P&G suspension physics

[NPP]

someone has recently done some investigations and improvements on the original GTR2 physics involving the spring and damper multiplier settings in the .hdc-files:

http://www.nogripracing.com/details.php?filenr=8366&readme=1#readme

There was also a discussion of this over at RSC, but they seem to be down at the moment so I cannot post a link.

I'd be very happy to hear whether someone from the P&G development team might have an opinion on this. I tried out a Cortina with multipliers set at 1.0 and noticed that the car was much more predictable, allowing me to set three PBs at Goodwood in a row, easily beating my previous, knife-edge lap within two laps.

So the question would be: have I just improved the setup I was using, or is this indeed a physics tweak worth exploring for the future?

Cheers

NPP

[DucFreak]

I can't comment technically on it since it's one area I never handled in car-sims (just some physics tweaks in bike-sims).

...I'm just wondering where was this based on (real -accurate- data, etc) and how "accurate" the implementation of such changes are?

I have to say that, at least so far, I certainly trust the work by our physics experts in GTLW, the data available is pretty good, same for the "know-how" of these guys building and testing the physics for P&G.

...however, nothing is perfect (and the ISI physics engine surely isn't either), so there's always something worth a look as a kind of possible improvement. :)
...lets see what others more into this area will say about it. ;)

[David Wright]

someone has recently done some investigations and improvements on the original GTR2 physics involving the spring and damper multiplier settings in the .hdc-files:

http://www.nogripracing.com/details.php?filenr=8366&readme=1#readme

There was also a discussion of this over at RSC, but they seem to be down at the moment so I cannot post a link.


Sadly there are a lot of people out there editing physics who don't really know what they are doing. Doug Arnao has been producing ISI physics for years as of course have ISI themselves and to suggest you can't use multiplier settings other than 1.0 is ridiculuous, especially when its clear some of the people suggesting this don't even understand what the suspension multiplier is.

[NPP]

To be honest, I am myself sceptical when ground-breaking discoveries are announced; still one can never exclude that some serious mistakes are overlooked and exist for years in a piece of software - as any user of Windows systems will surely know ... Anyway, I am no expert, and already thinking about how changing this multiplier value will have different effects (or not) on a car with a live rear axle compared to a car with independent suspension is beyond me.

Best wishes

NPP

[GProKart]

There is a new version of car factory from Kangaloosh that it will help analising your physics files and see where and how are they broked, this tool will help you to build accurate suspensions.


http://www.rfactorcentral.com/detail.cfm?ID=Kangaloosh%21%20carFactory

carFactory helps you to create more realistic cars for rFactor.

carFactory V1.7.0 =================

As with all new versions of carFactory, please report any bugs you find to the RSC link below, thank you!

* Build and analyse complex suspension geometries * Design and implement realistic springs, dampers and roll-bars * Analyse and edit rFactor tyre curves * Full kinematic analysis of rFactor cars * Articulate suspension in 3D through full suspension travel

New in Version 1.7.0 ====================

* Tyre curve editor.

* Tyre analysis, dynamically charts lateral/longitudinal slip (Fy vs slip), Load sensitivity, camber effects, self aligning torque, redrawing as you edit the curve shape. Click 'Edit' to change the tyre's coefficients and watch charts redraw.

* All charts will zoom - just drag the mouse across the area you wish to see in more detail. Right click on the chart to 'Un-zoom' and to choose other options.

* Constraints - restrict where carFactory can place suspension hard-points, so wishbones do not bisect the engine, driver etc!

* CISH (corrected inner suspension height) applied to mods as they are loaded in for analysis

* Many, many minor bug-fixes, thank you to everyone who reported a bug.

Please, please report any bugs to the carFactory thread at RSC, the link is below.

Thanks,

Kangaloosh!

[DucFreak]

There is a new version of car factory from Kangaloosh that it will help analising your physics files and see where and how are they broked, this tool will help you to build accurate suspensions.


http://www.rfactorcentral.com/detail.cfm?ID=Kangaloosh%21%20carFactory

:up:

[GProKart]

Duckfreack,

Real feel plugin is not supported by GTR2 so you cant really feel the real forces produced at the steering rack and selfaligned torque produced by pneumatic trail, but you can probably use mules to test them out in rFactor.

I live in Oeiras, I belive you are quite close to me, so if you want to try what you can feel with this plugin you would be welcome to came here and test it.

I've read a lot of negative comments about this FFB plugin too, but its understandable... after checking the physics files from almost every mod out there, some might prefer to shut the light off again and keep playing with cannon ISI FFB using faked inputs.

From recent tests I've been doing with some corrected suspensions not released yet, I can tell you that even reverting back to cannon ISI FFB the the feel is away better too.

Just drop me a PM if you are intrested

Love your work btw, keep it up! :)

[spin_doctor]

Not to challenge the discussion above but more to set the record straight. There are details in RF and GTR physics that do not quite correspond to Real world vehicles and in some instances such as rear suspension Caster cannot. When an engine fails in RF or GTR it gets hot and then dies. There is no gradually worsening cloud of steam or oil smoke blinding following drivers and making the track slippery. It is patently ludicrous to assert that the tire physics or the track physics are accurate since you neither have realistic tire wear or reaction to changing track surface conditions like the layer of oil, dust and rubber marbles outside the racing line or the ability to lay down a "groove" during a race or practice sessions. Which is to say nothing of what happens on that surface when and after it rains. In most SIMs we are doing the best we can with moderately accurate ideas of how vehicle and tire dynamics operate as applied within the limits of personal computers or on dedicated platforms such as PS2 or Xbox.

Assertions of "realism" are at best relative to the individual and specific PC used to run the SIM, the software and hardware connecting the "driver" to the PC, and after that the Sim software... rather than the other way around as is often assumed. The specific PC because of the relative rate of processing including the base OS, sound and graphics drivers and hardware. The hardware (wheel, pedals, shifter, keyboard and etc.), driver software and add-ons have ranges of effect on the physical experience of the SIM outside the game itself. Personal settings and preferences for more or less FF along with many other subtle compensating adjustments, depending on the quality, complexity and brand of equipment often have far more effect on the sense of "realism" than any particular variant of Sim. Finally the Sim software itself is developed to operate best within what must be viewed as a brief span of time relative to the evolution of PC hardware and OS. Most game/Sim developments are usually designed to suit a production and marketing strategy within a product year defined by certain sales "seasons". They are often not coordinated to produce optimum performance but rather an average that is better enough than the preceding season's offering to warrant new purchases of one or more of those items.

One reason for the spread of Sim Mods has been to improve or even optimize existing games to better perform on the hardware and OS they were produced to operate on, or in some cases to adapt them to perform on improved OS or Hardware. If you wonder what I mean ask the guys who swear by GPL, NR2003 or any other long term modded Sims. Physics Mods depend on exploiting the limits of the Sims to best advantage or on enhancing aspects of the game engine not originally applied by the developers to emulate features lacking or inadequate in the original release of the Sim. In neither case are we talking of truly realistic physics as such but "improved" physics application within the limits of the game so that it "feels" more real than it did at release.

If you want to to discuss truly realistic simulations we need to leave the world of individual stand alone personal computers, as well as branded game "boxes".

[Phantom Mark]

Like I said elsewhere on these forums, always surprises me how many F1 driving physics engineering experts we have amoung us in these forums.

If a "sim" game manages to convey an artists impression of a particular subject then the mission is achieved, for the most part the P+G mod does that for me.

If anyone thinks they can do it better I will glady drive your claims, franky I dont give a rats behind what the numbers are as long as it drives right, the numbers are only as good as the source at the end of the day, and we all know the source is not "ideal" dont we !

[spin_doctor]

Mark,

I'm with you. I find it amazing how many people feel that only one aspect or dimension makes the whole Sim or mod work. They seem to believe that everyone gets exactly the same result from a given sim, add-on, or setting, never mind the variations in equipment, platform or graphics performance.

We mod makers do the best we can with what we understand of the game. Sometimes it works particularly well and sometimes it only just works. The quality or success of a mod is often very much in the eye of the beholder, and deserves to be considered that way as a creative act imho.

One of the great joys I had playing with Lego blocks ever so long ago was that I could create objects which resembled sufficiently what I wanted to play with that my imagination could complete the vision. Computer Sims are capable of much greater texture and shape than my Legos ever were. To some extent that ability to visibly represent with such accuracy drives the need for the sense of accurate feel that is so much and often discussed.

To those who find the mod work of myself and my friends sufficient to satisfy their desires for realistic Sim racing we are glad we have made your time worthwhile and earnestly hope to improve as we go along.

To those who find our work lacking in some important way we must advise you we are working with the best imagination we have and earnestly hope to improve as we go along.

We try to do the best we can to make the P&G cars look and feel as realistic as our humble talents will allow....However, we do consider that your mileage may vary. :)

[NPP]

We mod makers do the best we can with what we understand of the game. (...) We try to do the best we can to make the P&G cars look and feel as realistic as our humble talents will allow....However, we do consider that your mileage may vary. :)

As I started this discussion, I would just like to point out that it was not my intention to question the knowledge and competence of those who have produced the physics of P&G. Quite on the contrary, the reason I asked the question on this forum was that I was hoping that people who have created a mod that in my mind has one of the most "credible" physics on the market might be able to enlighten me as to whether there was anything to the claims made in respect to the multiplier settings.

I have been following discussions about sims' physics for several years now and I am very much aware of the precarious nature of the relationship between a physics model, the numbers fed into it, and the "feel" that comes out of it after passing through the individual users' particular hardware and operating system.

And, yes, your work certainly satisfies my desires (at least as far as simracing is concerned ;) ), as anyone trying to tear me out of the Cortina to do something considered "useful" may attest ...

All the best

NPP

[spin_doctor]

Though I am not a physics expert by any means I have found from conversation and practice that the tire files can produce AND hide a wide range of physics "sins" in GTR2 and other ISI based games. Without specific proprietary standards and physics design criteria to refer to it is difficult to know Why, what and how much the mutliplier factors are affecting mod car performance and experience of it.

I am certain that experimentation and simple intuition will probably tell us as much as any other source what meaningful gains are to be had by adjusting the multiplier values. I regret that I have no other helpful observations or conclusions at this point. Like you I am primarily an observer of other's work on mod physics and count myself lucky to contribute to this ongoing investigation. The true artists in this field rarely comment in public, so it is left to punters and casual labor such as ourselves to discuss and puzzle out what we may.

********

BTW under no conditions should you leave the cockpit of the Cortina while it is in motion. We cannot be held accountable for psychological trauma or side effects resulting from Cortina Interutpus. Likewise we bear no blame for conditions such as "whiplash" arising from extended seat time in this Sim vehicle. The S.F.I.A. and others charged with regulating safe SIM racing practices will be reporting shortly on approved guidelines for acceptable driver duration in extended events such as 8, 16, and 24 hour endurance races.

;)

[Phantom Mark]

I just wanted to add, my comment was not aimed directly at you NPP, it was more of a global observation at peoples comments on physics amoung all the forums in sim racing land........I am always open to new ideas and observations regarding the improvement of the driving models, and always willing to give some new idea or approach a run on track, trouble is many of the ideas are completely unfounded and based purely on peoples expectations of plugging in an uber realistic value only to find it destroys the end result because the physics engine is not capable enough of receiving it without wrecking another aspect of the dynamics.

The ISI engine in my experience is an engine which often demands comprimise, and only the well balanced and carefully considered comprimses work well and play well.

[DucFreak]

(at least as far as simracing is concerned ;) ), as anyone trying to tear me out of the Cortina to do something considered "useful" may attest ...

NPP
under no conditions should you leave the cockpit of the Cortina while it is in motion. We cannot be held accountable for psychological trauma or side effects resulting from Cortina Interutpus. Likewise we bear no blame for conditions such as "whiplash" arising from extended seat time in this Sim vehicle. The S.F.I.A. and others charged with regulating safe SIM racing practices will be reporting shortly on approved guidelines for acceptable driver duration in extended events such as 8, 16, and 24 hour endurance races.

;)

LOL @ both of you guys! :roflmao: ..."S.F.I.A." hehehehe :D:up: