GT5 simulation (driving physics)

[Slash]

GT4 was IMO much worse as far as every car understeering horribly. Every corner entry was a wrestling match with the front wheels in that game. Much better turn in with every car I've driven in GT5.

Amen to that. That p*ssed me off more than anything.

 

[Tenacious D]

GT5 physics are far from being "close enough", and there's no need to "torture test" them to see that: just a wheel and some real life driving experience and technical knowledge. There's still a long way to go in many areas and personally I find that justifying those (often blatant) flaws and inaccuracies with PD trying to not make the game too difficult for the general audience is both demoralizing and defeatist for something that is intended to be a general purpose (ie not focusing on certain car types or racing speeds) car simulator.

Well, I didn't say GT5 was perfect. But how perfect is GTR or LFS when cars handle almost exactly the same when I drive similar cars in them? Or any sim? I know you can point out specific very narrowly defined issues - and I know your fave is the rollover, but rollovers seldom happen in racing, so harping on it is going to get a big yawn from me. Move on to things like lift oversteer and hard throttle tailouts or brake fade or proper draft physics or something. But overall, when I'm racing, GT5 feels very close to my PC sims - which I have yet to experience a rollover in either.

Except GT5 is more immersive, more engaging, more enjoyable and just darn more fun.

Honestly, if Gran Turismo has a long way to go, so do all the other games.

 

[shirakawaa]

Well, I didn't say GT5 was perfect. But how perfect is GTR or LFS when cars handle almost exactly the same when I drive similar cars in them? Or any sim? I know you can point out specific very narrowly defined issues - and I know your fave is the rollover, but rollovers seldom happen in racing

When I write about rollovers obviously I don't only mean how unrealistically cars bounce and roll over on the road when they do in GT5, but mainly how that situation is attained, which involves factors that are important for general driving realism and accuracy, such as:

- Tire grip when sliding at certain angles and speeds, and the way it changes when tires are loaded, their carcass gets deformed and their sidewall gets used;
- the way suspension behave under such loads (when the car is sliding sideways at a high angle and suspensions/chassis are not set up for that - drifting - suspension hop due to quick and repeated gain/loss of tire grip can happen. In GT all happens always very smoothly);
- how easy it is to lift off one or more wheels when cornering, due to suspension constraints, therefore losing grip on them and overloading those that aren't lifted. In GT5 unless obstacles are hit, most of the time wheels are all planted to the ground (even on those supposedly tail-happy hot hatches or minivans/small MPVs)
- [...]

So, ultimately, that rollovers aren't as possible as in real life - and I mean mainly street cars - means that other aspects of driving are affected negatively, and this in GT5 mainly translates in getting away in many cars with maneuvers that wouldn't be possible for them, or excessive grip/stability especially when fitting more grippy tires.

, so harping on it is going to get a big yawn from me. Move on to things like lift oversteer and hard throttle tailouts or brake fade or proper draft physics or something.

It looks like you misunderstood what I really meant with "unrealistic rollovers". It's not that I've discussed only about them anyway, but you essentially forced me to in this post. But of course, there's much else to talk about too.

But overall, when I'm racing, GT5 feels very close to my PC sims - which I have yet to experience a rollover in either.

I rarely play PC sims. I mostly refer to my real life driving experience and I feel a lack of accuracy and dynamics detail in many areas. Anyway, as far as I can see pc sims mostly (if not almost completely) focus on racecars which very rarely roll over unless when crashing and this means developers can take shortcuts on certain aspects of driving dynamics. GT5 on the other hand, focuses mainly on normal, non-sporty even, street legal cars, on race tracks and (closed) public roads, which means a much more diverse range of vehicle dynamics that have to be correctly simulated.

Except GT5 is more immersive, more engaging, more enjoyable and just darn more fun.

Honestly, if Gran Turismo has a long way to go, so do all the other games.

I don't deny that GT5 is more "fun" than PC sims, but that doesn't mean it's ok for it to have "least efforts"-level physics as a simulator and call them "good enough". That's even mortifying for its official 500$ wheel too, supposedly the best on the market regarding force feedback.

 

[Exorcet]

GT5 on the other hand, focuses mainly on normal, non-sporty even, street legal cars, on race tracks and (closed) public roads, which means a much more diverse range of vehicle dynamics that have to be correctly simulated.

The physics are all the same. Road Car - Race Car, Race Car - City Bus, Road Car - Airliner.

Now of course, simulators can't use real physics. They use models instead, so the specific equations used to generate motion may differ, but ultimately it should all boil down to forces and masses. I don't think that the difference between street and race cars is enough to warrant different details in the physics though. GT5 does have a wider selection of cars to model, but it's performing the same calculations that a specialized PC sim would. I'd think that the loss of fidelity in GT's physics would come from the amount of data that needs to be collected to model 1000 cars as opposed to 100 or so.

 

[shirakawaa]

The physics are all the same. Road Car - Race Car, Race Car - City Bus, Road Car - Airliner.

Now of course, simulators can't use real physics. They use models instead, so the specific equations used to generate motion may differ, but ultimately it should all boil down to forces and masses. I don't think that the difference between street and race cars is enough to warrant different details in the physics though.

I understand what you mean, what I wanted to say however was that depending on the application a simulator might use different approaches on certain problems than others, not simulating at all certain details or simulate them in a loose way. For example what happens on grip when camber on a wheel becomes positive (relatively to the road) might not be important for a simulator focusing mainly on road circuits and open wheel race cars where roll angles are usually very small and high negative cambers are used most of the time on all four wheels.

GT5 does have a wider selection of cars to model, but it's performing the same calculations that a specialized PC sim would. I'd think that the loss of fidelity in GT's physics would come from the amount of data that needs to be collected to model 1000 cars as opposed to 100 or so.

That might be one of the reasons, but most of the complex car data that is hard to come by and/or measure and GT5 probably lacks is for suspensions (think of suspension type, linkages, dynamics especially on multilink systems, etc. This is the area where PC sims with a very limited amount of cars shine the most). However many flaws in physics in car dynamics in GT that I can track are not car-specific, but more general (for example, tire model, ABS, brake fade simulation, limited slip differentials, base differences between different suspension types, etc).

Anyway, at least for Premium cars, since their creation process is painfully long, I would have expected more accuracy, but it except some details that appear to be slightly better represented (center of gravity for example) it doesn't seem they are much more detailed in behavior (suspensions especially) than legacy, virtually untouched (they retain the same specifications errors they had in GT4, in some cases) Standard cars.

 

[tka_tha]

If the current physics in GT5 is constrained by the limits of PS3's processing power, would it be possible to release a special "Light" version of GT5. A special version in which most of the PS3 resources are directed towards better physics.

 

[xSNAKEx]

Exactly.




I honestly find arcade games more difficult because they just don't make [physics] sense. I have to completely relearn how to drive when realism goes out the window.

I'm like this too, expect these days I dont even bother learning it, I just dont play the game. I am horrible at racing games that don't make sense physics wise. Even old games like Need for speed 1 make 20x more sense than most car games these days.
Download the Demo of Wheelman Its hilarious.

I play them and just feel

at the stupidity of it. Especially these days when you have ultra realistic graphics so your mind can conceive this happening for real, but the physics is like looking into a microscope expecting to see magnification of whatever is under it instead you see dancing hamsters (thanks Rodney McKay).

The worst part is, even in GT5, Cockpit view is totally useless for me since the wheel animation does not correspond to how you turn you wheel. It is half what is should be. This puts me of so much PD practically wasted their efforts on cockpit view a far as I am concerned.

 

[xSNAKEx]

Playing Wheelman is like this trust me lol, these aren't cheats or hacks.

 

[Tenacious D]

I don't deny that GT5 is more "fun" than PC sims, but that doesn't mean it's ok for it to have "least efforts"-level physics as a simulator and call them "good enough". That's even mortifying for its official 500$ wheel too, supposedly the best on the market regarding force feedback.

Okay, but you're ignoring my experience - and a number of other gamer's - when comparing GT5 to other PC sims. Or even PC sims against each other. rFactor gets a lot of praise, but to me, it's like there's a little Mod Wheels racer on a center-of-gravity pindle, while the world spins around beneath me, rather than a car muscling around on a track I'm driving. The impression of this after playing other games like LFS or GTR, even GT4, is particularly strong. And yet it's heralded as a good realistic racer. Something critically failed somewhere.

Comparing LFS and GTR games, they both get some things pretty badly wrong. In fact, so does the apparent pinnacle of racing, iRacing, which you have to pay exorbitant amounts to play. By your standards, there is no good racer because they all focus on a few details they find crucial and gloss over the rest with "least effort." In the case of LFS, they broke the tire model somewhere along the line, and I haven't checked since to see if they fixed it because it just another PC sim to me, rather flat and lifeless.

Evidently, you find a flaw, and no matter how off it is, you give it a fail. But when those who do race give GT5 very high marks as far as car behavior, I think this is where the real crux is. If the game can manage to perform very closely to what you'd expect in real life, which is still about all you can expect from a racer, then it mostly boils down to personal impressions as to how realistic it is. If you think GT5's realism is particularly shoddy, this view isn't universally shared. It's a different matter from wanting to see things being improved, but as I'm unaware that there's a perfect racing game on the market, singling out Gran Turismo on that point seems rather biased.

 

[Bye Ya]

I have a question about GT5 physics.

How is it that you can lose control and veer off the road into a straight line barrier, still heading 85-90% in a forward direction, then hit the wall and the back end of your car comes from the WRONG direction putting you into a 360º+ spin???

In other words, you hit the wall at a right angle of say 15º, with a ton of FORWARD momentum, and the back end of your car comes counterclockwise sending you into a spin after hitting the wall at such a small angle?

I understand in terms of making a game challenging with a "Don't run off the road or else..." aspect. But in terms of reality, it has nothing to do with physics. This is again fine in and of itself, but this is supposed to be a "real" driving simulator, no?

 

[Bottoz]

Walls are bad, yes. But, I think it's to keep people from 'riding the rail' around a track.

Personally, I dislike tracks with walls... mostly city courses. Not a fan of London, SSx, Madrid, Rome or any of the tracks without run off. Most folks just bounce off and keep driving... while in a non-city course if you go off, you have to work to get back on.

 

[Tenacious D]

I've had problems with walls in a few of my racing games. Forza1 (and 2 I believe) has magnetic walls that grab you every time you brush up against them. All of them have issues if you touch them in a way the game finds inappropriate. The cars can do some frantic dances. Don't you love innuendos?

 

[Kryz11]

I don't know may be the audience console it's for kid... But it's crap. A lot of old gt fan gonna play forza for sure (i'm not a fanboy)... I buy a ps3 for GT but on the next gen i think i'm gonna buy a xbox. I hope the dlc will be huge but i'm dreaming about it...

I feel the same, I am going back to Forza 4 as my primary racers once that games comes out, GT5 will be back to number 2 spot.

 

[Exorcet]

I have a question about GT5 physics.

How is it that you can lose control and veer off the road into a straight line barrier, still heading 85-90% in a forward direction, then hit the wall and the back end of your car comes from the WRONG direction putting you into a 360º+ spin???

In other words, you hit the wall at a right angle of say 15º, with a ton of FORWARD momentum, and the back end of your car comes counterclockwise sending you into a spin after hitting the wall at such a small angle?

I understand in terms of making a game challenging with a "Don't run off the road or else..." aspect. But in terms of reality, it has nothing to do with physics. This is again fine in and of itself, but this is supposed to be a "real" driving simulator, no?

Wall impacts are probably unrealistic because everything in GT5 is an ultra rigid body. Walls don't deform when hit. Cars don't deform when hit. Deformation accounts for a lot of energy in a crash. Physics says that energy and momentum are conserved, so GT5 must conserve them too. The result is that the car has too much energy after crashing, and acts strange.

There is some damping going on, otherwise hitting a wall at 200 mph would result in your car bouncing off and going backwards at 200 mph, but this only seems to apply to head on crashes.

 

[Bye Ya]

I'm talking more about hitting a parallel wall at a 10-20º angle, not hitting one head on. But I know what you mean, although I don't think that any game is necessarily required to conserve energy as in real life. They can do what they want with in-game physics.

 

[shirakawaa]

Regarding collisions, here's another flaw which affects significantly the way one can drive certain cars. I mentioned briefly this on page one, but I'll expand it more here:

While collision detection with insurmountable obstacles (like walls, etc) and the car chassis appears to be correct, it doesn't seem to work correctly when the car collides with the road (steep slopes, small hills, curbs, sidewalks). Very low cars (like the X2010) or cars with long overhangs (like the Ferrari F40 in the picture above) in GT5 can go effortlessly over track/road elements that in real life would cause them to get stuck, suffer from extensive damage and/or cause immediate loss of control.

While the picture above shows a blatant and extreme example, this is the reason why in GT5 cars (race cars especially) can, for example, go over curbs essentially without any consequence at almost any speed.

 

[FuSiioN_HaVoC]

I don't think the physics are real I've played other games and driven other cars and the game I completely different.

 

[MrFish]

I'm amazed. To think that a PS3 and GT is in anyway comparable to the simulators used by F1 teams, and that the hardware and game can come anywhere near to reproducing realistic simulations of real cars... Really?

As fun and exciting as it is, it is only a game; not a real driving simulator - that's a marketing gimmick.

 

[sinbad]

I get plenty of lift off oversteer. I don't drive FFs unless I'm forced to so I can't speak for them, but in everything else it does it almost every time. Whether it's 100% accurate to real life, I don't know, but it certainly does it.

And GT4 was IMO much worse as far as every car understeering horribly. Every corner entry was a wrestling match with the front wheels in that game. Much better turn in with every car I've driven in GT5.

It tightens the line, but actual oversteer? You sure?

I hardly get any in even the most prone to it cars irl, which when you compare that reaction to how easily a 120bhp car can oversteer on the power (tyre grip is not the issue) in gt5 always leaves me feeling like it's a bit dumbed down. Some fwd cars should be on a knife edge, many rwd cars should require you to stay on the power to stop oversteer, all gt5 seems to be about is power oversteer. Probably for the drifters, it would explain the stupid amounts of tyre smoke too. Fwd cars are very dull as a result, though. You can pitch them in hard off the power and the most you get is a gentle 4 wheel drift before the understeer comes back.

Only if you put a grade or two lesser tyres on the back do you get a bit of fun.