(1) When and what
caused you to first fall in Love with Racing?
It was probably a slot car set that my parents got me for
1972. Oddly enough, the cars that came with it were 1967-like GP
(pre-wing), and the track was supposed to be Monza (but only by
having a crossover and one banked turn.) My family lived in what
Rhodesia, in southern Africa, which explains how a US citizen
get his hands on a Grand Prix-based slot car set. :-) We then
to the US, specifically Indiana, which, for those of you fresh in
outer space, is the home of the Indianapolis Motor Speedway (tm).
remember sitting in the car one beautiful, sunny Memorial Day
while my parents and sisters enjoyed a picnic, so that I could
exploits of my hero, Tom Sneva (aka "The Gas Man"), on
and what caused you to first become interested in the physics of
The physics started to interest me only when we (Papyrus) had
decided to do
Indianapolis 500 for EA. At the time I was actually more
doing a flight sim--I was very interested in real-time 3D
graphics. But I
knew right away that a Pole Position-like arcade game at Indy
hold anyone's interest for long--most especially mine. So I
decided to try
to do "Flight Simulator on a race track." I started
looking into the
physics involved--doing a lot of reading--and pretty soon I was
(3) Who is
your favorite race car driver of all time and why?
Graham Hill, I would say. I read his autobiography, and apart
being a tremendously talented driver, he seemed to be someone who
to enjoy life. He had a great attitude toward adversity: laugh at
accept it, put your head down and move on.
(4) What is
your favorite race car and why?
The '67 Championship winning Brabham BT24. It was judged at the
time to be
underpowered old technology, but in fact it was a triumph of
practical design--the holy grail of engineering.
made you decide to create your own computer racing simulation
We wanted to develop an original game--I most wanted to do a
sim--and after talking with EA, I decided that doing a real-time
game would be just as interesting. Even better, EA was willing to
money to do it! Of course, it turned out that I was wrong--doing
real-time 3D racing game was much _more_ interesting than a
flight sim. :-)
challenges did you have to overcome to create Indy 500?
At the time, many people still had 4.77 MHz 8088 PC's, the 80286
machines were fairly new, and the smoking hot top-end machines
were 25 Mhz
386's--with EGA graphics! Remember that flight simulators were
good at the time if they got frame rates above 8-10 fps. I felt
important to have the highest frame rate possible, and I was
we could get up to 15 fps sustained! :-) I also wanted to have a
field of 33 cars (player plus 32 AI cars), since this _was_ Indy.
everything was written in assembly language, for speed. Space was
a premium, since we couldn't use more than about 570K of RAM.
physics in assembler, using fixed-point math, was one large
Another was creating a graphics database that looked like the
used no more than about 30 polygons per frame! (We use that many
a tire, today.) The other main challenge was getting the CPU to
AI cars without slowing to a crawl.
(7) What is
the most difficult part of getting a racing simulation to
It's all physics. The most difficult part is writing a multi-body
simulation, followed closely by writing functions to calculate
from the tires, aero drag, etc. that feed into that simulation.
wait, the most difficult part is getting it all to run in
sufficient CPU cycles left over to put some kind of graphics on
have your own real life racing experiences helped you in the
development of a racing simulation?
The single biggest thing that I learned from racing real cars is
much steering is done with your feet. I actually started racing a
months before I was able to "drive" the GPL physics
engine--although it was
already well along in development. Having actually driven at
me to understand what was going on when I first started to slide
physics model. There were a lot of times that I thought to
had that happen in the Barber cars," rather than, "I
wonder if that's what
it's like." The biggest help has been the other way around:
has helped me quite a bit in driving the real cars. I find that I
developed a lot of good car control habits, and I actually find
thinking, "I've had that happen in GPL, so _that's_ what it
courses in College best prepared you for creating a motorsports
There are no surprises here: Calculus, Physics (mechanics),
Algebra, Numerical Analysis. I now wish I had gone to an
school, and studied Mechanical Engineering. Oh, a few Computer
courses can't hurt--although you should start programming as soon
can read--learn assembly language, too.
someone was interested in learning how to create a racing
simulation or wants to learn about racing physics what three
books would you
1) Race Car Vehicle Dynamics, by Bill & Doug Milliken
2) Tune to Win, by Carroll Smith (read anything and everything by
3) The Classic Motorbooks catalog :-)
The best book about race driving technique is _Going Faster_,
from The Skip
Barber Racing School.
(11) Do you
have any other suggestions for those who may be interested in
getting involved creating a racing simulation?
Get into therapy, now. :-)
you give people insight into how complex the Grand Prix Legends
simulation is? For example I heard somewhere that you model the
into or through the engine? What are some of the most complex
aspects of GPL?
For the engines, I use a model for engine friction that I got
from a couple
of SAE papers--the friction is a function of inlet valve
length, etc.--and it seems to be pretty close (we have data for
parameters for each of the cars). The most complex aspects of
much time do you have? :-) The multi-body simulation is very
accurate--each GPL car is made up of the chassis, the fuel mass
changes), four wheels with independent hops and spins, an engine
rotor, clutch & transmission input shaft, transfer shaft, and
Each of these bodies maintains its own linear and angular
basically. You can see some of this if you watch the car land on
after flying through the air (and who hasn't seen this?)--just
when the car
lands, you'll see the wheels each continue to travel downwards
springs stop them. If you jump the car in the air (the
can see all the gyroscopic effects that occur when you turn the
wheel in mid-flight, or stay on the throttle, or jump on the
Some might say this is overkill, but not those of us who know the
before Schwedenkreuz. :-) The tire model is also extremely
accurate. There has been a lot of excellent work recently by
have PhD's in the physics of tire and rubber friction, and we
incorporated a lot of that into the current model. The
deserves some mention--notice that with a near open diff (85/85,
clutch), you have no trouble getting inside rear wheelspin. Or
starting with one wheel on the grass and one on the road. The
which apply within the drivetrain are non-trivial. The collision
pretty complex--and that's an understatement. Outside of the
obviously the graphics system is pretty complex, the multiplayer
design, the AI--I can't do anything but scratch the surface here,
suffice it to say that the GPL model is several orders of
complex than anything we've done before.
aspects of GPL would you like to improve on in the near future?
The graphics, sound, AI... I'm happy with the physics model, for
GPL is actually the first simulation that I'm really happy with,
out of all
the sims we've done. I'm still having a lot of fun with it, and
playing for years!
the leader in the motorsports simulation field and taking into
consideration the rapid advancements in 3D cards and processors
what do you
visualize the typical racing simulation to be like 5 years from
I think without a doubt the graphics will be approaching
photorealism--higher resolutions, more visual detail in the
and cars, greatly enhanced lighting and shadows, variable weather