John Wann (j.p.wann++at++reading.ac.uk)
Thu, 12 Nov 1998 09:56:53 +0000
Dear Roy, Angus, others with this problem
With any degree of inward convergence of the screen axes you will get more
than 100% overlap at infinity. A total convergence of 4deg produces a
point of convergence at 1m
What I think Roy/V-Res means is an outward vergence (divergence) - this is
a trick to reduce the overlap of symmetrical FoVs. With a parallel set-up
and a symmetrical 48deg FoV then you have overlap for objects as close as
7cm from your nose (closest stereo point: CSP) - which is a bit pointless
(no pun inteaded). If you diverge the axes then you reduce this overlap
and you also gain a bit extra total FoV. The 2deg per eye, however, only
pushes out the CSP to 8cm, which makes me think the FoV must be
assymetrical (Sorry Roy - back to the phone?).
Anyway it underlines the issue that if you don't know the di/convergence of
the axes (or the symmetry of the FoV) and set up the viewing parameters
incorrectly then objects in the distance will only be fusable by the
observer diverging from parallel when viewing them - which is a potential
source of stress.
Confused ? - Join the crowd.
JW
*********************************************************
Dr John P. Wann < J.P.Wann++at++rdg.ac.uk>
**********************************************************
Action Research Laboratory:
Development, Rehabilitation, Immersive Virtual Environments
(Wann, Mon-Williams, Langaas, Smyth , Swapp, Plooy, Lima, Wilkie)
Supported by: Action Research; EPSRC: European Commission
ARL - DRIVE
Department of Psychology
University of Reading
PO Box 238, Reading RG6 6AL, UK
+44 118 9318532
Fx +44 118 9316715
***********************************************************
This archive was generated by hypermail 2.0b2 on Thu Nov 12 1998 - 01:51:48 PST