Be Excellent To Each Other

The BBC has a gushing story about the super amazing technology that will allow you to race against real drivers in the virtual world of your racing game.

http://news.bbc.co.uk/1/hi/technology/7440658.stm

Basically, the game takes telemetry recorded from real races and recreates the real drivers as virtual drivers.

Except...



Which means this isn't that big a deal... all they're basically doing is giving you AI cars which follow a prescripted path but will take steps to avoid crashing into you - like in, say, Ridge Racer, 15 years ago. Ho hum.

Yeah, sounds crap.

Also the act of overtaking would take time, thereby making the rest of the lap meaningless compared against the original data.

Fixed.

And also, wouldn't we hopelessly rubbish compared to real F1 drivers? I'm sure even in a game I'd end up lapping about 20-30 seconds slower than them. How dull.

I don't know if you saw the episode of Top Gear where Clarkson got a lap time for Laguna Seca in a Honda NSX on Gran Turismo, then tried beat it in real life.

The time he got in the game was basically impossible to beat unless you were an extremely talented driver due to, for example, the easy with which you can tear round corners at high speed in a game but would be too terrified to replicate in real life.

Although this was also partly due to the game letting you brake/corner etc in a manner that was impossible in reality, with practice you could probably give the pros a run for their money.

The thing is, the game would likely use freaky catch-up logic and other physics-bending to get VirtuaHamilton back on course in the face of determined (and let's admit it, deliberate) actions on your part to obstruct him. Race Driver: GRID apparently does this in a very inconspicuous way (the rubberbandy catch-up logic is so extreme, says PC Gamer, that you'll have AI cars gliding sideways back onto the track after crashes to ensure you still have a pack to race against)... but this is all assuming that you can't just smash VirtuaHamilton off the track once and for all.

It sounds to me like the racing game equivalent of those 'not a cinematic, honest' sequences in Half-Life 2. All the other characters have been given their stage directions around the scene, while you the player stand around helplessly, not really sure where you're supposed to be standing or who you're supposed to be focusing your attention on while they all natter away around you. Then, suddenly, Barney turns and starts walking away from Dr Kleiner... directly to you, and pushes you out of the way as he crabwalks sideways past you (you're standing in his preset path, after all).

Substitute a virtual Mercedes/McLaren for Barney and I think you'll have this 'amazing' new racing thing.

Telemetry from a recently completed race IS a cool idea, though, but in effect it's a ghost race with several more (and solid) ghosts.

Nah, it'd be a simple interpolation. At x point of the track he's doing y. It wouldn't be at all hard to resync after any deviation.

But if virtual Hamilton has to overtake on a straight where real Hamilton didn't, he would have to go faster after the overtake than real Hamilton in order to catch up to the velocity real Hamilton would have at that point. It would therefore have to cheat.

No it wouldn't. Modern realistic racing game architectures don't control velocity as the input from the AI, they either input a target velocity, which the physics system will try and reach, but not necessarily reach, or, more usually just input the forces being applied (in which case, it'll just take the same input system as the player car, and so be incapable of doing anything more or less than the player is capable of). It wouldn't have direct control over the velocity.

It would be relatively simple to use the data from hamilton through blending and interpolation, absolutely no cheating required.

Ah - I assumed when you spoke of 'resync after deviation', that it would somehow be able to just return to the original path, velocity, and timings of the original - which would require cheating.

Bear in mind that there would probably be more than one 'input lap' for each driver anyway, and it would be divided into sections rather than just one lap as a chunk. Easy enough to find a match from that set anyway, but even if there wasn't, a blend between the current fields and the desired fields would provide a sensible and legal AI target.

No developer in their right mind would control inputs by timings in this case, far too much factor for error.

The main differences, if I remember rightly, were the braking and the speed which at which the game let you go through corners. The braking in the game was far superior to real life, allowing you to brake much later, and you could take corners at speeds in excess of what you could on the track.

This would be even more acute in a F1 car, as it is essential to keep enough heat in the brakes otherwise they don't provide enough friction but if they stay too hot, they wear out too quickly. Apparently, a F1 drive has to press down very hard (almost slamming down) when using carbon brakes during a Gran Prix, as opposed to a simple button press.

So if I stop at the end of the pits, Hamilton will crash into me and ruin my race?

I doubt they'd include that in the sample set.

It's not new either, Simbin were trying it with the original GTR until they realised it really didn't work. It's also very dull if you know exactly where each driver is going to finish.

Speaking of which, it looks like a version of GTR is coming out for the 360 this year.

Switching to simulation tyres would inevitably make a difference, as the more realistic the simulation, the more realistic the time.

However, the reasons citied for such a large variance in times between the virtual world and the real world were the brakes (which could probably be more accurately simulated) and the physiological, as well as the skill, differences between driving at high speed in a game compared with on a track (which will never be truly simulated accurately).

These differences would be even greater with a F1 car.

This feature was by no means comprehensive and there are many more reasons for the differences in the times.

They do indeed, as do lots of other things, more specifically the brakes.

On a track at high speed the braking is applied before going into the corner so as to ensure that the maximum friction from the tyres when going through the corner is being used for cornering, also known as the traction cycle, traction control helps with this but I believe it has been banned again by F1.

The amount of grip you have effects this, so the tyres play an important part of this cycle but so does everything else that effects grip (road surface, dry/wet/dirty track, down force, gradient of the road,the weight of the car changing as more fuel is being consumed etc), and it will all effect when you apply the brakes.

The braking system in F1 cars are so fundamental to the way the car is driven that they are one of the areas of F1 car design that they are looking at applying technology limitations on to make races more entertaining to watch (in fact there already is with ABS and power brakes being banned), as braking for a corner is arguable the most important test for a F1 driver.

In the Top Gear episode, which is what I was taking about in the first place, the brakes where mentioned as one of the main reasons for the massive difference in lap time.

Again? It was announced for XB1 and cancelled, announced for 360 (there's even a demo video from 2006 on the marketplace) and then cancelled. Again.

Are they actually getting their act together at last?

The brakes are the single biggest influence on braking ability. The tyres are the biggest influence on grip which is what a F1 driver has to maintain around corners and so has an influence on how they use the brakes.

That's why F1 tyre technology is centered around increasing cornering and acceleration speeds, not braking ability.

The heat build up in brakes on a F1 car is enormous (up to 1000 degrees C, and have to be kept over 400 degrees C to work) as a result of the car's required stopping distances, to use cheaper brakes would increase a F1 car's stopping distance and so greatly reduce the cars effective top speed.

Watch the clip. When playing the game with the circuit instructor, they agree that the brakes in the game are better than in reality. The brakes in the clip also end up burning enough that they could all smell them when he pulls up in the car.

I reference F1 as the thread was originally about F1 and it takes driving to the extremes so is useful for illustrating various principles related to driving.

Something else that I'm interested to know (about this AI thing) is how it will handle your interference if it's got more than one real driver running as an AI. Assuming you didn't do anything, assume that we have VirtuaHamilton finishing first, CyberMassa second and RoboRaikonnen third.

What happens if you cause CyberMassa to screw up a bit? Real Raikonnen only finished third as he was stuck behind real Massa, with that obstacle gone will the game adapt his in-game performance, or will he still drive slower as if he's closely following another car that isn't there any more?

If they continue on as their pre-recorded movements dictate, it's rubbish because the real drivers would adapt their tactics to the changing situation. If they do adapt their tactics, using all this telemetry is pointless since as soon as something unusual happens, the game has to just start running them as normal AI drivers like in most games anyway.

It would have a range of options for each section of the trck, and chose the most applicable.

5) Agree, strongly.

What, that the tyres affect braking ability in high performance/F1 cars more than the brakes?

Your kidding right?

Once a brake can lock a wheel, what's the point of it doing anymore?

If you've a tyre that , for the same amount of braking force, slides later across the road, then you brake betterer, unless I'm horribly mistaken.

When braking, there is a huge transfer of energy as the kinetic energy of the car is converted into heat energy cause by friction.

The brakes in F1 cars reach up to 1000 degrees C at times because they are responsible for dissipating the vast majority of this converted heat energy that is produced when a high performance/F1 car brakes hard.

To illustrate the point. Get in your car, drive around town braking hard, pull over and touch your tyres. Then touch your brakes.

Take car, drive at 60mph on tarmac. Stamp on brakes. See how far it takes car to stop.

Take car, drive on ice at 60mph. Stamp on brakes. See how far it takes to stop.

Take car, change car to ice tyres, drive to 60mph, stamp on brakes. See how far it takes to stop.

Take a car, drive to 60 mph. Don't use your brakes. See how far it takes to stop.

Take car, drive on ice at 60mph. Don't use your brakes. See how far it takes to stop.

Take car, change car to ice tyres, drive to 60mph, don't use your brakes. See how far it takes to stop.

Once the brakes have locked the wheel, the tyre is sliding across the surface of the track.whatever and isn't decellerating the car as well as an unlocked wheel. See?

I was trying to illustrate that point, by designing a thought experiment to keep the braking system constant, and reduce the amount of grip that the tyre (good tyre, lots of grip, bad tyre, little grip) had before locking up (tarmac, then ice) to demonstrate that once a tyre slips, and locks, it really isn't doing a lot anymore.

It is in locking the car's wheel that the majority of the car's kinetic energy is dissipated.

So that's why, when people are taught to do emergency stops, locking the wheels is considered a 'bad thing'?

Surely arguing about whether brakes or tyres are the most important component in stopping a car is like arguing over whether an engine or wings are the most important thing in getting a plane to take off.

Well yes, I was just using the terminology you used in your post, that's why we have ABS.

It is important that a wheel is allowed to continue rotating to prevent a loss of steering.

I'll argue engine, you argue wings.

But earlier you said:



So the two statments contradict each other, although I do feel that we are getting somewhere now.

Dont forget, ABS turns the brakes on and off and on and off very rapidly to prevent the tyre from locking (losing grip) so if the brakes are able to lock the wheel, causing the tyre to lock and lose grip, then it is reasonable to state that, in the system, the tyre is the weakest link, and most likely to have a greatest effect on that system, so making the tyres grip longer, before sliding, then cars tops quicker, so tyres > brakes.

No.

As stated before, braking is all about dissipating a car's kinetic energy. The brakes play the biggest part in this and so are the most important component in braking.

However, for the sake of road safety, braking quickly has to be balanced with allowing the driver to maintain control of the vehicle.

ABS aids a driver in doing this, it is also why it is banned in F1.

Take an F1 car going full tilt in a straight line. Apply full brakes at marker. Measure distance it takes for car to come to a complete stop

Remove tyres. Replace tyres with tyres half the width (halving the amount of rubber on the road) keeping all other tyre variables the same. Full tilt straight line. Apply brakes at marker. measure distance it takes for car to come to a complete stop.

Which stops sooner?

Hi. What's this argument about? I'd like to help.

The tyres play an important role in bringing the car to a halt, so the former example would obviously be correct.

As before, in both examples, the immense kinetic energy required to be dissipated to bring the F1 car to a halt would be dissipated primarily by the brakes.

"Car braking is about brakes and not a lot to do with tyres"

No it's not. I'm not sure where you are quoting that from.

It's about what has the biggest influence on braking, the brakes or the tyres.

Because, at present, brakes exist where they CAN lock a wheel up in a tiny amount of time, this has been the same for a long time. Now, tyre compunds are getting better and better and the tyres can grip more before lockig, so they have become the most important part of a braking system in an F1 car, that's why the FIA took steps to remove this grip, and not mess with the braking systems.

incidentally, the kinetic energy of an F1 car at 200mph is 2338288 Joules.

No, it's about both, but determining the more 'important' one depends on the car (i.e. what brakes and tyres are used) and what you're doing. Unless you define that precisely, you're going to end up with a big pointless argument.