Car Physics: Arcade mode in car sim games

Hello everyone, I've noticed that many car sim games have an arcade mode. This mode usually has simpler handling than sim mode, so that it's more difficult to lose control and go into a spin, and it's easier to regain control once it's been lost. I thought it might be nice to include this in a sim using a difficulty slider e.g. going from 1 - 10, with 1 being complete novice and 10 being hardened sim player (rather than the usual beginner/advanced/expert options). The problem is, I'm not sure how an arcade mode would be derived from a simulation. It seems to me that the most obvious way of doing this would be to artificially limit something in the simulation. My initial thoughts on this are to limit either the angular velocity in the yaw axis or to limit the ratio of lateral forces applied to the front and rear tyres. But with either of these approaches I can see unnatural side effects ocurring (most arcade modes derived from sims do retain a degree of naturalness). Has anybody else had any thoughts about this? Cheers, Mike.

Hi Mike, I indeed have thought about this, and my conclusions were surprisingly similar. If I were to do it, the first thing I would take care of would be yaw dampening. I would introduce an additional torque on the car that would be proportional and inverse to the angular velocity vector (sort of as if rotating the object in a viscous fluid). This should help with the requirement that arcade players tend to not use smooth inputs, as they usually play with a digital (style) control. If that is not enough, then at least the front tyres need to have their lateral grip vs. slip curve altered; arcade players like their car to go left when they select left, the control reversals or inefficiency when past limit isn't quite something that is expected, control should be had at all times. This means that the grip curve should not reverse after a certain point, but that it should at least saturate or even have a constant small positive slope, so that control is maintained at all slip angles. You probably want spins to happen, but you also want to make them catchable; I believe this could be the key. The proportionality constant for yaw dampening and the interpolation from a proper slip curve to a more controlable one can be done continuously (the slider idea), and without introducing any hard constraints, which would probably make the arcade mode still feel quite natural. Anyway, I'd love to hear more thoughts on the topic, especially from people who actually have experience implementing such things. -Gregor Mike Stanley wrote:

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> > Hello everyone, > > I've noticed that many car sim games have an arcade mode. This mode usually > has simpler handling than sim mode, so that it's more difficult to lose > control and go into a spin, and it's easier to regain control once it's been > lost. I thought it might be nice to include this in a sim using a difficulty > slider e.g. going from 1 - 10, with 1 being complete novice and 10 being > hardened sim player (rather than the usual beginner/advanced/expert > options). > > The problem is, I'm not sure how an arcade mode would be derived from a > simulation. It seems to me that the most obvious way of doing this would be > to artificially limit something in the simulation. My initial thoughts on > this are to limit either the angular velocity in the yaw axis or to limit > the ratio of lateral forces applied to the front and rear tyres. But with > either of these approaches I can see unnatural side effects ocurring (most > arcade modes derived from sims do retain a degree of naturalness). > > Has anybody else had any thoughts about this? > > Cheers, > > Mike.

Hi Gregor, "Gregor Veble" <[email hidden]> wrote in message news:[email hidden]...

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> Hi Mike, > > I indeed have thought about this, and my conclusions were surprisingly > similar. If I were to do it, the first thing I would take care of would > be yaw dampening. I would introduce an additional torque on the car that > would be proportional and inverse to the angular velocity vector (sort > of as if rotating the object in a viscous fluid).

... which would help to avoid spinouts. Sounds good, think I'll give this one a try. >This should help with > the requirement that arcade players tend to not use smooth inputs, as > they usually play with a digital (style) control. Digital controllers are something I have given thought to (since I mostly use one anyway). I thought a good way to deal with these would be to have a dynamic maximum turn angle depending upon the slip angle. You don't want the slip angle to exceed the maximum on the traction curve too much since this will cause reduced grip. I thought I might calculate a turn angle that would give a slip angle which is close to this maximum value, ie. try to keep the front wheel's direction close to its velocity direction. This would mean that if your backend was sliding out, you could steer the front wheels so that they were in line with their motion, resulting in more torque coming from the rear wheels than the front and hopefully stabilising the car into a powerslide. Haven't implemented this yet but it's on my todo list.

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> > If that is not enough, then at least the front tyres need to have their > lateral grip vs. slip curve altered; arcade players like their car to go > left when they select left, the control reversals or inefficiency when > past limit isn't quite something that is expected, control should be had > at all times. This means that the grip curve should not reverse after a > certain point, but that it should at least saturate or even have a > constant small positive slope, so that control is maintained at all slip > angles. You probably want spins to happen, but you also want to make > them catchable; I believe this could be the key.

I've tried altering the traction curve so that it becomes level after it's maximum. This definitely makes the car more responsive to inputs (perhaps a little too responsive, but that could easily be tweaked). I intend to spend more time looking into this.

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> The proportionality constant for yaw dampening and the interpolation > from a proper slip curve to a more controlable one can be done > continuously (the slider idea), and without introducing any hard > constraints, which would probably make the arcade mode still feel quite > natural. > > Anyway, I'd love to hear more thoughts on the topic, especially from > people who actually have experience implementing such things.

me too :) > > -Gregor >

a good arcade mode is one where the car easily loses grip and heads off into broadside land, but is easy to hold or correct at will. in this way the player thinks that he/she is god because they can hold 80yd powerslides. i think obtaining this functionality from a real sim is quite difficult, so i am trying to develop an arcade handling routine to go alongside the realistic one in my game. if anybody knows a site with some arcade handling code on then the url would be much appreciated, coz it's turning out harder to do the arcade handling than the realistic :-)

Kirk House <[email hidden]> wrote in message news:3b7d7d31$0$73969$[email hidden]... > I'm a big proponent of easy driving through setup tweaks. When myfriends > try out GPL I usually use my newbie setup which is 59% front brakebias, > 85/30/5 diff settings and not much rear roll bar for understeer.For > instance road cars have lots of understeer built in so that whenpeople > swerve to miss a deer or pedestrian, etc. they can keep the car from > spinning. This way they can still get a feel for the dynamics ofbraking > and balance without having to relearn everything after graduatingfrom an > "arcade" physics engine. Valid for learning, but unfortunately (IMO) consistent understeer is about the most boring trait a car can have. Not quite the aim for an 'arcadey' driving game. Jonny

I'm a big proponent of easy driving through setup tweaks. When my friends try out GPL I usually use my newbie setup which is 59% front brake bias, 85/30/5 diff settings and not much rear roll bar for understeer. For instance road cars have lots of understeer built in so that when people swerve to miss a deer or pedestrian, etc. they can keep the car from spinning. This way they can still get a feel for the dynamics of braking and balance without having to relearn everything after graduating from an "arcade" physics engine. "Mike Stanley" <[email hidden]> wrote in message news:xF6f7.5045$[email hidden]... > Hello everyone, > > I've noticed that many car sim games have an arcade mode. This modeusually > has simpler handling than sim mode, so that it's more difficult to lose > control and go into a spin, and it's easier to regain control once it'sbeen > lost. I thought it might be nice to include this in a sim using adifficulty

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> slider e.g. going from 1 - 10, with 1 being complete novice and 10 being > hardened sim player (rather than the usual beginner/advanced/expert > options). > > Cheers, > > Mike. > >

I'm totally confused. If you can't spin the car you necessarily have consistent understeer. I think that's why most of us consider arcadey physics engines totally boring. You propose having a car with lots of oversteer but that is difficult to spin? "Jonny Hodgson" <[email hidden]> wrote

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> Valid for learning, but unfortunately (IMO) consistent understeer is > about the most boring trait a car can have. Not quite the aim for an > 'arcadey' driving game. > > Jonny > >

Personally I like the way Papy did it in N4, which is to have not only an arcade mode, but also separately selectable but realistic driving aids such as ABS, traction control, and stability control (yes stability control is a real thing). The arcade mode then keeps all the normal physics, but adds a setup designed for control and stability, and could artificially boost the performance characteristics of the car (grip, downforce, power). The reason I suggest that is that I think arcade players are looking for a thrill rather than realism, but if you don't still have a realistic physics model underlying the whole thing it won't respond like they expect it to. "Mike Stanley" <[email hidden]> wrote in message news:xF6f7.5045$[email hidden]... > Hello everyone, > > I've noticed that many car sim games have an arcade mode. This modeusually > has simpler handling than sim mode, so that it's more difficult tolose > control and go into a spin, and it's easier to regain control onceit's been > lost. I thought it might be nice to include this in a sim using adifficulty > slider e.g. going from 1 - 10, with 1 being complete novice and 10being > hardened sim player (rather than the usual beginner/advanced/expert > options). > > The problem is, I'm not sure how an arcade mode would be derived froma > simulation. It seems to me that the most obvious way of doing thiswould be > to artificially limit something in the simulation. My initial thoughtson > this are to limit either the angular velocity in the yaw axis or tolimit > the ratio of lateral forces applied to the front and rear tyres. Butwith > either of these approaches I can see unnatural side effects ocurring(most

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> arcade modes derived from sims do retain a degree of naturalness). > > Has anybody else had any thoughts about this? > > Cheers, > > Mike. > >

Kirk House <[email hidden]> wrote in message news:3b7d8953$0$283$[email hidden]... > I'm totally confused. If you can't spin the car you necessarilyhave > consistent understeer. I think that's why most of us considerarcadey > physics engines totally boring. You propose having a car with lotsof > oversteer but that is difficult to spin? > > "Jonny Hodgson" <[email hidden]> wrote > > Valid for learning, but unfortunately (IMO) consistent understeeris > > about the most boring trait a car can have. Not quite the aim foran > > 'arcadey' driving game. My understanding of arcade "physics" is that you want to be able to hold the car sideways without spinning it - that way it's fun, and you feel like you're an expert driver. Just having a car that won't turn is boring - that's more like the ancient "fly spaceship through caverns" game than "driving". Yes, I think I do propose exactly that: lots of *linear region* oversteer to make the car feel like it drifts and powerslides, but with the *limit* handling capped so that it'll only spin if you're extremely silly with it. Any clearer? ;-) Jonny

OK, I get what you're saying now. Maybe the front roll bar could suddenly stiffen up when the driver gets sideways. Probably would have made learning GPL much easier. Good idea :) "Jonny Hodgson" <[email hidden]> wrote >

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> Yes, I think I do propose exactly that: lots of *linear region* > oversteer to make the car feel like it drifts and powerslides, but > with the *limit* handling capped so that it'll only spin if you're > extremely silly with it. > > Any clearer? ;-) > Jonny > >

Hi Nick, I disagree that obtaining a good arcade mode from a real sim is difficult. It just depends how arcadey you want it to be. This may be true for a game like Mario Kart, where you'd probably just end up discarding most of the real physics to get the handling you want. But for a game with a bit more realism I think it's possible. A good example of this is Driver. It seems to me that behind it there is a realistic handling model (for the tyre forces at least), but they obtain quite a good arcade feel by using the auto-handbrake feature. I'm not completely sure of the mechanics of this, but basically the handbrake is automatically engaged on hard turns, causing mucho powerslides. The car rarely looses control due to the slowdown incurred by this, and the result is handling which is a lot of fun and easy to get in to, while also feeling pretty realistic. Try disabling the autohandbrake feature and you'll get the spins at low speed/understeer at high speed behaviour you associate with a sim. Like I said though, it really depends on what level of realism you want. But for anything other than a Mario Kart clone, I reckon that beginning with a realistic mode then limiting it for an arcade mode is the way to go. Mike. "Nick G" <[email hidden]> wrote in message news:[email hidden]... > a good arcade mode is one where the car easily loses grip and heads offinto > broadside land, but is easy to hold or correct at will. in this way the > player thinks that he/she is god because they can hold 80yd powerslides. i > think obtaining this functionality from a real sim is quite difficult, soi > am trying to develop an arcade handling routine to go alongside the > realistic one in my game. if anybody knows a site with some arcadehandling > code on then the url would be much appreciated, coz it's turning outharder > to do the arcade handling than the realistic :-) > >

That's really an advanced sim feature though. You're probably quite an advanced player, so you know what to tweak and how it will affect the handling. My point is that most arcade players will not want to (or even know how to) set up the car in this way. They want to simply pick up a game, get straight into it and have fun. Messing around with front end options and setups is not really something they want to do. "Kirk House" <[email hidden]> wrote in message news:3b7d7d31$0$73969$[email hidden]...

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> I'm a big proponent of easy driving through setup tweaks. When my friends > try out GPL I usually use my newbie setup which is 59% front brake bias, > 85/30/5 diff settings and not much rear roll bar for understeer. For > instance road cars have lots of understeer built in so that when people > swerve to miss a deer or pedestrian, etc. they can keep the car from > spinning. This way they can still get a feel for the dynamics of braking > and balance without having to relearn everything after graduating from an > "arcade" physics engine. >

Kirk House <[email hidden]> wrote in message news:3b80a712$0$347$[email hidden]... > OK, I get what you're saying now. Maybe the front roll bar couldsuddenly > stiffen up when the driver gets sideways. Probably would have madelearning > GPL much easier. Good idea :) I think whoever mentioned tyre curves without a peak had the right idea - possibly with different initial gradients, too, to get oversteer followed by understeer...

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> "Jonny Hodgson" <[email hidden]> wrote > > > Yes, I think I do propose exactly that: lots of *linear region* > > oversteer to make the car feel like it drifts and powerslides, but > > with the *limit* handling capped so that it'll only spin if you're > > extremely silly with it. > > > > Any clearer? ;-) > > Jonny

I agree but if the default setups are easy then there is no need for modification unless the user really feels like tweaking. "Mike Stanley" <[email hidden]> wrote > That's really an advanced sim feature though. You're probably quite an > advanced player, so you know what to tweak and how it will affect the > handling. > > My point is that most arcade players will not want to (or even know howto) > set up the car in this way. They want to simply pick up a game, getstraight > into it and have fun. Messing around with front end options and setups is > not really something they want to do.

"Mike Stanley" <[email hidden]> wrote in message news:B27g7.10992$[email hidden]... > A good example of this is Driver. It seems to me that behind it thereis a > realistic handling model (for the tyre forces at least), but theyobtain > quite a good arcade feel by using the auto-handbrake feature. I'm not > completely sure of the mechanics of this, but basically the handbrakeis > automatically engaged on hard turns, causing mucho powerslides. Thecar > rarely looses control due to the slowdown incurred by this, and theresult > is handling which is a lot of fun and easy to get in to, while alsofeeling > pretty realistic. Try disabling the autohandbrake feature and you'llget the > spins at low speed/understeer at high speed behaviour you associatewith a > sim. Driver has a nifty driving model, but its collision model needs MAJOR work. Traction is handled quite nicely, and cars in general do behave as they should... Until you hit something. Of course, being limited to automatic transmissions and top speed of 87 mph (except certain cars) is not exactly realistic either. :-D --KC