Car physics

Hi there! I've noticed that there are plenty of people who knows a great deal about car physics in this newsgroup. So, I will try my luck with a couple of questions for you. Bear with me if my post gets a bit loooong, but please read it through. I'm trying to develop my own little car simulator and so far I have just implemented acceleration forces and weight transfer, i.e. my car can't brake or turn. I have one problem with my simulation and I was hoping that someone would perhaps give me some answers. When I try to run the simulation at higher frequencies, e.g. 60Hz, my car doesn't get anywhere. The reason is that after the first frame, my engine speed drops to about 26 rpm. I start with an engine speed of 2000 rpm and after one frame I calculate the new engine speed according to the speed the car has reached in this frame. Something like this: wheelAngularSpeed = carSpeed / wheelRadius engineSpeed = 60 * 1/2pi * wheelAngularSpeed * totalRatio Is this a correct calculation do you think? The rev drop decreases the acceleration force too much to overcome the rolling resistance, which is about 130N. Maybe this resistance is too high? I used Zuvich's approximation formula RX = 0.01(1 + V/100) * W, where V is the speed in mph and W is the weight of the car in Newton. I have put a restriction on the acceleration force so that it doesn't decrease below 0. Otherwise, the car would go backwards in this simulation. Now it just goes forward with the frightening speed of 0.23 km/h... At lower frequencies, e.g. 10Hz, this is not a problem, since the linear interpolation makes the speed rise to 0.78 km/h at the first frame, which means that the rev drops down to 90 rpm. This makes a acceleration force of 145N which overcomes the rolling resistance force of 130N. The following is some prints from my simulation at 60Hz: Ntf is the combined gear and final ratio. ntf is the total efficiency. r is the wheel radius. RX is the rolling resistance. DA is the drag. Tractive force is torque * Ntf * ntf / r Facc is the acceleration force = torque * Ntf * ntf / r - RX - DA 0 km/h, 2000 rpm at 0 seconds Torque at 2000 rpm: 163 Ntf: 12.8142 ntf: 0.7 r: 0.293 RX: 0 DA: 0 Tractive force: 4990.1 Facc: 4990.1 0.226823 km/h, 26.3136 rpm at 0.0166667 seconds Torque at 26.3136 rpm: 2.63136 Ntf: 12.8142 ntf: 0.7 r: 0.293 RX: 129.807 DA: 0.00151679 Tractive force: 80.5567 Facc: 0 0.226823 km/h, 26.3136 rpm at 0.0333333 seconds Torque at 26.3136 rpm: 2.63136 Ntf: 12.8142 ntf: 0.7 r: 0.293 RX: 129.807 DA: 0.00151679 Tractive force: 80.5567 Facc: 0 I hope someone could find the time to read this loooong post through and answer some of my questions. If I was unclear in any part, please ask me to explain it better. Thanks in advance, Andreas Ekstrand

On Sat, 28 Jul 2001 17:44:08 GMT, "Andreas Ekstrand" <[email hidden]> wrote: >I'm trying to develop my own little car simulator and so far I have just >implemented acceleration forces and weight transfer, i.e. my car can't brake >or turn. Welcome to the club. :) >The rev drop decreases the acceleration force too much to overcome the >rolling resistance, which is about 130N. Maybe this resistance is too high? No, sounds ok. Sounds like you either do something bad with the time, multiplying something with 'dt' where you shouldn't, or you are not caculating engine torque correctly. That last one is my first bet. Do you have an engine torque that drives the wheels? If this torque exceeds the 130N at the wheel's contact patch, it should be ok. And as an engine might easily produce 200Nm, that would mean about 3x4x200=2400Nm at the wheel (3 and 4 are gear rations). As T=F*r, you get F=T/r, so 2400Nm/0.33 (radius of wheel) ~ 7200N at the wheel's contact patch. And 7200N >> 130N. Somewhere in all this it goes wrong for you I think. Good luck, Ruud van Gaal, GPL Rank +53.25 Pencil art : http://www.marketgraph.nl/gallery/ Free car sim : http://www.marketgraph.nl/gallery/racer/

Andreas Ekstrand wrote:

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> I'm trying to develop my own little car simulator and so far I have just > implemented acceleration forces and weight transfer, i.e. my car can't brake > or turn. > > I have one problem with my simulation and I was hoping that someone would > perhaps give me some answers. When I try to run the simulation at higher > frequencies, e.g. 60Hz, my car doesn't get anywhere. The reason is that > after the first frame, my engine speed drops to about 26 rpm. I start with > an engine speed of 2000 rpm and after one frame I calculate the new engine > speed according to the speed the car has reached in this frame. Something > like this: > > wheelAngularSpeed = carSpeed / wheelRadius > engineSpeed = 60 * 1/2pi * wheelAngularSpeed * totalRatio > > Is this a correct calculation do you think? > > The rev drop decreases the acceleration force too much to overcome the > rolling resistance, which is about 130N.

engineSpeed = 60 * 1/2pi * wheelAngularSpeed * totalRatio I assume wheelAngularSpeed is radians per second. (This assumes that carSpeed and wheelRadius are in units of length/second and length. That is, make sure you aren't using kph or something for carSpeed.) Once wheelAngularSpeed is in radians / second, then I think your conversion from radians per sec to revolutions per minute may be wrong. It is (60 / (2 * PI)) or about 9.55. This may indeed be what you meant by your equation, but be wary you use enough parentheses for your programming language ;) Finally, setting engine speed like this means you have no engine dynamics. The engine speed appropriate to a near zero speed at startup may indeed be so slow as to stall the engine. What happens in real life is the driver either declutches to reduce the torque dragging down the engine speed or revs the engine prior to clutching or engaging first gear. To make this work properly you need a lot more dynamics for the engine and cluch. One quick patch you could make is to filter the engineSpeed. This will slow the engines response to gear / clutch changes like your step down at starting and get you past this type of problem for awhile. (This is actually a simplified version of what adding all the dynamics mentioned above would result in anyway ;) The easiest filter to use may be a "first order low pass filter" because you can use it in situations where the frame rate varies. In the pseudo code below, "//" is a comment to end of line engineSpeed_raw = (60 / (2 pi)) * wheelAngularSpeed * totalRatio // constant for your application // try 1.0 to 0.1 cycles per second or lower. // higher values are more smoothing, // lower is quicker response (less smothing) cutoffFrequency = 0.5 // filter: timeStep = time - time_previous // this is in seconds filterCoefficientA = exp(-TWO_PI * cutoffFrequency * timeStep) filterCoefficientB = 1 - filterCoefficientA engineSpeed = engineSpeed_previous * filterCoefficientA + engineSpeed_raw * filterCoefficientB engineSpeed_previous = engineSpeed Whenever you add a filter, you should add code to "reset" the filter whenever you do a step change to the filter state. (For instance, if you have a "Reset" command that starts the car back at starting states, the filter reset would be: engineSpeed_previous = engineSpeed ) Otherwise the filter will smooth in the step change you wanted to take place instantly. The filter coefficient equation above is exact and will automatically correct for changing frame rates and maintain the same lag characteristics for all. You can approximate the desired coefficient various ways if you don't want to do the exponential each frame. - Matt

Erm, it looks like your car is effectively stalling (I don't think internal combustion engines work very well at 26 rpm...) If everything "feels good" when you try it with a 5 mph rolling start then maybe you might want to look at your clutch code and try to get underway without being quite so brutal to your engine. I'm no programmer but this is the way it looks to me :0) Cheerio Jim S "Andreas Ekstrand" <[email hidden]> wrote in message news:IRC87.7360$[email hidden]...

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> Hi there! > > I've noticed that there are plenty of people who knows a great deal about > car physics in this newsgroup. So, I will try my luck with a couple of > questions for you. Bear with me if my post gets a bit loooong, but please > read it through. > > I'm trying to develop my own little car simulator and so far I have just > implemented acceleration forces and weight transfer, i.e. my car can't

brake

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> or turn. > > I have one problem with my simulation and I was hoping that someone would > perhaps give me some answers. When I try to run the simulation at higher > frequencies, e.g. 60Hz, my car doesn't get anywhere. The reason is that > after the first frame, my engine speed drops to about 26 rpm. I start with > an engine speed of 2000 rpm and after one frame I calculate the new engine > speed according to the speed the car has reached in this frame. Something > like this: > > wheelAngularSpeed = carSpeed / wheelRadius > engineSpeed = 60 * 1/2pi * wheelAngularSpeed * totalRatio > > Is this a correct calculation do you think? > > The rev drop decreases the acceleration force too much to overcome the > rolling resistance, which is about 130N. Maybe this resistance is too

high?

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> I used Zuvich's approximation formula RX = 0.01(1 + V/100) * W, where V is > the speed in mph and W is the weight of the car in Newton. I have put a > restriction on the acceleration force so that it doesn't decrease below 0. > Otherwise, the car would go backwards in this simulation. Now it just goes > forward with the frightening speed of 0.23 km/h... > > At lower frequencies, e.g. 10Hz, this is not a problem, since the linear > interpolation makes the speed rise to 0.78 km/h at the first frame, which > means that the rev drops down to 90 rpm. This makes a acceleration force

of

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> 145N which overcomes the rolling resistance force of 130N. > > The following is some prints from my simulation at 60Hz: > Ntf is the combined gear and final ratio. > ntf is the total efficiency. > r is the wheel radius. > RX is the rolling resistance. > DA is the drag. > Tractive force is torque * Ntf * ntf / r > Facc is the acceleration force = torque * Ntf * ntf / r - RX - DA > > 0 km/h, 2000 rpm at 0 seconds > Torque at 2000 rpm: 163 > Ntf: 12.8142 > ntf: 0.7 > r: 0.293 > RX: 0 > DA: 0 > Tractive force: 4990.1 > Facc: 4990.1 > > 0.226823 km/h, 26.3136 rpm at 0.0166667 seconds > Torque at 26.3136 rpm: 2.63136 > Ntf: 12.8142 > ntf: 0.7 > r: 0.293 > RX: 129.807 > DA: 0.00151679 > Tractive force: 80.5567 > Facc: 0 > > 0.226823 km/h, 26.3136 rpm at 0.0333333 seconds > Torque at 26.3136 rpm: 2.63136 > Ntf: 12.8142 > ntf: 0.7 > r: 0.293 > RX: 129.807 > DA: 0.00151679 > Tractive force: 80.5567 > Facc: 0 > > I hope someone could find the time to read this loooong post through and > answer some of my questions. If I was unclear in any part, please ask me

to > explain it better. > > Thanks in advance, > Andreas Ekstrand > >

I've been drinking tonight but helpfully this will clarify my previous post, I've no idea if either make sense, except to me :0) > wheelAngularSpeed = carSpeed / wheelRadius > engineSpeed = 60 * 1/2pi * wheelAngularSpeed * totalRatio This equation looks to be fine, but it does make several assumptions, such as zero wheelspin, no skidding, car isn't airborne, car isn't cornering (where carSpeed won't necessarily equal wheelSpeed) etc. Another assumption is that the clutch isn't slipping. Some amount of clutch slip (or alternatively wheelspin!) is necessary when moving off from a standstill or you'll stall the engine. This is what's happening in your sim - the clutch isn't modelled so the car stalls when you slam it into first gear. I think. :0) Hope that helps Jim

> I assume wheelAngularSpeed is radians per second. > (This assumes that carSpeed and wheelRadius are in units of length/second > and length. That is, make sure you aren't using kph or something forcarSpeed.) > > Once wheelAngularSpeed is in radians / second, > then I think your conversion from radians per sec to revolutions perminute > may be wrong. It is (60 / (2 * PI)) or about 9.55. > This may indeed be what you meant by your equation, but be wary > you use enough parentheses for your programming language ;) Yep, that's exactly what I meant - the following is what I wrote in the real code: rpm = (60.0/(2.0*M_PI) * vx_/r) * Ntf; vx_ is the speed in the x direction, r is the wheel radius and Ntf is the total ratio.

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> Finally, setting engine speed like this means you have no engine dynamics. > The engine speed appropriate to a near zero speed at startup may indeed > be so slow as to stall the engine. What happens in real life is the driver > either declutches to reduce the torque dragging down the engine speed > or revs the engine prior to clutching or engaging first gear. > To make this work properly you need a lot more dynamics for the engine > and cluch.

Yes, I realize that. I thought I could omit the clutch for now though, and get a fairly realistic behavior anyway. So now I have cheated a bit and assumes that the engine delivers torque even at 0 rpm. What do you think about that approximation? Thanks a lot for the filtering function! I will try it out as soon as I find the time to hack away again. /Andreas

> > wheelAngularSpeed = carSpeed / wheelRadius > > engineSpeed = 60 * 1/2pi * wheelAngularSpeed * totalRatio > > This equation looks to be fine, but it does make several assumptions, such > as zero wheelspin, no skidding, car isn't airborne, car isn't cornering > (where carSpeed won't necessarily equal wheelSpeed) etc. Yes, I know. I haven't modelled cornering yet. Neither have I given it any thought about the differential, which is the reason why carSpeed won't always be the same as wheelSpeed, I guess? My plan is to refine the model gradually. But dont' get me wront, I really appreciate these thoughts! They really help to think about every aspect of this complicated task. I heard someone say that developing a car simulator is twice as hard compared to developing a flight simulator. Well, I guess that's not entirely exaggerated... :-) > Another assumption is that the clutch isn't slipping. Some amount ofclutch > slip (or alternatively wheelspin!) is necessary when moving off from a > standstill or you'll stall the engine. This is what's happening in your > sim - the clutch isn't modelled so the car stalls when you slam it into > first gear. I think. :0) Yes...so maybe I'll just have to model the clutch? Can you see any way to make the behaviour fairly realistic without this, until I find the energy to implement the clutch? Thanks! /Andreas

"Andreas Ekstrand" <[email hidden]> wrote in message news:uuF97.7703$[email hidden]... > Yes...so maybe I'll just have to model the clutch? Can you see any way to > make the behaviour fairly realistic without this, until I find the energyto > implement the clutch? Just start your test at 5 mph? That way you can avoid the awkward "getting going" bit which won't really work without a clutch I don't think... Ruud, Gregor, Ash, Todd and a whole bunch of others are really the best people to ask :0) Cheers Jim

Andreas Ekstrand wrote:

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> > Yes, I know. I haven't modelled cornering yet. Neither have I given it any > thought about the differential, which is the reason why carSpeed won't > always be the same as wheelSpeed, I guess? My plan is to refine the model > gradually. But dont' get me wront, I really appreciate these thoughts! They > really help to think about every aspect of this complicated task. I heard > someone say that developing a car simulator is twice as hard compared to > developing a flight simulator. Well, I guess that's not entirely > exaggerated... :-) >

Indeed, that should be true. In a flight sim the application of forces is straightforward, as they all just act in a very numerically stable way (they go to 0 with velocity), so it's much easier. That's if you fudge the taxiing behaviour of course, which effectively makes it a car sim :). > > Yes...so maybe I'll just have to model the clutch? Can you see any way to > make the behaviour fairly realistic without this, until I find the energy to > implement the clutch? > To do it properly you do need a clutch. However, if purely for gameplay reasons, as clutches aren't that common on wheels these days, just make the available torque nonzero for 0 RPM. It's a fudge practically all sims out there make, so why can't we as well :)? -Gregor

On Wed, 01 Aug 2001 08:34:48 +0200, Gregor Veble <[email hidden]> wrote: >To do it properly you do need a clutch. However, if purely for gameplay >reasons, as clutches aren't that common on wheels these days, just make >the available torque nonzero for 0 RPM. It's a fudge practically all >sims out there make, so why can't we as well :)? Well, WSC will probably stall as one of the few sims. :) I just ordered a fullblown Force RS wheel with RS Shifter and clutch pedal thingy. Couldn't find it up until today, and even then I was lucky when there was this checkmark stating 'you want a clutch pedal with that?'. :) Will take a month probably to arrive, but hm, the fun starts! Or at least, the programming, to get the Act Labs shifter and clutch pedal to work (when I have it, I surely have to get it working right). 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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>> Finally, setting engine speed like this means you have no engine dynamics. >> The engine speed appropriate to a near zero speed at startup may indeed >> be so slow as to stall the engine. What happens in real life is the driver >> either declutches to reduce the torque dragging down the engine speed >> or revs the engine prior to clutching or engaging first gear. >> To make this work properly you need a lot more dynamics for the engine >> and cluch. > >Yes, I realize that. I thought I could omit the clutch for now though, and >get a fairly realistic behavior anyway. So now I have cheated a bit and >assumes that the engine delivers torque even at 0 rpm. What do you think >about that approximation?

That's a good way to do it. Let the engine deliver torque even at 0 rpm. What I did (before I did a clutch model) was seperate the "displayed" engine speed from the true engine speed. They'd be equal unless the true engine speed dropped below 1500 rpm or whatever. Then, the displayed rpm would stick there. If you've got sound in yet, then run the sound off the displayed engine speed. It works just like a clutch then, you can't tell much difference. Todd Wasson --- Performance Simulations Drag Racing and Top Speed Prediction Software http://PerformanceSimulations.Com

Hi Uwe, I am trying to develop a sim of my own. I love what Ruud has done, it is awesome in such a small amount of time too, I am sure it will develop into one of the great sims of all time. Ruud has helped me a number of times with physics questions and I have helped him a few times (i hope). The reason I don't really want to combine efforts with anyone else (yet?) is that I am doing this as much for the learning experience as anything else. I guess its kind of selfish to some extent, but I would like to learn enough myself so that I could set up a small company some time in the future and develop racing sims full time. All the "physics" guys have been great to one another when anyone has needed help. I think that having people doing different race-sims is ultimately great for the sim-racing community, and the fact that we call call upon each other's knowledge as it grows will increase the quality for everyone :). Sometimes reinventing the wheel leads to a better wheel :) or at least a better tyre model <G> All the best, Ash - who must start some hard work on his sim again and stop farting about with his new cockpit :)

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| | Sorry to follow up on such an ancient post, but with so many | creative, talented developers in this group why don't you concentrate | your efforts on one product, so that re-inventing the wheel can | be prevented? I think "Racer" by Ruud van Gaal is the most advanced | free car sim out there, so it would be cool if people would pour | their energy into this one, write extensions, converters, AI and | what not. | | What's everybody's take on this? I cannot imagine the rifts between | sim authors being as deep as the "emacs vs. vi" crowd, for instance, | so there should be a way for all to get along, no? | | cheers, | | uwe

On Tue, 31 Jul 2001 00:22:41 GMT, Matthew V. Jessick <[email hidden]> wrote:

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> > > Andreas Ekstrand wrote: > >> I'm trying to develop my own little car simulator and so far I have just >> implemented acceleration forces and weight transfer, i.e. my car can't brake >> or turn.

Sorry to follow up on such an ancient post, but with so many creative, talented developers in this group why don't you concentrate your efforts on one product, so that re-inventing the wheel can be prevented? I think "Racer" by Ruud van Gaal is the most advanced free car sim out there, so it would be cool if people would pour their energy into this one, write extensions, converters, AI and what not. What's everybody's take on this? I cannot imagine the rifts between sim authors being as deep as the "emacs vs. vi" crowd, for instance, so there should be a way for all to get along, no? cheers, uwe

I think you will find that currently Ruud isnt actually looking for people to take the code away and add to it, its still a personal project from Ruud but one that we can join in by creating assets for it in the way of cars and tracks. Its a learning process for Ruud as it is for the other chaps developing sims in here, and I think ras is a nice place for them to trade thoughts and ideas, without giving up the fun they are having in creating their own sims. "Uwe Schuerkamp" <[email hidden]> wrote in message news:[email hidden]... > On Tue, 31 Jul 2001 00:22:41 GMT, Matthew V. Jessick <[email hidden]>wrote: > > > > > > Andreas Ekstrand wrote: > > > >> I'm trying to develop my own little car simulator and so far I havejust > >> implemented acceleration forces and weight transfer, i.e. my car can'tbrake

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> >> or turn. > > Sorry to follow up on such an ancient post, but with so many > creative, talented developers in this group why don't you concentrate > your efforts on one product, so that re-inventing the wheel can > be prevented? I think "Racer" by Ruud van Gaal is the most advanced > free car sim out there, so it would be cool if people would pour > their energy into this one, write extensions, converters, AI and > what not. > > What's everybody's take on this? I cannot imagine the rifts between > sim authors being as deep as the "emacs vs. vi" crowd, for instance, > so there should be a way for all to get along, no? > > cheers, > > uwe

hi, i'm also doing my own car simulators ;o) I doing it for me , it's not a project developed to do a game, and released it, i'm doing it just because i like programming physics stuff to develop my knowledge on the subject. So use other people code doesn't interrested me. regards, -- Sebastien TIXIER - Game Developer Dynamics and Car Physics http://www.eden-studios.fr GPLRank Normal:-44.24 Monster:-124.44

On Fri, 26 Oct 2001 15:21:53 +0100, "Carol Bekker" <[email hidden]> wrote:

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>I think you will find that currently Ruud isnt actually looking for people >to take the code away and add to it, its still a personal project from Ruud >but one that we can join in by creating assets for it in the way of cars and >tracks. Its a learning process for Ruud as it is for the other chaps >developing sims in here, and I think ras is a nice place for them to trade >thoughts and ideas, without giving up the fun they are having in creating >their own sims.

Yes, I think that about sums it up. Uwe has been and is a great help, I must say. Hope to get that RacerRank up one day. :) But the fact is, most physics/programmer people here create their sim for fun, to find it all out. And indeed, I'm not too keen on having people develop large components in my source code. It may not be good for the longer term, in most cases, IMHO. There's another set of people though, who don't *want* to create an entire sim or do radical stuff like that, but do want to write external programs, like converters (although ZModeler has DOF (Racer's 3D file format) support at the moment, so converting between NFS or whatever is quite easy already), or neat setting dialogs for example. And more importantly at the moment is track and car designers (mainly tracks though I think). I've just added vertex colored capabilities to the tracks (still some bugs to iron out though) so it can looks quite good by now. I'm also looking very much into getting the Ferrari 312 from GPL into Racer (well, the physics data) together with a Salisbury differential to try and get very close to a GPL car to see where my physics are different from GPL. Problem here is rollcenters for example. I know they're low for todays cars, but I don't know exactly about the cars back then. Weight ratio is known, I know a bit how the diff angles work (getting a resulting torque bias ratio, which should work ok except for a 'magic' factor which still has to be applied in the end). The programmers here want to take care of their own babies, but if you're a modeler or like to tweak cars in every which way, than Racer has a very easy entry path and is by now quite worth taking a look at, even if I say so myself. :) Ruud PS vi rules! ;-) Ruud van Gaal Free car sim : http://www.marketgraph.nl/gallery/racer/ Pencil art : http://www.marketgraph.nl/gallery/

> And more importantly at the moment is track and car designers (mainly > tracks though I think). I'd love to have a go at creating some tracks. Is there a how-to somewhere so I can get started? I've got a few ideas which may make for an interesting track. Andy -- PC-Based Multimedia System http://www.andylaurence.pwp.blueyonder.co.uk/pcbmms NB: Spamtrap - my name @yahoo.co.uk

On Mon, 29 Oct 2001 09:38:22 -0000, "Andy Laurence" <[email hidden]> wrote: >I'd love to have a go at creating some tracks. Is there a how-to somewhere >so I can get started? I've got a few ideas which may make for an >interesting track. > >Andy All you need is here: http://home.online.no/~bi-knu/editing/ But beware.. track creating is a LOT of work.. I just read in the just released Mt.Tremblant readme file that the guy worked on the track 17 months 2-3 hours a day.. Andre

> >I'd love to have a go at creating some tracks. Is there a how-tosomewhere

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> >so I can get started? I've got a few ideas which may make for an > >interesting track. > > All you need is here: http://home.online.no/~bi-knu/editing/ > But beware.. track creating is a LOT of work.. I just read in the just > released Mt.Tremblant readme file that the guy worked on the track 17 > months 2-3 hours a day..

OMG! That's a looonng time. Check back in a couple of years.... Andy (off to see what's involved) -- PC-Based Multimedia System http://www.andylaurence.pwp.blueyonder.co.uk/pcbmms NB: Spamtrap - my name @yahoo.co.uk

On Mon, 29 Oct 2001 10:35:19 GMT, [email hidden] (Andre Warringa) wrote:

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>On Mon, 29 Oct 2001 09:38:22 -0000, "Andy Laurence" ><[email hidden]> wrote: > >>I'd love to have a go at creating some tracks. Is there a how-to somewhere >>so I can get started? I've got a few ideas which may make for an >>interesting track. >> >>Andy > >All you need is here: http://home.online.no/~bi-knu/editing/

That's GPL. :) For Racer, check the documentation on the website; mainly the TrackEd docs. For modeling, you can use Max, SoftImage, Maya, whatever. Some people are also using Blender (which is free) or perhaps even ZModeler is abused for this type of stuff. In the end though, I'm currently supporting vertex colored tracks, which require some functionality which mostly exists I think only in the commercial 3D modelers. Still, it makes lighting 10x better. The idea is very much based on SCGT's track format (as the first real track for Racer was just a conversion); that format chops up the track in parts, so you get for example 30 or so road objects in Racer. You start out with a generic loft mostly though, and get the entire track as one big extrusion. Splitting up is done later (and I'm thinking of one day doing the splicing in software). More help can be found on Racer's forum, which is at: http://dynamic2.gamespy.com/~hg/forums/forumdisplay.php?s=&forumid=38 A simple track is easy to make though. But real art ofcourse takes time, as with all really beautiful things. Ruud van Gaal Free car sim : http://www.marketgraph.nl/gallery/racer/ Pencil art : http://www.marketgraph.nl/gallery/

> >>I'd love to have a go at creating some tracks. Is there a how-tosomewhere

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> >>so I can get started? I've got a few ideas which may make for an > >>interesting track. > > > >All you need is here: http://home.online.no/~bi-knu/editing/ > > That's GPL. :) > For Racer, check the documentation on the website; mainly the TrackEd > docs. For modeling, you can use Max, SoftImage, Maya, whatever. Some > people are also using Blender (which is free) or perhaps even ZModeler > is abused for this type of stuff. > In the end though, I'm currently supporting vertex colored tracks, > which require some functionality which mostly exists I think only in > the commercial 3D modelers. Still, it makes lighting 10x better. > The idea is very much based on SCGT's track format (as the first real > track for Racer was just a conversion); that format chops up the track > in parts, so you get for example 30 or so road objects in Racer. > You start out with a generic loft mostly though, and get the entire > track as one big extrusion. Splitting up is done later (and I'm > thinking of one day doing the splicing in software). > More help can be found on Racer's forum, which is at: > http://dynamic2.gamespy.com/~hg/forums/forumdisplay.php?s=&forumid=38

Cheers, I'll nip over there now to see what I can do. > A simple track is easy to make though. But real art ofcourse takes > time, as with all really beautiful things. I just fancy building a track which I can drive to start with. Then it's justa matter of time to make it look nice. Andy -- PC-Based Multimedia System http://www.andylaurence.pwp.blueyonder.co.uk/pcbmms NB: Spamtrap - my name @yahoo.co.uk

On Mon, 29 Oct 2001 13:06:15 -0000, "Andy Laurence" <[email hidden]> wrote: >> More help can be found on Racer's forum, which is at: >> http://dynamic2.gamespy.com/~hg/forums/forumdisplay.php?s=&forumid=38 > >Cheers, I'll nip over there now to see what I can do. Cool. :) >> A simple track is easy to make though. But real art ofcourse takes >> time, as with all really beautiful things. > >I just fancy building a track which I can drive to start with. Then it's >justa matter of time to make it look nice. Yes, understanding the basics is the main thing to start out with something that you don't have to throw away later. Loft is your friend... Ruud van Gaal Free car sim : http://www.marketgraph.nl/gallery/racer/ Pencil art : http://www.marketgraph.nl/gallery/

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> >> More help can be found on Racer's forum, which is at: > >> http://dynamic2.gamespy.com/~hg/forums/forumdisplay.php?s=&forumid=38 > > > >Cheers, I'll nip over there now to see what I can do. > > Cool. :) > > >> A simple track is easy to make though. But real art ofcourse takes > >> time, as with all really beautiful things. > > > >I just fancy building a track which I can drive to start with. Then it's > >justa matter of time to make it look nice. > > Yes, understanding the basics is the main thing to start out with > something that you don't have to throw away later. Loft is your > friend...

I don't suppose there is a how-to for this sort of thing (tracks or cars)? I can't seem to find anything more than 3DSmax would be a good tool. I suppose the first thing to do would be to create a car/track in 3DS max and ask in the forum where to go from there. Andy -- PC-Based Multimedia System http://www.andylaurence.pwp.blueyonder.co.uk/pcbmms NB: Spamtrap - my name @yahoo.co.uk

On Mon, 29 Oct 2001 16:45:47 -0000, "Andy Laurence" <[email hidden]> wrote:

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>> >> More help can be found on Racer's forum, which is at: >> >> http://dynamic2.gamespy.com/~hg/forums/forumdisplay.php?s=&forumid=38 >> > >> >Cheers, I'll nip over there now to see what I can do. >> >> Cool. :) >> >> >> A simple track is easy to make though. But real art ofcourse takes >> >> time, as with all really beautiful things. >> > >> >I just fancy building a track which I can drive to start with. Then it's >> >justa matter of time to make it look nice. >> >> Yes, understanding the basics is the main thing to start out with >> something that you don't have to throw away later. Loft is your >> friend... > >I don't suppose there is a how-to for this sort of thing (tracks or cars)?

It's really just like regular modeling (although things may change for scenery as I intend to be able to repeat objects (trees are a good example) from inside TrackEd, instead of directly from your modeler (like SCGT does for example). >I can't seem to find anything more than 3DSmax would be a good tool. I >suppose the first thing to do would be to create a car/track in 3DS max and >ask in the forum where to go from there. If you have Max, than that's a great start. Try lofting an entire looped track. Export that as ASE and try to import it into Modeler. You can also batch import ASE files from TrackEd directly. Just keep your scenery completely in Max, don't mix images for textures that are functionally different (as surface types (road, sand, ice) are detected based on texture filename). For efficiency, large track must be split so cubes of scenery can be culled away in big chunks if not visible. This is done with Max's detach function. Load Carrera in TrackEd, select Object Properties (F4) and click around; you'll see the objects. Other than that; if it looks ok in Max than it's ok to export into Racer. I have no real splitting experience myself. The first custom track was also a track with just 5 objects; trees, road, rocks etc. Not too efficient but it actually ran pretty well even. :) Just always keep your track unsplit on disk somewhere in case you want to reloft. And ofcourse asking on the forum always helps yes. :) Good luck, Ruud van Gaal Free car sim : http://www.marketgraph.nl/gallery/racer/ Pencil art : http://www.marketgraph.nl/gallery/

> >I don't suppose there is a how-to for this sort of thing (tracks orcars)?

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> > It's really just like regular modeling (although things may change for > scenery as I intend to be able to repeat objects (trees are a good > example) from inside TrackEd, instead of directly from your modeler > (like SCGT does for example). > > >I can't seem to find anything more than 3DSmax would be a good tool. I > >suppose the first thing to do would be to create a car/track in 3DS max

and

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> >ask in the forum where to go from there. > > If you have Max, than that's a great start. Try lofting an entire > looped track. Export that as ASE and try to import it into Modeler. > You can also batch import ASE files from TrackEd directly. > Just keep your scenery completely in Max, don't mix images for > textures that are functionally different (as surface types (road, > sand, ice) are detected based on texture filename). > > For efficiency, large track must be split so cubes of scenery can be > culled away in big chunks if not visible. This is done with Max's > detach function. Load Carrera in TrackEd, select Object Properties > (F4) and click around; you'll see the objects. > Other than that; if it looks ok in Max than it's ok to export into > Racer. I have no real splitting experience myself. The first custom > track was also a track with just 5 objects; trees, road, rocks etc. > Not too efficient but it actually ran pretty well even. :) > Just always keep your track unsplit on disk somewhere in case you want > to reloft.

Cheers for the in-depth response. I'll jump on it when I have time. > And ofcourse asking on the forum always helps yes. :) ;-) Andy -- PC-Based Multimedia System http://www.andylaurence.pwp.blueyonder.co.uk/pcbmms NB: Spamtrap - my name @yahoo.co.uk