Mintmaster
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That actually only averages 3g, but I'm sure it nears 5g at the beginning. F1 cars have ridiculous downforce and super-sticky tires. It's insane how fast they can corner without losing grip.
The GT5 expectation thread (including preview titles)*
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Because for cars which depend on downforce at high speeds for their grip, this is the way it works. Extreme examples are found in the really big Le Mans cars, which are actually much harder to steer around corners and keep on the road in general at lower speeds.
Now I am not sure enough of the cars driving here, but if this particular R8 is the road going version of a Le Mans car, then it is typically going to be one of those cars of which the production line has been limited to the absolute minimum requirement for a racing version of the car to be allowed at Le Mans (e.g. you need to have at least 60 road-legal cars out there before you are allowed to use that as a basis for your Le Mans cars). These 60 road-legal cars are special little things.
But as said, it is also not known what other settings were available and have been applied. Anyway, whatever you say doesn't matter that much. My offer stands ... name a car in GT4 and I will do a brake test for you. Then we can discuss whether or not the results are reasonable or not. I will gladly also do the brake tests in GT:HD, but there isn't any decent bit of flat track to do it on at the moment so that could be hard.
While I agree with you in general, there are more things going on. In my estimation, GT4 is the least realistic when it comes to simulating racing cars, and the most realistic when it comes to simulating regular street cars. It's there particularly where the biggest differences show up. In terms of accellerating and braking, GT4 is usually quite accurate and this is fairly easy to measure. You can even create graphs of this from replays. The discussions usually pertain more to the amount of grip you have in corners, or how long it actually takes the car to shift from one gear to the next (which for some cars seemed a bit overstated in GT4). Few people take the time to even test with tire-wear (which also seems to take temperature into account), or select a suitable tire type (or even stick to the stock tires that you are provided with when you get the car in simulation mode).
And again, it's not just playability that we are talking about. We are also talking about a machine with 32+4mb of hardware, and limited calculation abilities. I think Polyphony themselves once claimed in an interview that they had a 90% accurate driving model, but that the PS2 limited them to implementing about 10% of it. That could be overstated either way, but I reckon there is probably some truth in it.
And yes, they could probably do a better job if they limited themselves to one type of car rather than anything from 3-wheelers and pre-1900 carriages to the latest 2004 concept car (GT4 for obvious reasons contains cars up to and including 2004
). But it is a lot of fun to be able to pick a car that you or someone you know actually owns. And I know for a fact, and from some very hands on testing, that a decent amount of fairly low-powered FF cars are actually modelled very realistically in GT4. Dude, its a normal production audi. Its a basically a gallardo with a V8 producing 420hp. It has NOTHING to do with the R8 Le Mans car.
Mintmaster
Veteran
Arwin, you gotta pay more attention.
I don't have a big problem with GT4 being less than perfect with physics. I'm a graphics guy anyway, so DiRT and GT:HD are the best sims for me. As long as it has damage to add tension and is reasonably realistic (NFS can kiss my ass), then after that graphics will be the primary criteria for me.
Did you even read beyond my first sentence? I just said the same thing.
Cyan is obviously talking about this video that was just posted. It's not a roadgoing version of a LeMans car, it's the 2007 Audi R8.
It's the regular road cars that are having the biggest inaccuracies pointed out. That NSX test from Top Gear, the ridiculous braking of this R8, the grip they have, etc.
That's complete BS. Anyone who's done any physics coding at all can see that car simulation is very, very easy on the CPU. Even stacking some interacting boxes is an order of magnitude more difficult. The hard part is getting all the right parameters when making car models.
I don't have a big problem with GT4 being less than perfect with physics. I'm a graphics guy anyway, so DiRT and GT:HD are the best sims for me. As long as it has damage to add tension and is reasonably realistic (NFS can kiss my ass), then after that graphics will be the primary criteria for me.
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makaveli87
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Your thinking of breaking distance not time. Think of it this way, a car breaking from 155 to 135mph will cover a huge distance compared to going from 60-40. The time however will be quicker. Try googling 100-0 and 60-0 times not distance.
Ok, but you should too.
I got that by now. I was not aware of the relation between these two cars. But it is very much unlike PD to get the braking speeds wrong, so I am skeptical by default. What can I say? They earned it.
Now you are the one really not paying attention. I have criticised the NSX test long ago. The only thing wrong on the GT4 part was a small part of the track, and the fact that it doesn't scare you enough through lack of depth perception and g-forces that you experience in the real car. However, all the other bits of the test were flawed - he drove using the d-pad (which has heavy assists) instead of the wheel, he did not take the same car on the track and in the game, he did not say anything about which tires he used, he did not run the test with tire wear on, and so on and so forth.
That's complete BS? Lol. Sure, I guess if the PS2 had nothing else to do whatsoever, and there was only one car, then I guess, maybe. No further comment on this one ...
(though partly because I finally finished work at 3:20 and should be in bed).Mintmaster
Veteran
No, I'm thinking average acceleration, hence my statement of deceleration at just over 1g. a = v^2/2d. Distance is a lot longer - almost 3 times as much. I can calculate time as well, but I get the same results relatively speaking (as expected).
Times are not generally available for both. Here is one example where only distance is shown. There is little difference in average deceleration there, but for 100-0 it's actually a tad slower for both cars.
Yeah, I'm assuming constant deceleration in the calculation, but the fact remains that if slowing down from 100-60 was faster than from 60-0, we'd see a faster average deceleration from 100-0 than 60-0. Maybe brake fatigue is a problem, but that's all the data we have. Either way, it's enough to disprove the theory that you get much faster deceleration at higher speeds for road cars.
Mintmaster
Veteran
Not paying attention? How am I supposed to keep track of all your posts, especially one in another thread that's currently on the third page of the Console Games forum behind 60+ other more recently updated threads?
You don't understand. A 386 has enough horsepower to do a convincing car simulation for 10 cars, and would spend more time trying to visually portray the results. The fact that the only multibody interaction - wheels connected to the body - happen through a suspension makes it much, much easier to compute the physics than for the kinds of physics needed for HL2 or other FPS. Collision testing needs more CPU time than the car physics.That's complete BS? Lol. Sure, I guess if the PS2 had nothing else to do whatsoever, and there was only one car, then I guess, maybe. No further comment on this one ...
Now, you could spend as much CPU time as you want on car physics, but you won't really notice a difference on the screen that you can feel. It's the modeling that impacts the sim, not the CPU power. All this talk of GT:HD being non-representative of GT5 because there's only one car is rather silly from the point of view of Cell. It could handle 1000 cars if it wanted to. The GPU load, however, is another story.
AI is a lot harder to judge, but there you have lots of flexibility with how sophisticated you want to make it. GT3/4 didn't have a particularly good AI anyway.
I agree. It's much easier to spin out, for example, if you let your foot off the accelerator too late into a corner, in an FR car, in real life, than in GTx. It could be the extra grippy tires, but it could also be the guiding hand of residual stability control (like the residual steering/speed compensation even with steering aids turned off).
Mintmaster, I believe you're right about deceleration under constant braking being mostly constant regardless of speed, at speeds where (or for cars with which) aerodynamic lift/downforce is not significant. Assuming perfect threshold braking, the deceleration force from the solid mechanics is entirely dependent on the force of the brake calipers on the disc. Air drag is an additional contributor, but I agree probably not significant enough at 150MPH to be more than a 10% assist. In other words, braking from 150MPH to 75MPH should be only slightly faster than from 75MPH to 0MPH. (It shouldn't be slower.)
Engine braking is another reactive force that is roughly proportional to speed, and would help decelerate more at higher speeds, but I don't know if that'd be at play in racing...
However, Arwin brought up the issue of cars with net downforce at speed, something which I admittedly did not consider. Aerodynamic downforce increases grip without an offseting increase in mass, and could obviously help braking from speeds where downforce is significant. We'd only see this probably in race cars.
Engine braking is another reactive force that is roughly proportional to speed, and would help decelerate more at higher speeds, but I don't know if that'd be at play in racing...
However, Arwin brought up the issue of cars with net downforce at speed, something which I admittedly did not consider. Aerodynamic downforce increases grip without an offseting increase in mass, and could obviously help braking from speeds where downforce is significant. We'd only see this probably in race cars.
makaveli87
Newcomer
Mintmaster, you cannot use distance traveled when comparing breaking at different speeds the way you are if you don't have the time it took to stop.
It is hard to find breaking data but i managed to find two different publications using a car with the same model and year.
http://www.autobild.de/heftarchiv/v...YgDZ23W9l49AMcF2BaEkFF3PrfrOezE9VqnCIvz2u7A==
#43 on the list. A 2003 Dodge Viper 60-0 in 2.66 seconds.
22.56mph per second.
http://www.motortrend.com/features/scenes/112_0306_spdtest/photo_05.html
another 03' Viper 100-0 in 3.81 seconds.
26.25mph per second.
I'll admit, not the greatest example since the conditions were likely different. You also have to take into account that the viper breaking from 100-0 likely had a slower 60-0 time because of break fatigue.(i'm assuming the breaks on both cars were warmed up first as their both respectable site/magazine companies) whether this was the case or not the car going from 100-0 had a better average deceleration.
I thought this was a fairly easy concept to comprehend. I'll try to explain it in simple terms again.
The force required to propel an object becomes greater as you speed up. And in this case slowing a car down at higher speeds requires less energy.
For example, the amount of energy spent to move an object from 50mph to 60 is much less then 145 to 155. Likewise the amount of resistance needed to slow an object moving at a very fast speed(155 to 95mph) is less then you need to slow the same object down from 60 mph to zero.
Or how about a car moving at 120mph vs the same one going 20. Tap the breaks, which one do you think will slow down more. sure the one going faster will cover a greater distance but it will slow down much faster too.
Sorry i dont want to sound like an ass but i thought this was common sense. More wind/air resistance plus more friction(tires to asphalt, axles and anything else on the car having to maintain a higher speed) = more energy consumed to maintain speed, thus less energy to decrease your speed by the same amount.
You need more power to go fast for a reason.
It is hard to find breaking data but i managed to find two different publications using a car with the same model and year.
http://www.autobild.de/heftarchiv/v...YgDZ23W9l49AMcF2BaEkFF3PrfrOezE9VqnCIvz2u7A==
#43 on the list. A 2003 Dodge Viper 60-0 in 2.66 seconds.
22.56mph per second.
http://www.motortrend.com/features/scenes/112_0306_spdtest/photo_05.html
another 03' Viper 100-0 in 3.81 seconds.
26.25mph per second.
I'll admit, not the greatest example since the conditions were likely different. You also have to take into account that the viper breaking from 100-0 likely had a slower 60-0 time because of break fatigue.(i'm assuming the breaks on both cars were warmed up first as their both respectable site/magazine companies) whether this was the case or not the car going from 100-0 had a better average deceleration.
I thought this was a fairly easy concept to comprehend. I'll try to explain it in simple terms again.
The force required to propel an object becomes greater as you speed up. And in this case slowing a car down at higher speeds requires less energy.
For example, the amount of energy spent to move an object from 50mph to 60 is much less then 145 to 155. Likewise the amount of resistance needed to slow an object moving at a very fast speed(155 to 95mph) is less then you need to slow the same object down from 60 mph to zero.
Or how about a car moving at 120mph vs the same one going 20. Tap the breaks, which one do you think will slow down more. sure the one going faster will cover a greater distance but it will slow down much faster too.
Sorry i dont want to sound like an ass but i thought this was common sense. More wind/air resistance plus more friction(tires to asphalt, axles and anything else on the car having to maintain a higher speed) = more energy consumed to maintain speed, thus less energy to decrease your speed by the same amount.
You need more power to go fast for a reason.
I think you're underestimating how complex suspension, tire contact, and drivetrain models can be. Multi-link suspension, for example, tilts the wheels as a function of displacement and steering. This tilting will have an impact on tire contact, and cornering force will depend on this as well as the material of the road (dirt or asphalt, for example). When you're trying to model hundreds of cars according to factory specs, as well as under tuning, your model needs to be quite complex to be accurate.
And while collision is simpler in a racer than in HL2, integration has to be a lot more accurate in a racer than an FPS. An FPS just has to look approximately right, but a racer better be able to reproduction acceleration times, stopping distances, cornering speeds, etc., accurately to real-world counterparts or players will gripe.
Sorry, I don't mean to be arguing with every other post of yours.
Yes, the calculations were wrong. Should it not look something like:
(73 x 1.61) / (3.6 x 2.1 x 9.81 ) = 1.59 g
Oh dear, here we go again. Some people just don't give up!
Did you ever address the fact that on race tracks, grip levels are commonly more agressive than the surface on a public road? That pretty much nullfies any "real-worl" comparison you ever made... Lets just put this to rest, shall we?
Oh dear, here we go again. Some people just don't give up!
Did you ever address the fact that on race tracks, grip levels are commonly more agressive than the surface on a public road? That pretty much nullfies any "real-worl" comparison you ever made... Lets just put this to rest, shall we?
Oh dear, here we go again.
Yes i did address that fact. Did you ever begin to address that PD might get something wrong, that GT isn't 100% perfect? Or is this going to be like the time you acted like a god in the forza 2 thread, and had no intention of actually listening to other peoples input, because they disagreed with you?
Grip is to high. I have tested this, in my own car vs the game, on nurburgring. But i have allready talked about this. Lets take another example.
Mazda Miata, or the Mx-5 like europeans call it, this car is super easy to drift with in real life. In GT4, not at all.
Oh dear, here we go again. Some people just don't give up!
Did you ever address the fact that on race tracks, grip levels are commonly more agressive than the surface on a public road? That pretty much nullfies any "real-worl" comparison you ever made... Lets just put this to rest, shall we?
With what Tires?
Because:
here comes the REST. (Rammstein, Hier kommt die Sonne, *humming*)
From what you stated in the last topic, your method of testing left out quite a few rather important facts which pretty much make any results you gained from them useless. Grip is a product of surface, surface temperature, tyre temperature, tyre compound, contact patch (tyre pressure, size), weight and the speed of the vehicle.
I mentioned a couple of times that
a.) surface on race tracks differ from those on public roads
b.) surface temperature is not variable in the game
c.) no game simulates all different tyres supplied with each car, especially if the focus is on racing tyres
d.) tyre pressure is very important in real life and makes a huge difference on grip level
e.) driving GT with the wheel or controller makes a huge difference in how easy it is to provoke oversteering
In other words, you could probably look at GT "simulating" the best case scenerio: Hot, grippy surface, ideal tyre pressures/temp etc.
As an example: I'm using Toyo R888 tyres on my car and the grip level varies from not good (cold tyres) to amazing levels when they get up to temp. Most cars are also not ideally set up and are under too much pressure. As a result, when driving the car to the limit, tyres are overinflated and grip is decreased substantially. Even under ideal conditions, grip levels vary substantially depending on the surface. From what I have seen in the game, taking real-world conditions, it seems fairly accurate most of the time.
Having said that, Polyphony might have better taken less ideal conditions for their game to make it more comparable with what average Joe is used to on normal public roads and less setup car/tyres. When you offer a game with 600 cars in the game, it's fairly impossible to make each car match any situation accurately. Things are simplified and a lowest common denominator is used (i.e. ideal temperatures, one "road tyre" type) etc.
In an effort to end this, how about we just leave it at that, that Polyphony should have used less ideal conditions in the game which would result in less grippy cars?
This is ironic, since whenever anybody brings up one of Forza's flaws, you get all defensive and start talking about Gran Turismo.
I'm expecting great things from the next game, and even you have to admit its already ahead of Forza graphically. If PD can get the physics right (and correctly balanced) this should be the best GT yet.
Actually Vic, i don't have any problem pointing out flaws in Forza 2. Just like i don't have a problem pointing out flaws in GT. Neither is perfect.
I do get defensive for a title when people make arguments about a game thats clearly the successor of a prior title, a sequel, is not really a true sequel.
As far as graphics goes, i have hailed both GT:HD and GT4 as amazing.
I do get defensive for a title when people make arguments about a game thats clearly the successor of a prior title, a sequel, is not really a true sequel.
As far as graphics goes, i have hailed both GT:HD and GT4 as amazing.
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