Re: Distortion Correction

New Message Reply Date view Thread view Subject view Author view

Javier Castellar (javier++at++sixty)
Thu, 5 Oct 1995 11:47:36 -0700


The older example that i know was written in GL in 1989 by our beloved Paul
Haberli and is performed moving the vertex location to match the LEEP lens
optical/perspective distortion. This is not exactly perperctive distortion. You
can find a basic example in the DT 1.0 (the famous Totally Insane).

Another aproach was proposed mixing distortion correction + stereo correction
in the equivalent to the today's CULL transversal, taking advantage of the LoD
precalculation. In this approach a different perspective matrix was applied to
correct a non uniform projection in function of the distance. The problem was
that at that time the morphing process was like a SF chapter. (yes, morphing is
much more that an exotic feature for performer, it is important not only for
character animation in Disney ...)

Anyway when the Reality Engine came up and the fbsubtexload service was
provided. The perfomance is good but not enough for high resolution. It is also
depends on the trade off between color resolution + space resolution ... etc.
Some people have made some tests using fbsubtexload for optical correction in
some hi-price "rated R" HMD, but only as an experiment.

Another example which uses fbsubtexload was written by ANgus Henderson in the
Reality Center and it is available. Mainly it corrects the perspective
distortion due to planar proyection. I cannot remember the location but
probably someone from the reality center will know the latest version location.
Anyway in sgigate using the ftp anonymus account you can find some old
versions. It works on reality engine but with low resolutions (due to
fbsubtexload limitations).

Regarding current plans ... well ... we are working on it taking in account
much more effects than perspective distortion ... maybe the final result will
be either a pfu or an example for performer...

It will cover:

1) Perspective Distortion

2) Offset distortion

3) Optical Map correction

All at the same time and with ways to demostrate the accurancy of the
correction.

I can't tell you any date yet.

-Javier

-- 

************************************************************************* * Javier Castellar Arribas * Email: javier++at++asd.sgi.com * * * Vmail: 3-1589 * * Member of Technical Staff * Phone: (415)-390-1589 * * Real-Time Graphics * Fax: (415)-964-8671 * * Advanced Systems Division * MailStop: 8U-800 * ************************************************************************* * Silicon Graphics Inc. * * 2011 N. Shoreline Boulevard, * * Mountain View, California 94043-1386, USA * ************************************************************************* "Violence is the last refuge of the incompetant" Hari Seldon


New Message Reply Date view Thread view Subject view Author view

This archive was generated by hypermail 2.0b2 on Mon Aug 10 1998 - 17:51:56 PDT

This message has been cleansed for anti-spam protection. Replace '++at++' in any mail addresses with the '@' symbol.