[GP3] AI question

Hi ! The thing that really piss me off in GPL are the AI that are IMHO bad, i.mean. they can do good times but they don't have the same physics than the player , and even NO physics !!! So they can do impossible things like, that would put them out the tracks or slower ( cold tire, lots of fuel ). So my questions is Do GP3's AI has the same physics than the player ? or simplyfied physics ( for example simplified suspension,engine,etc...), or NO physics at all ( trajectory line interpolated .. bah.... crapy shit ...) -- Sebastien Tixier Susuki 650 SVS - No Driving Licence yet (MagicFr) GPLRank handicap -17.05 Game Developper ( A.I. in V-Rally2, Need For Speed 5 PSX ) personal : http://magicfr.multimania.com company : http://www.eden-studios.fr

Well, some say they play GP3, so maybe they have seen strange AI behaviour or not. That could be a clue. When you see GPL AI, you can see quite easily that it use trajectories interpolation. > And you really expect somebody to know? :-) > > JoH -- Sebastien Tixier Susuki 650 SVS - No Driving Licence yet (MagicFr) GPLRank handicap -17.05 Game Developper personal : http://magicfr.multimania.com company : http://www.eden-studios.fr

On Fri, 30 Jun 2000 10:08:38 +0200, =?iso-8859-1?Q?S=E9bastien?= Tixier <[email hidden]> wrote:

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>Hi ! > >The thing that really piss me off in GPL are the AI that are IMHO bad, >i.mean. they can do good times but they don't have the same physics than >the player , and even NO physics !!! So they can do impossible things >like, that would put them out the tracks or slower ( cold tire, lots of >fuel ). > >So my questions is > >Do GP3's AI has the same physics than the player ? or simplyfied physics >( for example simplified suspension,engine,etc...), or NO physics at all >( trajectory line interpolated .. bah.... crapy shit ...)

And you really expect somebody to know? :-) JoH

In article <8jshd0$k5h$[email hidden]>, "Andy Marson" <[email hidden]> writes:

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>> The main problem I have with the GPL AI is when they hit me in braking >> zones. :) >> >> > >I have never had the AI hit me in braking zones, I've played GPL ever since >it came out. >This seems to be common problem for quite a few people. Is it just that >you're braking too early or something? seems a bit strange to me.... >

If I brake early enough for ME to make the corner, any AI close behind will either hit me(if I'm on the racing line), or make a bonzai pass to the inside(if I'm wide of the line). Not much fun to see them go by at 10mph faster when I'm scrambling for traction as it IS... Eldred -- Tiger Stadium R.I.P. 1912-1999 Homepage - http://www.umich.edu/~epickett GPL hcp. +70.45 Never argue with an idiot. He brings you down to his level, then beats you with experience... Remove SPAM-OFF to reply.

> The main problem I have with the GPL AI is when they hit me in braking > zones. :) > > I have never had the AI hit me in braking zones, I've played GPL ever since it came out. This seems to be common problem for quite a few people. Is it just that you're braking too early or something? seems a bit strange to me....

On Tue, 04 Jul 2000 08:56:05 +0200, S�bastien Tixier <[email hidden]> wrote: >That the time i spent on real driving AI on V-Rally 2 and NFS5 PSX plus cops and >traffic cars. No offense, but I wouldn't call the AI of the cops and traffic cars in NFS5 a 'plus'. :-) (can only talk about the PC version though) Blaze

eldredp wrote;

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>>I have never had the AI hit me in braking zones, I've played GPL ever since >>it came out. >>This seems to be common problem for quite a few people. Is it just that >>you're braking too early or something? seems a bit strange to me.... >> > >If I brake early enough for ME to make the corner, any AI close behind will >either hit me(if I'm on the racing line), or make a bonzai pass to the >inside(if I'm wide of the line). Not much fun to see them go by at 10mph >faster when I'm scrambling for traction as it IS... > >Eldred

A simple and common way of dealing with this is to edit the gpl_ai.ini file in your gpl folder. Near the bottom: braking_efficiency_coeff = 0.8000 change it to 1.9 and the AI can come to a dead stop instantly when caught in heavy traffic. It also adds about a second to their laptime. 1.0 or 1.2 works well and still looks fairly realistic. The ultimate method is to edit the race.lp file and change the braking points at the specific corner. There is a utility out there by Francois Dubuc. Use it to convert the race.lp file from the desired track folder to a txt file. Then use notepad to edit it. Don't touch the first 3 lines. The first field is the target speed for the AI. Scroll down the file until you see a high value followed by a sharp dropoff. That is a corner following a long straight. Just move the drop in speed sooner a bit. Don't change the other fields, so you can't just cut and paste, you have to do some typing. Use the editor to convert back to lp format. And now you get respect! Tom

No sim can possibly afford to use the same physics model for the AI cars as for the player. And if they could, writing AI code that could cope with realistic physics would take a 100 programmer team fifty years to code. Imagine trying to write an AI routine to drive GPL!!! <shudder> :) All AI opponents in all racing sims are to a large extent running on "rails". It is more noticeable in GPL because of the extreme driving style. GP2 also used a similar system, and presumably so will GP3. The trick is to make is "look" real. The main problem I have with the GPL AI is when they hit me in braking zones. :)

With simplified physics its very possible. I can't tell you much, but i worked on V-Rally 2 and NFS5 psx. If i compare their physics with GPL, i would say, we don't have toe-in/out settings on wheels, less complex differential and relieved body inertia. Imagine you make a GPL simplified physics, simplified tire grip, simplify suspension, etc... So you only need 1 developper and 6month to have your real driving AI. That the time i spent on real driving AI on V-Rally 2 and NFS5 PSX plus cops and traffic cars. Maybe it's possible maybe not, i beleive it is. And if it's sound to complex maybe they could just calculate the real collisions between the car, i can't stand see an GPL AI push me, then i go into spin, and the AI don't even slide !!! Simon Brown wrote:

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> No sim can possibly afford to use the same physics model for the AI cars as > for the player. And if they could, writing AI code that could cope with > realistic physics would take a 100 programmer team fifty years to code. > Imagine trying to write an AI routine to drive GPL!!! <shudder> :) > All AI opponents in all racing sims are to a large extent running on > "rails". It is more noticeable in GPL because of the extreme driving style. > GP2 also used a similar system, and presumably so will GP3. The trick is to > make is "look" real. > The main problem I have with the GPL AI is when they hit me in braking > zones. :)

regards, -- Sebastien Tixier Susuki 650 SVS - No Driving Licence yet (MagicFr) GPLRank handicap -17.05 Game Developper personal : http://magicfr.multimania.com company : http://www.eden-studios.fr

Andy Marson wrote:

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> > The main problem I have with the GPL AI is when they hit me in braking > > zones. :) > > > > > > I have never had the AI hit me in braking zones, I've played GPL ever since > it came out. > This seems to be common problem for quite a few people. Is it just that > you're braking too early or something? seems a bit strange to me....

Braking too early ! I don't think so :o) -- Sebastien Tixier Susuki 650 SVS - No Driving Licence yet (MagicFr) GPLRank handicap -17.05 Game Developper personal : http://magicfr.multimania.com company : http://www.eden-studios.fr

Jan Loebzien wrote:

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> On Tue, 04 Jul 2000 08:56:05 +0200, S�bastien Tixier > <[email hidden]> wrote: > > >That the time i spent on real driving AI on V-Rally 2 and NFS5 PSX plus cops and > >traffic cars. > > No offense, but I wouldn't call the AI of the cops and traffic cars in > NFS5 a 'plus'. :-) > (can only talk about the PC version though) >

The AI in NFS version PC is an offense for AI developper IMHO. I'm talking about the PSX version that i've coded, and i can assure you that there driving like they has a steering wheel and pedals ! > > Blaze -- Sebastien Tixier Susuki 650 SVS - No Driving Licence yet (MagicFr) GPLRank handicap -17.05 Game Developper personal : http://magicfr.multimania.com company : http://www.eden-studios.fr

Yes, but I said no "sim" can have the same physics for the AI cars and in my opinion those game you mention probably are not sims (although I haven't played either). The amount of physics calculations in GPL is probably more than ten times that in NFSPU. I think I read somewhere that the GPL phsyics runs at 288 Hz!

Simon Brown wrote: > Yes, but I said no "sim" can have the same physics for the AI cars and in my > opinion those game you mention probably are not sims (although I haven't > played either). The amount of physics calculations in GPL is probably more > than ten times that in NFSPU. I think I read somewhere that the GPL phsyics > runs at 288 Hz! I totally agree with you ! Maybe it's to hard for me to explain it in English and you don't understand what i try to explain :o((( I mean, simplified AI car physics + AI driving IS BETTER THAN AI on static interpolated trajectory line IMHO. with "my" method you can't see an AI has strange car behaviour, like, slide driving when overtaking or thing like thats because they has real car physics ( very simplified ). king regards, -- Sebastien Tixier Susuki 650 SVS - No Driving Licence yet (MagicFr) GPLRank handicap -17.05 Game Developper personal : http://magicfr.multimania.com company : http://www.eden-studios.fr

In article <[email hidden]>, [email hidden] (TToommLL) writes:

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>>If I brake early enough for ME to make the corner, any AI close behind will >>either hit me(if I'm on the racing line), or make a bonzai pass to the >>inside(if I'm wide of the line). Not much fun to see them go by at 10mph >>faster when I'm scrambling for traction as it IS... >> >>Eldred > >A simple and common way of dealing with this is to edit >the gpl_ai.ini file in your gpl folder. Near the bottom: >braking_efficiency_coeff = 0.8000 >change it to 1.9 and the AI can come to a dead stop instantly >when caught in heavy traffic. It also adds about a second to >their laptime. 1.0 or 1.2 works well and still looks fairly realistic. > >The ultimate method is to edit the race.lp file and change >the braking points at the specific corner. There is a utility >out there by Francois Dubuc. Use it to convert the race.lp >file from the desired track folder to a txt file. Then use notepad >to edit it. Don't touch the first 3 lines. The first field is the target >speed for the AI. Scroll down the file until you see a high value >followed by a sharp dropoff. That is a corner following a long straight. >Just move the drop in speed sooner a bit. Don't change the other >fields, so you can't just cut and paste, you have to do some typing. >Use the editor to convert back to lp format. >And now you get respect! > >Tom

Ok, thanks. I'll try the first method first. It's easier.<g> Eldred -- Tiger Stadium R.I.P. 1912-1999 Homepage - http://www.umich.edu/~epickett GPL hcp. +70.45 Never argue with an idiot. He brings you down to his level, then beats you with experience... Remove SPAM-OFF to reply.

Wasn't Microprose's GP500 supposed to use a toned-down physics model for the computer riders? Stephen S�bastien Tixier <[email hidden]> wrote in message news:[email hidden]...

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> When I read all this, why how we call them AI ? > I'm now calling them AD. > Artificial Drivers, because it's a shame to say they're Intelligent : > - breaking point > - race.lp > > please take a look at real AI : ( my bot is Magic ) > http://www.ebc.ee/~mremm/rars/rars.htm > > regards, > -- > Sebastien Tixier > Susuki 650 SVS - No Driving Licence yet > (MagicFr) GPLRank handicap -17.05 > Game Developper > personal : http://magicfr.multimania.com > company : http://www.eden-studios.fr > >

When I read all this, why how we call them AI ? I'm now calling them AD. Artificial Drivers, because it's a shame to say they're Intelligent : - breaking point - race.lp please take a look at real AI : ( my bot is Magic ) http://www.ebc.ee/~mremm/rars/rars.htm regards, -- Sebastien Tixier Susuki 650 SVS - No Driving Licence yet (MagicFr) GPLRank handicap -17.05 Game Developper personal : http://magicfr.multimania.com company : http://www.eden-studios.fr

Stephen Ferguson wrote: > Wasn't Microprose's GP500 supposed to use a toned-down physics model for the > computer riders? Yep, GP500 AI are quite good, i'm working with one of the developer of GP500 ( an australian ) and he tell me that GP500 AI used genetic alogrithm for computing racing line, moreover AI drives modified motocycle ( gravity center lowered ), but with the same physics as player. They take advatage of slipstream . However, they needed sometime to edit the trajectory line and put some tag in the tracks where it was forbiden for the AI to overtake. They need nearly 2 years to make their AI ! But developping an AI whuch drive motocycle is more difficult to make AI wich drive a car ! Very impressive ! -- Sebastien Tixier Susuki 650 SVS - No Driving Licence yet (MagicFr) GPLRank handicap -17.05 Game Developper personal : http://magicfr.multimania.com company : http://www.eden-studios.fr

Andy Marson wrote:

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> > > The main problem I have with the GPL AI is when they hit me in braking > > zones. :) > > > > > > I have never had the AI hit me in braking zones, I've played GPL ever since > it came out. > This seems to be common problem for quite a few people. Is it just that > you're braking too early or something? seems a bit strange to me....

If you're running at the back, there's no one to hit you in the ass, try speeding up and run up front for a change :-))) Beers and cheers (uncle) Goy "Team Mirage" http://www.teammirage.com/ "The Pits" http://www.theuspits.com/ * Spam is for losers who can't get business any other way * "Spamkiller" http://www.spamkiller.com

I see now. Yes, I agree totally. For me the AI in GP2 and GPL is good enough, you have to really know what you're looking for to be able to spot when the game "cheats" to get the AI cars out of a tricky spot. Watch the AI cars through the chicane at Monaco in GPL and you can just about spot it, but like I say, this implementation is good enough for me.

Maybe you're just the luckiest guy on the planet. :) Hold on, you can pick me some lottery numbers....i'll just get a pen...

Bruce Kennewell wrote: > > Not quite true, Uncle. > I have been running at the rear end on several occasions and had the leader > trying to lap me run up my arse! :-) Ah, of course :-) Beers and cheers (uncle) Goy "Team Mirage" http://www.teammirage.com/ "The Pits" http://www.theuspits.com/ * Spam is for losers who can't get business any other way * "Spamkiller" http://www.spamkiller.com

Not quite true, Uncle. I have been running at the rear end on several occasions and had the leader trying to lap me run up my arse! :-) -- Regards, Bruce Kennewell, Canberra, Australia. --------------------------- Goy Larsen <[email hidden]> wrote in message news:[email hidden]... > > > Andy Marson wrote: > > > > > The main problem I have with the GPL AI is when they hit me in braking > > > zones. :) > > > > > > > > > > I have never had the AI hit me in braking zones, I've played GPL ever since > > it came out. > > This seems to be common problem for quite a few people. Is it just that > > you're braking too early or something? seems a bit strange to me.... > > If you're running at the back, there's no one to hit you in the ass, try > speeding up and run up front for a change :-))) > > > Beers and cheers > (uncle) Goy > > "Team Mirage" http://www.teammirage.com/ > "The Pits" http://www.theuspits.com/ > > * Spam is for losers who can't get business any other way * > "Spamkiller" http://www.spamkiller.com

On Tue, 04 Jul 2000 14:04:20 +0200, S�bastien Tixier <[email hidden]> wrote:

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> > >Andy Marson wrote: > >> > The main problem I have with the GPL AI is when they hit me in braking >> > zones. :) >> > >> > >> >> I have never had the AI hit me in braking zones, I've played GPL ever since >> it came out. >> This seems to be common problem for quite a few people. Is it just that >> you're braking too early or something? seems a bit strange to me.... > >Braking too early ! I don't think so :o)

Well, I think we're talking mostly of people who qualify near "Surtees the Sado" on the grid. He has a definite preference of bumping his screaming Honda shitbox (sorry, just quoting Briatore on his view of the current Benetton ;-) into your gearbox because it frustrates him no end being such a slowcoach off the grid ;-) Uwe -- Uwe Schuerkamp http://www.schuerkamp.de/ uwe.schuerkamp at telemedia.de for direct mail (from: is spambox) PGP Fingerprint: 2E 13 20 22 9A 3F 63 7F 67 6F E9 B1 A8 36 A4 61