FM4 Physics - Houston, We Have a Problem

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Shouden
Not everyone can afford luxuries like Xboxes.
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Sure, but their opinons tend to carry more weight when they've actually played the game their criticising for a bit. Can you imagine someone going to GT Planet and trying to convince the fans that their game sucks even though they can't afford a PS3? :lol:

(treed by F. Wawa)
 
Shouden
As far as can tell from watching some videos, it seems that FM4 is simply FM3 with some minor tweaks to the physics. Cars are still incredibly easy to roll. (There's a particular turn at Sebring that flips cars for no real reason. I experienced it in FM3, and it's kind of silly to see it return in FM4. But seriously...I remember Rage Quitting over that corner a LOT.) The biggest changes appear to have been to the graphics. So...kinda like how FM2 felt like a shiny FM1...FM3 appears to be a shiny FM4.
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You're wrong.

-Physics are massively improved.
-Rivals mode adds a complete new dimension to single player / hotlapping.
-New tracks (Infineon & Bernese Alps are superb, Hokenheim & Indy are meh IMO)

Edit: oh and having slower traffic on track days is really good.
 
Also, the reason so many people flip in the Forza games is because they have their suspensions set a lot harder than they would be in real life, combined with the only consequence of wrecking a virtual car being to simply have to pause the game and restart the race. Most real-life racing series either have slightly softer suspensions to deal with raised curbs,or simply don't hit the curbs at all.

Correct me if I am wrong, of course, I could very well be.
 
I have yet to roll over on Sebring in FM4. I know in FM3 there was a Sedona turn, Road Atlanta turn and some other one, forget which course, which I would roll on the norm. I drive with very stiff suspension on a very light car. In FM4 I have only rolled over like twice so far. Maybe I'm getting better, maybe I'm not driving a car as stiff or as light... i dunno
 
Ironically Shouden's observation is similar to my own, that probably not a lot has changed from FM3 except for the tire model. With all the reworking they did to incorporate Pirelli's data, it would not be surprising if they didn't really alter the core physics model. As it's often said, change one thing at a time...

However the tire model is literally where the rubber meets the road; it makes or breaks a simulator. In FM4's case it completely transformed a lukewarm semi-sim console game into a contender for one of the best racing sims on any platform. It's not at the top, but it's in the neighborhood.

The physics are way, way better. But they might not technically be "different."

(Nonetheless, you gotta play the game to know.)

The Ratling
Also, the reason so many people flip in the Forza games is because they have their suspensions set a lot harder than they would be in real life...

Correct me if I am wrong, of course, I could very well be.
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I can't really speak for racing teams, but some players online do need to stop chasing ultimate grip and reconsider the importance of making it to the finish line. :)

Wolfe
Come to think of it, FM4 has the Cobra, doesn't it? I'm gonna try it now.
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Yeah...this didn't go well. Turning in and lifting the throttle at 60mph in 1st gear leads to a bit of oversteer that segues into a mild 4-wheel drift and finally understeer, ending in a lazy arc.

Anyone remember San Francisco Rush? "IT'S DANGEROUS!!" :lol:

For those who haven't yet tried the Cobra, I suggest giving it a spin. See if you can tell what Bill Cosby was going on about...or if you just feel like Keiichi Tsuchiya. ;)
 
suspension modelling isn't rocket science, as long as you have the basic type of suspension covered there's not much you can add except feeding it better data. (suspension hardpoints, clearance travel and all.)
 
Wolfe
For those who haven't yet tried the Cobra, I suggest giving it a spin. See if you can tell what Bill Cosby was going on about...or if you just feel like Keiichi Tsuchiya. ;)
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I'm not expecting the car to stop rumbling and say "WHAT!?!" to me when I put it into first.

:p
 
JJ72
suspension modelling isn't rocket science, as long as you have the basic type of suspension covered there's not much you can add except feeding it better data. (suspension hardpoints, clearance travel and all.)
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Which is why it's so puzzling that Forza's suspension model is so unnatural and exhibits such strange behavior. It's really just one equation to define a spring, so if your basic mechanical physics are correct your suspension should be correct too. But the way Forza suspension reacts to bumps and especially lands jumps is unrealistic and unnatural. For an example of really good suspension, see Shift 2. You could really feel the negative effects of overly stiff suspension because your car was losing grip all the time, and landing and going over bumps actually really unsettled your car. In Forza it always feels like something fake is going on making the suspension more effective at soaking up bumps than it should be.

http://www.youtube.com/watch?v=GsOvDvnjSaA

Look at the way the car suddenly jerks to a stop when it hits the ground, like all the energy just... goes away. It's especially visible in the Dodge Ram. These kinds of glitched wheelie setups shouldn't even be possible if the physics are correct.

2:05. Stock Jaguar XFR lands a pretty big jump and there's absolutely no bounce afterwards, the suspension just uncompresses and it's on its merry way. No loss of grip

http://www.youtube.com/watch?feature=endscreen&v=WfSwScCTrJQ&NR=1

Compare to a real Mustang (yeah I know, not the same car, but they're both stock street cars with similar suspension stiffness). Look at how much it bounces over a smaller jump at lower speed. There's also a loud thunk and a tire chirp.

http://www.youtube.com/watch?v=p0DgCPsl_aU

Check this one too. It bounces like 3-4 times after initial impact. No car in Forza will do that stock.

http://www.youtube.com/watch?v=6Zvh0e2zilA&feature=related
 
I can't view YouTube videos on the internet connection here, but I know what you mean and agree, buttsneeze. Properly realistic compression/rebound isn't utterly essential to make a game drive correctly, but it does wonders for immersion and communication. Such subtlety separates sims like Live for Speed from the others -- in LFS I know what's going on with my car at all times.

On the topic of suspension modelling, I took a '54 300SL out for some testing and think the game's swing-axle suspension modelling might be backwards. It's hard to tell because the telemetry only compares a tire's camber to the ground, not the chassis, but this doesn't happen:
Swing.jpg


In FM4, in a corner the inside tire gains quite significant negative camber, and the outside tire positive camber. When you brake hard (to lift the rear end as on top), both tires increase in negative camber for some odd reason, not positive.

Other cars I tested were faithful to their suspension types, at least on a basic level -- the Mustang's rear tires maintain 0-ish camber in cornering (live-axle) and the Datsun 510's rear tires maintain 0-ish camber relative to the chassis (trailing-arm), confirmed via Photomode.

The swing-axle may be a rare example among the game's car list, but it's telling that the telemetry only gives us a simplistic ride-height measurement for the suspension, rather than any sort of geometric depiction or even camber/toe/track (relative to the chassis). I would bet there's not much sophistication here, just compression/rebound/ride-height being run through a hard-coded "camber adjustment" curve for each suspension type.

We all know the game drives OK, but it's ridiculous to imply it couldn't be better.
 
Indeed. Modelling a single spring and damper is fairly simple, modelling several that are interconnected in various mechanical ways gets tricky fast, and I'd be surprised if they're not still fudging the numbers a bit to save on computational power.
 
there are 4 to 5 suspension type in the game AFAIK from developer interviews.

so I don't think the swing axle will be correctly modeled.

Except in sims where you have a few dozen cars or when each car cost $5 each to download, you won't get bespoke suspension modeling for every car, GTR2, Rfactor etc all have the same "generic" suspension modeling.

I can't say for Iracing because nobody really knows how they build it.

Also Turn 10 mentioned they are provided with very few datas to work on, most of the time they have to find out about the spring rates through the car community etc, so expecting a console sim to have dead on suspension modeling, including correct geometry is current a bit far fetched. let alone the modelling of progressive spring rates, magnetic suspension etc.
 
JJ72
there are 4 to 5 suspension type in the game AFAIK from developer interviews.

so I don't think the swing axle will be correctly modeled.

Except in sims where you have a few dozen cars or when each car cost $5 each to download, you won't get bespoke suspension modeling for every car, GTR2, Rfactor etc all have the same "generic" suspension modeling.

I can't say for Iracing because nobody really knows how they build it.

Also Turn 10 mentioned they are provided with very few datas to work on, most of the time they have to find out about the spring rates through the car community etc, so expecting a console sim to have dead on suspension modeling, including correct geometry is current a bit far fetched. let alone the modelling of progressive spring rates, magnetic suspension etc.
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Yeah, but they don't even get the very basic mechanics of suspension right, something every other sim has had no problem with. Even GTA IV's suspension simulation is more inherently correct the way springs and shocks work and how cars react to bumps and jumps.
 
JJ72
Except in sims where you have a few dozen cars or when each car cost $5 each to download, you won't get bespoke suspension modeling for every car, GTR2, Rfactor etc all have the same "generic" suspension modeling.

...expecting a console sim to have dead on suspension modeling, including correct geometry is current a bit far fetched. let alone the modelling of progressive spring rates, magnetic suspension etc.
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I'm not asking for bespoke suspension modelling for each car, but the 300SL isn't the only car in the world with a swing-axle either. For all we know T10 could add the Triumph Spitfire, Chevrolet Corvair, or VW Beetle Type I in future DLC. Or the 356 if they ever get the green light for Porsches. An oversight is an oversight but that doesn't mean it couldn't be better.

Generic suspension modelling is acceptable but that doesn't preclude generic geometry-based modelling of major suspension types. That's what Live for Speed has done, considering most of its cars are fictional. For practicality's sake you could even have a generic multi-link to apply to the numerous modern cars with that setup.

buttsneeze
Yeah, but they don't even get the very basic mechanics of suspension right, something every other sim has had no problem with. Even GTA IV's suspension simulation is more inherently correct the way springs and shocks work and how cars react to bumps and jumps.
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I agree, there's room for improvement on what we have already.

What you're feeling in GTAIV is probably less the suspension modelling, and more the kinetics; literally the physics of the game. When a game gets those right, inputs and reactions feel natural. Personally, I don't get that feeling from FM4 (or GT5). Either the right stuff is hidden behind a curtain of transparent assists and dampers (on the physics, not the controls), or the core physics model is a legacy "sliding brick" type with an array of subsystems and checks and balances to construct something resembling reality.

Contrary to popular belief, your endorsement of GTAIV is no joke -- although the tire model, engine/transmission simulation, etc. aren't terribly accurate, Rockstar has always avoided the "sliding brick" approach for a more natural model. Vehicles are literally suspended above the ground by the wheels, freeing them to flip and roll and jump as they please, necessary things considering the diversity of terrain and objectives.

Compare the rollovers in GTAIV and FM4 and anyone could understand what I mean.
 
Wolfe
I'm not asking for bespoke suspension modelling for each car, but the 300SL isn't the only car in the world with a swing-axle either. For all we know T10 could add the Triumph Spitfire, Chevrolet Corvair, or VW Beetle Type I in future DLC. Or the 356 if they ever get the green light for Porsches. An oversight is an oversight but that doesn't mean it couldn't be better.

Generic suspension modelling is acceptable but that doesn't preclude generic geometry-based modelling of major suspension types. That's what Live for Speed has done, considering most of its cars are fictional. For practicality's sake you could even have a generic multi-link to apply to the numerous modern cars with that setup.


I agree, there's room for improvement on what we have already.

What you're feeling in GTAIV is probably less the suspension modelling, and more the kinetics; literally the physics of the game. When a game gets those right, inputs and reactions feel natural. Personally, I don't get that feeling from FM4 (or GT5). Either the right stuff is hidden behind a curtain of transparent assists and dampers (on the physics, not the controls), or the core physics model is a legacy "sliding brick" type with an array of subsystems and checks and balances to construct something resembling reality.

Contrary to popular belief, your endorsement of GTAIV is no joke -- although the tire model, engine/transmission simulation, etc. aren't terribly accurate, Rockstar has always avoided the "sliding brick" approach for a more natural model. Vehicles are literally suspended above the ground by the wheels, freeing them to flip and roll and jump as they please, necessary things considering the diversity of terrain and objectives.

Compare the rollovers in GTAIV and FM4 and anyone could understand what I mean.
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Yep, there's something amiss with the core physics of Forza that they've put a million bandaids on instead of just redoing. If you build a car in Garry's Mod out of a dumpster and some springs it's got more realistic body motion than Forza just because the core physics are correct. I can't imagine proper physics are that hard to implement. Most of what Forza gets wrong is like, high school physics. Maybe the issue is that it's all based on legacy code from Forza 1 back when it didn't really have aspirations of being a serious sim, and they were just going for the simplest possible representation of a car's physics. I wouldn't attribute Forza's physical failings to computational power, since Enthusia got everything right that Forza got wrong and it ran on the PS2.
 
t.o.
Not surprising. At 16 to 20-something people think they have the wisdom of Solomon while having a teaspoon of actual experience in life. And even some believe the experience isn't needed because of their greatness.
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Well spoken.

I'm probably in the category of people who want a balance between ultra realism and arcade fun. I tried Iracing. My general consensus was - if you breathe too hard the car loses control.
 
the skippy is extremely tossable, it drive like a gutless caterham. :p

The Legends are good too, the rest ain't so forgiving. I especially hate the star mazda.
 
I get lift off-oversteer in plenty of MR cars. The MR2 SC is really sensitive to it as stock. It's really quite a pain at times. That's all I have to say regarding this topic really
 

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