[Plib-devel] off-axis stereo projection with plib

[Bram S. <br...@sa...>]

ssgHello(ALL)


I'm trying to add a stereo option to a PLIB application.
Now, I want to do the stereo properly.
This means not using the 'toe-in' method.
Instead a proper off-axis projection. This method is described
very accurately by Paul Bourke at:
http://local.wasp.uwa.edu.au/~pbourke/stereographics/stereorender/

I'm not really sure about the approach I should take.
Currently, in the monoscopic case, I am using a ssgContext class, 
and call setFrustum() in glut's reshape() callbacks.

When moving to a stereo app, I guess my options are:

-1- Drop the use of ssgContext and make direct calls to glu and friends
-2- Create two ssgContext instances. One for L and one for R
-3- Derive a ssgStereoContext from ssgContext class, and do all the
    handling in there (e.g. eye-sep calculations and maintaining
    two Frusti).
    Maybe have a ssgStereoContext->makeCurrent(LEFT | RIGHT) ?
-4- Use a single instance of the ssgContext, and change all its
    settings twice each frame I draw.

Also, in my case there are extra complicating factors, as my
target platform is a passive stereo system. This means even more
options: two viewports in a single window? two windows?

Currently, I nigh to the class derivation, maybe even two
classes ssgActiveStereoContext and ssgPassiveStereoContext ?
Or a unified stereo class with a boolean active/passive ?

But maybe people on this list have some good insights on how
to do stereo with plib properly, or maybe even have some experience
with it.

The only sample use of stereo in plib I could find was a old
tuxkart, but that one does not use ssgContext, and neither does
it do off-axis projection.

thx,

   Bram




-- 
Bram Stolk, VR Engineer SARA, Amsterdam.   tel +31 20 592 3000

"Windows is a 32-bit extension to a 16-bit graphical shell for an 8-bit 
 operating system originally coded for a 4-bit microprocessor by a 2-bit 
 company that can't stand 1 bit of competition."