torcs-users Mailing List for TORCS - The Open Racing Car Simulator

This patch has more suspension improvements lifted from
TORCS on Sourceforge, and further tweaks to my code.

----- David Savinkoff wrote:
> Hi,
> torcs-1.3.6/src/modules/graphic/ssggraph/grskidmarks.cpp:
> 
> if (cur_clr[3] > 0.06f) {
> // 0.06 works better than 0.1 // something here improves traction ?!
> 
> ----- David Savinkoff wrote:
> Hi,
> 
> This patch applies the latest change to wheel.cpp in
> TORCS on Sourcforge:
> $Id: wheel.cpp,v 1.26.2.6 2016/03/06 20:59:31 berniw Exp $
> 
> This patch (see patch) also removes a discontinuity by tanh() in
> modules/graphic/ssggraph/grskidmarks.cpp
> (The Magic Formula in wheel.cpp should determine traction)
> 
> Good to see torqs-1.3.7 on the way.
> 
> ----- David Savinkoff wrote:
> Hi,
> 
> This patch removes an un-needed tanh() from
> modules/graphic/ssggraph/grskidmarks.cpp
> and re-arranges some of my changes in wheel.cpp
> ( the tanh() trick was used to range limit input: -1 to 1 )
> 
> This patch is the most physically correct,
> and the best performing one yet.
> 
> Please apply this patch.
> 
> ----- David Savinkoff wrote:
> Hi,
> 
> This patch fixes a performance issue without compromise.
> Smaller, Faster, and Better sound and driving performance.
> You can hear which tire is squealing as you drift past
> another car. Yahoo!
> 
----- David Savinkoff wrote:
> OK,
> 
> This patch goes beyond traction; it includes 2 bug fixes
> from Speed Dreams.
> 
> Yes, two serious physics impacting bugs.
> 
> Now you can get twice the realism by driving to the
> track in one car, and racing at the track in another.
> 
> ----- David Savinkoff wrote:
> Hi,
> This patch implements rolling resistance correctly along
> with some small changes. (wheel.cpp car.cpp)
> 
> Massive improvement. The TORCS simuv2 reference
> measure 'is' about to show all car sims 'how it is done'.
>
> ----- David Savinkoff wrote:
> Hi,
> 
> Yet another small improvement. Note that if some of these
> improvements appear odd, they are indicating problems
> hidden elsewhere.
> 
> ----- David Savinkoff wrote:
> Hi,
> This patch will probably be the last I make for
> wheel.cpp because I've meticulously examined and
> tested the code here repeatedly with results that have
> converged to perfection.
> 
> Please apply this patch.
> 
> ----- David Savinkoff wrote:
> > This patch removes legacy duct tape which was used as a
> > work-around for a previously nonexistent friction circle.
> > 
> > There is another piece of duct tape which impedes the car
> > from accelerating forward while allowing unimpeded sideways
> > acceleration when drifting. I'll remove that when I find it.
>
> This problem seems to be diminished as TORCS is made more
> correct.
> 
> > Note that RELAXATION2 is a low-pass Infinite Impulse Response
> > filter of the form: f(s) = (1/as) / (b+1/as) where s is in the s-domain,
> > 'a' is a spring-constant, and 'b' is a friction constant
> > mechanically acting on the rotation of the wheel. This will
> > certainly affect the physics of TORCS.
> 
 ----- David Savinkoff wrote:
> Hi Everybody,
> 
> This patch makes TORCS the best simulator wherever
> 'The Rubber meets the Road' is concerned. Try it.
> 
> ----- David Savinkoff wrote:
> > Hi,
> > 
> > In my last patch I had the following code:
> > slip_magnitude = 0.3f + sqrt( MAX(MAX((vn*vn + vt*vt)
> > 
> > Where (v2) should be equal to (vn*vn + vt*vt) but is not,
> > because of lack of precision of the float data type.
> > 
> > Here I use (v2) for velocity squared because the car drives
> > noticeably better, and (v2) is obviously more accurate.
> > 
> slip_magnitude = 0.3f + sqrt( MAX(MAX((v2)
> > 
> > BTW is there somewhere I can find recent TORCS source code
> > changes so that I can test and experiment?
> > 
> > Sincerely,
> > David Savinkoff
> 
> Hi,
> 
> Here is another patch for floating point improvements.
> 
> I used sqrtf() where it seemed to make a speed improvement
> on my slow computer.
> 
> I used (double) to get more accuracy for CosA and SinA
> 
> It is obvious that (float) is not sufficient in some
> circumstances, and that (double) is slower in others.
> 
> I hope these improvements in wheel.cpp help with making
> other problems more characterizable.
> 
> Sincerely,
> David Savinkoff
> 
> ps.
> 
> Speed Dreams should incorporate this patch too.
> Note that this patch will give you deja vu a few times
> per lap.

----- Carlos Massera FIlho wrote:
> Hi,
> 
> Is there any reference material for the equations used to implement the vehicle
> dynamics?
> I’m familiar with most of them but curious to what goes into the torcs source code.
> I’m trying to read the source directly but the dynamics part is very convoluted.
> 
> Thanks,
> Carlos Massera Filho

Hi,
The following sheds some light on TORCS:
http://phors.locost7.info/files/Beckman_-_The_Physics_of_Racing.pdf

Hi,

Is there any reference material for the equations used to implement the vehicle dynamics? I’m familiar with most of them but curious to what goes into the torcs source code.
I’m trying to read the source directly but the dynamics part is very convoluted.

Thanks,
Carlos Massera Filho

Hi all

Currently there is no telemetry activated in stock TORCS, but you can 
just write the data you need into a file:

http://www.berniw.org/trb/forum/showthread.php?topicid=4049

Kind regards

Bernhard

On 03/22/2016 10:23 AM, Roger Frigola wrote:
> Hi berkanay,
>
> I've seen this question asked three times in just a few months but it
> has never been answered.
>
> Being able to record telemetry easily is particularly useful to use
> torcs for research but this feature is not available at the moment. I
> am not able to comment on whether this is an intentional barrier of
> entry for newcomers or if it is simply technically difficult and
> unrewarding to add (again?) this feature.
>
> All the best in finding a solution to your problem.
>
> Cheers,
>
> Roger.
>
>
>
> On Sat, Mar 19, 2016 at 2:04 PM, berkanay . <ber...@gm...> wrote:
>> Hello dear friends,
>> i plan to research on tracks with neural network algorithms etc. Can anybody
>> help me to find or send tracks sensors data. Thanks for valuable helps. Nice
>> to meet to you.
>>
>> ------------------------------------------------------------------------------
>> Transform Data into Opportunity.
>> Accelerate data analysis in your applications with
>> Intel Data Analytics Acceleration Library.
>> Click to learn more.
>> http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140
>> _______________________________________________
>> Torcs-users mailing list
>> Tor...@li...
>> https://lists.sourceforge.net/lists/listinfo/torcs-users
>>
>
> ------------------------------------------------------------------------------
> Transform Data into Opportunity.
> Accelerate data analysis in your applications with
> Intel Data Analytics Acceleration Library.
> Click to learn more.
> http://pubads.g.doubleclick.net/gampad/clk?id=278785351&iu=/4140
> _______________________________________________
> Torcs-users mailing list
> Tor...@li...
> https://lists.sourceforge.net/lists/listinfo/torcs-users
>

Hi berkanay,

I've seen this question asked three times in just a few months but it
has never been answered.

Being able to record telemetry easily is particularly useful to use
torcs for research but this feature is not available at the moment. I
am not able to comment on whether this is an intentional barrier of
entry for newcomers or if it is simply technically difficult and
unrewarding to add (again?) this feature.

All the best in finding a solution to your problem.

Cheers,

Roger.



On Sat, Mar 19, 2016 at 2:04 PM, berkanay . <ber...@gm...> wrote:
> Hello dear friends,
> i plan to research on tracks with neural network algorithms etc. Can anybody
> help me to find or send tracks sensors data. Thanks for valuable helps. Nice
> to meet to you.
>
> ------------------------------------------------------------------------------
> Transform Data into Opportunity.
> Accelerate data analysis in your applications with
> Intel Data Analytics Acceleration Library.
> Click to learn more.
> http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140
> _______________________________________________
> Torcs-users mailing list
> Tor...@li...
> https://lists.sourceforge.net/lists/listinfo/torcs-users
>

Hello dear friends,
i plan to research on tracks with neural network algorithms etc. Can
anybody help me to find or send tracks sensors data. Thanks for valuable
helps. Nice to meet to you.

Hi,
torcs-1.3.6/src/modules/graphic/ssggraph/grskidmarks.cpp:

if (cur_clr[3] > 0.06f) {
// 0.06 works better than 0.1 // something here improves traction ?!

----- David Savinkoff wrote:
> Hi,
> 
> This patch applies the latest change to wheel.cpp in
> TORCS on Sourcforge:
> $Id: wheel.cpp,v 1.26.2.6 2016/03/06 20:59:31 berniw Exp $
> 
> This patch (see patch) also removes a discontinuity by tanh() in
> modules/graphic/ssggraph/grskidmarks.cpp
> (The Magic Formula in wheel.cpp should determine traction)
> 
> Good to see torqs-1.3.7 on the way.
> 
> ----- David Savinkoff wrote:
> > Hi,
> > 
> > This patch removes an un-needed tanh() from
> > modules/graphic/ssggraph/grskidmarks.cpp
> > and re-arranges some of my changes in wheel.cpp
> > ( the tanh() trick was used to range limit input: -1 to 1 )
> > 
> > This patch is the most physically correct,
> > and the best performing one yet.
> > 
> > Please apply this patch.
> > 
> > ----- David Savinkoff wrote:
> > > Hi,
> > > 
> > > This patch fixes a performance issue without compromise.
> > > Smaller, Faster, and Better sound and driving performance.
> > > You can hear which tire is squealing as you drift past
> > > another car. Yahoo!
> > > 
> > > ----- David Savinkoff wrote:
> > > > OK,
> > > > 
> > > > This patch goes beyond traction; it includes 2 bug fixes
> > > > from Speed Dreams.
> > > > 
> > > > Yes, two serious physics impacting bugs.
> > > > 
> > > > Now you can get twice the realism by driving to the
> > > > track in one car, and racing at the track in another.
> > > > 
> > > > ----- David Savinkoff wrote:
> > > > > Hi,
> > > > > This patch implements rolling resistance correctly along
> > > > > with some small changes. (wheel.cpp car.cpp)
> > > > > 
> > > > > Massive improvement. The TORCS simuv2 reference
> > > > > measure 'is' about to show all car sims 'how it is done'.
> > > > > 
> > > > > ----- David Savinkoff wrote:
> > > > > > Hi,
> > > > > > 
> > > > > > Yet another small improvement. Note that if some of these
> > > > > > improvements appear odd, they are indicating problems
> > > > > > hidden elsewhere.
> > > > > > 
> > > > > > ----- David Savinkoff wrote:
> > > > > > > Hi,
> > > > > > > This patch will probably be the last I make for
> > > > > > > wheel.cpp because I've meticulously examined and
> > > > > > > tested the code here repeatedly with results that have
> > > > > > > converged to perfection.
> > > > > > > 
> > > > > > > Please apply this patch.
> > > > > > > 
> > > > > > > ----- David Savinkoff wrote:
> > > > > > > > This patch removes legacy duct tape which was used as a
> > > > > > > > work-around for a previously nonexistent friction circle.
> > > > > > > > 
> > > > > > > > There is another piece of duct tape which impedes the car
> > > > > > > > from accelerating forward while allowing unimpeded sideways
> > > > > > > > acceleration when drifting. I'll remove that when I find it.
> > > > > > > >
> > > > > > > This problem seems to be diminished as TORCS is made more
> > > > > > > correct.
> > > > > > > > 
> > > > > > > > Note that RELAXATION2 is a low-pass Infinite Impulse Response
> > > > > > > > filter of the form: f(s) = (1/as) / (b+1/as) where s is in the s-domain,
> > > > > > > > 'a' is a spring-constant, and 'b' is a friction constant
> > > > > > > > mechanically acting on the rotation of the wheel. This will
> > > > > > > > certainly affect the physics of TORCS.
> > > > > > > > 
> > > > > > > > ----- David Savinkoff wrote:
> > > > > > > > > Hi Everybody,
> > > > > > > > > 
> > > > > > > > > This patch makes TORCS the best simulator wherever
> > > > > > > > > 'The Rubber meets the Road' is concerned. Try it.
> > > > > > > > > 
> > > > > > > > > ----- David Savinkoff wrote:
> > > > > > > > > > Hi,
> > > > > > > > > > 
> > > > > > > > > > In my last patch I had the following code:
> > > > > > > > > > slip_magnitude = 0.3f + sqrt( MAX(MAX((vn*vn + vt*vt)
> > > > > > > > > > 
> > > > > > > > > > Where (v2) should be equal to (vn*vn + vt*vt) but is not,
> > > > > > > > > > because of lack of precision of the float data type.
> > > > > > > > > > 
> > > > > > > > > > Here I use (v2) for velocity squared because the car drives
> > > > > > > > > > noticeably better, and (v2) is obviously more accurate.
> > > > > > > > > > 
> > > > > > > > > > slip_magnitude = 0.3f + sqrt( MAX(MAX((v2)
> > > > > > > > > > 
> > > > > > > > > > BTW is there somewhere I can find recent TORCS source code
> > > > > > > > > > changes so that I can test and experiment?
> > > > > > > > > > 
> > > > > > > > > > Sincerely,
> > > > > > > > > > David Savinkoff
> > > > > > > > > 
> > > > > > > > > Hi,
> > > > > > > > > 
> > > > > > > > > Here is another patch for floating point improvements.
> > > > > > > > > 
> > > > > > > > > I used sqrtf() where it seemed to make a speed improvement
> > > > > > > > > on my slow computer.
> > > > > > > > > 
> > > > > > > > > I used (double) to get more accuracy for CosA and SinA
> > > > > > > > > 
> > > > > > > > > It is obvious that (float) is not sufficient in some
> > > > > > > > > circumstances, and that (double) is slower in others.
> > > > > > > > > 
> > > > > > > > > I hope these improvements in wheel.cpp help with making
> > > > > > > > > other problems more characterizable.
> > > > > > > > > 
> > > > > > > > > Sincerely,
> > > > > > > > > David Savinkoff
> > > > > > > > > 
> > > > > > > > > ps.
> > > > > > > > > 
> > > > > > > > > Speed Dreams should incorporate this patch too.
> > > > > > > > > Note that this patch will give you deja vu a few times
> > > > > > > > > per lap.
> > > > > > > > 
> > > > > > > 
> > > > > > 
> > > > > 
> > > > 
> > > 
> >

The whole site is gone, I am looking into it with my provider... the 
site stopped working this morning around 8:20 am local time. It could 
take some more than a day till it is up again.

Kind regards

Bernhard

On 03/07/2016 11:01 AM, Arnaud Ceyrolle wrote:
> Hello,
>
> for the 3 events, the links seems broken :
>
>
>   Not Found
>
> The requested URL /trb/events/event_view.php was not found on this server.
>
>
>
>
> 2016-03-06 22:55 GMT+01:00 Bernhard Wymann <be...@bl...
> <mailto:be...@bl...>>:
>
>     Hi all
>
>     I set up the 2016 championships, as usual there are is a test
>     championship and the real one:
>     http://www.berniw.org/trb/events/event_view.php?vieweventid=23
>     http://www.berniw.org/trb/events/event_view.php?vieweventid=22
>
>     The last years competitors sources can be downloaded here and can be
>     used as starting point:
>     http://www.berniw.org/trb/events/event_view.php?vieweventid=20
>
>     Hope to meet you on the track.
>
>     Kind regards
>
>     Bernhard
>
>     ------------------------------------------------------------------------------
>     _______________________________________________
>     Torcs-users mailing list
>     Tor...@li...
>     <mailto:Tor...@li...>
>     https://lists.sourceforge.net/lists/listinfo/torcs-users
>
>
>
>
> --
> *Arnaud Ceyrolle*

Hi,

This patch applies the latest change to wheel.cpp in
TORCS on Sourcforge:
$Id: wheel.cpp,v 1.26.2.6 2016/03/06 20:59:31 berniw Exp $

This patch (see patch) also removes a discontinuity by tanh() in
modules/graphic/ssggraph/grskidmarks.cpp
(The Magic Formula in wheel.cpp should determine traction)

Good to see torqs-1.3.7 on the way.

----- David Savinkoff wrote:
> Hi,
> 
> This patch removes an un-needed tanh() from
> modules/graphic/ssggraph/grskidmarks.cpp
> and re-arranges some of my changes in wheel.cpp
> ( the tanh() trick was used to range limit input: -1 to 1 )
> 
> This patch is the most physically correct,
> and the best performing one yet.
> 
> Please apply this patch.
> 
> ----- David Savinkoff wrote:
> > Hi,
> > 
> > This patch fixes a performance issue without compromise.
> > Smaller, Faster, and Better sound and driving performance.
> > You can hear which tire is squealing as you drift past
> > another car. Yahoo!
> > 
> > ----- David Savinkoff wrote:
> > > OK,
> > > 
> > > This patch goes beyond traction; it includes 2 bug fixes
> > > from Speed Dreams.
> > > 
> > > Yes, two serious physics impacting bugs.
> > > 
> > > Now you can get twice the realism by driving to the
> > > track in one car, and racing at the track in another.
> > > 
> > > ----- David Savinkoff wrote:
> > > > Hi,
> > > > This patch implements rolling resistance correctly along
> > > > with some small changes. (wheel.cpp car.cpp)
> > > > 
> > > > Massive improvement. The TORCS simuv2 reference
> > > > measure 'is' about to show all car sims 'how it is done'.
> > > > 
> > > > ----- David Savinkoff wrote:
> > > > > Hi,
> > > > > 
> > > > > Yet another small improvement. Note that if some of these
> > > > > improvements appear odd, they are indicating problems
> > > > > hidden elsewhere.
> > > > > 
> > > > > ----- David Savinkoff wrote:
> > > > > > Hi,
> > > > > > This patch will probably be the last I make for
> > > > > > wheel.cpp because I've meticulously examined and
> > > > > > tested the code here repeatedly with results that have
> > > > > > converged to perfection.
> > > > > > 
> > > > > > Please apply this patch.
> > > > > > 
> > > > > > ----- David Savinkoff wrote:
> > > > > > > This patch removes legacy duct tape which was used as a
> > > > > > > work-around for a previously nonexistent friction circle.
> > > > > > > 
> > > > > > > There is another piece of duct tape which impedes the car
> > > > > > > from accelerating forward while allowing unimpeded sideways
> > > > > > > acceleration when drifting. I'll remove that when I find it.
> > > > > > >
> > > > > > This problem seems to be diminished as TORCS is made more
> > > > > > correct.
> > > > > > > 
> > > > > > > Note that RELAXATION2 is a low-pass Infinite Impulse Response
> > > > > > > filter of the form: f(s) = (1/as) / (b+1/as) where s is in the s-domain,
> > > > > > > 'a' is a spring-constant, and 'b' is a friction constant
> > > > > > > mechanically acting on the rotation of the wheel. This will
> > > > > > > certainly affect the physics of TORCS.
> > > > > > > 
> > > > > > > ----- David Savinkoff wrote:
> > > > > > > > Hi Everybody,
> > > > > > > > 
> > > > > > > > This patch makes TORCS the best simulator wherever
> > > > > > > > 'The Rubber meets the Road' is concerned. Try it.
> > > > > > > > 
> > > > > > > > ----- David Savinkoff wrote:
> > > > > > > > > Hi,
> > > > > > > > > 
> > > > > > > > > In my last patch I had the following code:
> > > > > > > > > slip_magnitude = 0.3f + sqrt( MAX(MAX((vn*vn + vt*vt)
> > > > > > > > > 
> > > > > > > > > Where (v2) should be equal to (vn*vn + vt*vt) but is not,
> > > > > > > > > because of lack of precision of the float data type.
> > > > > > > > > 
> > > > > > > > > Here I use (v2) for velocity squared because the car drives
> > > > > > > > > noticeably better, and (v2) is obviously more accurate.
> > > > > > > > > 
> > > > > > > > > slip_magnitude = 0.3f + sqrt( MAX(MAX((v2)
> > > > > > > > > 
> > > > > > > > > BTW is there somewhere I can find recent TORCS source code
> > > > > > > > > changes so that I can test and experiment?
> > > > > > > > > 
> > > > > > > > > Sincerely,
> > > > > > > > > David Savinkoff
> > > > > > > > 
> > > > > > > > Hi,
> > > > > > > > 
> > > > > > > > Here is another patch for floating point improvements.
> > > > > > > > 
> > > > > > > > I used sqrtf() where it seemed to make a speed improvement
> > > > > > > > on my slow computer.
> > > > > > > > 
> > > > > > > > I used (double) to get more accuracy for CosA and SinA
> > > > > > > > 
> > > > > > > > It is obvious that (float) is not sufficient in some
> > > > > > > > circumstances, and that (double) is slower in others.
> > > > > > > > 
> > > > > > > > I hope these improvements in wheel.cpp help with making
> > > > > > > > other problems more characterizable.
> > > > > > > > 
> > > > > > > > Sincerely,
> > > > > > > > David Savinkoff
> > > > > > > > 
> > > > > > > > ps.
> > > > > > > > 
> > > > > > > > Speed Dreams should incorporate this patch too.
> > > > > > > > Note that this patch will give you deja vu a few times
> > > > > > > > per lap.
> > > > > > > 
> > > > > > 
> > > > > 
> > > > 
> > > 
> > 
>

Hi all

I set up the 2016 championships, as usual there are is a test 
championship and the real one:
http://www.berniw.org/trb/events/event_view.php?vieweventid=23
http://www.berniw.org/trb/events/event_view.php?vieweventid=22

The last years competitors sources can be downloaded here and can be 
used as starting point:
http://www.berniw.org/trb/events/event_view.php?vieweventid=20

Hope to meet you on the track.

Kind regards

Bernhard

Hi,

This patch removes an un-needed tanh() from
modules/graphic/ssggraph/grskidmarks.cpp
and re-arranges some of my changes in wheel.cpp
( the tanh() trick was used to range limit input: -1 to 1 )

This patch is the most physically correct,
and the best performing one yet.

Please apply this patch.

----- David Savinkoff wrote:
> Hi,
> 
> This patch fixes a performance issue without compromise.
> Smaller, Faster, and Better sound and driving performance.
> You can hear which tire is squealing as you drift past
> another car. Yahoo!
> 
> ----- David Savinkoff wrote:
> > OK,
> > 
> > This patch goes beyond traction; it includes 2 bug fixes
> > from Speed Dreams.
> > 
> > Yes, two serious physics impacting bugs.
> > 
> > Now you can get twice the realism by driving to the
> > track in one car, and racing at the track in another.
> > 
> > ----- David Savinkoff wrote:
> > > Hi,
> > > This patch implements rolling resistance correctly along
> > > with some small changes. (wheel.cpp car.cpp)
> > > 
> > > Massive improvement. The TORCS simuv2 reference
> > > measure 'is' about to show all car sims 'how it is done'.
> > > 
> > > ----- David Savinkoff wrote:
> > > > Hi,
> > > > 
> > > > Yet another small improvement. Note that if some of these
> > > > improvements appear odd, they are indicating problems
> > > > hidden elsewhere.
> > > > 
> > > > ----- David Savinkoff wrote:
> > > > > Hi,
> > > > > This patch will probably be the last I make for
> > > > > wheel.cpp because I've meticulously examined and
> > > > > tested the code here repeatedly with results that have
> > > > > converged to perfection.
> > > > > 
> > > > > Please apply this patch.
> > > > > 
> > > > > ----- David Savinkoff wrote:
> > > > > > This patch removes legacy duct tape which was used as a
> > > > > > work-around for a previously nonexistent friction circle.
> > > > > > 
> > > > > > There is another piece of duct tape which impedes the car
> > > > > > from accelerating forward while allowing unimpeded sideways
> > > > > > acceleration when drifting. I'll remove that when I find it.
> > > > > >
> > > > > This problem seems to be diminished as TORCS is made more
> > > > > correct.
> > > > > > 
> > > > > > Note that RELAXATION2 is a low-pass Infinite Impulse Response
> > > > > > filter of the form: f(s) = (1/as) / (b+1/as) where s is in the s-domain,
> > > > > > 'a' is a spring-constant, and 'b' is a friction constant
> > > > > > mechanically acting on the rotation of the wheel. This will
> > > > > > certainly affect the physics of TORCS.
> > > > > > 
> > > > > > ----- David Savinkoff wrote:
> > > > > > > Hi Everybody,
> > > > > > > 
> > > > > > > This patch makes TORCS the best simulator wherever
> > > > > > > 'The Rubber meets the Road' is concerned. Try it.
> > > > > > > 
> > > > > > > ----- David Savinkoff wrote:
> > > > > > > > ----- David Savinkoff wrote:
> > > > > > > > > Hi,
> > > > > > > > > 
> > > > > > > > > In my last patch I had the following code:
> > > > > > > > > slip_magnitude = 0.3f + sqrt( MAX(MAX((vn*vn + vt*vt)
> > > > > > > > > 
> > > > > > > > > Where (v2) should be equal to (vn*vn + vt*vt) but is not,
> > > > > > > > > because of lack of precision of the float data type.
> > > > > > > > > 
> > > > > > > > > Here I use (v2) for velocity squared because the car drives
> > > > > > > > > noticeably better, and (v2) is obviously more accurate.
> > > > > > > > > 
> > > > > > > > > slip_magnitude = 0.3f + sqrt( MAX(MAX((v2)
> > > > > > > > > 
> > > > > > > > > BTW is there somewhere I can find recent TORCS source code
> > > > > > > > > changes so that I can test and experiment?
> > > > > > > > > 
> > > > > > > > > Sincerely,
> > > > > > > > > David Savinkoff
> > > > > > > > 
> > > > > > > > Hi,
> > > > > > > > 
> > > > > > > > Here is another patch for floating point improvements.
> > > > > > > > 
> > > > > > > > I used sqrtf() where it seemed to make a speed improvement
> > > > > > > > on my slow computer.
> > > > > > > > 
> > > > > > > > I used (double) to get more accuracy for CosA and SinA
> > > > > > > > 
> > > > > > > > It is obvious that (float) is not sufficient in some
> > > > > > > > circumstances, and that (double) is slower in others.
> > > > > > > > 
> > > > > > > > I hope these improvements in wheel.cpp help with making
> > > > > > > > other problems more characterizable.
> > > > > > > > 
> > > > > > > > Sincerely,
> > > > > > > > David Savinkoff
> > > > > > > > 
> > > > > > > > ps.
> > > > > > > > 
> > > > > > > > Speed Dreams should incorporate this patch too.
> > > > > > > > Note that this patch will give you deja vu a few times
> > > > > > > > per lap.
> > > > > > > 
> > > > > > 
> > > > > 
> > > > 
> > > 
> > 
> 

Hi,

This patch fixes a performance issue without compromise.
Smaller, Faster, and Better sound and driving performance.
You can hear which tire is squealing as you drift past
another car. Yahoo!

----- David Savinkoff wrote:
> OK,
> 
> This patch goes beyond traction; it includes 2 bug fixes
> from Speed Dreams.
> 
> Yes, two serious physics impacting bugs.
> 
> Now you can get twice the realism by driving to the
> track in one car, and racing at the track in another.
> 
> ----- David Savinkoff wrote:
> > Hi,
> > This patch implements rolling resistance correctly along
> > with some small changes. (wheel.cpp car.cpp)
> > 
> > Massive improvement. The TORCS simuv2 reference
> > measure 'is' about to show all car sims 'how it is done'.
> > 
> > ----- David Savinkoff wrote:
> > > Hi,
> > > 
> > > Yet another small improvement. Note that if some of these
> > > improvements appear odd, they are indicating problems
> > > hidden elsewhere.
> > > 
> > > ----- David Savinkoff wrote:
> > > > Hi,
> > > > This patch will probably be the last I make for
> > > > wheel.cpp because I've meticulously examined and
> > > > tested the code here repeatedly with results that have
> > > > converged to perfection.
> > > > 
> > > > Please apply this patch.
> > > > 
> > > > ----- David Savinkoff wrote:
> > > > > This patch removes legacy duct tape which was used as a
> > > > > work-around for a previously nonexistent friction circle.
> > > > > 
> > > > > There is another piece of duct tape which impedes the car
> > > > > from accelerating forward while allowing unimpeded sideways
> > > > > acceleration when drifting. I'll remove that when I find it.
> > > > >
> > > > This problem seems to be diminished as TORCS is made more
> > > > correct.
> > > > > 
> > > > > Note that RELAXATION2 is a low-pass Infinite Impulse Response
> > > > > filter of the form: f(s) = (1/as) / (b+1/as) where s is in the s-domain,
> > > > > 'a' is a spring-constant, and 'b' is a friction constant
> > > > > mechanically acting on the rotation of the wheel. This will
> > > > > certainly affect the physics of TORCS.
> > > > > 
> > > > > ----- David Savinkoff wrote:
> > > > > > Hi Everybody,
> > > > > > 
> > > > > > This patch makes TORCS the best simulator wherever
> > > > > > 'The Rubber meets the Road' is concerned. Try it.
> > > > > > 
> > > > > > ----- David Savinkoff wrote:
> > > > > > > ----- David Savinkoff wrote:
> > > > > > > > Hi,
> > > > > > > > 
> > > > > > > > In my last patch I had the following code:
> > > > > > > > slip_magnitude = 0.3f + sqrt( MAX(MAX((vn*vn + vt*vt)
> > > > > > > > 
> > > > > > > > Where (v2) should be equal to (vn*vn + vt*vt) but is not,
> > > > > > > > because of lack of precision of the float data type.
> > > > > > > > 
> > > > > > > > Here I use (v2) for velocity squared because the car drives
> > > > > > > > noticeably better, and (v2) is obviously more accurate.
> > > > > > > > 
> > > > > > > > slip_magnitude = 0.3f + sqrt( MAX(MAX((v2)
> > > > > > > > 
> > > > > > > > BTW is there somewhere I can find recent TORCS source code
> > > > > > > > changes so that I can test and experiment?
> > > > > > > > 
> > > > > > > > Sincerely,
> > > > > > > > David Savinkoff
> > > > > > > 
> > > > > > > Hi,
> > > > > > > 
> > > > > > > Here is another patch for floating point improvements.
> > > > > > > 
> > > > > > > I used sqrtf() where it seemed to make a speed improvement
> > > > > > > on my slow computer.
> > > > > > > 
> > > > > > > I used (double) to get more accuracy for CosA and SinA
> > > > > > > 
> > > > > > > It is obvious that (float) is not sufficient in some
> > > > > > > circumstances, and that (double) is slower in others.
> > > > > > > 
> > > > > > > I hope these improvements in wheel.cpp help with making
> > > > > > > other problems more characterizable.
> > > > > > > 
> > > > > > > Sincerely,
> > > > > > > David Savinkoff
> > > > > > > 
> > > > > > > ps.
> > > > > > > 
> > > > > > > Speed Dreams should incorporate this patch too.
> > > > > > > Note that this patch will give you deja vu a few times
> > > > > > > per lap.
> > > > > > 
> > > > > 
> > > > 
> > > 
> > 
>