Racer v0.4.7 in the release pipeline

Hi all, A new Racer (free carsim) version is underway; I'm uploading it to High Gear, where it will hopefully be up somewhere during tomorrow. NOTE!! It is Windows only; I screwed up my Linux OpenGL environment a bit, so I couldn't compile the Linux versions yet. Should be fixed during the week. And because my main development machine is not in the office, I cannot update the source code yet. Racer v0.4.7 ------------ v0.4.6.1 release notes (v0.4.6.1 never had its proper release text): - Fixes major grip bug; now it finally feels a bit realistic. You now get twice as much grip, like it should be. v0.4.7: NOTE: - Windows-only version still because of missing development machines; Linux/SGI version will follow later. Bugfixes: - Modeler's ASE loader improved (had some bugs with some models, esp. with UVW unwrapping); also improved the optimizer to handle the new methods better. - TrackEd & Modeler popup dialogs are now not overdrawn anymore. This problem was most apparent on Win98. It is a driver problem still, but I'll just circumvent it then. :( - Debug output to COM1 is now optional (setenv QDBG_COM=1). This may resolve problem with wheels that are hooked on COM1. - On Win98, a lot of people had trouble running Racer more than twice. My sound code is better now, in that COM is uninitialized at exit time. This is likely to fix the two-time running problem. - FF jittering at low speed is damped more. New features: - Added a new friction combination method, courtesy from Gregor Veble for the idea, which gives better behavior, meaning more warning before the tire starts slipping. This friction method is now the default. It resembles very much the method from chapters 24/25 from Brian Beckman. - Mipmapping, trilinear and anisotropic filtering support. See gfx.ini's new options. - Aero drag for the body - Wings aerodynamics - Engine torque reaction on the body (like in GPL) - Improved skid sound code (I think). - Support for more than 1 controller - Dual controller controlset for Logitech FF wheel and CH Pro Pedals (courtesy from Alison Hine) - TSW2mod controlset (courtesy from Uwe Schuerkamp) - Non-linear control support (variable from linear to non-linear) - Improved the JoystImm utility (Win only) so it now handles more than 1 controller (you can select it). - Improved TrackEd movement and selection - Car selection screen - Track selection screen - Best laps are recorded per track (10 per track) and per driver (just 1 driver for now in data/drivers/default) - Some transparency support for the cars. Still rudimentary, but working a bit (see the first screenshot on the website's news page). Get it at http://www.marketgraph.nl/gallery/racer/ Enjoy! Ruud van Gaal Ruud van Gaal, GPL Rank +53.25 Pencil art : http://www.marketgraph.nl/gallery/ Free car sim : http://www.marketgraph.nl/gallery/racer/

SLOW DOWN :) Woh, you have put so much more stuff in there, awesome going!! I will give it a go when I get home, but now I feel that I should really do some work when I get home! :) All the best, Ash | Free car sim : http://www.marketgraph.nl/gallery/racer/

I don't think Christmas ever came this early ;). About the new tyre method, I might have come to it independently, but since Brian did it far before me (and it's partially in a book by Genta as well from what I heard), I can't take any credit for it. I only might have formulated it slightly nicer, without all the special sign requirements, that's all the claim I can put in. Thanks for mentioning my name anyway :). -Gregor Ruud van Gaal wrote: > > Hi all, > > A new Racer (free carsim) version is underway; I'm uploading it to > High Gear, where it will hopefully be up somewhere during tomorrow. >

On Tue, 31 Jul 2001 09:51:43 +0200, Gregor Veble <[email hidden]> wrote: >I don't think Christmas ever came this early ;). LOL! >About the new tyre method, I might have come to it independently, but >since Brian did it far before me (and it's partially in a book by Genta >as well from what I heard), I can't take any credit for it. I only might >have formulated it slightly nicer, without all the special sign >requirements, that's all the claim I can put in. Thanks for mentioning >my name anyway :). Ah well, I did read about Brian's method, but it was quite a read and sounded a little obscure. Your more direct formula approach made me see the light. :) The Genta book does describe some normalizing method, but it is explained as somewhat experimental and that more work is done on the subject. So that didn't give a really good feel, and there are a LOT of divisions by potentially zero in there. Which is a shame. Ruud van Gaal, GPL Rank +53.25 Pencil art : http://www.marketgraph.nl/gallery/ Free car sim : http://www.marketgraph.nl/gallery/racer/

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> >About the new tyre method, I might have come to it independently, but > >since Brian did it far before me (and it's partially in a book by Genta > >as well from what I heard), I can't take any credit for it. I only might > >have formulated it slightly nicer, without all the special sign > >requirements, that's all the claim I can put in. Thanks for mentioning > >my name anyway :). > > Ah well, I did read about Brian's method, but it was quite a read and > sounded a little obscure. Your more direct formula approach made me > see the light. :) > The Genta book does describe some normalizing method, but it is > explained as somewhat experimental and that more work is done on the > subject. So that didn't give a really good feel, and there are a LOT > of divisions by potentially zero in there. Which is a shame.

Come on you guys, you are bloody killing me, could either Gregor or Ruud, kindly explain this method in nice easy to swallow chunks. I have just waded through Brians explaination, what WAS he smoking when he wrote that??!?!? I must say that you physicist blokes seem to be getting the best dope around :-) I have no desire to just use the method as is from Racer as that defeats the point of learning all of this stuff (although I am taking a quick peak now to see how the method correlates to Brian's explaination). As we say here, Yoroshiku Onegaishimasu :-) Colin BTW Ruud, you rock man, all the best, you are like this one man coding warrior, are you married? No married man (who wants to stay married) has the time to do the amount of research / work that you are.

Hi Colin, OK, if you ask this politely ;). Basically, the idea is the following; there is no actual independent slip ratio or slip angle acting on its own, but this are components of the joint slip vector, and its the (appropriately normalized) magnitude of this vector which determines the total force. However, experimental data usually only gives you tyre behaviour in ether lateral or longitudinal direction. Let's denote the lateral force in uncombined operation F_y(S_y), where S_y is the slip angle, or tan(slip angle), or sin(slip angle) or whatever you use (I use sin), it's not really that important at smaller angles, and F_x(S_x) the longitudinal force in pure longitudinal operation, with S_x being the slip ratio. If you have a working sim, you probably have these functions defined somewhere already. How to combine the two? Let's introduce the total size of slip, sigma = sqrt( (S_x/S0_x)^2 + (S_y/S0_y)^2 ), where S0_x and S0_y are the peak values for slip angle/ratio (where the force in uncombined operation is maximal). The symbol ^2 means the value squared, of course. These can be rather pesky to determine from e.g. Pacejka, but a rough estimate within about 20% error is most likely good enough, the equations hardly critically depend on these parameters (when in uncombined operation there is no dependence on them at all). We'll now use the independent functions F_x and F_y to constuct actual combined forces Fc_x and Fc_y from them. I'll just give the result here, and explain it afterwards. For the x direction, the result is (get your pencils out :) ) Fc_x = abs( S_x / (sigma * S0_x) ) * F_x( sigma * S0_x * sgn(S_x) ) and in the y direction, similarly Fc_y = abs( S_y / (sigma * S0_y) ) * F_y( sigma * S0_y * sgn(S_y) ). It's hard to explain the thought process on how to get to these equations (and I'm not giving you the stuff we physicists are on :) ), but let's look at why it's a good one. Let's first assume that S_x=0, which means that the tyre is sliping purely sideways (slip ratio=0). Fc_x is equal to 0 in this case because of the abs () prefactor being 0. The slip size s equal to sigma = sqrt( (S_y/S0_y)^2 )= abs( S_y/S0_y), and inserting this into the equation for Fc_y will yield exactly Fc_y (uncombined) = F_y( S_y ), which is just what we want. A simiar thing of course also holds for the x direction. On the other hand, in combined operation, and assuming for a second that the peak force F_peak = F_x(S0_x) = F_y(S0_y) is (at least roughly) the same for both the longitudinal and lateral direction, and the value of sigma is 1 (this is the optimal slip) the size of the total force is, after a few straightforward steps and taking the definition of sigma into account to cancel the abs() prefactors, F_total = sqrt( F_x ^2 + F_y ^2) = F_peak, while looking at the abs() prefactors the result will show that it points in the opposite direction to the total slip vector with components (S_x,S_y). It's also pretty straightforward to show that for small values of S_x, S_y, the system behaves linearly and the same as if longitudinal and lateral directions are taken separately, which they can be for very small slips. That's about it :). Cheers, -Gregor Colin Reed wrote:

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> > Come on you guys, you are bloody killing me, could either Gregor or > Ruud, kindly explain this method in nice easy to swallow chunks. I > have just waded through Brians explaination, what WAS he smoking when > he wrote that??!?!? I must say that you physicist blokes seem to be > getting the best dope around :-) > > I have no desire to just use the method as is from Racer as that > defeats the point of learning all of this stuff (although I am taking > a quick peak now to see how the method correlates to Brian's > explaination). > > As we say here, Yoroshiku Onegaishimasu :-) > > Colin > > BTW Ruud, you rock man, all the best, you are like this one man coding > warrior, are you married? No married man (who wants to stay married) > has the time to do the amount of research / work that you are.

On 31 Jul 2001 18:31:13 -0700, [email hidden] (Colin Reed) wrote: >Come on you guys, you are bloody killing me, could either Gregor or >Ruud, kindly explain this method in nice easy to swallow chunks. Phew, glad that Gregor took this option. :) > I >have just waded through Brians explaination, what WAS he smoking when >he wrote that??!?!? I must say that you physicist blokes seem to be >getting the best dope around :-) Actually, it makes sense after a while; but it's a bit of magic that it works so well. :) But the rules of overshooting your slipratio/slipangle to cross the optimum peak are important here. >BTW Ruud, you rock man, all the best, you are like this one man coding >warrior, are you married? No married man (who wants to stay married) >has the time to do the amount of research / work that you are. I'm not married. Do have a girlfriend though, and other girl-friends as well. Certain things in life are more important the carsims. ;-) Like the bottle of wine on the beach (with that girl) 2 days ago; you can't beat that with the best powerslide, lol. Ruud van Gaal, GPL Rank +53.25 Pencil art : http://www.marketgraph.nl/gallery/ Free car sim : http://www.marketgraph.nl/gallery/racer/

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| | I'm not married. Do have a girlfriend though, and other girl-friends | as well. Certain things in life are more important the carsims. ;-) | Like the bottle of wine on the beach (with that girl) 2 days ago; you | can't beat that with the best powerslide, lol. | |

Powerslide in what car? :) lol You are right of course, you just seem to do so much in so little time, I need to get my brain accustomed to long periods of clear thinking and concentration. It is not easy to do. Off to the movies tonight with my girlfriend - just to prove a point you'll understand :) Ash

<sigh> all this talk of girlfriends, and I just had to take mine to the train this morning as she went to Germany for a month... Oh, well, maybe I'll do some further programming during the long evenings then :). -Gregor Ashley McConnell wrote:

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> > Powerslide in what car? :) lol > > You are right of course, you just seem to do so much in so little time, I > need to get my brain accustomed to long periods of clear thinking and > concentration. It is not easy to do. > > Off to the movies tonight with my girlfriend - just to prove a point you'll > understand :) > > Ash

Gregor Veble <[email hidden]> writes: > <sigh> all this talk of girlfriends, and I just had to take mine to the > train this morning as she went to Germany for a month... I usually call that a luxury problem. Some people doesn't even have one to take to the train station... :) -- Olav K. Malmin remove .spam when replying

"Ruud van Gaal" <[email hidden]> wrote in message news:[email hidden]...

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| On Wed, 01 Aug 2001 13:05:44 +0200, Gregor Veble | <[email hidden]> wrote: | | ><sigh> all this talk of girlfriends, and I just had to take mine to the | >train this morning as she went to Germany for a month... | > | >Oh, well, maybe I'll do some further programming during the long | >evenings then :). | | We'll be expecting massive-multiplayer, AI and 50 new cars then after | this month, Gregor! ;-) |

Yeah gregor! Any Chance? :P Ash

Well, I was thinking more in terms like road bumps at most, but you never know :). -Gregor Ruud van Gaal wrote:

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> > We'll be expecting massive-multiplayer, AI and 50 new cars then after > this month, Gregor! ;-) > > Ruud van Gaal, GPL Rank +53.25 > Pencil art : http://www.marketgraph.nl/gallery/ > Free car sim : http://www.marketgraph.nl/gallery/racer/

On Wed, 01 Aug 2001 13:05:44 +0200, Gregor Veble <[email hidden]> wrote: ><sigh> all this talk of girlfriends, and I just had to take mine to the >train this morning as she went to Germany for a month... > >Oh, well, maybe I'll do some further programming during the long >evenings then :). We'll be expecting massive-multiplayer, AI and 50 new cars then after this month, Gregor! ;-) Ruud van Gaal, GPL Rank +53.25 Pencil art : http://www.marketgraph.nl/gallery/ Free car sim : http://www.marketgraph.nl/gallery/racer/

And don't forget the LEAGUE REPORTING tools, damage model etc blah blah bhal <VBG> dave henrie "Ruud van Gaal" <[email hidden]> wrote in message news:[email hidden]... > On Wed, 01 Aug 2001 13:05:44 +0200, Gregor Veble > <[email hidden]> wrote: >

On Wed, 01 Aug 2001 13:47:07 GMT, "Dave Henrie" <[email hidden]> wrote: > And don't forget the LEAGUE REPORTING tools, damage model etc blah blah >bhal <VBG> And if you skip dinner (no need to eat on your own), just implement weather inbetween watching the news and the late night movie. :) Ruud van Gaal, GPL Rank +53.25 Pencil art : http://www.marketgraph.nl/gallery/ Free car sim : http://www.marketgraph.nl/gallery/racer/

On Wed, 1 Aug 2001 14:46:31 +0100, "Ashley McConnell" <[email hidden]> wrote: >| We'll be expecting massive-multiplayer, AI and 50 new cars then after >| this month, Gregor! ;-) > >Yeah gregor! Any Chance? :P And ofcourse little hedgehogs and deer running around on the green track. And drink-o-rama, an alcohol emulation suite which measures the alcohol level in your blood and modifies the anisotropic filters and car inertia's accordingly. :) But road bumps will be fine, but let's call them bump curvatures in honour of our girlfriends. ;-) Ruud van Gaal, GPL Rank +53.25 Pencil art : http://www.marketgraph.nl/gallery/ Free car sim : http://www.marketgraph.nl/gallery/racer/

In article <[email hidden]>, Gregor Veble <[email hidden]> writes: ><sigh> all this talk of girlfriends, and I just had to take mine to the >train this morning as she went to Germany for a month... > >Oh, well, maybe I'll do some further programming during the long >evenings then :). Well, at least you guys HAVE girlfriends... :( Eldred -- Dale Earnhardt, Sr. R.I.P. 1951-2001 Homepage - http://www.umich.edu/~epickett F1 hcp. +16.36...Monster +366.59... Never argue with an idiot. He brings you down to his level, then beats you with experience... Remove SPAM-OFF to reply.

writes: Well, at least you guys HAVE girlfriends... :( Eldred -- Dale Earnhardt, Sr. R.I.P. 1951-2001 Homepage - http://www.umich.edu/~epickett F1 hcp. +16.36...Monster +366.59... Never argue with an idiot. He brings you down to his level, then beats you with experience... Remove SPAM-OFF to reply.

See EP, there's this thing called "outside". That's where the girls are! <g> Just messing with you Eldred, please don't get pissed off and take me out at the Kya race on Sat (not that I wouldn't have it coming after punting you at the Ring...) "EldredP" <[email hidden]> wrote in message news:[email hidden]... > In article <[email hidden]>, Gregor Veble<[email hidden]>

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> writes: > > ><sigh> all this talk of girlfriends, and I just had to take mine to the > >train this morning as she went to Germany for a month... > > > >Oh, well, maybe I'll do some further programming during the long > >evenings then :). > > Well, at least you guys HAVE girlfriends... :( > > Eldred > -- > Dale Earnhardt, Sr. R.I.P. 1951-2001 > Homepage - http://www.umich.edu/~epickett > F1 hcp. +16.36...Monster +366.59... > > Never argue with an idiot. He brings you down to his level, then beats

you > with experience... > Remove SPAM-OFF to reply.

On 1 Aug 2001, EldredP wrote:

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> In article <[email hidden]>, Gregor Veble <[email hidden]> > writes: > > ><sigh> all this talk of girlfriends, and I just had to take mine to the > >train this morning as she went to Germany for a month... > > > >Oh, well, maybe I'll do some further programming during the long > >evenings then :). > > Well, at least you guys HAVE girlfriends... :(

In college these were called the lower case problem ("secret of the universe", or whatever problem was the current top priority) and the Capital Letter Problem (opposite sex)...just a convenient shorthand, which I see EldredP has already started to adopt<grin>.

In article <c6%97.19232$[email hidden]>, "Rob Adams" <[email hidden]> writes: >See EP, there's this thing called "outside". That's where the girls are! <g> > >Just messing with you Eldred, please don't get pissed off and take me out at >the Kya race on Sat (not that I wouldn't have it coming after punting you at >the Ring...) Hehe... In order to punt you, I'd have to get CLOSE to you. That won't happen until you lap me...<g> I haven't even run any *practice* laps, yet. I think I have to replace my steering pot AGAIN... I just did it about 1 1/2 months ago. I must have had a defective replacement. :( Eldred -- Dale Earnhardt, Sr. R.I.P. 1951-2001 Homepage - http://www.umich.edu/~epickett F1 hcp. +16.36...Monster +366.59... Never argue with an idiot. He brings you down to his level, then beats you with experience... Remove SPAM-OFF to reply.