Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!wuarchive!rice!hsdndev!dartvax!eleazar.dartmouth.edu!npw
From: npw@eleazar.dartmouth.edu (Nicholas Wilt)
Newsgroups: comp.graphics
Subject: Re: Digital Holography
Message-ID: <1991May11.152915.6488@dartvax.dartmouth.edu>
Date: 11 May 91 15:29:15 GMT
References: <261@rins.ryukoku.ac.jp> <1991May9.153446.21742@leland.Stanford.EDU> <1991May10.165256.12414@nas.nasa.gov>
Sender: npw@eleazar.dartmouth.edu (Nicholas Wilt)
Organization: Dartmouth College, Hanover, NH
Lines: 43

In article <1991May10.165256.12414@nas.nasa.gov> uselton@nas.nasa.gov (Samuel P. Uselton) writes:
>In article <1991May9.153446.21742@leland.Stanford.EDU> rick@pangea.Stanford.EDU (Rick Ottolini) writes:
>>Even with all kinds of shortcuts thrown in, it will take
>>billions to trillions of calculations per second to display interesting
>>holographic images.  
>	Current realistic image synthesis techniques can take from 100 million
>	 to 1 billion operations per image.  Laser holography is AT LEAST
>	a couple of orders of magnitude more.  And you still WANT the animation
>	so add another one or two orders of magnitude.  I see trillions of
>	operations per second as a LOWER bound on what it might take.
>	The NAS project at NASA Ames regards pushing industry into producing
>	a teraflops computer by the year 2000 as a "Grand Challenge" problem.
>	It'll be quite a while longer before that capacity finds its way
>	into workstations for the broad market.
>>With the computing speeds increasing an order of magnitude
>>every five years and no end in sight, 
>	          ^^^^^^^^^^^^^^^^^^^
>	There is a growing number of "experts" pointing out limits to current
>	hardware techniques that we ARE rapidly approaching.  We need 
>	BREAK-THROUGH improvements in technology, not just incremental
>	improvements in the technology we have now.

What about massively parallel architectures?  If digital holography
techniques are as trivially parallelizable as ray tracing, then you don't
even need any bandwidth between nodes.

Sure there are issues (load balancing and stuff).  That's just software.
_Lots_ of people are working on better software for parallel architectures.

>>The Popular Science article of last year equates
>>the complexity of MIT Media Lab holo-images with 2-D graphics on oscilloscopes 30
>>years ago.  So this technology is probably realizable in most readers lifetimes.
>	Some yes. Most? That depends as much on health technology as 
>	anything.

The hardware guys specialize in disproving statements like this.

>
>Sam Uselton		uselton@nas.nasa.gov
>employed by CSC		working for NASA (Ames)		speaking for myself

--Nick
  npw@eleazar.dartmouth.edu