rec.autos.simulators

The game engine is the most important part of a racing simulator for
fanatics like us.  Whatever graphics it has, it will always be judge on how
realistic it feels and how realistic is acts.

GPL runs at 288hz for its physics, something NO other title has ever
achieved from what we see, and not even close.  Nascar Racing 2 was run IIRC
around 48hz for it's physics.  It means that you now have incredible amount
of calculation to create realistic physics.  All the suspension calculation,
bump ***s, suspension movement, chassis torque, engine torque,
independent tyre grip, weight transfer, etc.. all of this is done so much
superior to anything at the moment.  The game engine is also how the 3d
environment reacts to different effects.  3d spatial movement everywhere you
want, accuracy of the geometry model (take a hike at Zandvoort in the hills
!!), etc..

That's what a great game engine is.  But GPL is not perfect and I do expect
that the next Papyrus title using that game engine would have more accuracy
after two years.  It should be better. It should have more and more
calculation towards high-frequency bumps since it is important in stock-car
racing imho.  It should have more accurate sound, perhaps physics for the
sound itself like N:Rev.  More accurate AI, etc..

--
-- Fran?ois Mnard <ymenard>
-- May the Downforce be with you...

"People think it must be fun to be a super genius, but they don't realise
how hard it is to put up with all the idiots in the world."

I don't know, but I'm convinced that the Papy guys just plop in some
new tables (of numbers) describing springs, tires and downforce, and
with little work you could drive a modern race car.

BTW, if the sim simulates driving a Pinto over a parking lot, it would
not be hard, driving an F1 car of 1967 at the limit at the Nuerburgring
IS hard...

l8er
ronny

--
The box said "Windows 95 or better", so I installed LINUX!

          |\      _,,,---,,_        I want to die like my Grandfather,
   ZZZzz /,`.-'`'    -.  ;-;;,_              in his sleep.
        |,4-  ) )-,_. ,\ (  `'-'     Not like the people in his car,
       '---''(_/--'  `-'\_)            screaming their heads off!

David

. The physics engine used for GPL crunches

But the thing is, all the rigid body dynamics behave quite nicely and can
be modelled by Sir Newton's basic equations.  Therefore, one can design a
nice physics engine that does all this modelling to the Nth degree.  Aero,
on the other hand, is a largely empirical science, or at least, empirical
knowledge goes a long way to describing things.  Since we're not going to
see full blown CFD (computational fluid dynamics) on PCs in real time for
many years (and CFD is dubious for turbulent airflow in all but the most
controlled situations) I think a whopping big aero lookup table would be
fine to handle the wings.

Stephen

:       A sim that is as hard as GPL! ;-)

  (Grin) I would go for "a sim that is not as hard as GPL" - a monkey
could write something that was harder to driver than GPL.

:       Seriously, I'd say a sim that gives the same feel of being in the car
: as GPL,
:       A sim that models all the effects that GPL has,
:       A sim that is as close, or closer to driving a real car as GPL
: that GPL gives

  Indeed - I feel that while GPL's engine is definitely the "king"
so far, there are a number of areas where it could be improved.
Particularly, everything in the GPL physics world seems rather hard and
absolute.  Perhaps it's just me being a physics/dynamic systems person
but the GPL cars feel sometimes like they're made of stone - absolutely
ungiving rigid cars running up rigid and ungiving bankings.  There's
little room in the GPL world for flex and bend.  If I were to look for
an improved physics model I would look for something with "softer edges"
than the physics model used by GPL that would (for example) more model
the tendency of real world cars to absorb energy.  In rare collision,
GPL cars can skitter round like they're on a frictionless surface -
spinning 3 or 4 times from a small spin.

  While GPL is far and away the best there is, it is certainly not the
best that could ever be written and the physics model seems to
critically fail at extremes.  Bump ***s for example are far too harsh
and, when you hit the bump ***s, you really do feel the "stone car"
effect I'm talking about.  Real life drivers can drive cars which hit
the bump ***s - they won't be happy about it but they can feel it and
it doesn't make the car totally undriveable.

  So, my ideal, post GPL sim has the same degree of feel as GPL but with
the physics improved to model extreme conditions better where the GPL
engine fails.  Places where chassis flex and irregular track surfaces
would "save" the real life driver but which are disasterous for the GPL
driver.  I also feel there's something wrong with the tyre
adhesion model they use - perhaps related to the high-frequency bumps
problem.  I think those high-frequency bumps would also dissapate energy
in a spinning car, preventing the rapid "whirling dervish" spins that
GPL cars can get into (there's also the side issue of the ping-time
related collision with other cars problem which is I believe mitigated
slightly in 1.2).  I would hope that also a side issue of solving the
high-frequency bump problem would also make the GPL cars more stable and
"catchable" from oversteer.  Real 60s/70s drivers could get the cars very
sideways and recover.  I've never seen online or offline drivers get
Ronnie Peterson style angles on the cars and get them back.  (Well, not
often anyway).  And Peterson was doing that every lap.

  Perhaps I'm wrong but I get the feeling that the GPL tracks are
modelled as "of uniform smoothness" in this section.  A real piece of
track has a different coefficient of friction everytime you go over it
(as it changes in temperature and amount of *** etc).  This may
sound like a nightmare for the driver, but my feeling is that modelling
this would actually make things easier for the GPL driver since, when
you lost traction you wouldn't lose it "forever" as you do in GPL but
would slide a bit and regain and slide some more - e.g your car would be
more progressive in its transition from cornering to sliding.  I think
that the current GPL model has too sharp a transition to be realistic
from cornering safely to breaking away and I think this is part of what
makes it difficult to drive.  My feeling is that this may stem from
their modelling of the coefficient of friction of the race-track.

  Finally, as ever, the AI could use work.  I realise that this is true
of every racing game but the GPL AI does behave unrealistically and you
do quickly get the feeling that they're not playing by the same rules.
(Especially when they get a tap which you KNOW would have sent you off
into the bushes and they simply wiggle a bit and carry on).

  Weather effects, extra tracks whatever, I can live without.  Different
period makes no difference to me.  I had no interest in 60s racing
before GPL and I doubt I would have developed such an interest without
GPL.  To be honest, the few tracks in GPL have enough depth to them to
keep me interested for a long long while.  It's a superb game and a
marvellous piece of work - but, like any piece of simulation software,
there's always more detail that you could capture that would make it
better.  

  Richard.

--
Richard G. Clegg       Only the mind is waving
    Networks and Non-Linear Dynamics Group
      Dept. of Mathematics, Uni. of York
    www:  http://www.racesimcentral.net/

: For me.. just a game engine better than GPL.  That's all, nothing more.  I
: personally do not care about better or more realistic graphics, since it's
: icing on the cake.  If it's equal, I'll continue to race GPL as my primary
: simulator, and that means even if it's Nascar4 with the GPL game engine.
: But if it's a better game engine, it will be a great thing for the community
: finally.  Not that I want to low-down GPL immediately, but the same 11tracks
: start to be a little boring after a year, imho.

  Actually, better graphics would persuade me to buy a game with the GPL
engine.  I cannot find braking points on some tracks because of the
sparse nature of GPL graphics.  My graphics card is so dark on Kyalami
that I can't see where the racing groove darkens and there is nothing
whatsoever on T2R to judge braking buy.  I would pay a goodly amount of
money for something which simply put vegetation by the side of the track
that I could judge braking by.  (There's such a convenient bush stuck
out of the side of Spa on the approach to La Source).

--
Richard G. Clegg       Only the mind is waving
    Networks and Non-Linear Dynamics Group
      Dept. of Mathematics, Uni. of York
    www:  http://manor.york.ac.uk/top.html

  'taint true though.  Rigid body dynamics is my chief complaint with
the GPL engine.  Drive up a muddy banking and you will, in fact, bounce
off it like a pool ball going into a wall.  A real life car has all
kinds of chassis flex and tyre deformation and the like which GPL
doesn't do.

:  Aero,
: on the other hand, is a largely empirical science, or at least, empirical
: knowledge goes a long way to describing things.  Since we're not going to
: see full blown CFD (computational fluid dynamics) on PCs in real time for
: many years (and CFD is dubious for turbulent airflow in all but the most
: controlled situations) I think a whopping big aero lookup table would be
: fine to handle the wings.

  I think you're absolutely right - an aero lookup table with forward
speed, lateral speed, wing angle and resultant force on that car part
would be absolutely fine.  You'd have to capture some secondary effects,
(apparently the front wing can guide some aero onto the back wing).  But
actually this is not computationally intensive at all.  It's just an
extra force to bung into the model.

--
Richard G. Clegg       Only the mind is waving
    Networks and Non-Linear Dynamics Group
      Dept. of Mathematics, Uni. of York
    www:  http://manor.york.ac.uk/top.html

My $0.02
--
                    | "Instead of letting the moon be the
Bill Mette          |  gateway to our future, we have let
Enteract, Chicago   |  it become a brief chapter in our

I know about engines but telling me that "a better engine" as the original
post did, would make GPL better but I wanted to ask, in waht ways should it
be better?

...If you like GPL, let the whole world know, I don't mind, but GPL does
tend to hog the spotlight a bit.....

..ok, better drop it:-)

:   'taint true though.  Rigid body dynamics is my chief complaint with
: the GPL engine.  Drive up a muddy banking and you will, in fact, bounce
: off it like a pool ball going into a wall.  A real life car has all
: kinds of chassis flex and tyre deformation and the like which GPL
: doesn't do.

Not really my point.  I agree that the model, despite its sophistication
versus other games, is still a long way from being a perfect model.  I use
DYNA-3D to do some dynamic models with impact and crush, and that is
starting to approach reality :)  Anyway, my point was more that everyone
says the GPL suspension models etc. are great, and that an aero lookup
table would be sacrilige if grafted onto this holy of holy physics
model.  I say it wouldn't be a kludge, but rather just as sophisticated as
the chassis model.  Just make sure they go look in the table 288 times per
second :)

But I think you and I basically agree.

Stephen

( snippety)
Anyway, my point was more that everyone

Just stuff... better stuff ;)

Track detail accuracy that allows for higher frequencies in the bumps.  More
details on the patch surfaces for a more accurate traction.  Realistic body
flex, a more accurate AI engine (who could now use the full physics like a
normal client).  Engine sounds modeled by it's own physics.  More accuracy
on the tracks.  Collision detection has to be at least as good as N3 or
Viper.  What about tyre deformation, or rigid body parts and chassis that
reacts according to the real 3d environment that it races on.

Of course, in all those aspects GPL is far better than anything (and very
far away) else on the market, but it doesn't mean that for the second game
using the GPL game engine they should stick with the same stuff.  We have to
live with the limitations of the current PC power, but the future is very
good indeed.

Even Mr. Kaemmer admitted there was things he would love to see getting
better you know :)

--
-- Fran?ois Mnard <ymenard>
-- May the Downforce be with you...

"People think it must be fun to be a super genius, but they don't realise
how hard it is to put up with all the idiots in the world."