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From: thomas@utah-gr.UUCP (Spencer W. Thomas)
Newsgroups: net.graphics
Subject: Re: holography
Message-ID: <1413@utah-gr.UUCP>
Date: Sat, 13-Apr-85 23:23:42 EST
Article-I.D.: utah-gr.1413
Posted: Sat Apr 13 23:23:42 1985
Date-Received: Thu, 18-Apr-85 03:20:19 EST
References: <7931@rochester.UUCP> <9914@brl-tgr.ARPA>
Reply-To: thomas@utah-gr.UUCP (Spencer W. Thomas)
Distribution: net
Organization: Univ of Utah CS Dept
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I did some computer-generated holography way back when I was a senior in
college.  It was pretty trivial - just did multi-plane stuff using
Fresnel xforms (i.e., 2 1/2 D).  I plotted the results on a Calcomp
plotter, then reduced them photographically (so much for needing a
"precise film recorder").  Considering their size (grid of 64x64, as I
recall), the results were pretty good -- I could even get a virtual
image reconstruction by looking through the hologram at a bright
non-coherent point source.

The issue of doing a correct 3-D implementation with hidden surfaces,
shading, &c is, in my humble opinion, much harder (not that I've thought
about it too much).  You need, at least, much greater computing
resources (just a 3-D FFT, which is minimally what you need, is
O((n*log(n))^3).  This grows pretty rapidly for reasonable values of n.)


-- 
=Spencer   ({ihnp4,decvax}!utah-cs!thomas, thomas@utah-cs.ARPA)
	"The meaning and design of a problem seem not to lie in the solution,
	 but in our working at it incessantly." -- Jung