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

Post a reply to this message

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

Post a reply to this message

Am 08.01.2016 um 01:01 schrieb Mike Horvath:
> 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?

Unless you have a display specifically designed for 3D -- in which case
some 3D glasses should have come with it -- the glasses they give you at
movie theaters are of no use to you. So either way you could just as
well have been a good boy and returned them. (Even if your display is
designed for 3D, the glasses might be incompatible with the system used.)

The only glasses that work with traditional displays are those good old
red-green or red-cyan glasses; if they gave you a set of /those/ at the
theater you should have demanded to get your money back.

Post a reply to this message

Le 16-01-07 19:01, Mike Horvath a écrit :
> 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

The 3D glasses used for colour movies normaly use polarised glasses, 
vertical polarisation on one side, horizontal for the other.
The projectors also have coresponding polaroid filters.
I tried this trick: Hold the 3D glasses upside down. The resuld is 
inverted perspective.
Holding the glasses and pivoting them 90° and you can see the shift from 
one image to the other very clearly.
Take two, hold them in such a way that you look through the left glass 
from une and the right glass of the other, you'll only see black.

The only 3D glasses that you can use at home and in a cinema, are the 
red-cyan ones used for black and white 3D movies.

3D TV and monitors use alternating right-left images and you need 
special switching glasses to get the 3D effect. Special care must be 
given to the synchronisation between the screen and the glasses, usualy 
provided through a bluetoot signal.



Alain

Post a reply to this message

>> 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
>
> The 3D glasses used for colour movies normaly use polarised glasses,
> vertical polarisation on one side, horizontal for the other.

They can also use circularly polarised light (opposite handed-ness of 
polarisation for each eye) as this doesn't require you to keep the 
glasses horizontal.

Every LCD I've come across has linear polarised light coming out of it, 
so if you can rotate your glasses in front of an LCD to make the image 
go completely black then they're linear glasses, if not they're circular.

If you've got a TV/monitor that works with passive glasses then give it 
a shot, you might get lucky. Often the TV will have a setting to 
override the 3D image format (side-by-side, interlaced etc) - you just 
need to match you POV images to the format the TV is expected, 
side-by-side is probably easiest to create.

Post a reply to this message

On 1/8/2016 8:53 AM, scott wrote:
> If you've got a TV/monitor that works with passive glasses then give it
> a shot, you might get lucky. Often the TV will have a setting to
> override the 3D image format (side-by-side, interlaced etc) - you just
> need to match you POV images to the format the TV is expected,
> side-by-side is probably easiest to create.


Yes, you need a TV/monitor that is 3D Ready. If it is a monitor you need 
a GPU and drivers. You will also need a transmitter to sync the glasses.

Reminds me of the opera glasses that turned up at jumble sales for 
years. Long after theatres stopped putting them in the dress circle. 
Where you could rent them for about sixpence. (Or am I just showing my age?)


-- 

Regards
     Stephen

Post a reply to this message

>> If you've got a TV/monitor that works with passive glasses then give it
>> a shot, you might get lucky. Often the TV will have a setting to
>> override the 3D image format (side-by-side, interlaced etc) - you just
>> need to match you POV images to the format the TV is expected,
>> side-by-side is probably easiest to create.
>
> Yes, you need a TV/monitor that is 3D Ready. If it is a monitor you need
> a GPU and drivers. You will also need a transmitter to sync the glasses.

You are talking of active (shutter) glasses. Passive (polarising) 
glasses do not need a transmitter or any sync, the glasses are literally 
just two bits of polariser film stuck to some cardboard (hence very 
cheap). Obviously an "active" type TV will not work with passive 
glasses, or vice-versa.

Post a reply to this message

On 1/8/2016 11:40 AM, scott wrote:
>>> If you've got a TV/monitor that works with passive glasses then give it
>>> a shot, you might get lucky. Often the TV will have a setting to
>>> override the 3D image format (side-by-side, interlaced etc) - you just
>>> need to match you POV images to the format the TV is expected,
>>> side-by-side is probably easiest to create.
>>
>> Yes, you need a TV/monitor that is 3D Ready. If it is a monitor you need
>> a GPU and drivers. You will also need a transmitter to sync the glasses.
>
> You are talking of active (shutter) glasses. Passive (polarising)
> glasses do not need a transmitter or any sync, the glasses are literally
> just two bits of polariser film stuck to some cardboard (hence very
> cheap). Obviously an "active" type TV will not work with passive
> glasses, or vice-versa.
>

Oh! I've not seen a 3D film at the cinema. I obviously havn't thought 
about it much, Supplying shutter glasses would be a big layout as well.


-- 

Regards
     Stephen

Post a reply to this message

Alain <kua### [at] videotronca> wrote:

> The 3D glasses used for colour movies normaly use polarised glasses,
> vertical polarisation on one side, horizontal for the other.
> The projectors also have coresponding polaroid filters.

There appear to be different technologies out there, but state of the art
actually is not horizontal and vertical polarization, but left-handed and
right-handed circular polarization -- the advantage being that you don't need to
keep your head exactly level.

This is often also combined with a slight red/cyan tint.


> 3D TV and monitors use alternating right-left images and you need
> special switching glasses to get the 3D effect. Special care must be
> given to the synchronisation between the screen and the glasses, usualy
> provided through a bluetoot signal.

There /are/ also displays out there that use polarization filters.

Post a reply to this message

On 1/7/2016 8:15 PM, clipka wrote:
> Am 08.01.2016 um 01:01 schrieb Mike Horvath:
>> 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?
>
> Unless you have a display specifically designed for 3D -- in which case
> some 3D glasses should have come with it -- the glasses they give you at
> movie theaters are of no use to you. So either way you could just as
> well have been a good boy and returned them. (Even if your display is
> designed for 3D, the glasses might be incompatible with the system used.)
>
> The only glasses that work with traditional displays are those good old
> red-green or red-cyan glasses; if they gave you a set of /those/ at the
> theater you should have demanded to get your money back.
>

Crap. I guess I should return them then.

There are also chromatek glasses that work with regular PC monitors, but 
they mess up the colors considerably.

http://chromatek.com/what-is-chromadepth/chromadepth-basic-explanation/

Mike

Post a reply to this message

"clipka" <nomail@nomail> wrote:

>
> There appear to be different technologies out there, but state of the art
> actually is not horizontal and vertical polarization, but left-handed and
> right-handed circular polarization -- the advantage being that you don't need to
> keep your head exactly level.
>

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.

Post a reply to this message

On 1/8/2016 3:32 PM, Kenneth wrote:
> "clipka" <nomail@nomail> wrote:
>
>>
>> There appear to be different technologies out there, but state of the art
>> actually is not horizontal and vertical polarization, but left-handed and
>> right-handed circular polarization -- the advantage being that you don't need to
>> keep your head exactly level.
>>
>
> 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.
>
>
>

I got a headache watching Avatar, but the new Star Wars was okay. Maybe 
they used different technologies?


Mike

Post a reply to this message

Am 08.01.2016 um 21:51 schrieb Mike Horvath:

>> 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.

Circular polarization isn't necessarily active either. Not sure if it's
even suited to make shutter glasses out of it. It's just another
polarization mode of light.


> I got a headache watching Avatar, but the new Star Wars was okay. Maybe
> they used different technologies?

It simply depends on the theater; both movies can be shown with either
technology.

When I watched Avatar, they already had the very same circular
polarization glasses with slight green/cyan tint.

Post a reply to this message

Am 08.01.2016 um 22:21 schrieb clipka:

> When I watched Avatar, they already had the very same circular
> polarization glasses with slight green/cyan tint.

Just did a bit of browsing on the 'net, to find out that I'm entirely
mistaken; so here's the deal about professional theater 3D technology:


IMAX 3D:
--------
Steer clear of these theaters. They use linear polarization, i.e. the
thing that makes you not want to tilt your head.

Needs a special silver screen.
The glasses may be compatible with some passive (i.e. non-shutter) 3D TVs


Cinema 3D:
----------
Never seen or heard of these brands before myself, but should be ok.
They use circular polarization.

Needs a special silver screen.
The glasses may be compatible with some passive (i.e. non-shutter) 3D TVs.


Real-D:
-------
Never seen or heard of these brands before myself, and not sure what to
make of these theaters. They also use circular polarization, but employ
a shutter-like apparatus in front of the single projector, which I
suspect might be more prone to giving you a headache due to flickering.

Needs a special silver screen.
The glasses may be compatible with some passive (i.e. non-shutter) 3D TVs.


XpanD 3D:
---------
Never seen or heard of this brand before myself, and not sure what to
make of these theaters. They use shutter glasses, which I suspect might
be more prone to giving you a headache due to flickering.

Does not need a special silver screen.
Does need expensive glasses, which /are/ probably compatible with active
(i.e. shutter) 3D TVs.


Dolby 3D:
---------
This is what I was referring to, and they're a perfectly good choice,
but they do /not/ use circular polarization. Instead, amazingly it /is/
a variation on the old red/cyan theme. BUT: Rather than two broad colour
channels, one for each image channel, they use /six/ narrow colour
channels, assigned to the image channels in an alternating fashion; this
significantly reduces the apparent colour shift, as each eye gets its
own R, G and B channel, albeit with slightly different primary hues. The
residual shift is noticeable as a slight red/cyan tint of the glasses,
but is completely eliminated in the projection by digital colour correction.

Doesn't need a special silver screen.
Does need expensive glasses -- which are /not/ compatible with /any/
contemporary 3D TVs.

(Not to be confused with the display technology of same name that is
currently being developed for home use, and allegedly will not need any
glasses whatsoever.)


Given this broad range of 3D theater technology in current use, I'm not
/that/ surprised anymore to hear entirely different opinions about the
3D movie experience.

Post a reply to this message

Am 08.01.2016 um 23:44 schrieb clipka:

> Cinema 3D:

Forget about this brand name; apparently it's not a 3D theater
technology, but a 3D TV/monitor technology.

Post a reply to this message

On 01/07/2016 06:51 PM, Alain wrote:
> Le 16-01-07 19:01, Mike Horvath a écrit :
>> 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
>
> The 3D glasses used for colour movies normaly use polarised glasses, vertical
polarisation on
> one side, horizontal for the other.

A point of trivia...  I know for a fact that the original 3D movies did not use 
horizontal/vertical polarization -- they were both at 45°, one was / and the other
was \.  I 
*assume* this is still the case but don't know.

Aside:  My father used to be a projectionist, and over the years worked at several
different 
theaters.  So when I was young (a llooong time ago) I got to see movies for free
anyplace he 
worked.  He retired, then later passed away quite some time ago, so these days I have
to pay. 
:-(   So I rarely go to movies anymore (I'm cheap!)  ;-)

      -=- Larry -=-

Post a reply to this message

On 1/7/2016 7:01 PM, Mike Horvath 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

I did a bit of browsing of Amazon looking for a nice stereoscope. 
However, they run between $40 - $100 which is too much.


Mike

Post a reply to this message

Am 10.01.2016 um 01:53 schrieb Mike Horvath:
> On 1/7/2016 7:01 PM, Mike Horvath 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
> 
> I did a bit of browsing of Amazon looking for a nice stereoscope.
> However, they run between $40 - $100 which is too much.

Indeed, given that Google Cardboard and variations on the theme are
around $30 bucks. If 3D image viewing is all you want, and you happen to
own a smartphone, that might be an alternative to examine. (And if you
happen to not own a smartphone, it might be worth investigating whether
you can convert one of those into a classic stereoscope ;)

Also, if you even happen own a Samsung Galaxy Note 4 or 6, Samsung's
Gear VR might definitely be worth a look.


And of course Oculus are now accepting pre-orders, but their price is in
an entirely different ballpark B-) (unless you compare it to Samsung's
Gear VR /plus/ a brand-new Samsung Galaxy).

Post a reply to this message

On 1/9/2016 9:04 PM, clipka wrote:
> Am 10.01.2016 um 01:53 schrieb Mike Horvath:
>> On 1/7/2016 7:01 PM, Mike Horvath 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
>>
>> I did a bit of browsing of Amazon looking for a nice stereoscope.
>> However, they run between $40 - $100 which is too much.
>
> Indeed, given that Google Cardboard and variations on the theme are
> around $30 bucks. If 3D image viewing is all you want, and you happen to
> own a smartphone, that might be an alternative to examine. (And if you
> happen to not own a smartphone, it might be worth investigating whether
> you can convert one of those into a classic stereoscope ;)
>
> Also, if you even happen own a Samsung Galaxy Note 4 or 6, Samsung's
> Gear VR might definitely be worth a look.
>
>
> And of course Oculus are now accepting pre-orders, but their price is in
> an entirely different ballpark B-) (unless you compare it to Samsung's
> Gear VR /plus/ a brand-new Samsung Galaxy).
>

My smartphone has a low resolution 480 x 854 pixels (~221 ppi pixel 
density), and it's a Windows Phone, so there are few apps for it.

http://www.gsmarena.com/nokia_lumia_635-6254.php

Post a reply to this message

Le 16-01-09 19:53, Mike Horvath a écrit :
> On 1/7/2016 7:01 PM, Mike Horvath 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
>
> I did a bit of browsing of Amazon looking for a nice stereoscope.
> However, they run between $40 - $100 which is too much.
>
>
> Mike

In several cases, you don't realy need a stereoscope.
If the images are side by side, and suficiently small, then parallel 
viewing can work nicely. You look at the images as if they where farther 
away than they are.
Often, when the side by side images are larger, you need to use the 
crosswed eyes viewing method where you cross your eyes as if the images 
where much closer than they actualy are.
Cost: Free.
With some practice, it won't cause eye fatigue. I can use bot parallel 
and crossed view for hours.

If the images are supposed to be viewed with polaroid filters, you can 
repurpose old polaroid sun glasses by removing the glasses and mounting 
them in a cardboard frame at the correct angles.

Obviously, if you need shutter glasses, then, you just can't make a home 
made version and need to buy some that are compatible with your equipment.

Post a reply to this message

> 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.

Post a reply to this message

scott <sco### [at] scottcom> 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.

Post a reply to this message

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

Post a reply to this message

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

Post a reply to this message

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.

Post a reply to this message

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

Post a reply to this message

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

Post a reply to this message

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.

Post a reply to this message

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

Post a reply to this message

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

Post a reply to this message

Am 12.01.2016 um 22:06 schrieb Stephen:

>>> 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.

Judging from the article description, I /think/ his choice of software
is called "printer driver" ;)

Post a reply to this message

On 1/12/2016 4:06 PM, Stephen wrote:
> 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.
>

I am not using Google Cardboard. I am going to print the pictures and 
use this:

http://www.amazon.com/gp/product/B004EDB1S4?keywords=stereoscope&qid=1452568122&ref_=sr_1_90&sr=8-90


Mike

Post a reply to this message

Le 16-01-12 14:52, Mike Horvath a écrit :
> 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"?

Depending on your scene, and the location of the camera, rotating the 
camera can result in uterly unreasonable offsets, like accidently 
diverging camera axis or excessive convergence.
It's usualy beter to translate the camera /after/ you set the look_at 
point for images like paysages or points of interest a fair distance 
from the camera.
If the point of interest is close to the camera, then, it may beter to 
translate the camera, then, set the look_at point at the same location 
for both views. This correspond to the natural converging of the eyes 
when looking to something close.

>
>>>
>>> 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?

Yes, the camera's horizontal field ov fiew in degrees.
A "natural" angle can be something between 30° and 70°. It's highly 
dependent on how the image is to be viewed.

>
>
> Mike

Alain

Post a reply to this message

On 1/12/2016 10:07 PM, Mike Horvath wrote:
> On 1/12/2016 4:06 PM, Stephen wrote:
>> 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.
>>
>
> I am not using Google Cardboard. I am going to print the pictures and
> use this:
>
>
http://www.amazon.com/gp/product/B004EDB1S4?keywords=stereoscope&qid=1452568122&ref_=sr_1_90&sr=8-90
>
>

Oh! I saw "cardboard" in the title and jumped to conclusions. That makes 
more sense now..


-- 

Regards
     Stephen

Post a reply to this message

Mike Horvath <mik### [at] gmailcom> wrote:
> On 1/12/2016 4:06 PM, Stephen wrote:

>
> I am not using Google Cardboard. I am going to print the pictures and
> use this:
>
>
http://www.amazon.com/gp/product/B004EDB1S4?keywords=stereoscope&qid=1452568122&ref_=sr_1_90&sr=8-90
>

A bit of trivia: There's another stereoscope on that Amazon page called the
'Owl' viewer-- designed by Brian May, the lead guitarist of the supergroup QUEEN
(!)  Apparently, he is an avid 3D-stereoscope fan.

About 'convergence' of the two camera views:  When I was younger, I did lots of
3D photo experiments, and found that the best 3D effect (for me at least) was to
have both camera views looking off into *infinity* (that is, no 'convergence' of
the cameras onto a nearer object) and to just move one of the cameras laterally
a couple of inches. This produced less eyestrain when viewing the 3D, and didn't
produce any 'odd' convergence-related perspective shifts of other objects in the
scene. In other words, I never converged the two cameras to look at a 'closer'
object, even if that object was the focus of attention.

Just my two-cents worth.

Post a reply to this message

"Kenneth" <kdw### [at] gmailcom> wrote:

>
> About 'convergence' of the two camera views: [clip]... I and found that the
> best 3D effect (for me at least) was to
> have both camera views looking off into *infinity* (that is, no 'convergence' of
> the cameras onto a nearer object) and to just move one of the cameras laterally
> a couple of inches. This produced less eyestrain when viewing the 3D, and didn't
> produce any 'odd' convergence-related perspective shifts of other objects in the
> scene...

Let me try and explain that a little better: Converging the two camera views
onto a nearer object can produce unwanted parallax shift of more distant objects
(at least in a real camera lens), the result being that those further-away
objects don't 'line up' correctly (and have unequal 'lens distortion') when
viewed in 3D-- especially when using a wide-angle lens setting. It's an odd
effect to describe, but it results in eye strain.

POV-Ray's typical perspective camera is essentially a 'pinhole' camera-- not
quite the same behavior as a real lens (the lens distortions are... different)
so it might be worth experimenting with 'convergent' views vs. non-convergence
views, to see if there is any real difference. I don't know; strange as it
sounds, I've never made a 3D scene in POV-Ray (!) It's now on my to-do list....

Post a reply to this message

Le 16-01-13 11:05, Kenneth a écrit :

> Let me try and explain that a little better: Converging the two camera views
> onto a nearer object can produce unwanted parallax shift of more distant objects
> (at least in a real camera lens), the result being that those further-away
> objects don't 'line up' correctly (and have unequal 'lens distortion') when
> viewed in 3D-- especially when using a wide-angle lens setting. It's an odd
> effect to describe, but it results in eye strain.
>
> POV-Ray's typical perspective camera is essentially a 'pinhole' camera-- not
> quite the same behavior as a real lens (the lens distortions are... different)
> so it might be worth experimenting with 'convergent' views vs. non-convergence
> views, to see if there is any real difference. I don't know; strange as it
> sounds, I've never made a 3D scene in POV-Ray (!) It's now on my to-do list....
>
>
>
>

Having a convergence can be beter, for cases when the center of interest 
is close, less than 10 times the spacing of the cameras, and the 
background don't contain far objects or is highly out of focus.
Think about 3D macro-photography. Very close, small, objects, tight area 
of focal sharpness.

Post a reply to this message

Mike Horvath <mik### [at] gmailcom> wrote:
> 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?

I'm not sure if I'm replying to the right post, but anyway. If you have MegaPOV,
I wrote a macro to generate a cross-eye pair image in a single parse and render,
using the camera pigment feature. I've listed it below for interest - if you're
after a parallel pair you can just swap the sign of the CamX vectors in the
location statements of each pigment camera. I can't remember exactly but I think
you just set the macro parameters as if for a single view, call the macro
instead of making a camera, then use double the horizontal resolution for the
render size (I don't really run MegaPOV any more these days so I can't check
quickly).

It generates images like these:
http://news.povray.org/povray.binaries.images/thread/%3C4f0b6ac6@news.povray.org%3E/?ttop=374865&toff=50

If this isn't any use to you, never mind, maybe someone else will find it
interesting!

Bill


----------------------------------------
// Stereo pair camera macro
// needs megapov for camera view pigment

#version unofficial megapov 1.21;

#macro StereoPair(CPos, CLook, CAngle, CRight, CUp, BaseLine, Border)
 // camera coord system
 #local CamZ = vnormalize(CLook - CPos);
 #local CamX = vnormalize(vcross(CUp, CamZ));
 #local CamY = vnormalize(vcross(CamZ, CamX));
 // replacement camera
 camera {
  location CPos
  up CUp
  right x*CRight
  angle CAngle
  look_at CLook
 }
 // coordinates for mesh screen
 #local XDist = tan(radians(CAngle/2));
 #local YDist = XDist / CRight;
 #local LeftP1 = CPos + CamZ - XDist*CamX - YDist*CamY;
 #local LeftP2 = CPos + CamZ - YDist*CamY;
 #local LeftP3 = CPos + CamZ + YDist*CamY;
 #local LeftP4 = CPos + CamZ - XDist*CamX + YDist*CamY;
 #local RightP1 = CPos + CamZ - YDist*CamY;
 #local RightP2 = CPos + CamZ + XDist*CamX - YDist*CamY;
 #local RightP3= CPos + CamZ + XDist*CamX + YDist*CamY;
 #local RightP4 = CPos + CamZ + YDist*CamY;
 // mesh screen
 // left
 mesh {
 triangle { LeftP1, LeftP2, LeftP3 uv_vectors <0, 0>, <1, 0>, <1, 1> }
 triangle { LeftP1, LeftP3, LeftP4 uv_vectors <0, 0>, <1, 1>, <0, 1> }
 texture {
  uv_mapping
  pigment {
   camera_view {
    location CPos + CamZ*1.1 + CamX*BaseLine/2
    up CUp
    right x*CRight/2
    angle CAngle/2
    look_at CLook }
  }
  finish { ambient 1 }
 }
 no_shadow
 no_reflection }
 // right
 mesh {
 triangle { RightP1, RightP2, RightP3 uv_vectors <0, 0>, <1, 0>, <1, 1> }
 triangle { RightP1, RightP3, RightP4 uv_vectors <0, 0>, <1, 1>, <0, 1> }
 texture {
  uv_mapping
  pigment {
   camera_view {
    location CPos + CamZ*1.1 - CamX*BaseLine/2
    up CUp
    right x*CRight/2
    angle CAngle/2
    look_at CLook }
  }
  finish { ambient 1 }
 }
 no_shadow
 no_reflection }
 #local R = Border * vlength(RightP2 - LeftP1);
 union {
  cylinder { LeftP1, RightP2, R }
  cylinder { RightP2, RightP3, R }
  cylinder { RightP3, LeftP4, R }
  cylinder { LeftP4, LeftP1, R }
  cylinder { LeftP2, LeftP3, R/2 }
  pigment { rgb 0 }
  finish { ambient 0 diffuse 0 }
  no_shadow
  no_reflection
 }
#end

Post a reply to this message

I still don't understand what is the difference between a cross-eye pair 
and a parallel pair? Also, which should I be making for the glasses I 
ordered?

http://www.amazon.com/gp/product/B004EDB1S4?keywords=stereoscope&qid=1452568122&ref_=sr_1_90&sr=8-90

Post a reply to this message

Mike Horvath <mik### [at] gmailcom> wrote:
> I still don't understand what is the difference between a cross-eye pair
> and a parallel pair? Also, which should I be making for the glasses I
> ordered?
>
>
http://www.amazon.com/gp/product/B004EDB1S4?keywords=stereoscope&qid=1452568122&ref_=sr_1_90&sr=8-90

A parallel pair is when you have the left eye image on the left, and the right
eye image on the right. If the separation is small, you can view these by
looking 'through' them and resolving the 'third' image in between to get the
stereo effect. This is what the viewing glasses use. This is also how dot
stereograms or 'magic eye' pictures work.

A cross-eye pair is swapped; the left eye image is on the right, and the right
eye image on the left. These can be viewed by looking 'in front of' them, by
going slightly cross-eyed to resolve the 'third' image in between to get the
stereo effect. This can be easier than the parallel method, and is not
restricted so much by image size / separation. I don't know if any devices exist
to help viewing these.

hope that helps!
Bill

Post a reply to this message

Le 16-01-13 15:40, Bill Pragnell a écrit :
> Mike Horvath <mik### [at] gmailcom> wrote:
>> I still don't understand what is the difference between a cross-eye pair
>> and a parallel pair? Also, which should I be making for the glasses I
>> ordered?
>>
>>
http://www.amazon.com/gp/product/B004EDB1S4?keywords=stereoscope&qid=1452568122&ref_=sr_1_90&sr=8-90
>
> A parallel pair is when you have the left eye image on the left, and the right
> eye image on the right. If the separation is small, you can view these by
> looking 'through' them and resolving the 'third' image in between to get the
> stereo effect. This is what the viewing glasses use. This is also how dot
> stereograms or 'magic eye' pictures work.
>
> A cross-eye pair is swapped; the left eye image is on the right, and the right
> eye image on the left. These can be viewed by looking 'in front of' them, by
> going slightly cross-eyed to resolve the 'third' image in between to get the
> stereo effect. This can be easier than the parallel method, and is not
> restricted so much by image size / separation. I don't know if any devices exist
> to help viewing these.
>
> hope that helps!
> Bill
>
>
For the cross eyed view, there are devices that do exist, but they are 
bulkier and heavier as they rely on crossed periscope like setup.
They use 4 mirrors to swap the view points.

Post a reply to this message

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
>
>
>
>
>

That's a cool program. It doesn't support chromadepth glasses as far as 
I can tell, though. Luckily I ordered anaglyph and standard 
stereographic glasses as well.


Mike

Post a reply to this message

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
>
>
>
>
>

Is there a particular image resolution, physical size, and aspect ratio 
I should be aiming for when generating images in POV-Ray? Or will the 
software automatically take care of issues regardless of how I render 
the images?


Mike

Post a reply to this message

Am 16.01.2016 um 07:07 schrieb Mike Horvath:

> Is there a particular image resolution, physical size, and aspect ratio
> I should be aiming for when generating images in POV-Ray? Or will the
> software automatically take care of issues regardless of how I render
> the images?

Image resolution: Ideally the same as the highest-resolution device you
intend to view it on -- unless the device you're most keen on viewing it
on doesn't support image scaling, in which case that's the resolution
you want to choose.

Physical image size: Ideally the same as the device you're most keen on
viewing it on.

Aspect ratio: Ideally the same as the device you're most keen on viewing
it on.

Whether "the software" on the target device will automatically take care
of issues entirely depends on "the software".

Post a reply to this message

I've been shopping for a stereoscope that uses mirrors and works with 
larger images. They are *really* expensive though. The cheapest ones are 
over $100, and some are over $500. Yikes!


Mike

Post a reply to this message

Am 19.01.2016 um 19:28 schrieb Mike Horvath:
> I've been shopping for a stereoscope that uses mirrors and works with
> larger images. They are *really* expensive though. The cheapest ones are
> over $100, and some are over $500. Yikes!

And people are whining about the price tag on the Oculus Rift CV1.

Post a reply to this message

Le 16-01-19 13:28, Mike Horvath a écrit :
> I've been shopping for a stereoscope that uses mirrors and works with
> larger images. They are *really* expensive though. The cheapest ones are
> over $100, and some are over $500. Yikes!
>
>
> Mike

You can make your own with some cardboard, glue and 4 mirrors. As for 
the tools needed: Cisors, utility knife, glass cutter.

Home made mirror based steoscopes can cost very little, as low as a few 
cents is you appen to have some small mirrors on hand.

Post a reply to this message