Slime,
Your absolutely right. The cameras should be kept parallel rather than
trying
to angle them to imitate convergence. That is why the 30:1 rule (which isn't
a
law mind you, but just a rule of thumb) is so useful.

Harold


<msk### [at] msncom> wrote in message news:387f120e@news.povray.org...
> Just imagine how far apart in your scene the human eyes would be, and for
the second picture translate the camera that much.  make
> each image look in a parallel direction - when people are looking at the
stereo image, the eye-crossing differences will be done by
> their own eyes; it shouldn't be done by the camera.  That's how I did my
image earlier, and it looks fine.
>
> - Slime
>
>
> Sigmund Kyrre Aas <as### [at] studntnuno> wrote in message
news:387E5F6F.350AD066@stud.ntnu.no...
> > Harold Baize wrote:
> > >
> > > Sigmund,
> > > Alright, I realize my last message didn't really answer the question-
why.
> > > Well, when we look at things in the distance (infinity) the line of
> > > sight of each eye is parallel. It is still pretty much parallel at
> > > 195cm. Given an average human eye separation of 6.5cm that works out
> > > to be 1:30. When we look at things closer than this our eyes converge
> >
> > ahhh ooohh It's coming to me .. gotta.. _think_... Nah. G'night everone!
> >
> > sig., still cuious about that ratio..
>
>

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Bob,
Are you trying to view Sigmound's image in parallel? I'm pretty sure
that the image is a cross-eye presentation. I works well for me viewed
cross-eyed. What you describe is a good way to learn to "free-view"
parallel images.

HB

omniVERSE <inv### [at] aolcom> wrote in message
news:387f1667@news.povray.org...
>   Curious that this doesn't look exactly right, the left/right shift seems
> enough based on the apparent displacements of the dart fins against the
board.
> When I see it in stereo it's flat, which kind of goes with what you say
about
> using 1cm instead of a wider 7cm, so maybe 3cm would have been better.
>   The way I use to see these is just hold my hand flatout and aligned with
my
> nose between my eyes and angle my hand enough to only be able to see each
> picture with the corresponding eye, closing each one at a time to be sure
I have
> only the full left or right image in view.  Sometimes I don't need to do
this at
> all for the small pictures or just a quick hand divider for my eyes for
others.
> I think another thing to keep in mind about it is these can be fairly deep
3D
> and require some focusing.  By that I mean there can be near and far parts
which
> have to be looked upon as separate parts, otherwise you don't ever see the
whole
> picture forward to back "in focus" without actually looking at those parts
> alone.  This can make for a seemingly distorted and nonmergeable
stereopair.
> Probably the predominate factor with this particular rendering.  That in
mind I
> believe it needs the wider camera separation.
>
> Bob
>
>
>

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I can finally say I can see one of these images.  Probably because this one is
smaller.  The other ones were too far apart for me to focus on.

-Mike

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Sigmund,
Love you image and it has great depth.
Don't want to nit-pick but thought I should let you know about the
"violation of the stereo window". The term stereo window is used to
describe the plane defined by the edges of the image. It is as
if you were looking through a window. It is fine for things to come
trough the window into the space in front of this plane, but not to
be cut off, as this does not happen in the "real" world. The tail of
two of the darts is cut off by the edge of the image. In stereo
photography this is considered a big mistake. There is probably
a way to avoid this in the rendering, but it is easy to fix
after the images are rendered, you just trim the images a little to
move the centers a little apart, that will move everything in the
image back behind the plane of the stereo window. You take a few
pixels off the left side of the left image (on the right side in
this cross-eyed pair), and a few pixels off the right side of the
right image (on the left). Then the two darts that are further
away will fall behind the stereo window, while the other three
come out into the viewers space. A good way to think about this is
that the pixels that are at the same position in the two images
will be at the plane of the stereo window (your computer screen).

Harold


Sigmund Kyrre Aas <as### [at] studntnuno> wrote in message
news:387E0D16.FE6D484F@stud.ntnu.no...
> I just crammed a stereogram out of an unfinished scene of mine.
>
> Just wondering; shy can't I use 'actual' eye distance? I tried 7 cm
> between the cameras, but that produced far too different images. This
> one uses 1 cm and the camera is ca. 50 cm away from.
>
> sig.


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

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> To wiew these I just cross my eyes till I see 3 images and let my built
> in autofocous do the rest. This usually takes .2-.5 seconds.
Then your eyes/brain are faster than mine. I tried 5 minutes and still
couldn't read the numbers on the board. But it still became better and
better. Maybe it's training or I need new eyes :)

CU

	Bjoern

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> Just imagine how far apart in your scene the human eyes would be, and > for the
second picture translate the camera that much.  make
> each image look in a parallel direction - when people are looking at 
As I said, when the cameras were 7 cm apart the images became far too
different to get a 3d effect. Making those cameras parallel (if that's
what you mean) won't be any different. The camera position in space is
all that matters. The look_at position is only used for panning so that
all the objects stays in the frame.

> their own eyes; it shouldn't be done by the camera.  That's how I did > my image
earlier, and it looks fine.

Actually, I had difficulties viewing your image. Too much camera
separation, I believe.

sig.

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Harold Baize wrote:
> 
> Sigmund,
> Love you 

Thanks

> two of the darts is cut off by the edge of the image. In stereo
> photography this is considered a big mistake. There is probably

and thanks again, you're absolutely right. Saving the best advice till
last, eh? This looks so much better now.

sig.

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"Harold Baize" <bai### [at] itsaucsfedu> wrote in message
news:387f6134@news.povray.org...
> Bob,
> Are you trying to view Sigmound's image in parallel? I'm pretty sure
> that the image is a cross-eye presentation. I works well for me viewed
> cross-eyed. What you describe is a good way to learn to "free-view"
> parallel images.
>

YeEs, I was making that mistake.  Although I would still think the depth focus
thing occurs with either type.  That being that since near parts are at
different depths than far parts you still have to train your view on each
individually.

Bob

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