after spending some time in netkar and going back and forth with LFS i found the distinct impression that in other sims the vehicle yaws as soon as you turn the steering wheel.

in LFS it seems like the sim wants the front tires to prove the car should be yawing and it waits for the feedback to come on a later update cycle. (i'm talking in terms of program design and how in the physics loop the steering angle affects the car.)

i think it's the reason LFS feels more organic: the forces that are produced by the tires are calculated and then applied to the inertia of the car (including rotational inertia of the tires which at speed damp the yaw as well). other sims are happy to yaw the car as a result of the steering angle directly.

what do you think? do you agree there is a delay in LFS compared to other sims? do you think there is an extra fidelity that is gained in exchange?

There is delay though not in a sense how i understand you put it. Physics in LFS run at 200 Hz, so give or take 5 ms. There is also hardware interaction delay between wheel to PC and back to wheel, etc. So far this kind of delay is only affected by individual sim physics frequency. Hardware interaction delay across sims i would assume is pretty much equal. 5 ms that is left is too low of an interval to notice the effect of a delay. If other sims physics run at faster interval it's not noticeable. If it runs few times slower then there would be more delay in them which seem not to be the case.

The only thing that comes to my mind is both the visual and physical tire deformation. Tire deforms depending on the car setup to it's max value when you turn the wheel and then starts to noticeably affect car handling. This deformation results in roughly 5 cm translation of car's center of mass before it can't move anymore. I'm thinking this is delay you're talking about.
I've singled out tire deformation specifically because i bet other sims you have played don't have this.

In LFS it feels as if road cars response is quite progressive when compared to AC. In LFS I can throw the steering wheel around and feel that the response is "slow". In AC road cars want to respond RIGHT NOW, it feels very different around the centre of the axis. I don't know if that is because of tyre deformation, load sensitivity, weight transfer, physics loop resolution or what. Netkar was somewhere in between LFS and AC in that respect, from what I can remember.

Try setting center spring @ 30% at global settings in the logitech profiler.

WORKS ONLY AT GLOBAL SETTINGS

I had the same feeling in the beginning but by doing that it felt way different. Try that option and tell me how it feels for you.

Quote from CarlLefrancois :

other sims are happy to yaw the car as a result of the steering angle directly.

That's a massive shortcut isn't it? I doubt any serious sim uses that kind of simplification.

Quote from Nilex :

...
Physics in LFS run at 200 Hz, so give or take 5 ms.
...

I guess it is 500 hz... It is max FPS possible for the game.

But ofcourse user input might be slower, like 200 Hz or even less.

The physics loop, if I remember correctly, runs at 2000 Hz.

[EDIT]

Quick search of the forums, says my memory is correct.

Quote from Scawen :

One example in LFS is the spring above the wheel which is supported by a tyre below. The wheel is light compared with those two large spring effects and can easily cause instability. That is the reason for LFS's high update rate of 2000 Hz in the sub-updates, which avoids the cars jumping up and down all on their own due to jumping wheels! You saw in the google video, at one point, in a crash when some vertices went a bit wrong.

What happens is you have some very stiff springs for the chassis members, supporting a node which let's say is 10 kg. The physics engine finds out in one update that the springs are stretched by 5 cm. Now the super string spring applies a force of [A LOT] to that 10 kg mass. So in the next update you find that 10 kg mass has gone maybe 10 metres away or whatever, when really it should only have moved a mm or so.

The update time steps must be small enough so that large force acting on the small mass at the node, doesn't push the node too far away.

Car data, user input run at 100Hz. (split time resolution)

For tyre physics I counted 1000Hz. According to upper post it can also run at 2000Hz (at high rate).

FPS isnt exactly limited. Lower you graphics details, put up a small resolution, set view to some simple (or no) object and you'll easily reach much higher FPS. Though Minimum sleep of 1 ms makes it limited to 1000 FPS.

Quote from Dygear :

The physics loop, if I remember correctly, runs at 2000 Hz.

[EDIT]

Quick search of the forums, says my memory is correct.

Only parts of the physics run at higher than 100Hz ("That is the reason for LFS's high update rate of 2000 Hz in the sub-updates"). The 'main' physics loop 'only' runs at 100Hz (source 1, source 2).

Kunos has mentioned in a Go development thread that he intends to hit "300-400Hz on the physics side" for Assetto Corsa (source). The traction control on one of the road cars in-game is set at 400Hz, suggesting (but not necessarily confirming...) they're hitting the upper bound of that at the moment.

Quote from amp88 :

Kunos has mentioned in a Go development thread that he intends to hit "300-400Hz on the physics side" for Assetto Corsa (source). The traction control on one of the road cars in-game is set at 400Hz, suggesting (but not necessarily confirming...) they're hitting the upper bound of that at the moment.

Hz are not everything. Forza runs at 360Hz to be better at 30FPS, other sims do not make anything special despite running at a very decent rate (rFactor at 400HZ...). Though, obviously, having more Hz is hardly ever a bad thing.

https://www.lfsforum.net/showthread.php?t=48927

Quote from Whiskey :

Hz are not everything. Forza runs at 360Hz to be better at 30FPS, other sims do not make anything special despite running at a very decent rate (rFactor at 400HZ...). Though, obviously, having more Hz is hardly ever a bad thing.

It's true that simply increasing the frequency of the physics loop isn't going to make an unrealistic sim magically realistic, but having a high frequency physics loop (at least in critical aspects) is a requirement for an accurate (real-time driving) simulation.

Obviously that's not to say that AC is necessarily more realistic than LFS because of the higher frequency ('main') physics loop either. I do, however, think that AC's higher system requirements is a better path for more realistic and more complete physics simulation than the LFS path. The LFS path seems to be to try and be inclusive to those with obsolete hardware/software, possibly at the expense of those with newer hardware/software, whose equipment is able to run a simulation with higher fidelity/realism.

The fact that the devs are trying to cater to a now unsupported OS and it's hardware is just another fine example of wasted time on things that need to be forgotten and moved on from.

XP IS DEAD, do yourself a favor and buy a new PC. Any new PC that is purchased today or any day after this day will more than be capable of running LFS without any sort of upgrade.

Quote from amp88 :

It's true that simply increasing the frequency of the physics loop isn't going to make an unrealistic sim magically realistic, but having a high frequency physics loop (at least in critical aspects) is a requirement for an accurate (real-time driving) simulation.

Obviously that's not to say that AC is necessarily more realistic than LFS because of the higher frequency ('main') physics loop either. I do, however, think that AC's higher system requirements is a better path for more realistic and more complete physics simulation than the LFS path. The LFS path seems to be to try and be inclusive to those with obsolete hardware/software, possibly at the expense of those with newer hardware/software, whose equipment is able to run a simulation with higher fidelity/realism.

That's exactly my thoughts. You still need a programer that codes good physics, Hz won't help you if your math is wrong or too simplistic. Though if you aim for the best simulation you need them.

Ironically, if your math is more complex you probably will be forced to decrease the Hz, so... yeah, there must be a sweet spot, but this spot should keep up with the times. If LFS just doubled its physics rate now that computers are more than capable of that...

Quote from PhilS13 :

That's a massive shortcut isn't it? I doubt any serious sim uses that kind of simplification.

would you think using a lookup table instead of doing any calculations is something a serious sim programmer would never consider? yes it is a huge shortcut but i get the feeling some sims do yaw = steer angle * reduction factor where the reduction factor is like tire heat, how much it's locked, etc.

Quote from edge3147 :

XP IS DEAD, do yourself a favor and buy a new PC.

XP alive and well in my sim cockpit! i could have bought a license for windows 7 but i bought two power leather seats out of a volvo S80 instead. difference of OS in LFS: did not notice any yet. difference of cockpit with new seat:

Quote from NotAnIllusion :

In LFS it feels as if road cars response is quite progressive when compared to AC.

that's good to know notanillusion. if you can notice what i mean with the mouse then what i'm experiencing is not an illusion

Quote from Nilex :

The only thing that comes to my mind is both the visual and physical tire deformation.

that's a good point. you would get some delay in steering feel with a low pressure tire like the ones we use a lot in lfs.

i don't think LFS has any delay in the controller to speak of. i'm running the sim at a steady 144fps and if i sit in a parked f1 car with the brake on and turn the wheel i feel the fronts gripping and see them moving pretty much instantly.

the effect i mean is really the yaw rate of the car.

I don't know why, but to me LFS physics feels most natural. Somehow, the car behavior is more predictable. It feels that there is rubber between the car and the road. Feels like the tire physics are (already) better than in most of the other sims.

Contact between the road and car feels more... softer.

I've tried and played several other sims.

SimRaceBin, quite arcade to me. Still fun thou.

iRacing, that's what i currently play. It's closest to LFS.

AC, tire contact feels somehow harder. Not harder to drive, but harder compared to softer LFS physics.

Quote from CarlLefrancois :

XP alive and well in my sim cockpit!

No. XP is dead. Microsoft isn't releasing ANY security updates to consumer versions of XP (only the embedded versions), thus by running XP you are a malware target and a potential malware hellstew to infect others.

Quote from dawesdust_12 :

No. XP is dead. Microsoft isn't releasing ANY security updates to consumer versions of XP (only the embedded versions), thus by running XP you are a malware target and a potential malware hellstew to infect others.

uh no... not quite. More like comatose and on life support with the doctors telling the family to pull the plug.

There are still some software developers out there making updated patches for XP users.
A lot of high end equipment has software that just isn't compatible with windows 7. At work, we would have to replace several hundred thousand dollars worth of equipment if we wanted to switch to windows 7. We get around that problem with dedicated machines and I have an XP emulator on my computer....
That I avoid like the plague.
Thankfully I can dummy down things instead of opening up that nasty crash monster.
But now it seems the industry is catching up. I know the new waterjet software will work in windows 7, but the computer still uses an XP system.
Our flat jet printer? The operating software works great with windows 7.
The graphics processing software not so much. I'm guessing that the hd space taken up by the operating system as well as the drivers of the program might have something to do with that.
The program runs horribly slow and prone to locking up when scaling or touching up files with windows 7. And even though the company gave us updated drivers to work with win 7, it really doesn't make much difference.
I dunno. Someone else runs that and that's how they do it.

But again, it's just a matter of time before XP joins 98, 95, 3.5. and whatever.
I wouldn't be interested in something stuck in an XP operating system.

No. XP is dead. The people who continue to use it (outside of literally massive corporations with technical debt that require XP) are equivalent to necrophiliacs.

It's one thing to use some antique OS for hobbying like Amiga or even Classic Mac OS. But to want to use it as your daily OS is just flat out retarded. I don't know why Windows users seem to never want to upgrade.

At least Android users have the excuse of "Our carrier left us on Android 2.2 and never realeased an update".

Consumer Windows users have literally no excuse not to upgrade other than outright stupidity or just plain stubbornness.

There is no excuse to still run XP, particually in a business.

Win 7's built in virtual XP will run almost all older software that won't run on 7 or later. It really is shocking business practice ( I'm looking at my local hospital here, ) to continue running XP, there's been long enough to plan to upgrade.

These same people will be the ones whining about not being able to run later software on their XP box in years to come.

Technology does move on, if you dislike the later windows versons then run a version of Linux, mind you OS2 still lives so I'm just waiting for someone to want to run LFS on it........

http://www.ecomstation.com/ there you go........

The only places where I find XP to be "tolerable" is basically in manufacturing. Where there's millions of dollars of engineering and technical debt invested into a manufacturing device, and it's not networked at all. Any XP device that is networked in any way, is a terrible idea. It's vulnerable as hell, and unsafe.

Running a networked XP device is analogous to the anti-vaxers. You don't upgrade/vaccinate just for yourself, you do it to protect everyone.

Whats the title of this thread?

BTW XP rocks

I still have to use 98 and XP, both at work and for racing. At home I have 7.

It's weird that people think it's suddenly less secure than it was though.

Quote from dawesdust_12 :

But to want to use it as your daily OS is just flat out retarded.

I believe Scawen said that he will stick to XP...

Quote from dawesdust_12 :

I don't know why Windows users seem to never want to upgrade.

Some might had bad experience with upgrading to Vista. And for example - why should I want to upgrade to W8 from W7?

(OT) I prefer by far XP ... Options easily available, perfectly known (when looking for tricks on internet), etc ... Win7 is clearly not simple when you play with network feature for example ... We are loosing so many times in my job making several computers based on Win7/Server2008 behaving correctly on a lan ... while with XP/server2000 it was almost instaneous ^^

to be clear, if there was not some #%$* game that are forcing you to upgrade to win7 at least (translation : without willing to test AC), I would have kept XP and still be happy with it !

Quote from tristancliffe :

I still have to use 98 and XP, both at work and for racing. At home I have 7.

It's weird that people think it's suddenly less secure than it was though.

It's less secure because it's no longer getting windows updates (for Consumers at least). It means that any 0-day that a hacker finds in XP, will never get fixed. Over time, the list of vulnerabilities will grow and grow.

At least Win7 gets regular security patches still.

And I don't care if ****ing bill gates said he was gonna stick to XP, it's still downright moronic to keep it.