Tire Deformation.

[Griffith500]

how do they simulate tire pressures without it being merely a extension of suspension rates, therefore redundant?

The overall "order" of the system is increased by having a separate spring attached to the end of the actual suspension spring, and the physics calculations altered to suit.

There are dynamic effects that you cannot model with just one spring, since there are different characteristic interactions that occur as the individual spring rates (etc.) change relative to each other. This is because a spring's force is not constant: see Hooke's law for starters, then some kind of equation of state for the air in the tyre, plus the carcass tension (the hard part) is technically another spring, and it has a base rigidty in three dimensions etc. Damping is hideously complex beast, too, and fairly non-linear in real life, which makes modeling difficult.

Here is a rundown (and "simulation") of what's going on with two springs, but I doubt those are the calculations you'd apply in a game, there'd be some equivalent but more useful form for that.


Iceman: If it's unintended, you're assuming it wasn't spotted when editing the footage (or it was, and some other complicated set of events...), which is surely highly unlikely. Occam's razor is sharp, be careful...
If we're looking for the "simplest" explanation, maybe we should start with a definition of simplest.

 

[Zer0]

PD would be announcing stuff like that if it was implemented.

They have done:

At E3 2013, the “GT6 Concept Movie #2 2013 E3” was released, showing the highlights and new evolutions made in Gran Turismo 6.

Tyre Modelling
With the help of our technical partner, the Yokohama Rubber, a new tyre model has been introduced that reflects the tyre compound, tyre structure, and changes in characteristics under extreme load conditions.

http://www.gran-turismo.com/gb/news/00_4937863.html

 

[Ridox2JZGTE]

Seems to me, even in GTA 2013, the tires is still the same as in GT5 - try to drive tuned GTA 370Z on GT5 - default stock tune with max aero - similar grip and characteristics close to the limit.

 

[Imari]

They have done:

At E3 2013, the “GT6 Concept Movie #2 2013 E3” was released, showing the highlights and new evolutions made in Gran Turismo 6.

Tyre Modelling
With the help of our technical partner, the Yokohama Rubber, a new tyre model has been introduced that reflects the tyre compound, tyre structure, and changes in characteristics under extreme load conditions.

http://www.gran-turismo.com/gb/news/00_4937863.html

That's marketing speak.

You could have a tyre model that reflects aspects of the tyre compound (relative amounts of grip, CH/CM/CS/etc), tyre structure (how the tyre responds to camber and toe) and characteristics under extreme load (sensitivity to weight transfer and relative grip resultant) without going anywhere near deformation.

In fact, you could use GT5s tyre model, plug some new numbers in that were somehow derived from Yokohama data and describe it in the exact way that you quoted.

You're going to have to be more specific as to how that quote states that there is a deformation model in GT6.

 

[Cheshyrkat]

Probably just a graphical oddity and the tires are clipping through track surface however, I dont think it is much of a stretch to believe that it could be some form of tire deformation model in at least the Y axis. Some spring/tire model that accounts for the type of tire, shape, compound etc.. for X amount of give and just graphically passes through the track.

 

[amar212]

That's marketing speak.

Well, that is probably the best *example* available, besides the video itself.

Third *example* would be Audi-guys saying what they said about GT6 tyre-modelling.

Personally, I am not sure can we actually expect deformation modeling regarding actual carcass and surface, especially in the visual field. I would be very surprised if PD managed to find more RAM resources to allocate toward that aspect, but we will have to wait and see.

It will be interesting to find out every news about tire-model and see the first testings once game hit the shelves. If they manage to achieve that on PS3, they deserve nothing but eternal praise IMO. But again, really highly doubtful that both simulation-modlling and accompanied visual-modelling will be achievable. I would really love to be wrong though.

 

[grashopper]

Well, that is probably the best *example* available, besides the video itself.

Third *example* would be Audi-guys saying what they said about GT6 tyre-modelling.

Personally, I am not sure can we actually expect deformation modeling regarding actual carcass and surface, especially in the visual field. I would be very surprised if PD managed to find more RAM resources to allocate toward that aspect, but we will have to wait and see.

It will be interesting to find out every news about tire-model and see the first testings once game hit the shelves. If they manage to achieve that on PS3, they deserve nothing but eternal praise IMO. But again, really highly doubtful that both simulation-modlling and accompanied visual-modelling will be achievable. I would really love to be wrong though.

If they gave 3D the boot and didn't design the game around that requirement do you think it would free up a decent chunk of RAM?

 

[Griffith500]

If they gave 3D the boot and didn't design the game around that requirement do you think it would free up a decent chunk of RAM?

Not likely. Turning 3D off would only free resources in 3D mode. But then you're left with a downscaled, lower detail version of the game. That extra memory (and bandwidth) is put into making 2D look the way it does.

 

[grashopper]

Not likely. Turning 3D off would only free resources in 3D mode. But then you're left with a downscaled, lower detail version of the game. That extra memory (and bandwidth) is put into making 2D look the way it does.

Yeah, I was wondering if they could have used a physics model that used less RAM in order to be sure there was enough memory while running 3D to insure both 3D and 2D played the same physics wise.
Didn't realize the just nerfed the whole visual side on 3D.

 

[Imari]

If they manage to achieve that on PS3, they deserve nothing but eternal praise IMO.

Forza has been doing it for some time. NFS:Shift does it, and it's barely a sim even in the broadest of terms.

Hardly revolutionary tech at this point.

 

[amar212]

Forza has been doing it for some time. NFS:Shift does it, and it's barely a sim even in the broadest of terms.

Hardly revolutionary tech at this point.

Full carcass real-time visual and physics deformation modelling? Hm?

 

[Zer0]

You're going to have to be more specific as to how that quote states that there is a deformation model in GT6.

It states that the new tyre physics takes things into account that some people thought that were assumptions or not offically announced, and that regarding the tyre physics not the visual representation of the physics.

Anyway I have encoded this gif for yourself:

Even with no 3D mesh tyre deformation some "marketing" speaks for itself in that tyre. I don't understand the denial.

Regarding the visual deformation I agree with what Amar said.

 

[Imari]

I don't understand the denial.

If the only swan you've seen is black, does it mean that all swans are black? Or is that swan a mutant?

Or do you think that making a judgement on a whole species of animals from the observation of a single member might be a bit premature?

A tyre model is a complex thing. And in this case, we've got a screencap of a tyre clipping through the ground and some interesting suspension movement.

Might it indicate that there's tyre deformation modelled but not visible? Sure. Might it just be a glitch? Sure.

Do you think that making a judgement on a complex thing like tyre deformation from the observation of a single, short, not entirely conclusive clip might be a bit premature?

Withholding judgement until sufficient data is available is also an option, we don't always have to jump to conclusions the moment we see something interesting.


@amar: Forza and Shift have visible deformation that is derived from and affects the physics. I imagine it's a simplified model, as everything is, but it's there. I'm not sure if that's what you'd class as "full carcass real-time visual and physics deformation modelling", but it's there. You can see it and you can test it.

But this is a bit close to veering into the GT vs. the world territory, so I'm not entirely sure this is the right place for this discussion..

 

[Griffith500]

So, in the interest of actually furthering this discussion, has anybody figured out what corner that is?

 

[marky5244]

I'd like it to be modeled in the physics, I don't care if it's represented in the graphics or not.

 

[tpark103]

Keen eye my friend. GT fans are passionate and this is another example of proof. Judging from the demo it's to early to tell if tell if what you are looking at is the results of physics or just beautiful graphics. We know that PD will be working with tire manufactures and suspension manufactures however, to what degree they will effect that the sim we truly have no idea.

Kudos

 

[MadmuppGT]

Does tyre deformation really matter in the grand scheme of things? there are many other things that would be more noticeable that could be fixed or implemented.

Plus the tyre deformation Ive seen in Forza looks overy exaggerated, like the tyres are made from marshmallow

 

[ReverenceSatans]

Does tyre deformation really matter in the grand scheme of things? there are many other things that would be more noticeable that could be fixed or implemented.

In a Simulator? Yes, it is important. The only part of the car that comes in contact with the road is the tyres so simulating them is by far the most important thing.

Plus the tyre deformation Ive seen in Forza looks overy exaggerated, like the tyres are made from marshmallow

 

[LVracerGT]

If you watch carefully, just after the rear tyre compresses, it regains it's shape pushing the suspension up some. It wouldn't have that effect unless tyre deformation physics were implemented. I'm with the OP on this one, well spotted sir!

👍

Exactly what I was thinking. Agreed.

 

[LMSCorvetteGT2]

If you watched that video, you wouldn't say that it's well spotted, I seriously agree that it may be in the engine. Yet it is not in the visual, and I doubt they cared to model it due to all the other stuff they were trying to plan for this game especially with the small amount of time compared to other games they try big things on.

 

[MadmuppGT]

In a Simulator? Yes, it is important. The only part of the car that comes in contact with the road is the tyres so simulating them is by far the most important thing.

I understand that its important for simulation, but surely putting in the physics of tyre deformation is more important than modelling the tyre to deform, which as you can see in the video shows the tyre flex and expand by about an inch or so... the only way you should be able to see this happen is if you have the camera right up against the wheel like in the video, but with forza you can see if happen from approx 10 feet away, its exaggerated in the game to show its been modeled.

my point is with the camera views being so far away that you cant see the tyres deform is it worth modelling the animation over say simply adding the physics.

 

[Imari]

my point is with the camera views being so far away that you cant see the tyres deform is it worth modelling the animation over say simply adding the physics.

How much work do you think it would take to model some simple deformation animations for the tyres?

How much work do you think it would take to adapt the tyre physics to account for tyre deformation?

You have to have already done the second, at which point you might as well do the first.

 

[Griffith500]

Not really, the visual mesh deformation isn't necessarily the same as the contact patch simulation, especially when you factor in LoD (tessellation!) into it. Animation isn't as cheap as you seem to be suggesting, either - hence the choppy windscreen wipers in GT5, which lack interpolation.

 

[I'm Motarded]

@amar: Forza and Shift have visible deformation that is derived from and affects the physics. I imagine it's a simplified model, as everything is, but it's there. I'm not sure if that's what you'd class as "full carcass real-time visual and physics deformation modelling", but it's there. You can see it and you can test it.

I hope he elaborates. I've been looking at it in the telemetry (in real time) where contact patch is clearly visible since Forza 1, and then the visual representation since FM3. At least I thought I was???

And make no mistake GT6, if it has it, will be a simplified version too. Too many calculations to go too hardcore on the hardware.

 

[MadmuppGT]

This is what I mean, I cant be the only one who thinks the deformation on that tyre is overly exaggerated. I'm pretty sure the tyre would be close to coming clean off the rim with that much flex in it... unless it was made from jelly

 

[Johnnypenso]

This is what I mean, I cant be the only one who thinks the deformation on that tyre is overly exaggerated. I'm pretty sure the tyre would be close to coming clean off the rim with that much flex in it... unless it was made from jelly

Check out the real life deformation in this little formula car (top of the page):

http://www.apexspeed.com/forums/showthread.php?p=7049

 

[SVX]

So, in the interest of actually furthering this discussion, has anybody figured out what corner that is?

Looks like the 'Ring GP circuit?

 

[MadmuppGT]

Check out the real life deformation in this little formula car (top of the page):

http://www.apexspeed.com/forums/showthread.php?p=7049

But isnt that a race car? would a normal run of the mill car with modern road tyres generate enough grip to pull the tyre that far out of shape?

While I fully understand people wanting it in the game and how it could be, I think there are more pressing matters to be sorted first

 

[Imari]

Seems like a decent amount of flex in the front left on what appears to be a dusty road.

 

[ReverenceSatans]

But isnt that a race car? would a normal run of the mill car with modern road tyres generate enough grip to pull the tyre that far out of shape?

And once again, in a simulator tyres are by far the most important aspect to get right.