From: pjm@bbn.com (Paul J. Metzger)
Newsgroups: sci.virtual-worlds
Subject: Re: LORE: SIMNET versus NPSNET
Date: 25 Aug 92 23:50:52 GMT
Organization: Bolt Beranek and Newman Inc., Cambridge MA
Originator: hlab@milton.u.washington.edu



There have been a few messages as of late comparing the SIMNET system
developed by BBN with the system developed by Mike Zyda and folks at
the Naval Postgraduate School.  There appear to be a few
misconceptions about BBN and SIMNET which we'd like to clarify.

In response to Chris Shaw's original posting, I must say we're a
little surprised!  We congratulate the NPS on the work they've done,
but Chris is comparing the legendary apples to oranges here, and a few
of his statements are simply incorrect.

>I think the most amusing anecdote about BBN's gold-plated SIMNET node
>technology is that Mike Zyda's lab at the Naval Postgraduate School
>built a SIMNET node with graphics using an SGI Indigo Elan.
>
>Cost of Indigo with Elan  -  $45,000 retail quantity one.
>
>Cost of BBN's SIMNET box - $300,000 (hopefully the Army gets a price
>break)
>
>The Indigo outperforms the BBN Box on every count.
>
>I believe Zyda's lab had a staff of 8 or so for this project. I have
>also been led to believe that the BBN box in question doesn't have
>graphics.  Up until recently, SIMNET was text only.

First of all, Chris, since its inception back in 1983 SIMNET was
designed to be graphically oriented.  From the first systems we put
together in 1984 to the systems we build today, it has been.

SIMNET in essence is a protocol definition -- nothing more, nothing
less.  You can attach whatever type of "node" you desire to the
SIMNET; single view, multiple view, no view, whatever.  We at BBN
routinely attach "nodes" to the SIMNET which simulate particular
vehicles.  When you're building a vehicle simulator, you need to
provide visual displays for all crew members.  In the case of a tank,
for example, you need displays for the driver, gunner, loader, and
commander.  These displays are commonly generated by Computer Image
Generators (CIGs).

The "BBN SIMNET box" you refer to is a specialized Computer Image
Generator designed explicitly for networked applications in virtual
environments with lots of moving entities.  While all of our present
systems are less than $300,000, the closest configuration we currently
offer that might come close to that price is a full blown GT111(TM)
system.  We offer a variety of CIGs now (as opposed to the mid 1980s)
for a variety of budgets.  The main differences in cost come down to
what performance you require, whether they're custom units or off the
shelf, how many units you're buying, things like that.  Keep in mind
also that BBN CIGs, like all of technology, tend to come down in price
as the technology advances ...

Back to the system I think you were describing, the GT111(TM).  This
particular configuration of CIG is capable of simultaneously providing
nine channels of video output.

If you take your estimate (not ours) of $300,000 for this particular
CIG configuration, and divide it by the number of channels it can
generate (9) then you come a little closer to comparing apples to
apples when you compare the BBN CIG against the SGI Indigo Elan (one
channel video output):

        BBN                     SGI
        $33K per channel        $45K per channel

In addition, our systems support 128 simultaneously moving entities in
the virtual environment (64 3-component and 64 1-component models, all
approximately 200 textured polygons each), 512 static non-moving
entities, 128 animated special effects, real time update of very large
virtual world databases (for example: 360km x 290km), and built in
support for ballistic projectile simulations with firing rates up to
900 shots per minute.  All of this is done in real time with a 15Hz
update rate, with viewing ranges out to 7000 meters.  The SGI Indigo
doesn't even come close, since it was designed for visualization
applications, not the real time display of hundreds of entities moving
around in a virtual environment.  I don't mean to downplay the
achievements of SGI -- their systems are very good at doing what they
were designed to do, and ours are very good at doing what we designed
them to do.  Believe it or not, we even use SGIs around BBN to perform
a variety of tasks (although real time display of complex virtual
environments usually isn't one of them).

It's probably also worth mentioning that SIMNET was an unclassified
project which was sponsored by the U.S. Defense Advanced Research
Projects Agency (DARPA), and as such, all of its software and
documentation is owned by the U.S. Government.  As a US citizen, you
have every right to obtain copies of this software (for a nominal
charge, no doubt) since it was, indirectly at least, your tax dollars
that paid for it.  I personally don't know about folks outside of the
US obtaining SIMNET source code, but since it's unclassified it should
be feasible.

Since SIMNET has progressed beyond the proof-of-principle stage and is
in daily use for training of US military forces, you'll need to
contact the following agency (not BBN) in order to obtain SIMNET
source code and documentation:

John Collins
U.S. Army Simulation, Training, and
Instrumentation Command (STRICOM)
(407) 380-4382

We (BBN) are still very much in the business of distributed simulations
and networked virtual environments, we're simply not the keepers-of-the-
gate any more when it comes to SIMNET software.

Since the BBN series of computer image generators were developed outside
of SIMNET funding, data on them remains proprietary to BBN.  For further
information on BBN products and services contact Mr. J.C. Wiliams at
(617) 873-3577 or via email at jcwilliams@bbn.com.

One last word ... as for your catch phrase:

>cdshaw@cs.UAlberta.ca    CatchPhrase: Bogus as HELL !

        we agree  ;-)
Newsgroups: sci.virtual-worlds