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From: liam@qmc-cs.UUCP
Newsgroups: net.graphics
Subject: Re: any multi-processor ray tracing?
Message-ID: <170@cs.qmc.ac.uk>
Date: Thu, 17-Jul-86 15:56:41 EDT
Article-I.D.: cs.170
Posted: Thu Jul 17 15:56:41 1986
Date-Received: Sat, 19-Jul-86 00:00:16 EDT
References: <249@vaxb.calgary.UUCP> <2742@columbia.UUCP>
Reply-To: liam@cs.qmc.ac.uk (William Roberts)
Organization: CS Dept, Queen Mary College, University of London, UK.
Lines: 38
Keywords: ray tracing, multi-processing
Summary: we do it on SIMD hardware

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Xpath: ukc eagle

We have a group in the Computer Science Department at Queen
Mary College  (University of London, England) which does
ray-tracing (amongst) other things.

The hardware is an ICL DAP: a 64 x 64 array of single-bit processors
with separate memory spaces and a common instruction stream.
The total memory is 8 Mbytes and it lives inside an ICL
mainframe as a memory-mapped peripheral. All the processors are
connected to their NSEW orthogonal neighbours and each
instruction can be "masked" so that only processors with a 1
in a selected memory location will obey it.

Pictures are usually processed on this machine in one of two
layouts: either split into tiles of 64x64 pixels, "stacked" in the
memory, or split into 64x64 tiles of nxn pixels and stored one
tile per processor.

We also have at QMC a 32x32 version which sits inside a PERQ
workstation and has sensible IO - the molecule ray-tracing
man at the DAP support unit here assures me he will be able to
generate ray-traced colour pictures of insulin moelecules in near
real-time with this device!

Contact addresses for the people doing this work are

Hilary Buxton   ( hilary@cs.qmc.ac.uk, hilary@qmc-cs.UUCP )
John Quinn      ( c/o liam@cs.qmc.ac.uk, liam@qmc-cs.UUCP )

(When I can get John Quinn's real login name I will post it -
 in any case I will try to prod them into giving some more
 details: it's a hard life being the Departmental electronic
 gossip!)

-- 

William Roberts         ARPA: liam@cs.qmc.ac.uk  (gw: cs.ucl.edu)
Queen Mary College      UUCP: liam@qmc-cs.UUCP
LONDON, UK              Tel:  01-980 4811 ext 3900