From: yiannis@ccad.uiowa.edu (Yiannis Papelis)
Subject: Re: What is realism? (Re: Falcon MC Demo (at la)
Organization: CAD-Research, University of Iowa, Iowa City
Date: Mon, 23 Nov 1992 17:32:31 GMT

In some article rdd@cactus.org (Robert Dorsett) writes:

>
>  GREAT classification of "realism" removed
>
>So, let's do a comparative evaluation of three highly "realistic" simulators:
>Microsoft Flight Simulator 4.0, Hellcats, and Falcon.  We'll rate them from
>0 (indicating low fidelity) to 10 (indicating high fidelity, what one would
>find in a "professional" airline-quality general-purpose flight simulator 
>
>1.  Flight dynamics.
>	MS FS: 	2.  Linear-motion.
>	Falcon: 2.  Linear-motion.
>	Hellcats: 3.  Appears to use a S&C partial-derivative model.
>
>2.  Control.
>	MS FS: 1.  Very kludgy: control surface indicator takes on an 
>             unacceptable importance in flying the simulator.
>	Falcon: 3.  Doesn't appear to support the F-16's FBW modes (!)
>	Hellcats: 5.  The S&C control model produces a very FBW feel: very 
>             easy to control the airplane and concentrate on the game.
>
>3.  Systems.
>	MS FS: 2.  Nav only: no systems.
>	Falcon: 3.  Good HUD, summarized secondary systems, non-existent
>               tertiary systems.  Lack of tunable navaids major minus.
>	Hellcats: 1.5.  Mostly nonexistent.  Fair to good instrumentation,
>
>4.  Powerplant.
>	MS FS: 2.
>	Falcon: 2.
>	Hellcats: 2.
>
>5.  The World.
>	MS FS: 3.
>	Falcon: 2.
>	Hellcats: 2.
>
>6.  Genesis.
>	MS FS: Graphics.
>	Falcon: Game.
>	Hellcats: ?
>
>7.  Game.
>	MS FS: 3.  Visual simulator.
>	Falcon: 4.  HUD simulator.
>	Hellcats: 6.  Classical ACM simulator.
>
>On the basis of all this, I'm not prepared to call *any* of these "high-
>fidelity" or realistic.  They all have their niches as effective games, 
>though.
>
>     GREAT list of things to do to 'test' a simulator removed
>
>
>"Too much of a perfectionist," you'll say.  Not really.  I'm not asking
>for component-level modelling of engine valves: just a decent simulation
>from the *pilot's* perspective.  Some degree of realistic modelling is 
>unavoidable: a lot can be done with "smoke and mirrors," just like it always 
>has been (*especially* in the Real Thing).
>
>A high-fidelity simulator IS possible on contemporary high-performance 
>computers, which greatly outperform most of the computers driving real flight 
>simulators in the 1970's.  None of these things are unreasoanble to expect--
>EXCEPT a manufacturer-originated S&C flight model, perhaps.  But Hellcats is 
>alleged to use a homebrew S&C flight model; so does Azuresoft's Elite (but 
>there are abrupt envelope limits, there).  
>
>None of these GAMES, though, quite fit the bill, but what chafes my hide is
>that the publishers (and their satisfied customers!) will make the most of 
>the product's "reputation" for *realism* to try to enhance sales (and then 
>try to DEFEND this nonsense).  I say: let them put their money where their 
>mouths are, and produce simulators which actually live up to the hype.  But 
>we won't see this, as long as they can get away with marketable, "low-tech" 
>solutions (which are MUCH cheaper to implement: just the cost of coding, no 
>need to spend several times that amount developing flight and systems models).
>
>Robert Dorsett
>rdd@cactus.org
>...cs.utexas.edu!cactus.org!rdd

First of all I would like to congratulate Robert on an article well
done!.  I have been involved with building simulators (for ground
vehicles) for two years now and these issues of high/low fidelity and 
realism are often being butchered by users and manufacturer's alike.  
I've been wanting to write a similar long article and try to explain 
certain things but Robert's article is a very good rundown of what 
is wrong with most PC based flight sims. I personally find the practices
of companies that try to attract customers by making statements like
"we are in the process of gaining FAA certification" almost unethical.

Some additional points about realism and fidelity.  Fidelity is something
that can be measured, for example one can capture the inputs to
an actual plane, feed the same inputs to the simulator and then
compare the output (i.e. envelope) of the simulator and the actual system.
The proximity of the data is a measure of fidelity.  Similar things can 
be done with visuals, instrumentation, control 
forces etc.  Realism on the other hand is how the user perceives 
the simulator to be.  If a person feels the simulator is realistic, 
then it is!!.  I agree that most PC based simulators are definately 
not high fidelity but to some people may be realistic. (I'm not one 
of them).  BTW, on most feedback elements of a flight sim. high fidelity is
impossible to achieve with only the standard equipment on the average
PC.  That includes tactile feedback (stick forces, stick vibration etc.), 
visual feedback (VFR cues are useless, IFR instumentation is possible but
needs more resolution especially for the AI), audio feedback(I guess a sound
blaster card could help here) and vestibular feedback (acceleration).

Another issue relates to training.  Fidelity and realism are not
necessarily important to training.  What is important is "transfer
of training" in other words, if using the simulator increases 
your skill level, will that skill be applicable to the real thing?
For certain tasks like understanding how navigational instruments
work the training transfer of games like fs4.0 etc. is good (that
statement is from personal experience).  Regarding flying skills though,
most of the time, spending time flying in FS4.0 just gets you better at
flying in FS4.0 not an actual cessna or whatever.

Having said all this, don't get the ideal that I don't enjoy the various
flight sim. games.  I have several and am always looking for the next
version ... :-), I just agree with Robert that we should admit they
are games and not fall into the marketing ploy of 'fidelity'.

Finally, I think Robert's list of elements to do to a simulator
along with the follow-up grading can be a very useful method for 
PC flight sim. bufs to communicate their impressions of the various 
games.  Anybody willing to make a standardized form which people can 
fill after test flying their favorite sim. and post it to the net?  
If there is enough interest and no volunters I'll do it!.

-- 
Yiannis E. Papelis,            - Electrical & Computer Engineering, U of Iowa
Center of Computer Aided Design- Home of the Iowa Driving Simulator & future
e-mail: yiannis@ccad.uiowa.edu - home of the National Advanced Driving Simulator