From: Tom Fuke (tom++at++sgi.com)
Date: 07/31/2001 04:11:46
Hi Frans,
Usually a display system with a curved display surface will employ some kind
of distortion-correction scheme. This can be achieved either:
- adjusting the geometry settings in the projector (in the case of CRT)
sometimes with the help of external amplifiers for really off-axis
setups.
- using a digital/framebuffer distortion box in the case of fixed-matrix
projectors (LCD, DMD, etc).
- some kind of software algorithm (e.g. see recent previous posts from
Angus Dorbie on the readback/texture method):
http://reality.sgi.com/performer/perf-01-07/0063.html
Some displays manufacturers also have distortion correction software that
re-tesselates and re-projects all the geometry on its way down to the
pipe.
The distortion is calculated and applied for a particular display surface
geometry and eye-point, and all the commercial systems in operation today
are static.
In all the installed SGI RealityCentre(TM) systems which are equipped with
distortion correction AND stereo, the distortion is still only applied for
the one "design-eye-point". Given that the inter-ocular distance is usually
quite small with respect to the scale of the display surface, you would
perceive very little (if any) difference if a slightly different distortion
was applied for each of the left/right eye pair; couple this with the fact
that the user's head can easily move a few centimetres around the DEP, even
whilst sitting still then you see my point.
Cheers,
Tom
---> -----Original Message----- > From: Frans van Hoesel [mailto:F.H.J.van.Hoesel++at++chem.rug.nl] > Sent: 31 July 2001 09:22 > To: info-performer++at++sgi.com > Subject: PF: reality center stereo > > > > Hi, > > I'm wondering if there is any special code needed to display something > correctly on a curved screen (reality center). I mean really correctly > so that (at least from one position) a straight line is > perceived as being > straight, a plane as a plane and a cube as a cube. This would > imply that > a checkerboard pattern parallel to the viewport would have different > stereo shifts varieing over the whole screen. > The stereo separation for a non curved screen is different from that > of a flat screen. What do people do to make this work? > > -frans > > _______________________________________________________________ > > "Hi, my name is Frans, I'm your crazy scientist for today." > > Frans van Hoesel hoesel++at++chem.rug.nl > http://hpcv100.rc.rug.nl/~hoesel > _______________________________________________________________ > -------------------------------------------------------------- > --------- > List Archives, FAQ, FTP: http://www.sgi.com/software/performer/ > Open Development Project: http://oss.sgi.com/projects/performer/ > Submissions: info-performer++at++sgi.com > Admin. requests: info-performer-request++at++sgi.com >
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