to be the polarized light technique or something
>>
>>   Polarized light? Isn't it just a simple occlusion technique where
>> you see just part of the image at a certain angle?
>>
>> --
>>                                                           - Warp
>
> It seems so.  Sort of like a poor man's version of the little hologram 
> cards
> that you could get in cereal boxes and such with the ridged plastic front.
> I may have to try it some time...
>
> -tgq
>

This thread provoked me to wondering whether this masking technique or the 
lenticular prints technique could be wrapped around a cylinder to give a 360 
degree rotatable 3D stereoscopic image. I figure that it should be possible 
to adjust the print line spacing and interlacing to compensate for the 
distortion of wrapping it into a cylinder, but I've never seen anything but 
flat ones.

Anyone ever seen or tried anything like this?

Regards,
Chris B.


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From: Alain
Subject: Re: Colograms
Date: 22 Sep 2006 19:32:06
Message: <45147276@news.povray.org>
Chris B nous apporta ses lumieres en ce 22/09/2006 08:10:
> "Trevor G Quayle" <Tin### [at] hotmailcom> wrote in message 
> news:web.4513463bb2c58e128fb5a6f0@news.povray.org...
>> Warp <war### [at] tagpovrayorg> wrote:
>>> Rene Bui <ren### [at] freefr> wrote:
>>>> It's seems to be the polarized light technique or something
>>>   Polarized light? Isn't it just a simple occlusion technique where
>>> you see just part of the image at a certain angle?
>>>
>>> --
>>>                                                           - Warp
>> It seems so.  Sort of like a poor man's version of the little hologram 
>> cards
>> that you could get in cereal boxes and such with the ridged plastic front.
>> I may have to try it some time...
>>
>> -tgq
>>
> 
> This thread provoked me to wondering whether this masking technique or the 
> lenticular prints technique could be wrapped around a cylinder to give a 360 
> degree rotatable 3D stereoscopic image. I figure that it should be possible 
> to adjust the print line spacing and interlacing to compensate for the 
> distortion of wrapping it into a cylinder, but I've never seen anything but 
> flat ones.
> 
> Anyone ever seen or tried anything like this?
> 
> Regards,
> Chris B. 
> 
> 
In that case, the needed offset will vary with your distance to the cylinder and 
wether you are vewing the middle part of the visible section, nearly 
perpendicular, or near the edge, grazing angle. This mean a variable distortion.

-- 
Alain
-------------------------------------------------


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