Update 1.06 possible changes to the physics + general physics discussion.

[nasanu]

Gravity when a car in GT6 is airborne does not operate like gravity does in real life and you can see this over the larger jumps like at Cape Ring and the huge jumps you used to get in the track creator.

No, it does act like in real life. The gravity part at least. What does not act quite right is the wind (but it IS there, the cars would flip insanely fast without it, just needs tweaking it seems) and the fact that the car does not deform (which account for much of what Griffith500 said).

If there wouldn't be centrifugal forces that act on a car we could take any turn at max speed.

As I said, you are mistaking centrifugal force with centripetal force.

 

[ColouredBadger]

This is on 1.06, when I tested my R8 LMS Ultra :

View attachment 140098​

View attachment 140100​

I didn't crashed, landed safely and keep on going

It does happen in real life too, maybe not to the extent shown in your photos though. But I'm guessing they have updated the physics to make them more realistic instead of the jumps the cars used to do of almost dead flat or nose dive. (from what I've experienced)

 

[karelpipa]

Improved framerate? After playing super-smooth 60fps PS2 games for few weeks, when i returned to GT6 yesterday, framerate still felt terrible for me.

I know EXACTLY what you mean. I played Enthusia and its super super smooth compared to GT5 or 6.

 

[karelpipa]

Well, speaking of physics, I spontaneously did something strange yesterday.

I was driving Tamya seasonal (Eiger Nordwand) and after I quit the game I saw the GT:HD (2007 PSN release) at the very end of my XMB Games list.

I fired it up just from curiosity and took an Integra Type-R for a spin.

I strongly recommend it to anyone who still have it installed. First question: why on Earth PD changed the way gearboxes work? In GT:HD the gearbox are phenomenal, they actual gear-changes are slower, more realistic and more "analogue". Why we lost that? I was not happy once I realized how much the gearbox system in GT5/GT6 is close to GT4's "digital" one.

Then I moved to GT4: Prologue for reasons of testing my favorite physics-detail in all GT games, and that is aerodynamic's stall in high speeds. And yes, it was still there and it is phenomenal.

We should get all of that back.

Please upload a video of the gear change. I dont have GT HD

 

[BrandonW77]

Please upload a video of the gear change. I dont have GT HD

 

[Mt. Lynx]

Are you sure?.. You are thinking of centripetal force, but its basically the same thing, just a matter of the frame of reference.

No, I am thinking about centrifugal force. But of course, if that is wrong(ish), then centripetal force would possibly be wrong aswell, since they are related.

 

[Nielsen]

At first I felt no difference but I actually think input lag has been reduced, making the physics feel more intuitive. It may also be the physics that have been tweaked but I feel more control with the DS3 now.

 

[BrandonW77]

At first I felt no difference but I actually think input lag has been reduced, making the physics feel more intuitive. It may also be the physics that have been tweaked but I feel more control with the DS3 now.

That combined with improved frame rate could very well explain it.

 

[Imari]

No, I am thinking about centrifugal force. But of course, if that is wrong(ish), then centripetal force would possibly be wrong aswell, since they are related.

Centripetal force is what's pushing the car around the corner.
Inertia is opposing that, the resistance of the car to deviate from a straight line.

Centrifugal force is not felt by the car at all, it's "felt" by the things inside the car. It's what pushes you against the door as you go around a corner. It's not really a force at all, just a byproduct of your forward momentum and you not being rigidly connected to the car when it starts to turn.

It's a convenient mental shortcut for what happens to objects inside a rotating enclosure, but it's not actually a thing. Everything that happens to a cornering car is explained by centripetal force and inertia.

 

[Vegard]

I've noticed the .20 rear toe-in* being more pronounced to the extent that it dominates the handling of several vehicles to an increased degree.
Inertia induced oversteer seem to have been reduced by a noticable amount.

I suspect that it is the tyre model that have recieved a minor tweak.

I'm going to do a little testing on a few different compounds to see if I can confirm anything.

*I run stock suspension on more or less all road cars in anticipation of a major overhaul.

Oh and to put this gravity thing to rest, don't you guys realize that a change to gravity would change the lap times significantly? Gravity effects everything, acceleration, braking, general tyre grip, car to car contact... Its too huge.

 

[Johnnypenso]

No, it does act like in real life. The gravity part at least. What does not act quite right is the wind (but it IS there, the cars would flip insanely fast without it, just needs tweaking it seems) and the fact that the car does not deform (which account for much of what Griffith500 said).

As I said, you are mistaking centrifugal force with centripetal force.

No, it doesn't. I can do the math if you like, it's basic physics. When a car "jumps" a ramp the front end start falling before the back end at a known rate (32 ft/s/s acceleration). In real life drivers on bikes and in cars use the forces generated by the spinning motor and tires to control the attitude of the car and probably aerodynamics to some degree, but those forces aren't modelled in GT. You can jump full throttle or no throttle and the jump is the same. This is what happens in real life when you make a long jump and cut the throttle:

​

 

[LVracerGT]

Yep, I remember playing Richard Burn Rally on PC and being in a long jump scenario where I panicked and went from throttle to the brakes in an attempt to start braking as soon as my wheels touched back down. As soon as I did that the nose dived and I flipped end over end just like the video.

Same thing when you watch the moto riders at the X-Games in the high jump. They use the throttle and brakes to manipulate the bike mid-air.

 

[Mt. Lynx]

Centripetal force is what's pushing the car around the corner.
Inertia is opposing that, the resistance of the car to deviate from a straight line.

Centrifugal force is not felt by the car at all, it's "felt" by the things inside the car. It's what pushes you against the door as you go around a corner. It's not really a force at all, just a byproduct of your forward momentum and you not being rigidly connected to the car when it starts to turn.

It's a convenient mental shortcut for what happens to objects inside a rotating enclosure, but it's not actually a thing. Everything that happens to a cornering car is explained by centripetal force and inertia.

Exactly. And this "force" (equal to, or opposite, centripetal force) is affecting tyre load, or "flex" if you will. The problem here is that we don't know for sure that tyre flex is even implemented, wich could of course be why centrifugal force feels iffy (and camber doesn't work as it should).

 

[GTP_CargoRatt]

As far as I'm concerned there's a new setting in suspension tune called placebo.
I believe this is what most of you are experiencing.

You know, I have seen that new setting myself. But, as is with the camber setting, I believe it too to be broken.

 

[Nielsen]

As far as I'm concerned there's a new setting in suspension tune called placebo.
I believe this is what most of you are experiencing.

I tend to agree but I became suspicious of a change when I picked up the game after a long break and was soon able to drive successive laps with great consistency on my DS3 controller. Before version 1.06 I hadn't really been able to do so since GT5. There's a chance that my hiatus from GT6 made me a better driver but that doesn't make much sense. However, it does make sense that PD won't mention every time they might tweak the physics because that would seriously challenge their ongoing claim of delivering the real driving simulator. Physics tweak or not, the physics are still not quite where they should be to justify such a sub-title.

 

[andryush]

No, it doesn't. I can do the math if you like, it's basic physics. When a car "jumps" a ramp the front end start falling before the back end at a known rate (32 ft/s/s acceleration). In real life drivers on bikes and in cars use the forces generated by the spinning motor and tires to control the attitude of the car and probably aerodynamics to some degree, but those forces aren't modelled in GT. You can jump full throttle or no throttle and the jump is the same. This is what happens in real life when you make a long jump and cut the throttle:

​

Same thing when you watch the moto riders at the X-Games in the high jump. They use the throttle and brakes to manipulate the bike mid-air.

Whaaat? Guys,are you serious?? How spinning or stopping wheels from spinning (throttle/brake) is supposed to affect trajectory of loosely falling object??
On this video entry speed was too high, front end should have start falling earlier, so car would hit the other ramp in perfect angle. But driver went too fast for this jump and car started falling too late, resulting in too high angle when landing.

Back on topic.

I tested another MR car beside Toyota MR2, Zonda C12 and it handles like a dream. Was it like that before patch? It drives almost like race car...

 

[Johnnypenso]

Whaaat? Guys,are you serious?? How spinning or stopping wheels from spinning (throttle/brake) is supposed to affect trajectory of loosely falling object??

Back on topic.

I tested another MR car beside Toyota MR2, Zonda C12 and it handles like a dream. Was it like that before patch? It drives almost like race car...

On the first part, you'll have to look that up, but it's true, in fact the video I left shows what happens when the engine is cut.

The Zonda C12 is an absolutely perfectly balanced MR, and IMO, drives the way MR's should, at least the modern ones. The balance of it seems ruined in my opinion when you slap SS or softer tires on it. It's perfect on Sports Hards and yeah, it's been that way since day 1, although I haven't driven it since the update to see if it's changed.

 

[Imari]

Exactly. And this "force" (equal to, or opposite, centripetal force) is affecting tyre load, or "flex" if you will. The problem here is that we don't know for sure that tyre flex is even implemented, wich could of course be why centrifugal force feels iffy (and camber doesn't work as it should).

Nope. Inertia affects tyre load. A heavier car requires more centripetal force to accelerate it around the turn.

Centrifugal force (as you're describing it) does not exist. It's a mental shortcut, and it's not appropriate when you're discussing physics seriously.

True centrifugal force is the force the tyres exert on the Earth.

On this video entry speed was too high, front end should have start falling earlier, so car would hit the other ramp in perfect angle. But driver went too fast for this jump and car started falling too late, resulting in too high angle when landing.

Nope.

The car landed at the correct point (more or less) on the other ramp, and so was going at the correct speed. If he had gone faster he would have overshot, or undershot if he'd gone slower.

You can hear him cut the throttle in the video, and see the car pitch when he does. Why? Newton's Third: For every action there is an equal and opposite reaction.

Consider the car and wheel as two separate entities. They're connected, but are free to rotate with respect to one another. Directly after the jump they're not exerting any forces on each other, the wheel is spinning at whatever speed, and the engine/car is matching that speed.

When the driver lets off the throttle, you now have a force acting to decelerate the rotating wheel. Say we're looking at the left rear wheel. The deceleration provides a force on the wheel in a clockwise direction. And so there's an equal and opposite force acting on the car, twisting it counterclockwise around the rear axle.

Were the car on the ground, it would not be free to rotate and would simply slow down. But in the air there's nothing to stop the car rotating. Energy is not destroyed, always conserved. The energy that the rotating wheel had when it left the jump has simply been transferred into rotating the body of the car instead. The car is much heavier than the wheel, and so will rotate much slower, giving decent fine control of the attitude of the car.

This is why jumping cars is very tricky. It's not just about driving at X speed, because any moron could do that. It's about getting the speed right AND having perfect timing and precision to control the attitude of the car before landing.

 

[Lewis_Hamilton_]

Just while people are on this sort of discussion, thought I would throw this in. I find it wonderful how physics works sometimes. Check out this early 80's video on gyroscopics affecting something's 'weight'. Sorry, I know it may be off topic, but everyone was discussing physics and all




Another similar video, with a lot of in depth explanation.

 

[LS Chiou]

Great video, thanks for sharing. It reminds me of the WWI fighter with rotary engine. (not the Wankel, but the big star-shape gyroscope in the nose)

 

[BrandonW77]

Whaaat? Guys,are you serious?? How spinning or stopping wheels from spinning (throttle/brake) is supposed to affect trajectory of loosely falling object??
On this video entry speed was too high, front end should have start falling earlier, so car would hit the other ramp in perfect angle. But driver went too fast for this jump and car started falling too late, resulting in too high angle when landing.

Back on topic.

I tested another MR car beside Toyota MR2, Zonda C12 and it handles like a dream. Was it like that before patch? It drives almost like race car...

They're correct, the gyroscopic force of the engine, transmission and wheels effect the attitude of an object. It's especially apparent on motorcycles, the rotating engine and heavy rear wheel do a lot to keep the bike upright. And the motocross guys use their throttle and brakes to adjust the attitude of their bike when in the air.

 

[Mt. Lynx]

Nope. Inertia affects tyre load. A heavier car requires more centripetal force to accelerate it around the turn.

Centrifugal force (as you're describing it) does not exist. It's a mental shortcut, and it's not appropriate when you're discussing physics seriously.

True centrifugal force is the force the tyres exert on the Earth.

I am talking about reactive centrifugal force here, wich from my understanding is equal/opposite of centripetal force.
Sorry for not making that clear.

 

[eclipsee]

If there wouldn't be centrifugal forces that act on a car we could take any turn at max speed.

As I said, you are mistaking centrifugal force with centripetal force.

No, I'm not, I'm really refering to centrifugal force, in addition to what I said, I'll say too that if there wouldn't be centrifugal forces people wouldn't get hurt in a car crash.

Nope. Inertia affects tyre load.

Inertia not just affects tire load but anything that has mass and it's in movement, hence it affects the whole car.

 

[Imari]

I am talking about reactive centrifugal force here, wich from my understanding is equal/opposite of centripetal force.
Sorry for not making that clear.

Except that reactive centrifugal effect doesn't act on the car. It's the force the car, or the tyres in this case, exert on the road/earth.

No, I'm not, I'm really refering to centrifugal force, in addition to what I said, I'll say too that if there wouldn't be centrifugal forces people wouldn't get hurt in a car crash.

You have no idea what you're talking about. Go read Wikipedia, then come back and join us. I'm sorry, but you're not even on the same page.

The only way you could slot the words "centrifugal force" into that sentence is if you're talking about reactionary centrifugal force. If there's no reactionary centrifugal force, there's no centripetal force either and YOU CAN'T TURN.

The centrifugal force that injures people when you have an accident, presumably by impalement on the steering column or something similarly gruesome, is not a force. It's a convenient mental shortcut, but there is no force there at all. None.

The car stops (because the tree won't let it keep going straight).
The occupants, being not solidly attached to the car keep going at their previous speed until they encounter something solid enough to stop them, like the steering column.

The steering column definitely produces a force against your ribs, but not a centrifugal one. It's an imaginary force designed to make rotating frames of reference work, and it's completely unnecessary if you're considering the situation correctly.

Inertia not just affects tire load but anything that has mass and it's in movement, hence it affects the whole car.

Certainly. And what's producing the force that acts on that momentum? The tyre. Increased inertia means increased tyre load (to produce increased force) to get through the same turn.

 

[andryush]

They're correct, the gyroscopic force of the engine, transmission and wheels effect the attitude of an object. It's especially apparent on motorcycles, the rotating engine and heavy rear wheel do a lot to keep the bike upright. And the motocross guys use their throttle and brakes to adjust the attitude of their bike when in the air.

Damn, GT Planet can be sooo educational sometimes! Great videos above by @Lewis_Hamilton_ , i apologize for my incompetence.

 

[nasanu]

No, it doesn't. I can do the math if you like, it's basic physics. When a car "jumps" a ramp the front end start falling before the back end at a known rate (32 ft/s/s acceleration). In real life drivers on bikes and in cars use the forces generated by the spinning motor and tires to control the attitude of the car and probably aerodynamics to some degree, but those forces aren't modelled in GT. You can jump full throttle or no throttle and the jump is the same. This is what happens in real life when you make a long jump and cut the throttle:

​

You are not even reading what I write are you?

And no, once a car is in the air drivers have basically no control. Rally drivers need to setup their car before the jump, using the brakes to throw the weight on the nose if they want the nose of the car to dive. And GT does model the wind, even if PD didn't tell us about how they were doing it (basically you are saying they lied about the game... why?) you should know just by playing the game and watching the cars.

 

[nasanu]

They're correct, the gyroscopic force of the engine, transmission and wheels effect the attitude of an object. It's especially apparent on motorcycles, the rotating engine and heavy rear wheel do a lot to keep the bike upright. And the motocross guys use their throttle and brakes to adjust the attitude of their bike when in the air.

This is a myth. The gyroscopic effect has very little to do with keeping a motorbike or bicycle upright. They proved this via installing counter gyroscopes and seeing how easy it was for people to ride. It made zero difference. The faster you go on a bike the easier it is to stay upright; this is because the effect of your steering adjustments is multiplied with speed. There is nothing more to it.

 

[Vegard]

Here and here are two free semesters of Fundamentals of Physics at Yale.
This is the lecture with the loop-the-loop.

Back on topic:
After a quick session yesterday I'm starting to think that the placebo effect and general rustiness have played a trick on me in regard to the 1.06 update. I couln't put my finger on anything in particular, at least not anthing of significance.

 

[whereSTheFUhd]

Another possibility is centrifugal forces, something that has always been poorly modeled.

Can't really see that there are centrifugal forces that act on a car...? Of course the wheels experience such forces, but not in way which would effect handling.

Drive on a banked turn, and you'll see what I mean.
But centrifugal forces act on a car whenever it turns.

Are you sure?.. You are thinking of centripetal force, but its basically the same thing, just a matter of the frame of reference.[...]

No, I am thinking about centrifugal force. But of course, if that is wrong(ish), then centripetal force would possibly be wrong aswell, since they are related.

If there wouldn't be centrifugal forces that act on a car we could take any turn at max speed.

There is no such thing as a centrifugal force - objects moving along a curved path do not undergo any force exerted radially outward from that curved path. Centripetal force actually exerts a force radially inward against that objects tendency to continue along its inertial trajectory, which is straight forward and tangential to the curve.

[...] As I said, you are mistaking centrifugal force with centripetal force.

Right, and the former does not exist.

Centripetal force is what's pushing the car around the corner.
Inertia is opposing that, the resistance of the car to deviate from a straight line.

Centrifugal force is not felt by the car at all, it's "felt" by the things inside the car. It's what pushes you against the door as you go around a corner. It's not really a force at all, just a byproduct of your forward momentum and you not being rigidly connected to the car when it starts to turn.

It's a convenient mental shortcut for what happens to objects inside a rotating enclosure, but it's not actually a thing. Everything that happens to a cornering car is explained by centripetal force and inertia.

Bingo.

I am talking about reactive centrifugal force here, wich from my understanding is equal/opposite of centripetal force.
Sorry for not making that clear.

Again, the two opposing forces are centripetal and inertial - centrifugal force, as it is being used here, does not exist.

I see air moving around the vehicle while I'm driving irl. xD But I'm being serious, some people's eyes are better than others, and some brains process faster, but tell me you see a Difference in 30 FPS to 60 FPS. (Max you can get with a standard LCD tv. NOT computer monitors.)

Tell me you don't see a difference: http://frames-per-second.appspot.com/

 

[BrandonW77]

This is a myth. The gyroscopic effect has very little to do with keeping a motorbike or bicycle upright. They proved this via installing counter gyroscopes and seeing how easy it was for people to ride. It made zero difference. The faster you go on a bike the easier it is to stay upright; this is because the effect of your steering adjustments is multiplied with speed. There is nothing more to it.

Nah. When I rode a motorcycle I would occasionally kill the engine and coast into my parking spot. As soon as the engine was cut I could feel the bike become a bit unstable and want to start leaning. It suddenly felt like I was riding a bicycle.