hi all

i am attempting to set up some equipment for a CAVE environment and
have come across some issues that i need some answers to.

i am also investigating the stereoscopic capabilities of a cave using
passive stereo, possibly utilising the cyviz xpo stereo converter
boxes. these boxes convert the 2 "interwoven" images from a video card
that can support 3d stereo as used with the lcd shutter glasses (this
is my understanding, whcih could also be wrong). does anyone know if
the way the cards implement this 3d stereo effect is based on quad
buffering?

now, these boxes only convert quad buffered opengl programs. i have
done basically no opengl programming, so these will be very newbie
questions. does a program have to be written specifically in opengl
with the quad buffering enabled? or is the quad buffering enabled by
the video card driver that will in turn run any opengl program using
quad buffering?

obviously many questions here, some a bit off topic from opengl. if
anyone has any knowedege of this sort of thing, or anything to add,
even a better newsgroup to post this, please go ahead.

cheers
evan

"ehendrikd" <ehendrikd@gmail.com> wrote in message
news:5b31ef19.0503151651.7ab8dc28@posting.google.com...
> hi all
>
> i am attempting to set up some equipment for a CAVE environment and
> have come across some issues that i need some answers to.
>
> i am also investigating the stereoscopic capabilities of a cave using
> passive stereo, possibly utilising the cyviz xpo stereo converter
> boxes. these boxes convert the 2 "interwoven" images from a video card
> that can support 3d stereo as used with the lcd shutter glasses (this
> is my understanding, whcih could also be wrong). does anyone know if
> the way the cards implement this 3d stereo effect is based on quad
> buffering?
>
> now, these boxes only convert quad buffered opengl programs. i have
> done basically no opengl programming, so these will be very newbie
> questions. does a program have to be written specifically in opengl
> with the quad buffering enabled? or is the quad buffering enabled by
> the video card driver that will in turn run any opengl program using
> quad buffering?
>
> obviously many questions here, some a bit off topic from opengl. if
> anyone has any knowedege of this sort of thing, or anything to add,
> even a better newsgroup to post this, please go ahead.
>
> cheers
> evan

hi, evan
 I know OpenGL has buffers for stereo, but being a bit of a newbie myself I
havent implemented that yet, only drew separate frusta on double buffers for
each eye.

 With shutter-glasses the jitter was so bad at lower framerates (and the
sync pulse keeps switching eyes) that I've switched to dual monitors and a
mirror,(extremely low budget target audience), which of course can only
facilitate 1 user per monitor pair, but the image quality per cost forgives
that.
  The resolution is amazing with dual monitors because its more naturally
fused so colors tend to blend instead of jitter. Polarizers should do as
well, but this beats anything I've seen at imax. :)  But imax is a framerate
issue too.
 Another stereo method I'm going to try is over/under format on a single
monitor and prismatic glasses.
 I guess all of this is irrelevant for group presentations unless you wanted
to invest in dozens of monitors. Just thought I'd throw in my 2 cents worth.




 For the OpenGL guru's, when using:
glutInitDisplayMode GLUT_RGBA GLUT_DOUBLE GLUT DEPTH GLUT_STEREO

anyone know what this OpenGL error implies?

'pixel format with necessary capabilities not found.'

Is this a PIXELFORMATDESCRIPTOR problem?
I'm using GLUT game mode.

Regards,
marcus

ehendrikd wrote:
> hi all
> 
> i am attempting to set up some equipment for a CAVE environment and
> have come across some issues that i need some answers to.
> 
> i am also investigating the stereoscopic capabilities of a cave using
> passive stereo, possibly utilising the cyviz xpo stereo converter
> boxes. these boxes convert the 2 "interwoven" images from a video card
> that can support 3d stereo as used with the lcd shutter glasses (this
> is my understanding, whcih could also be wrong). does anyone know if
> the way the cards implement this 3d stereo effect is based on quad
> buffering?

Which cards? Different cards can implement stereo with different methods.


> now, these boxes only convert quad buffered opengl programs. i have
> done basically no opengl programming, so these will be very newbie
> questions. does a program have to be written specifically in opengl
> with the quad buffering enabled? or is the quad buffering enabled by
> the video card driver that will in turn run any opengl program using
> quad buffering?

OpenGL does not automatically generate stereo views -- the application 
must render one frame and then the other. There is just one 
SwapBuffers() though, so you don't have to worry about one eye being 
more than one frame time off from the other.

--
Andy V

marcus wrote:

>  For the OpenGL guru's, when using:
> glutInitDisplayMode GLUT_RGBA GLUT_DOUBLE GLUT DEPTH GLUT_STEREO
> 
> anyone know what this OpenGL error implies?
> 
> 'pixel format with necessary capabilities not found.'
> 
> Is this a PIXELFORMATDESCRIPTOR problem?

Your board does not support stereo.

--
Andy V

> i am also investigating the stereoscopic capabilities of a cave using
> passive stereo, possibly utilising the cyviz xpo stereo converter
> boxes. 

Have a look at this simple code that does both frame sequential 
(what you are calling quad buffer) and passive stereo.
   http://astronomy.swin.edu.au/~pbourke/stereographics/vpac/opengl.html

Secondly, whatever you do don't get the cyviz boxes, or any rebadged 
versions from Barco or Christie. For a fraction of the price you can
get an nvidia card where the driver has a feature where the application
thinks it is doing frame sequential but the driver puts the odd (left
say) images onto one output display and the even (right eye) image
on the second display...hence passive stereo.

Feel free to bounce any other questions my way.
-- 
Paul Bourke
pdb_NOSPAMswin.edu.au