rec.autos.simulators

by **CART Te** » Tue, 11 Nov 1997 04:00:00

The only thing I can possibly think of is a drafting bug. We'll have a look.

by **Grant Reev** » Wed, 12 Nov 1997 04:00:00

> Hi. Does CPR model the car's turbulent wake, and loss of aero downforce for
> the car drafting behind? That might begin to explain some of what I think
> Randy is saying. I, for one, know that car to car contact is easily
> possible.

hmmm good point. i wonder how well does cpr do drafting? i know in all
previous sims i've played drafting is modelled as a mere lessening in
overall downforce as you come in behind another car. but when i think
about
it, what if CPR models it really well? if your car is only half behind
another car, then you have much less air resistance on the side of your
car that is in the draft, but you still have normal levels of air
resistance pulling the outer side of your car, effectively yanking the
car out of the draft, resulting in this curious behaviour of ending up
off the road whenever we come up behind the other cars, that Randy
noted,
and i've noticed myself and had just written off to me being useless :)
I have never driven a real race car, let alone driven a car at 300kph,
let alone tried to draft at that speed, so i don't know if this is
how drafting *really* affects cars, in which case it's an excellent
bit of simulation. of course, it could still just be a bug:)

that's my 2 cents for today :) let me know if all this theorising is
just a load of rubbish:)

Grant Reeve.

by **John Walla** » Wed, 12 Nov 1997 04:00:00

On Mon, 10 Nov 1997 08:37:40 GMT, rmagr...@concentric.net (Randy

Magruder) wrote:
>Okay, lets see.

Be that as it may (and interesting as it was), the point being made
was that ICR2 models wheelspin at low speed and not at rest, and CPR
models to some extent from rest and a much lesser extent from low
speed. How that wheelspin is induced, while interesting, is not the
point. If you apply power to a car in a stable condition (with
steering transients already completed) and you break traction, the
weight balance has undoubtedly contributed but the application of
power is what caused the rear to break loose. This happens in ICR2,
regardless of whether weight is being transferred.

>Its NOT induced by wheelspin. Agreed?

It _may_ not have been induced by wheelspin, but equally it may.

>Really? I didn't see an admission. I have seen this effect myself
>and agree with you that its there and needs to be addressed, but I saw
>the MS guy basically make some comment about how disastrous contact
>was between open wheel cars, and not come right out and admit that
>they put in a collision avoidance system.

Well, today we have another MS/TRI guy saying that the effect is _not_
there, so I guess the plot thickens :)

>I don't see where you get that its too easy to drive. Its easier than
>ICR2 in some ways, and harder in others. I would EXPECT that the cars
>would be grippier than in ICR2 mainly because of advances in the tire
>wars and chassis improvements.

True, but I was surprised to have to drive it like a kart in order to
achieve good laptimes. I'm basically hurling the car around the track
(and achieving very good times) as opposed to the balance and
precision necessary to achieve same in GP2. No less fun, just
different, and different to what I would have expected.

>I beg to differ. I think they went for ultra realism as far as the
>simple act of driving the car is concerned. If they failed to be
>ultra-realistic it was in terms of the actual competitive racing model
>(no yellows that I've seen, the collision avoidance system, choppy
>frame rate with other cars on the track, the way AI cars make NO move
>to avoid you in many cases).

Okay, a couple of other things. Why am I cnsistently 5mph faster in a
straightline when racing on-line compared to off-line? Why can I
achieve faster laptimes on-line than off? Why can I lap within 0.2s
per lap using rain tyres on a wet track compared to slicks on a dry
track?!?! Why are rain tyres faster than slicks on a dry track? Why
does the car hiccup when below 30mph? When I brake heavily in sixth
gear, why do I hear a downshift sound? There is a pretty extensive
list of wierd things which are not related to the AI, and an even
longer one when the AI are taken into account.

>Yeah, but I think CART has gotten more flack than praise. And I think
>the degree to which we should be going after them ought to be to some
>degree tempered by their responsiveness to our criticisms.

Granted, but response to our criticisms comes in the form of V1.1 or
V2, not in promises of what V1.1 or V2 will contain. Call me an old
cynic, but I've heard tell of great things so often before :)

>beat them to a pulp :) I don't want to give away my review at
>Digital Sports, (www.digitalsports.com), but I'll be done with it in a
>few days and you can read my ultimate conclusion for yourself. I'll be
>interested in hearing your feedback on it.

Nice plug :) Actually I stopped by over the weekend to see what you
had thought of it, but no review yet. I'll look out for it though.

>really good feeling they will do just that. So I'd say this game is
>great for hotlapping right now, but not so great for competitive play.

It's certainly a fun hotlapper (although I do like my eye-candy which
I am currently denied), but more than anything else I like racing. I
hotlapped only a few times with GP2 or ICR2, far preferring to set up
a race and do some wheel to wheel stuff. That was the real sucker
punch for me with CPR, the first time I got alongside a CC on a
straight and he plain drove straight into me. To add insult to injury
it's the old arcade syndrome of "I spin into the wall, he carries on
utterly unhindered". Pathetic, and I can't believe anyone could
release the game with AI in such a state. Try starting a race at
Milwaukee, Pro level and full field - it's hilarious.

>Perhaps we can agree that they've written an Indy Car "simulator" and
>a CART "game".

I'd go along with that, although issues exist with the simulator that
need attention (as we both know). (Actually I don't think the AI is
even fit for arcade to be honest, but what the heck).

>Were it not for that testing, those drivers would NOT be competitive.

Yup, but they do it because they get paid, or, more often than not
some upcoming David Coulthard or Damon Hill is paid to do it for them.
Heard of Alan McNish? Very talented Scottish driver of a few years
back, was the McLaren test driver at the time of Senna and Honda. Want
to guess where he'd rather have been?

The purpose of testing is to develop the car. The purpose of practice
is to develop a setup. The purpose of doing both of these is to race.
If you can't race....what's the point? Drivers endure the tedium of
testing because it will give a competitive advantage when racing (I
know I did, I hated every minute of it), but testing for testing's
sake sounds like a recipe for boredom. That's my own personal I know,
but I like to race rather than hotlap. I've always found it a very
false scenario, especially knowing that we cannot hurt ourselves -
gives you the freedom to try things that common-sense would hold you
back from otherwise.

>Agreed. I just don't feel that saying that this is not a simulation
>is a valid comment, and this is the basis upon which all our arguments
>rest, isn't it? I believe it to be a good heading towards great Indy
>Car simulation, but not yet a competitive racing simulation. So lets
>agree on terms, and we'll probably end up agreeing on conclusion :)

Even considering only hotlapping CPR doesn't quite push my buttons as
a sim, hence our differing opinions. I like it in much the same way as
I loved Monster Trucks when it first appeared - a game which I could
play on-line and with handling realistic enough to make it challengin
to drive. That said, I think a lot of the problems with CPR lie in a)
the unresponsive default setups, and b) the difficult to configure
controllers. It is extremely difficult to get the car to respond in a
consistent and stable manner, although the issue with the setups is
probably down to my own preference and detuned so people can at least
stay on the road.

>Perhaps its to some degree to balance the degree of anti-MS rhetoric
>shown here.

I feel the same way about Intel products, quite often they are bashed
simply because it is fashionable to do so rather than for any good
reason.

>Yup. We can only hope. However, it seems that the NASCAR is making
>the money for Papyrus right now, and it only makes sense for them to
>do whatever makes the most profitable return, even if Papyrus started
>out as a bunch of open-wheel fans, as they did....must be gut
>wrenching to come to the conclusion that you have to spend your
>efforts on a stock car game when you really prefer open-wheelers!

As far as I heard many of those who championed the open wheel cause at
Papyrus have moved on to pastures new, and you can't argue with sales
- the NASCAR games did a _lot_ more sales than the Indycar. Still, GPL
looks set to redress the balance, and NASCAR2 is still pretty fun,
watching the roundy-rounders trying to get a bus to handle around
Sears Point :)

>I think
>that we're right to criticise the AI, and they've been right so far in
>agreeing to look at the problems we're raising. If they do so, I'll
>be a happy guy, and so will you.

Undoubtedly. Please do understand that I'm Scottish, and as it is my
duty as a patriot to live up to my racial stereotype and find
something to moan about, but underneath it I'll be happy :)

>Absolutely, which is why it amazed me you would trot out superior GP2
>performance on your P225, a computer that didn't exist when GP2 was
>released!

Superior in the sense that I could get GP2 to run at max frame-rate in
high-res with the hardware I had at the time. I can't with MS-CART,
and the hardware I have now is a whole lot more powerful, AND
augmented by the 3D card that we begged for in GP2. Given the frame
rates we see in ICR2, GLQuake, Ubi-F1 and a host of others, I have to
question what MS-CART is doing with all my silicon.

>Many people have disagreed and still do disagree with this opinion.

Other than the graphics speed (which is unpatchable AFAIK), what about
GP2 rendered it unplayable and in need of a patch?

>True, but then CART is developed today with faster Pentium II's in
>mind. GP2 was not. As a P133 owner, GP2 + a 3D board would run just
>fine. It would not have required me to upgrade the CPU. CART is being
>developed out in front of the technology curve just as GP2 was at the
>time it came out. The only difference, apparently, is that you don't
>own a cutting edge CART computer-but you did and still do own a
>cutting edge GP2 computer.

Yes, but NOTHING will get CART to run at 30fps in high-res, even
turning off all the details. With a full field of AI it won't even
accept my steering inputs or gear shift instructions, that's how
overloaded it is. Until last night I'd only tried the demo and found
that frame-rate sensitive enough with AI around, but when trying the
full field at a friend's house I was stunned.

>Well, one of the things that the CART team has bragged about is its
>physics model with front tire physics instead of just having the car
<snip>
>rather faked). Who knows? Perhaps its just Direct3D...

A combination of both, but utterly infuriating. CPR looks quite spiffy
with all options on, but undrivable. Fun to drive with nice good
frame-rate, but nowt ...

read more »

by **Randy BO** » Wed, 12 Nov 1997 04:00:00

incredibly complicated and the interaction of the tyres and the road
surface is probably the most complicated area of all. >>

Yes, there's more to it than that. However, this is the most basic and
accurate statement. If you want me to go into static friction coefficients
vs. normal/motion friction coefficients, the effect of temperature on those
coefficients, *** deformation and slip angles, etc then we'll lose what few
people we have left actually reading this thread!

is a gross simplification of the physics.>>

Yes it is a simplified explanation. But it is not inaccurate. Simplifying
something does not make it wrong.

attention to the tyres / grip. I understand that one of the main reasons why
Grand Prix Legends is shaping out so well is because Papy have really gone to
town in modelling the tyre / road interaction. >>

I haven't seen it. I'll take your word for it. However, I find that a lot of
the criticisms of CPR regarding grip are coming from people who are using ICR2
as their basis. However, since ICR2 was done, CART has lowered boost to 40
inches, mandated reduced downforce in the chassis and wing configurations, and
yet the records still get shattered each year. Why? Two reasons: engine
manufacturers are finding enough extra horsepower to offset the drops in
boost, and the fact that there is now a fierce tire war going on in CART. The
tires in CART is going to contribute a lot to cars that slide less and grip
more, and this is going to help drop lap times in the absence of downforce or
boost, because cornering speeds can be high regardless.

are referring to is keeping the tyre from _not_ moving laterally.
When cornering oversteer occurs it is due to the _lateral_ force exceeding the
amount of _lateral_ grip in the rear tyres. Since "the friction force keeping
the tyre moving on the road" can only refer to the
grip that keeps the wheel rolling, this has relatively little impact on corner
oversteer.>>

Let me argue the "poorly expressed" angle. You are indeed correct, however,
there is still only so much work a tire can do, both in terms of lateral load
and acceleration/braking load. Hence the friction circle (or traction circle)
you see in textbooks. This is why you cannot corner as efficiently under
heavy braking as you can under trail braking or no braking. If you could
totally separate lateral force loads from the straightline force loads exerted
by the engine turning the wheel, then you braking forces would not affect
cornering and visa versa. But they ARE related and have to do with the total
work the tire can do as its subjected to various straight line and lateral
forces.

comes from the application of the _force_ supplied by the engine applied
to the frictional properties of the tyre and road surface. If the grip is
exceeded there is little or no acceleration! So the statement should read
something like "Wheelspin looseness is induced mainly by the power being
applied through the rear wheels exceeding the grip available from the
rear tyres and road surface.">>

I was referring to the acceleration of the wheel by application of power, but
your re-statement is correct. Yes, ultimately it boils down to an issue of
force: the force applied by the engine, the friction force applied by the
road, and the lateral force applied by weight transfer.

maybe for corners which tighten considerably.>>

Correct. But the term "power oversteer" is rather vague and doesn't really
accurately reflect what's going on. You might have the wheel turned the
proper amount and be unwinding it, but applying the power too fast (the "power
oversteer") or you might have the wheel turned too much for the amount of
power you should normally be putting down on exiting the turn. They are one
and the same, but viewed from opposite directions. Either way, the ratio of
wheel-lock To throttle-position is the problem. One of them has to give and
if it doesn't: OVERSTEER.

have lost grip the rear end will then pivot round the centre of gravity - or
front
wheels if they can retain grip ;-) >>

Sorta depends upon the nature of the turn. Grip can be lost all at once or
gradually. High speed turns where you might oversteer in the middle of the
turn is a more gradual because you might gradually push the wheel beyond its
limit as you transfer more and more weight to it at the same throttle
position. Slower speed turns tend to snap the car out pretty suddenly. My
personal worst was at Skip Barber at Laguna Seca pushing too hard through turn
4 and having to pinch the turn on exit. Thank God for grooved tires or I
would have spun for sure...but I caught it almost immediately.

?? IMHO, ICR2 _does_ model power oversteer (and by implication wheelspin), just
not terribly well when compared to GP2 ;-) >>

Well, unless we hear from Papyrus what they did and didn't model, I'm going to
continue to differ with you on this one.

Randy
Randy Magruder
Staff Writer
Digital Sportspage
http://www.racesimcentral.net/

by **Randy BO** » Wed, 12 Nov 1997 04:00:00

>> True, but I was surprised to have to drive it like a kart in order to

achieve good laptimes. I'm basically hurling the car around the track (and
achieving very good times) as opposed to the balance and precision necessary
to achieve same in GP2. No less fun, just
different, and different to what I would have expected. >>

Without saying for sure how realistic the CPR model is, I would say that it is
well within what I'd expect. A lot of my comparative data comes from comments
made by Jacques Villeneuve in his book: "My first season in Formula One". I
don't have it with me right now, but he discusses the way the two cars corner
and slide and what kinds of differences there are between the two. I find GP2
to be consistent to what he says about the cornering and handling of F1 cars,
and CPR to be consistent with what he said about Indy Cars. You definitely
wouldn't expect CPR to handle like GP2. Totally different formulae. (hey I
pluralized that, didn't I? <G>)

>> Okay, a couple of other things. Why am I cnsistently 5mph faster in a

straightline when racing on-line compared to off-line? >>

I haven't noticed that. I'll take for your word that its there. Is it
possible that they modelled the laying down of rubber on the track? It
wouldn't matter much on high speed straights, but if you got a better run off
of the corner on the racing line it might manifest itself in a higher top
speed at the end of the straight.

>> Why can I achieve faster laptimes on-line than off? >>

Uh, because that's the racing line for the track, and I'd be more concerned if
you were getting better times OFF line!

>> Why can I lap within 0.2s per lap using rain tyres on a wet track compared

to slicks on a dry
track?!?!>>

Sounds like a bona fide bug to fix.

>> Why are rain tyres faster than slicks on a dry track? >>

Are they that way even if you turn on temperature and tire wear options?

>> Why does the car hiccup when below 30mph?

Because it took a drink of methanol too fast? <GGG> Seriously, can you
describe "hiccup" in terms of what the car is doing?

>> When I brake heavily in sixth gear, why do I hear a downshift sound? >>

I'm not sure its a downshift ... I think it might be a turbocharger thing. I
need to look at some real in-car footage around a 6th gear oval to double
check this. I noticed it too...

>> There is a pretty extensive list of wierd things which are not related to

the AI, and an even
longer one when the AI are taken into account. >>

Hey, we're in agreement about the AI.

>> Granted, but response to our criticisms comes in the form of V1.1 or V2, not

in promises of what V1.1 or V2 will contain. Call me an old cynic, but I've
heard tell of great things so often before :) >>

I think the guys at MS are aware of who they are dealing with. :)

>> Nice plug :) Actually I stopped by over the weekend to see what youhad

thought of it, but no review yet. I'll look out for it though. >>

Sorry for the delay in getting it written. The problem is that I'm trying to
be both thorough and fair. I'm not a real-life Indy Car driver, so I have to
investigate a lot more to find out whether things are real concerns or just
perceptions. I'm also all too aware that it is simply not possible to write a
review of this game that is not going to get me flamed to a crisp by some
segment of the potential audience! So I'm trying to be as thorough as
possible to minimize the smoke coming out of my monitor the day after I write
it :)

>> It's certainly a fun hotlapper (although I do like my eye-candy which I am

currently denied), >>

There's still more eye-candy on my P133 w/3DFX than there is in ICR2, at least
so far as solitary hotlapping goes, but in a couple of weeks I'll have a P300
and then I can lord it over everyone else <GG>

>> but more than anything else I like racing. I

hotlapped only a few times with GP2 or ICR2, far preferring to set up a race
and do some wheel to wheel stuff. That was the real sucker punch for me with
CPR, the first time I got alongside a CC on a
straight and he plain drove straight into me. To add insult to injury it's the
old arcade syndrome of "I spin into the wall, he carries on utterly
unhindered".
<<

Agreed. Frustrating. Part of why I have to FORCE myself to do competitive
racing for the sake of my review, but I have to admit I'm not getting much
enjoyment from it.

>> Pathetic, and I can't believe anyone could release the game with AI in such

a state. Try starting a race at
Milwaukee, Pro level and full field - it's hilarious. >>

Take ANY track and you see it. I'm disappointed that the AI is in the state it
is, and you'll see that in the review. At the same time if they can turn
around updates fast enough to address these things, we won't care that much 6
months from now :)

>> I'd go along with that, although issues exist with the simulator that need

attention (as we both know). (Actually I don't think the AI is even fit for
arcade to be honest, but what the heck). >>

Aww..c'mon -- its better than in Psygnosis Formula One 1.0 for the Playstation
<G> -- just not by much :)

>> The purpose of testing is to develop the car. The purpose of practice is to

develop a setup. >>

Why did Jacques Villeneuve log so many thousands of hours of testing before his
rookie season in F1? Was it to develop the Williams car? Or to develop
Jacques Villeneuve *IN* the Williams car?

> but testing for testing's sake sounds like a recipe for boredom. >

Except for the rather fun hotlap competitions on the web, I agree with you. I
also agree that the purpose is to improve you for the race, so that you're
more instinctive and consistent around the course and can concentrate on the
competition instead of just making each corner. I'm simply saying that no
matter how you slice it, its a deep enough sim that even if the AI was decent,
a lot of people who buy it are gonna be backmarkers until they put in some
serious practice time, and the current 1.0 product is at least decent for
that. Of course that might buy MS a little time to get the patch out, but
peoples' patience is going to wear out quickly if something isn't done.

>> As far as I heard many of those who championed the open wheel cause at

Papyrus have moved on to pastures new, and you can't argue with sales
- the NASCAR games did a _lot_ more sales than the Indycar. >>

Yup, and you'll notice if you look in your NASCAR 2 or SODA manual that I beta
tested those products. Even though CART is my favorite series, I still love
Papyrus and the work they do.

>> Undoubtedly. Please do understand that I'm Scottish, and as it is my duty as

a patriot to live up to my racial stereotype and find something to moan about,
but underneath it I'll be happy :) >>

Well, given that my last name is Magruder, I guess I'm some kind of bastardized
Scot :). I guess that means I'll moan, just not as much as you :)

>> I have to question what MS-CART is doing with all my silicon. >>

Um, talking to a Windows COM interface ? <G>

>> Other than the graphics speed (which is unpatchable AFAIK), what about GP2

rendered it unplayable and in need of a patch? >>

Oh, man I really do NOT want to revisit our arguments of months ago, but I have
heard my comments on this echoed many times online. It boils down to the fact
that having to turn off all the graphics to get competitive starts, the fact
that the game slows down realtime to keep a 'frame rate' up, the missing
variable weather that is an important part of Formula One (important enough
that it was in the original World Circuit) and lots of other nits and gripes.

>> Yes, but NOTHING will get CART to run at 30fps in high-res, even turning off

all the details. >>

Really? Have you tried a P2 300 with a Monster 3D and 64 meg of RAM?

>> A combination of both, but utterly infuriating. CPR looks quite spiffy with

all options on, but undrivable. >>

Sounds like my assessment of GP2 with my P133 <G>. Occassionally I do turn on
everything at Monaco and let the computer drive just so I can enjoy the very
pretty slideshow.

>> Yep, tyre temps. Those are what define the adjustments of toe-in/toe-out as

well as camber, so unless the race engineer is privy to some information that
we're not being shown then it's down to trial
and error. >>

Well, first of all, does Pi provide realtime tire temperature telemetry ala
ICR2/NASCAR2? I was unaware that anything other than pressure could be
monitored in real time around the track. When the car pulls into the pits
they touch it with their little metal thermometer on the inside middle and
outside and make adjustments based upon that, but I'm unaware that's something
that they can see in realtime. At any rate, I'd like to see both tire wear
and tire temps shown when I pull into the pits or garage for setup changes. I
agree with you on this one -- just how the heck am I supposed to modify
those?!

>> Judging by the laptimes we're seeing they'd better be a field full of

Villeneuves and Sennas. Achim Trensz over on CompuServe is already knocking on
the door of a sub 1 minute lap for Laguna Seca, 1:00.2 or something last time
I checked. Sub 1 minute within a dy or so I guess. >>

Didn't Darrell Cherry do a 1:02 at Laguna in ICR2 with the OLD grip model and
physics model? If someone does a :58 in CPR then you're still looking at real
life-style improvements. Its like the real drivers are chasing the sim
drivers' lap times quite a bit, in ALL the sims including GP2, NASCAR 2 and
ICR2. CART is no exception here..but they aren't unique.

>> Hello!? Mark Blundell?! Any seats going over at Pacwest...? ;-) >>

Well, certainly if we're going to use THAT thinking I want a ride in a Williams
because I could certainly do better than the 18th spot that Jacques got on GP2
at Spa<G>

Randy
Randy Magruder
Staff Writer
Digital Sportspage
http://www.digitalsports.com/

by **Grant Reev** » Wed, 12 Nov 1997 04:00:00

Hi Dean:)

> One misconception (among many!) that is growing on this newsgroup regarding
> CPR I must just clear up - you are NEVER "steered away from AI cars to avoid
> crashes" - the only time your steering may be affected is when your front
> wheel(s) collide with another car - then your steering direction may be
> changed as a result of the collision.

> With driving aids off, the sim does not interfere with your control of the
> car in any way.

I have had my front steering affected in this manner when computer cars
bump my rear tyres. and i watch it about 20 times in replay to make
sure!
it screws up most of my race starts, when the ai cars pull in behind my
rear so close that they nearly hit me, i get thrown off the track when
the
game ***ly jolts my steering off to one side, when they haven't even
yet reached the point that they hit my rear tyres.
Eric Straub told me that the game often is looking 1 frame ahead so we
probably don't quite see collisions, as such, which strikes me as a
little
bit of a strange way to do it:) but it still doesn't explain why my
front tyres were getting jolted like that from having a stupid ai car
nearly touching my rear tyres.

suffice to say that I don't race the AI at all any more:)

hotlapping is excellent though, if you look past all the minor little
niggles.
i just got my sound drivers working right, some documentation for my
awe64
said that you should turn off full-duplex in directx games, but that
just
screws up my performance. turning it back on gave me another 3-4fps and
that gives me a much better feel of the car. the more framerate i get,
the
better the game feels. now i just need to try it when my Pure3D arrives
in the mail tomorrow morning:)

by **Richard Walk** » Wed, 12 Nov 1997 04:00:00

>Okay, lets see. There's this thing called a co-efficient of friction
>between the *** and the road, and when the force spinning the wheel
>exceeds the friction keeping it stuck to the road, it spins. It
>doesn't matter whether the car is moving or sitting still.

<gulp> Now there's a statement and a half! The physics of a moving car
are incredibly complicated and the interaction of the tyres and the road
surface is probably the most complicated area of all. To claim that "it
doesn't matter whether the car is moving or sitting still" is a gross
simplification of the physics.

BTW - this is probably where CPR is currently falling down; not enough
attention to the tyres / grip. I understand that one of the main reasons
why Grand Prix Legends is shaping out so well is because Papy have really
gone to town in modelling the tyre / road interaction.

Not quite correct (or maybe just poorly expressed). The friction force
you are referring to is keeping the tyre from _not_ moving laterally.
When cornering oversteer occurs it is due to the _lateral_ force
exceeding the amount of _lateral_ grip in the rear tyres. Since "the
friction force keeping the tyre moving on the road" can only refer to the
grip that keeps the wheel rolling, this has relatively little impact on
corner oversteer.

You are confusing force and acceleration. The _acceleration_ of the car
comes from the application of the _force_ supplied by the engine applied
to the frictional properties of the tyre and road surface. If the grip is
exceeded there is little or no acceleration! So the statement should read
something like "Wheelspin looseness is induced mainly by the power being
applied through the rear wheels exceeding the grip available from the
rear tyres and road surface."

Oversteer exiting a corner is almost always due to power oversteer,
except maybe for corners which tighten considerably. As it's name
implies, power oversteer is caused by applying excess power for the
current level of grip and is the result of wheelspin. Weight transfer
tends to be pretty insignificant, other than once the wheels have lost
grip the rear end will then pivot round the centre of gravity - or front
wheels if they can retain grip ;-)

No, see above <g>

IMHO, ICR2 _does_ model power oversteer (and by implication wheelspin),
just not terribly well when compared to GP2 ;-)

Cheers,
Richard

by **John Walla** » Thu, 13 Nov 1997 04:00:00

On 11 Nov 1997 21:11:02 GMT, randyb...@aol.com (Randy BORL) wrote:

> don't have it with me right now, but he discusses the way the two cars corner
> and slide and what kinds of differences there are between the two. I find GP2

There are undoubtedly differences between F1 and CART, but I was
considering more a difference between CPR and how I would expect and
"Indycar" (sic) to react, rather than any comparison with GP2 or
Formula One. Indycars are supposed to be more progressive, more slidy,
in the manner expressed (somewhat exaggeratedly perhaps) by ICR2. CPR
doesn't exhibit this at all, having a very slidy front-end to the car
and an extremely sticky rear-end (no jokes please!). Even when the
rear can break loose, it does so as a "jump", and is brought into line
with any correction you care to apply. The front, on the other hand,
seems almost too easy to slide, and I've been forced to hack the
garage file so that I can move my brake balance even further back to
avoid locking up the fronts. Once brake locking is removed from the
equation the fronts still seem to react incredibly differently from
the rear, e-a-s-i-n-g out of grip and back in, as opposed to the
rear's "jump". I'm still playing around with this in the garage to get
a handle on what I think the problem is, since I want to understand
what the problem is. One annoying thing about sims - when setting up a
real car you know what you're dealing with - it can't defy the laws of
physics. Sims can, so you've no idea if wierd behaviour is down to
you, the car, the setup or the game engine.

>I haven't noticed that. I'll take for your word that its there. Is it
> possible that they modelled the laying down of rubber on the track? It
> wouldn't matter much on high speed straights, but if you got a better run off
> of the corner on the racing line it might manifest itself in a higher top
> speed at the end of the straight.

By "on-line" I meant "connected to the internet gaming zone" rather
than "on the racing line" :)

>Uh, because that's the racing line for the track, and I'd be more concerned if
> you were getting better times OFF line!

As above, misunderstanding! :)

>Sounds like a bona fide bug to fix.

I wouldn't classify it as a bug, since if you go out with _slicks_ in
the wet the car is undrivable - obviously that has been taken into
account. With wets though it seems there is no work done on how much
grip there should be, how braking should be affected, cornering
speeds, remodelled tyre wear, likelihood of aquaplaning, no "rooster
tails", not even any of the graphical niceties like water on the
visor, visor steaming up, etc etc. Just seems to have been put in
because graphically it could be.

>>> Why are rain tyres faster than slicks on a dry track? >>
>Are they that way even if you turn on temperature and tire wear options?

Yes, although I haven't tested tyre wear yet (nowhere to measure it
anyway!).

>Because it took a drink of methanol too fast? <GGG> Seriously, can you
> describe "hiccup" in terms of what the car is doing?

It sort of "hops" along the track, or behaves very strangely. Try
slowing down below 30mph and you'll see this. I thought it was a dirty
pot (since that also causes hiccuping) so I tried with keys and got
the same thing.

>I'm not sure its a downshift ... I think it might be a turbocharger thing. I
> need to look at some real in-car footage around a 6th gear oval to double
> check this. I noticed it too...

As far as I can tell it seems to be the sound of the turbo spooling
down rather than a downshift. That seems reasonable enough if it's the
case.

>Sorry for the delay in getting it written. The problem is that I'm trying to
> be both thorough and fair.

Well, I guarantee you'll be flamed no matter what you say! I'll look
forward to it (the review, not the flaming!).

>There's still more eye-candy on my P133 w/3DFX than there is in ICR2, at least
> so far as solitary hotlapping goes, but in a couple of weeks I'll have a P300
> and then I can lord it over everyone else <GG>

Hey, be fair! A P-133 _with_ Rendition card will give you lots more
eye-candy at a given frame-rate than CPR will on a much higher spec
system. If CPR is tested with a 3D card then ICR2 should be considered
likewise, especially as the release of CART Racing has the 3D version
included. A shame no 3dFX or network support though, that would have
been perfect.

>Agreed. Frustrating. Part of why I have to FORCE myself to do competitive
> racing for the sake of my review, but I have to admit I'm not getting much
> enjoyment from it.

You have my sympathy! I long since gave up on the AI as utterly
unworkable, and recently I'm only playing CPR to test theories. I'll
wait for the full version and for it to be patched before I buy it or
spend further time with it.

>Aww..c'mon -- its better than in Psygnosis Formula One 1.0 for the Playstation
> <G> -- just not by much :)

In all honesty I thought the AI in Psy-F1 far superior, and it was
pretty awful. The reason being that, while not having any particular
good points, it had less bad points. There wasn't utter carnage every
lap, with CCs crashing into each other left and right, and the CCs at
least left you alone if you got alongside on a straight. In CPR they
seem blissfully unaware of your existence and try to use your piece of
road - with 'orrible results!

>Why did Jacques Villeneuve log so many thousands of hours of testing before his
> rookie season in F1? Was it to develop the Williams car? Or to develop
> Jacques Villeneuve *IN* the Williams car?

An isolated incident. How many hours of testing were done on Senna's
McLaren before the '92 season? How many hours of testing did Senna
himself do? Even with JV. you can be sure he tested because he felt he
needed to improve his ability to understand the car so that he could
race. If all he had to look forward to was zipping around an empty
circuit you can be sure that he would have stayed in the USA. So with
CPR - if there's no racing to follow the practice sessions, I've no
interest in being a test driver.

>Except for the rather fun hotlap competitions on the web, I agree with you.

Actually I pretty much hate hotlapping. Hotlapping is less about skill
and more about available time. Whoever is prepared to put in the most
practice time and to sit for hour after hour trying again and again
and again to thread a particular chicane flat in sixth will generally
be faster. In the real world the drivers have constraints on the
number of laps available as well as concern for their lives and cars.
If you take a chicane flat in sixth and mess up, at best you'll damage
the car and at worst you'll be killed. That imparts a measure of
caution which is simply not there in hotlapping, and as such it is a
false impression of speed. Those pole-position laps that we marvel
over are displays of speed and skill tempered with caution, and an
understanding of the risks involved. The knowledge of where your
personal limit is and how close to it you can go given the
circumstances is what fast laps are about, not who can do the most
laps.

Again, my own personal opinion, and I'm sure not one shared by the
majority.

>Oh, man I really do NOT want to revisit our arguments of months ago, but I have
> heard my comments on this echoed many times online. It boils down to the fact
> that having to turn off all the graphics to get competitive starts, the fact
> that the game slows down realtime to keep a 'frame rate' up, the missing
> variable weather that is an important part of Formula One (important enough
> that it was in the original World Circuit) and lots of other nits and gripes.

Other than the well-documented issue of frame-rate, there was
essentially nothing with GP2 that rendered any aspect of it unusable -
even the frame-rate could be cured on anything higher than a 486 by
messign with the graphics. In ICR2 the yellow-fla bug could turn any
race into a nightmare, in CPR we haev all the issues we're discussing
here. With GP2 we had complaints (canned spins etc), but the product
was essentially sound.

Regarding the wet weather, personally I'd rather wet weather had been
left out of CPR rather than implemented badly, and this is what
happend with GP2. In CPR even if thw weather was dynamic it would make
a difference, since you could conceivably have to drive some laps with
slicks on a wet track. As it stands just now for a wet race I put
wets, for a dry race I put slicks - no difference at all to car
performance. So the "wet weather" amounts to a raindrop effect
streaking the screen? Truly cutting edge....

>Really? Have you tried a P2 300 with a Monster 3D and 64 meg of RAM?

I've tried on a P-Pro 233 with Monster 3D and 96Mb of RAM, and no it
wasn't smooth with all eye-candy. AFAIK a PII will be around double
the speed of a P225 (if I'm optimistic), and since I get 12-14 fps I'd
expect <30 fps with a PII - on an empty track. Given that the
frame-rate drops _horribly_ when AI are around, Even a PII 300 would
choke from last on the grid at Long Beach with a full field of AI.
Even from first I guess it would have serious problems. Of course this
is conjecture, but when you get your PII soon you can test it out and
let everyone know :)

>Sounds like my assessment of GP2 with my P133 <G>. Occassionally I do turn on
> everything at Monaco and let the computer drive just so I can enjoy the very
> pretty slideshow.

Yep, then you can turn everything off and get the max 25.6 fps. I
don't even have that option in CPR.

>Well, first of all, does Pi provide realtime tire temperature telemetry ala
> ICR2/NASCAR2?

Not as far as I'm aware, I would imagine it would be impossible since
the friction of the contacts on the tyre surface would mess up any
temperature readings you could take. You'd need to embed sensors into
the surface of the tyre, and that sounds too hideously complicated to
even contemplated.

> At any rate, I'd like to see both tire wear
> and tire

...

read more »

by **John Walla** » Thu, 13 Nov 1997 04:00:00

If the cars in CPR are being simulated then it must be a new form of
"Artificial Stupidity" that is being used, although the stupidity
seems all to real to me.

In any case, while it is nice to fully simulate a field of cars you
must also consider what hardware it will be run on, and PII is
unlikely to become the *** MPU in the marketplace until after
CPR's shelf-life has expired. Perhaps it was just a goof like GP2,
overestimating what the engine was capable of or what would be the
standard system at the time of release?

Cheers!
John

by **Richard Walk** » Fri, 14 Nov 1997 04:00:00

Well those who aren't interested in this stuff will already be ignoring
it whilst those who are would be able to learn something <g>

Depends how far you are simplifying things. One problem with
simplification in this case is that a tyre at rest can be described with
a high degree of accuracy with relatively simple equations. But take that
tyre at racing speeds and we are really at the limits of mechanical and
mathematical understanding.

Tyres are good, but not that good <g> The main problem with CPR's tyre
modelling is the way in which the rear end starts sliding only for it to
seemingly catch itself. Maybe that's realistic (don't know, never driven
a real CART car) but it doesn't feel like what I believe to be realistic
or match what I see from in car cameras.

BTW - GP2 is my own personal yardstick for how a sim should model tyre
behaviour, even though it doesn't attempt to model some aspects.

OK, _much_ better explaination <g> The "traction circle" is something
that all aspiring racers (whether real or sim) need to grasp.

I always thought that "power oversteer" was a pretty well defined
concept! To me (at least <g>) it means that the rear wheels are spinning
due to excess power being applied. Obviously if the car is still
cornering then the rear wheels can take less lateral acceleration so are
more likely to spin.

I was referring specifically to exit oversteer, although your
explaination is of course true.

What were you driving at Skip Barber btw? My experience is all
theoretical I'm afraid (although I do take the theory quite seriously
<g>).

Cheers,
Richard

by **Richard Walk** » Fri, 14 Nov 1997 04:00:00

>>I am wondering if anyone out there really understands just how CPU
>>intensive it is to simulate a car.

>If the cars in CPR are being simulated then it must be a new form of
>"Artificial Stupidity" that is being used, although the stupidity
>seems all to real to me.

I think he was referring to the driver's car, not the A(un)I!

If we make the assumption that all of the setup options do influence the
driving model (everyone I've messed about with seems to) then it does
seem to imply that CPR is taking into account more variables than GP2, N2
& ICR2.

Having only tried the demo so far I can't comment on what it is like with
a full field, but for hotlapping CPR gives slightly better framerates on
my PC (o'clocked P166 + 3dfx) than I get with GP2. Undoubtedly CPR
framerates could be better, but I don't find them so awful that they need
especial comment considering the AI and blatant errors in the tyre
modelling.

BTW - liked your "kart" analogy. Yes it does feel like driving one round
the corners. Maybe they just mispelled the title <vbg>

Oh well, back to the zone <g>

Cheers,
Richard

by **Richard Walk** » Fri, 14 Nov 1997 04:00:00

Thanks for the info - it's a normal state of being alive to be both right
and wrong at the same time <g>

Out of interest, do you actually model it as a "circle"? The circle
analogy is a good one for explaining it but the non-circular contact
patch and ability of the wheel to roll makes the circle a bit of a
simplification <g>

Cheers,
Richard

by **Jim Sokolof** » Fri, 14 Nov 1997 04:00:00

> >ICR2 doesn't model unbounded wheelspin, but gets the traction circle
> >pretty right, which makes the car feel "right" for normal race
> >driving. (But it can't do donuts and other gratuitous displays of
> >excessive throttle application.) So, you're both right, and you're
> >both wrong. :-)

> Thanks for the info - it's a normal state of being alive to be both right
> and wrong at the same time <g>

> Out of interest, do you actually model it as a "circle"? The circle
> analogy is a good one for explaining it but the non-circular contact
> patch and ability of the wheel to roll makes the circle a bit of a
> simplification <g>

It's not actually a circle, but an elliptical shape that has a pretty
good resemblance to tire/road interfaces... The magnitude of the major
axes (throttle and brake) is higher than that for cornering (just as
the textbooks and real-life indicate).

Future Papyrus products will undoubtedly get it more right. ;-)

---Jim

by **Randy Magrud** » Fri, 14 Nov 1997 04:00:00

>There are undoubtedly differences between F1 and CART, but I was
>considering more a difference between CPR and how I would expect and
>"Indycar" (sic) to react, rather than any comparison with GP2 or
>Formula One. Indycars are supposed to be more progressive, more slidy,

It does feel that way to me, but not with the sample setups. Once I
got the control sliders right and tweaked the setup, INCLUDING the
steering lock, it seemed that it got that way. Btw, did you read
Mauricio Gugelmin's comments on the sim on the MS CART site? As
always, some people will immediately throw those comments out because
of the fact that its on an MS site, but if you reject them as just PR,
you're rejecting the comments of SEVERAL Indy Car drivers. Guess I'd
have to wait til next September at Laguna Seca to ask them personally
:)

Well, its up. Enjoy :)

Um...NO. Perhaps the PC version did, but the original Playstation
Formula One had cars moving right over into you and shoving you off
onto the grass. If you came onto the straight from a right hander and
then the turn at the end of the straight was a left hander, the AI
would move to the right to take the proper line and if you were
already there -- tough.

Yeah...the AI in GP2 is still the best in a sim that I've seen. I
just wish I could run it with more graphics on. Oh well, the P300
should solve THAT problem :)

You can be sure I'lldo that :)

Well, I'd love to see one of the real drivers address this point :)

Randy

by **Randy Magrud** » Sat, 15 Nov 1997 04:00:00

>What were you driving at Skip Barber btw?

Just the little Formula Dodge cars they use. No downforce, but put a
Dodge sedan engine into a car a third the weight, add treaded tires,
and there you have it. You can go to www.sequoia-dev.com/Hawaii and
you'll find a complete writeup of Skip Barber's Intro to Racing that
Dave Sparks and I did (we went and did the Intro together). You'll
see pictures of us, the cars, what it looks like going thre corkscrew,
etc.

Up until very recently, so was mine. My immediate impression of
driving a Skip Barber car was -- it feels like a more powerful go-kart
with a shifter added to it! The brakes do bite hard (again, you have
sedan-quality brakes on a car a third the weight) and of course you're
so snugly tucked into the car that you feel EVERYTHING the car is
doing. Going loose on the exit of turn 4 was fun because a) I caught
it exactly the way the sims tought my muscle memory to do it and b), I
really understood how you can feel the car going loose without
consciously even thinking about it.

Highly recommended. Of course, I'd love to do the 3-day Russell
School at Sears Pt with the downforce & slicks, but Dave would rather
do the 3 day Skip Barber school with no dowforce and grooved tires.
Different strokes I guess.

By the way, a really good book that I've read is "Drive to Win" by
Carroll Smith. Excellent, Excellent book.

Randy

rec.autos.simulators

CPR GREAT!! Framerate sucks!..I'm concerned

CPR GREAT!! Framerate sucks!..I'm concerned

CPR GREAT!! Framerate sucks!..I'm concerned

CPR GREAT!! Framerate sucks!..I'm concerned

CPR GREAT!! Framerate sucks!..I'm concerned

CPR GREAT!! Framerate sucks!..I'm concerned

CPR GREAT!! Framerate sucks!..I'm concerned

CPR GREAT!! Framerate sucks!..I'm concerned

CPR GREAT!! Framerate sucks!..I'm concerned

CPR GREAT!! Framerate sucks!..I'm concerned

CPR GREAT!! Framerate sucks!..I'm concerned

CPR GREAT!! Framerate sucks!..I'm concerned

CPR GREAT!! Framerate sucks!..I'm concerned

CPR GREAT!! Framerate sucks!..I'm concerned

CPR GREAT!! Framerate sucks!..I'm concerned

CPR GREAT!! Framerate sucks!..I'm concerned