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> I was in Las Vegas USA many years ago, and watched a 'special venue' 3D movie
> there on a large domed screen. (Some form of IMAX, probably.) I *think* the 3D
> glasses I wore were shutter glasses of some sort (but I could be wrong; I don't
> remember exactly.) The 3D effect was flawless-- and I was amazed that I could
> turn at any angle to look at the imagery, even directly overhead. I assume the
> 3D glasses were circularly-polarized-- my first experience with that technology.
>
> But when I went to see AVATAR in 3D-Imax at my local big cinema, I remember
> tilting my head to see what would happen-- and instead saw two overlapped images
> in each eye, with no 3D :-( The glasses they gave out (on loan!) were simple
> polarizers, nothing active. So no circular polarization there, AKAIK.
Both circular and linear polarised systems are passive, the filters in
both eyes are simple polariser sheets that are very cheap, small and
require no power source or electronics. The display equipment though
needs to be more complex as it needs to transmit two images with two
different polarisations. Normal TVs and monitors cannot do this.
Active, or shutter, as the name implies, works by quickly blacking out
one eye, then the other, in sync with each frame being shown. This
allows it to work with a normal TV or monitor (plus a device to
sync/transmit to the glasses). Note that these systems probably do
"black out" each eye using effectively a 1-pixel LCD in each eye (and
hence work due to polarisation), but they don't rely on any special
polarisation from the display device itself.
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scott <sco### [at] scott com> wrote:
> Active, or shutter, as the name implies, works by quickly blacking out
> one eye, then the other, in sync with each frame being shown. This
> allows it to work with a normal TV or monitor (plus a device to
> sync/transmit to the glasses). Note that these systems probably do
> "black out" each eye using effectively a 1-pixel LCD in each eye (and
> hence work due to polarisation), but they don't rely on any special
> polarisation from the display device itself.
I suspect the shutter glasses' orientation may matter though: As you say, there
is polarization involved in LCD: Essentially it is a sandwich of two
polarization filters, with a medium in between that can rotate the polarization
of the light in a controlled manner.
Thus, for shutter glasses to work with an LCD, the polarization orientation of
the glasses' sandwich filters needs to sufficiently match that of the display's.
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On 1/7/2016 7:37 PM, Norbert Kern wrote:
> Mike Horvath <mik### [at] gmailcom> wrote:
>> I just got done watching the new Star Wars movie in 3D. I kept the
>> glasses. How do I make images like that in POV-Ray?
>>
>>
>> Mike
>
>
> It seems, tonight I've all the answers...
>
> I use StereoPhotoMaker (free) to get *.jps files out of two left/right images (
> http://stereo.jpn.org/eng/stphmkr/index.html ).
>
> My LG TV-set understands this formate. The original images have to be squeezed
> first (look at binaries.images for an example).
>
> Norbert
>
>
>
>
>
I ordered one of these and should get it later this week.
http://www.amazon.com/gp/product/B004EDB1S4?keywords=stereoscope&qid=1452568122&ref_=sr_1_90&sr=8-90
Are there tutorials on how set up POV-Ray to make such images? I'm not
using the look_at keyword in my camera statement. I am using up, right,
and direction instead. How can I compensate for this?
Mike
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On 1/11/2016 10:11 PM, Mike Horvath wrote:
> I ordered one of these and should get it later this week.
>
>
http://www.amazon.com/gp/product/B004EDB1S4?keywords=stereoscope&qid=1452568122&ref_=sr_1_90&sr=8-90
>
>
> Are there tutorials on how set up POV-Ray to make such images? I'm not
> using the look_at keyword in my camera statement. I am using up, right,
> and direction instead. How can I compensate for this?
>
>
> Mike
Also, is there a particular angle of view I should be aiming for?
Mike
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Mike Horvath <mik### [at] gmailcom> wrote:
> On 1/11/2016 10:11 PM, Mike Horvath wrote:
> > I ordered one of these and should get it later this week.
> >
> >
http://www.amazon.com/gp/product/B004EDB1S4?keywords=stereoscope&qid=1452568122&ref_=sr_1_90&sr=8-90
> >
> >
> > Are there tutorials on how set up POV-Ray to make such images? I'm not
> > using the look_at keyword in my camera statement. I am using up, right,
> > and direction instead. How can I compensate for this?
By /adding/ a "look_at" statement? ;)
For starters you might get away ok without look_at.
What you really need to do is translate the camera a bit to the left (for the
left eye) or the right (for the right eye) -- which is actually a deal easier if
you don't use look_at, because with that statement you'd have to compute your
effective left/right axis "manually".
> > Mike
>
> Also, is there a particular angle of view I should be aiming for?
That depends on the (apparent) angle at which the image will be visible using
that contraption.
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On 1/12/2016 2:17 PM, clipka wrote:
> By /adding/ a "look_at" statement? ;)
>
> For starters you might get away ok without look_at.
>
> What you really need to do is translate the camera a bit to the left (for the
> left eye) or the right (for the right eye) -- which is actually a deal easier if
> you don't use look_at, because with that statement you'd have to compute your
> effective left/right axis "manually".
Okay, but I was thinking that rotating by a small amount would be
better. Otherwise the point of interest gets translated too. Should I
use real-world measurements for the distance between the "eyes"?
>>
>> Also, is there a particular angle of view I should be aiming for?
>
> That depends on the (apparent) angle at which the image will be visible using
> that contraption.
>
>
I don't understand what you mean. By angle of view I mean the camera
angle. Is there some natural angle that is most like human vision?
Mike
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On 1/12/2016 7:52 PM, Mike Horvath wrote:
> On 1/12/2016 2:17 PM, clipka wrote:
>> By /adding/ a "look_at" statement? ;)
>>
>> For starters you might get away ok without look_at.
>>
>> What you really need to do is translate the camera a bit to the left
>> (for the
>> left eye) or the right (for the right eye) -- which is actually a deal
>> easier if
>> you don't use look_at, because with that statement you'd have to
>> compute your
>> effective left/right axis "manually".
>
> Okay, but I was thinking that rotating by a small amount would be
> better. Otherwise the point of interest gets translated too. Should I
> use real-world measurements for the distance between the "eyes"?
>
I don't completly agree with Clipka. You can use the look_at to set the
convergance. That is how you place objects in front or behind the
screen. So with the look_at set you just translate the camera left and
right. As for the distance to use for your baseline. It should be the
distance between your eyes in relation to the scale of your scene.
A simple explanation at the beginning of this article.
http://www.sky.com/shop/__PDF/3D/Basic_Principles_of_Stereoscopic_3D_v1.pdf
>>>
>>> Also, is there a particular angle of view I should be aiming for?
>>
>> That depends on the (apparent) angle at which the image will be
>> visible using
>> that contraption.
>>
>>
>
> I don't understand what you mean. By angle of view I mean the camera
> angle. Is there some natural angle that is most like human vision?
>
Without getting arty ;) use between 40° and 60° that is roughly a 50mm lens.
How are you going to drive your "Cardboard", what software?
--
Regards
Stephen
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Am 12.01.2016 um 20:52 schrieb Mike Horvath:
> On 1/12/2016 2:17 PM, clipka wrote:
>> By /adding/ a "look_at" statement? ;)
>>
>> For starters you might get away ok without look_at.
>>
>> What you really need to do is translate the camera a bit to the left
>> (for the
>> left eye) or the right (for the right eye) -- which is actually a deal
>> easier if
>> you don't use look_at, because with that statement you'd have to
>> compute your
>> effective left/right axis "manually".
>
> Okay, but I was thinking that rotating by a small amount would be
> better. Otherwise the point of interest gets translated too. Should I
> use real-world measurements for the distance between the "eyes"?
>
>>>
>>> Also, is there a particular angle of view I should be aiming for?
>>
>> That depends on the (apparent) angle at which the image will be
>> visible using
>> that contraption.
>
> I don't understand what you mean. By angle of view I mean the camera
> angle. Is there some natural angle that is most like human vision?
It all depends on the contraption you use, and the size you print the
images at.
Let's forget about the stereoscope for a moment, and take a look at the
situation for a normal computer display. Suppose your display is WIDTH
cm wide horizontally, and you view it from a distance of DIST cm. The
display will occupy a certain portion of your field of vision, namely
ALPHA degrees in horizontally, where
tan (ALPHA/2) = (WIDTH/2) / DIST
Now for any image you display at full width on that computer display,
and view under the given parameters, the "natural angle that is most
like human vision" is exactly ALPHA.
With a stereoscope, the situation is more complex, because there are
lenses involved, so the /actual/ WIDTH and DIST parameters are of no use
-- you need to know the /apparent/ WIDTH and DIST, or the apparent ALPHA
itself. But the principle is always the same: The angle you want to
specify in POV-Ray is the horizontal angle that the image effectively
occupies in your field of view.
The lens also affects what camera type you should choose. With the
computer display, you want the default perspective camera; with the
spectroscope, you may want a more fisheye-like projection.
ultra_wide_angle projection may be ok for your purposes.
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On 1/12/2016 3:21 PM, Stephen wrote:
> A simple explanation at the beginning of this article.
>
> http://www.sky.com/shop/__PDF/3D/Basic_Principles_of_Stereoscopic_3D_v1.pdf
>
>
Thanks for that link. I will look at the StereoPhotoMaker software
documentation for more clues. I would like to rely on that software as
little as possible. Ideally I would do everything in POV-Ray and GIMP.
> Without getting arty ;) use between 40° and 60° that is roughly a 50mm
> lens.
>
Okay thanks.
> How are you going to drive your "Cardboard", what software?
>
>
I don't understand what you mean?
Mike
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On 1/12/2016 8:39 PM, Mike Horvath wrote:
> On 1/12/2016 3:21 PM, Stephen wrote:
>> A simple explanation at the beginning of this article.
>>
>> http://www.sky.com/shop/__PDF/3D/Basic_Principles_of_Stereoscopic_3D_v1.pdf
>>
>>
>>
>
> Thanks for that link. I will look at the StereoPhotoMaker software
> documentation for more clues. I would like to rely on that software as
> little as possible. Ideally I would do everything in POV-Ray and GIMP.
>
You can do it all in PovRay then combine the seperate images in
StereoPhotoMaker or similar.
>> Without getting arty ;) use between 40° and 60° that is roughly a 50mm
>> lens.
>>
>
> Okay thanks.
>
>> How are you going to drive your "Cardboard", what software?
>>
>>
>
> I don't understand what you mean?
>
Once you have made your 3d Stereo image. How are you going to use Google
Cardboard to view it? Or have you not got to that point yet?
I tried cardbord a few months ago and I think that downloaded a few demo
apps one had a gallery IIRC. Unfortunatly I've uninstalled tha apps and
can't remember which ones they were.
--
Regards
Stephen
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