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From: jwtlai@watcgl.waterloo.edu (Jim W Lai)
Newsgroups: sci.virtual-worlds
Subject: Re: We need a new language
Message-ID: <15639@milton.u.washington.edu>
Date: 1 Feb 91 20:33:57 GMT
References: <15594@milton.u.washington.edu>
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In article <15594@milton.u.washington.edu> pete_leaback@cix.compulink.co.uk (Pet
er Leaback) writes:
>You say VR is here, it is only *JUST* here. At the moment, the
>programming of VR's are coupled very tightly to the hardware because of
>the crippling restrictions of the hardware.
>
>A VR system has to display a frame at 50 or 60 Hz or else one tends to
>get sick. If one standardises the object destription and rendering, each
>machine that has implemented the language is required to render images at
>roughly the same *speed*.

These frame rate restrictions are due to currently available mass-produced
monitors.  Note that the 50Hz and 60Hz frame rates correspond to the rates
of the two dominant power standards.  Psychoperceptual studies done in HDTV
research.  Such studies have indicated that frame rates of 80Hz or higher
are improve the quality of the perceived image significantly.

>I suggest that a standard language should be layered in its definition.
>The highest would be such that it can be realistically implemented on
>most hardware.As our hardware progresses, subsequent levels would be
>defined.
>
>If a *complete* VR language is defined today, it would either be too
>restrictive or impossible to implement.

I generally agree.  Let's find out what works well in VR before deciding on
it as a standard, rather than jumping the gun and potentially being stuck
with the VR equivalent of COBOL.

However, I disagree with a standard that can be realistically implemented on
current hardware as being the solution.  HDTV research has been done for
approximately twenty years, but only with the relatively recent advances in
chip technology have such sets been feasible and mass producable.