PiBoSo Official Forum

GP Bikes => Mods => Topic started by: PiBoSo on January 03, 2014, 10:16:07 pm

Title: Modding tools and documentation
Post by: PiBoSo on January 03, 2014, 10:16:07 pm
There were no plans to release any tool or documentation for physics editing after Beta4 release.
Everything is still WIP and there is no time for that at the moment.

Anyway, the first mod already looks pretty accurate despite it all.

A few suggestions:
- the front suspension collides with the body when fully compressed. Probably the joint needs to be moved slightly down
- the fuel tank position is under the tip of the seat: is this correct?
- the collision objects would need some tuning: in particular the bottom sphere could be replaced with a box
- it is possible to move the boots link position in the gfx.cfg file

- when geometry and suspensions are perfect, tuning of the steer parameters is very important to make the bike stable... Unfortunately this is more of a black art than science, and requires a lot of trial and error
Title: Re: Modding tools and documentation
Post by: Arvoss on January 03, 2014, 10:25:54 pm
First mod and best mod ever! :D Those scooter races are going to be epic! :D Nice work of the modders and PiBoSo! :) PiBoSo, when can we see you on the track?  ::)
Title: Re: Modding tools and documentation
Post by: PiBoSo on January 03, 2014, 10:54:19 pm
Quote from: Arvoss on January 03, 2014, 10:25:54 pm
PiBoSo, when can we see you on the track?  ::)


Lulzwhat? Haven't started GPB since the day before beta4b was released.
Track tools and other bikes have taken the spotlight.

http://www.youtube.com/v/6Q00HQwO2Sg
Title: Re: Modding tools and documentation
Post by: Warlock on January 03, 2014, 11:00:11 pm
Thanks Piboso modders will appreciate this a lot

Epic music there, man  :)
Title: Re: Modding tools and documentation
Post by: neoraptor on January 03, 2014, 11:09:04 pm
Hi PiBoSo,
The tools looks really good ! It will be really helpful for modding new bikes in the future !!

Do you plan to release a first version of this tool soon?
Even a simple viewer for the geometry file would be a great start, to check if the parameters are in a good range.

Thanks again for your great work.
Being myself a developper, I know that it is far from easy !! ;)
Title: Re: Modding tools and documentation
Post by: SwarleyRuiz on January 04, 2014, 07:45:25 am
Thanks Piboso
Title: Re: Modding tools and documentation
Post by: _oDi_ on January 05, 2014, 07:06:04 pm
Thanks Piboso for the  support, I really appreciate it. Not having any tools, I went on trying, doing a lot of testing...is the only possible method for now ... and apparently the result is not bad. :) When tools will be ready our little evil Zip will be much better... Obviously. I cant' wait!  ;D
Title: Re: Modding tools and documentation
Post by: HornetMaX on January 08, 2014, 12:55:47 am
A few of questions people are asking around:



MaX.
Title: Re: Modding tools and documentation
Post by: C21 on January 08, 2014, 11:42:37 am
Thank you Piboso for your support. :)

The bike editor looks interesting.
This tool would be a big advantage in the hands of modders.....would allow to get the bikes more different in their behavior on the Track.
e.g. bikes of the same class (GP1000) are still using murusama geometry files , so they will behave more or less equal besides the engine power curves.
With this tool a fine tuning of the bikes would be clearly possible.
But for now we have to try and check again and again....
Title: Re: Modding tools and documentation
Post by: neoraptor on January 08, 2014, 01:19:05 pm
I put the variables from the geometry file in the drawing above and found this :
(http://img4.hostingpics.net/pics/348103Scootuncompressed2.jpg)

I am not 100% sure of the front reference and didn't manage to place the rear reference.
Does someone have an idea? I used ImageJ to scale the pixel to mm and make the measurement (ratio is 306.42 pxl/mm).

There is at least 3 reference systems:
* the bike
* the fork
* the rear (swingarm)

If we manage to have at least the position and references of each elements, it will be easier to build bikes with a correct geometry until the bike builder tool is released .
Any help is welcome to finish to place the various elements ;)

The collision spheres/boxes are probably used to determined where is the contact with other bike or elements.
Title: Re: Modding tools and documentation
Post by: PiBoSo on January 08, 2014, 02:07:34 pm
Quote from: HornetMaX on January 08, 2014, 12:55:47 am
A few of questions people are asking around:


  • Why is the mass of the front suspension separate from the steering head mass ? Is it the partial mass of the suspension that is unsprung ?

  • In the tyre model: Radius is the radius of the tyre (center to outmost circumference), torus radius is the radius of the torus "describing" the tyre profile. But what is Width ? For the 990 for example Radius is 0.325, Torus Radius is 0.13 and Width is 60. Is Width the half angle describing the tyre profile ? In other words, is the tyre width of the 990 equal to 225mm (calculated as 2 * Torus Radius * sin(Width)) ?

  • What the hell are the "Collision objects" ? Nobody seems to have a precise idea :)



MaX.


1. the "front suspension" mass is the sum of lower part of forks, calipers and front fender.
2. Width is the angle ( in degrees ) of the tread arc.
Title: Re: Modding tools and documentation
Post by: HornetMaX on January 08, 2014, 02:23:01 pm
Quote from: PiBoSo on January 08, 2014, 02:07:34 pm
Quote from: HornetMaX on January 08, 2014, 12:55:47 am
A few of questions people are asking around:


  • Why is the mass of the front suspension separate from the steering head mass ? Is it the partial mass of the suspension that is unsprung ?

  • In the tyre model: Radius is the radius of the tyre (center to outmost circumference), torus radius is the radius of the torus "describing" the tyre profile. But what is Width ? For the 990 for example Radius is 0.325, Torus Radius is 0.13 and Width is 60. Is Width the half angle describing the tyre profile ? In other words, is the tyre width of the 990 equal to 225mm (calculated as 2 * Torus Radius * sin(Width)) ?

  • What the hell are the "Collision objects" ? Nobody seems to have a precise idea :)



MaX.


1. the "front suspension" mass is the sum of lower part of forks, calipers and front fender.
2. Width is the angle ( in degrees ) of the tread arc.


Thx. So the above computation is correct, right ? The 990 has a 225mm wide rear tyre ? Wow ... that's some more than the current 195 for motoGP ...

MaX.
Title: Re: Modding tools and documentation
Post by: Hawk on January 08, 2014, 02:28:25 pm
This is becoming a very useful source of information. Is anyone eventually going to take all the information that is useful here and convert it into an organised post? Because it won't be long before trying to find specific info in this thread becomes a nightmare. :)
Title: Re: Modding tools and documentation
Post by: HornetMaX on January 08, 2014, 02:40:32 pm
An unofficial guide to modding is planned (chapter 5 of the unofficial guide currently under development: http://forum.piboso.com/index.php?topic=431.0 (http://forum.piboso.com/index.php?topic=431.0)).

The problem is that more than understanding the parameters of the models, many modders would need first a basic course in physics/mechanics :)
But there's always the approch "slam a number in and see how it feels"  ;D

MaX.
Title: Re: Modding tools and documentation
Post by: neoraptor on January 08, 2014, 03:11:28 pm
I started a wiki so that everyone can add/change info : http://gpbikes-mods.wikia.com/wiki/GPBikes_mods_Wiki

It is still a WIP, but I try to document as much as I can. ;)



Concerning the tyre, if I understand it correctly, we have the following "model" :

     Radius
     <------->
><=====   : 1/2 Tyre
^^
Torus


and the torus is like that :
  /   
/
/
\     ^
\    | width (in °)
  \   v

We can then found the width of the tyre : Wt = sin(width) * TorusRadius * 2

Is that right?
Title: Re: Modding tools and documentation
Post by: HornetMaX on January 08, 2014, 03:18:56 pm
Quote from: neoraptor on January 08, 2014, 03:11:28 pm
Is that right?

That was exactly my question #2 above. BTW, in your formula, the "Radius" is the Torus Radius and not the overall tyre radius, which is called ... Radius.

MaX.
Title: Re: Modding tools and documentation
Post by: neoraptor on January 08, 2014, 03:30:56 pm
I just changed it, so there is no confusion. ;)
What is a bit strange, is that we don't find 17" or 16.5" rim diameter. So I wonder if the model is not :

     Radius
   <-------->
><=====   : 1/2 Tyre
^^
Torus

With this "model", we have:
500 soft front : (28.75-7)*2/2.54=17.12"
500 soft rear : (30.5-11)*2/2.54=15.35"
1000 soft front : (29.5-7)*2/2.54=17.72"
1000 soft rear : (32.5-13)*2/2.54=15.35"

The other possibility is that we don't care about the rim diameter, but only about the tyre diameter.

Edit: I just had a look to the Scooter tyres, and to have the 10" wheel size, they are also based on this model (Tyre Radius - Torus Radius/2)*2/2.54 = 10"
Title: Re: Modding tools and documentation
Post by: HornetMaX on January 08, 2014, 06:05:40 pm
Quote from: neoraptor on January 08, 2014, 03:30:56 pm
The other possibility is that we don't care about the rim diameter, but only about the tyre diameter.

I think that's the case: the model used seems to be outer tyre radius + torus radius + tread arc (half) angle.

Quote from: neoraptor on January 08, 2014, 03:30:56 pm
Edit: I just had a look to the Scooter tyres, and to have the 10" wheel size, they are also based on this model (Tyre Radius - Torus Radius/2)*2/2.54 = 10"

Don't bother, I've already discussed with oDi, ALEAle and Buggi and they don't know how the model works exactly :)

MaX.
Title: Re: Modding tools and documentation
Post by: neoraptor on January 09, 2014, 11:05:03 am
OK. Thanks ;)


Could someone confirmed which model is used for the physic?
(http://www.ika.rwth-aachen.de/forschung/veroeffentlichung/1998/1998-6/im1212.gif)

Or is it more like this one ?
(http://www.ika.rwth-aachen.de/forschung/veroeffentlichung/1998/1998-6/im1223.gif)

Also where are the references for each part of the model?
Thanks for the help ;=
Title: Re: Modding tools and documentation
Post by: HornetMaX on January 09, 2014, 11:52:30 am
Quote from: neoraptor on January 09, 2014, 11:05:03 am
Could someone confirmed which model is used for the physic?

The high level model of GPB (Piboso briefly described it once on the old forum) is:

Joint-wise you have:

The front suspension is a spring + damper between lower and upper front fork.
The rear suspension is a torsional spring + damper between swingarm and chassis. The fact it's torsional is just a technical detail for our purposes, as in-game it is presented as an equivalent "linear" spring+damper. Using a torsional one instead of a "linear" one is just more convenient in terms of model simulation.

MaX.
Title: Re: Modding tools and documentation
Post by: neoraptor on January 09, 2014, 12:07:29 pm
Thank you very much for these info Max ! It is very useful.

Question 1
?1>Do you also know where are the reference point (ie 0,0,0) for each part?
The 0,0,0 from the chassis is already in the scooter schematic, but what about the other parts? It would be really helpful.

Question 2&3
Suppose I want to calculate the wheelbase of the bike (before adjusting it).
?2>Is it measure with the suspension fully compressed? uncompressed?
?3>I need to do some trigo to retrieve the complete wheelbase (from rake angle + fork length / the same for rear suspension) Correct?
Title: Re: Modding tools and documentation
Post by: HornetMaX on January 09, 2014, 01:28:07 pm
Quote from: neoraptor on January 09, 2014, 12:07:29 pm
Thank you very much for these info Max ! It is very useful.

Question 1
?1>Do you also know where are the reference point (ie 0,0,0) for each part?
The 0,0,0 from the chassis is already in the scooter schematic, but what about the other parts? It would be really helpful.

It shouldn't be to hard to figure out using the data of an existing bike. I'll have a look when I start the modding guide.

Quote from: neoraptor on January 09, 2014, 12:07:29 pm
Question 2&3
Suppose I want to calculate the wheelbase of the bike (before adjusting it).
?2>Is it measure with the suspension fully compressed? uncompressed?
?3>I need to do some trigo to retrieve the complete wheelbase (from rake angle + fork length / the same for rear suspension) Correct?

Yeah, you will have to compute it with some trivial trig. The day modtools are out, this would be done by them.

I'm tempted to say the wheelbase is measured with the susp (front and rear) fully uncompressed, because otherwise it will depend on the weight you put on the bike (with/without oil, fuel, rider etc) and on the suspension stiffness and preload. But I'm not sure.

MaX.

P.S.
Off topic, I stumbled on this page, some interesting info: http://www.yamaha-motor.eu/designcafe/en/about-design/technology/index.aspx (http://www.yamaha-motor.eu/designcafe/en/about-design/technology/index.aspx)
Title: Re: Modding tools and documentation
Post by: C21 on January 09, 2014, 02:52:42 pm
Max you´re my hero for today  :D
Great explanation!!
Title: Re: Modding tools and documentation
Post by: neoraptor on January 09, 2014, 03:04:17 pm
Thanks a lot Max ! This is some really good and useful info !!  :D
I will try to split the parts in the geom file into these categories and display their references in a schematic ;)

The 3D model doesn't use the same reference system? This might also be a point to document.


?> What is the influence of the "footpeg_left/right" parameter?
I noticed the position was wrong in the scooter model. Is it actually used?

?> Is the parameter "rear_length" the length of the shock travel?
?> Are "rear_upper" and "rear_lower" offset from a point? For what are they used?
Title: Re: Modding tools and documentation
Post by: neoraptor on January 10, 2014, 11:55:07 am
I made a first "dynamic" model with some parameters available.
This is only temporary, until the bike tool is released, but at least we have a tool to see the influence of the parameters. ;)


It still needs some works, but all points from the 500 bike are in this model.

For the moment, I have 3 references:
* classic 0,0,0
* chassisRsuspMinMax
* chassisSteer

As well, the rake angle is defined from the chassisSteer point, but I am not sure if this is the correct point.


Todo:
* animate rear suspension
* animate fork travel
* display other information (trail, swingarm length, ...)


Can someone review this model?
I attached the file with this post. Just go to http://www.geogebra.org/webstart/geogebra.html and open it ;)
You can change the points coordinate by right clicking it ;)



@Piboso: if you send me some additional info, we could have a temporary bike tool while waiting for yours ;)


(http://img4.hostingpics.net/pics/813129Capture.png)
Title: Re: Modding tools and documentation
Post by: Hawk on January 10, 2014, 03:45:30 pm
You guys are doing fantastic work here! ;)

Brilliant! Keep it up guys! ;D ;D
Title: Re: Modding tools and documentation
Post by: neoraptor on January 10, 2014, 05:35:41 pm
Thanks Hawk ;)
I have almost finished the tool. The only thing left is the fork !!
So I have a few question :

> How is the fork offset processed?

(https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcTrwrhrtC3s3bFwjsAfApdMxxjBb1maSXgrykywQ8yI0I2FdPv94Q)




The status of the latest version :
(http://img15.hostingpics.net/pics/839932gpbModel2.png)
Title: Re: Modding tools and documentation
Post by: Hawk on January 10, 2014, 08:08:30 pm
Hi neoraptor.

I noticed your tool above is in French? Will there be an English version?
Title: Re: Modding tools and documentation
Post by: neoraptor on January 10, 2014, 08:26:23 pm
Yes, of course. The tool is multilingual and at the end you will only push sliders and move some coordinates. ;)

But for the moment I need to complete the fork model !!!
Title: Re: Modding tools and documentation
Post by: C21 on January 10, 2014, 09:02:15 pm
 
QuoteHow is the fork offset processed

Do you mean how to find in the geom. File?
Title: Re: Modding tools and documentation
Post by: neoraptor on January 10, 2014, 09:39:47 pm
Check the model I used (file is attached to this message) with this applet : http://www.geogebra.org/webstart/geogebra.html (simply open the file there).

My problem is to find how it is referenced as there is 3 different reference system for the fork : the chassis, upper fork and lower fork.

I don't manage to put everything in the right order for now :S

It also looks like the fork is mounted reverse on the scooter according to the screenshot from PiBoSo.


I am happy for any help as I already look into it for a few hours without finding the correct reference for the front.  :-\
Title: Re: Modding tools and documentation
Post by: C21 on January 11, 2014, 01:26:58 pm
QuoteIt also looks like the fork is mounted reverse on the scooter according to the screenshot from PiBoSo.

But the fork is mounted reverse on the scooter isn´t it?

QuoteI am happy for any help as I already look into it for a few hours without finding the correct reference for the front.

Right now i don´t have a clue either.
maybe Max has...
Title: Re: Modding tools and documentation
Post by: HornetMaX on January 11, 2014, 02:20:34 pm
Quote from: C21 on January 11, 2014, 01:26:58 pm
QuoteIt also looks like the fork is mounted reverse on the scooter according to the screenshot from PiBoSo.

But the fork is mounted reverse on the scooter isn´t it?

Upside-down or normal fork does not make a difference for GPB: the fork will still have an unsprung mass and a sprung one (integrated in the steering head mass).

Quote from: C21 on January 11, 2014, 01:26:58 pm
QuoteI am happy for any help as I already look into it for a few hours without finding the correct reference for the front.

Right now i don´t have a clue either.
maybe Max has...

No time yet to have a look at what neoraptor has done (looks interesting).
However I never played seriously with 3d modeling and, to be honest, I don't plan to do it neither: my life is already not long enough without tinkering with 3ds :)

Once I start the physics modding doc, I may want to understand/crossreference the stuff that "links" physics and 3d model.

MaX.
Title: Re: Modding tools and documentation
Post by: neoraptor on January 11, 2014, 06:09:22 pm
I was not speaking about upside-down or normal fork.
If we look at the screenshot from Piboso, the fork offset seems negative (go back toward the rear) compared to the chassisSteer point (which is where the contact between the chassis and the fork is done).

It is like the triple clamp is not mounted toward the front, but toward the rear wheel).  :o
Title: Re: Modding tools and documentation
Post by: HornetMaX on January 11, 2014, 09:21:33 pm
Quote from: neoraptor on January 11, 2014, 06:09:22 pm
I was not speaking about upside-down or normal fork.
If we look at the screenshot from Piboso, the fork offset seems negative (go back toward the rear) compared to the chassisSteer point (which is where the contact between the chassis and the fork is done).

It is like the triple clamp is not mounted toward the front, but toward the rear wheel).  :o

I haven't verified, but if it is true, it is indeed an unusual setup, at least for a bike (maybe ok for a scooter, don't know).

RC bikes for example are typically like this: it gives a sort of cart-wheel self-stabilizing effect.

MaX.
Title: Re: Modding tools and documentation
Post by: HornetMaX on January 14, 2014, 02:18:56 pm
Some other random questions for Piboso:

MaX.
Title: Re: Modding tools and documentation
Post by: HornetMaX on January 20, 2014, 04:51:18 pm
Quote from: neoraptor on January 10, 2014, 11:55:07 am
(http://img4.hostingpics.net/pics/813129Capture.png)

neoraptor, I think there's one bug in your drawing above: you have a line between fwheel' and chassisSteer and it is likely in your mind this is the steering axis. I think that the steering axis should be between fwheel' and steerJoint'.

My interpretation of the points is the following:

MaX.
Title: Re: Modding tools and documentation
Post by: PiBoSo on January 20, 2014, 06:42:58 pm

"chassis_steer" is the position of the steer link in chassis coordinates. It is rotated by the rake angle.
"steer_joint" is the position of the same link relative to steer coordinates.
Same for "rsusp_joint", that is the position of the pivot in swingarm coordinates.
Title: Re: Modding tools and documentation
Post by: HornetMaX on January 20, 2014, 08:32:53 pm
Quote from: PiBoSo on January 20, 2014, 06:42:58 pm

"chassis_steer" is the position of the steer link in chassis coordinates. It is rotated by the rake angle.
"steer_joint" is the position of the same link relative to steer coordinates.
Same for "rsusp_joint", that is the position of the pivot in swingarm coordinates.

Thanks !

But how are steer coordinates (and swingarm coordinates) defined then ?

I know I can backward deduce them (knowing that steer_joint and chassis_steer are the same point in the two diff coord systems), but ...

MaX.
Title: Re: Modding tools and documentation
Post by: PiBoSo on January 20, 2014, 08:54:12 pm
Quote from: HornetMaX on January 20, 2014, 08:32:53 pm
Quote from: PiBoSo on January 20, 2014, 06:42:58 pm

"chassis_steer" is the position of the steer link in chassis coordinates. It is rotated by the rake angle.
"steer_joint" is the position of the same link relative to steer coordinates.
Same for "rsusp_joint", that is the position of the pivot in swingarm coordinates.

Thanks !

But how are steer coordinates (and swingarm coordinates) defined then ?

I know I can backward deduce them (knowing that steer_joint and chassis_steer are the same point in the two diff coord systems), but ...

MaX.


steer_world_matrix = steer_local_matrix * chassis_joint_world_matrix
steer_local_matrix = no rotation - steer_joint
chassis_joint_world_matrix = chassis_joint_local_matrix * chassis_world_matrix
chassis_joint_local_matrix = rake angle + chassis_steer
Title: Re: Modding tools and documentation
Post by: HornetMaX on January 21, 2014, 01:30:25 am
Quote from: PiBoSo on January 20, 2014, 08:54:12 pm
Quote from: HornetMaX on January 20, 2014, 08:32:53 pm
Quote from: PiBoSo on January 20, 2014, 06:42:58 pm

"chassis_steer" is the position of the steer link in chassis coordinates. It is rotated by the rake angle.
"steer_joint" is the position of the same link relative to steer coordinates.
Same for "rsusp_joint", that is the position of the pivot in swingarm coordinates.

Thanks !

But how are steer coordinates (and swingarm coordinates) defined then ?

I know I can backward deduce them (knowing that steer_joint and chassis_steer are the same point in the two diff coord systems), but ...

MaX.


steer_world_matrix = steer_local_matrix * chassis_joint_world_matrix
steer_local_matrix = no rotation - steer_joint
chassis_joint_world_matrix = chassis_joint_local_matrix * chassis_world_matrix
chassis_joint_local_matrix = rake angle + chassis_steer


Now I'm even more confused, doh !

Quote
chassis_joint_local_matrix = rake angle + chassis_steer

So this means the X axis goes through the chassis_steer point and has an angle of let's say 24deg (Rake) wrt to vertical. This X axis is the steering axis.
Y axis (the other axis in our 2d view) is in the bike's longitudinal plane and is orthogonal to X and goes through chassis_steer point too too.
Correct ?

Quote
chassis_joint_world_matrix = chassis_joint_local_matrix * chassis_world_matrix

OK, this accounts for chassis orientation in space (roll, pitch, yaw). For our purposes, we can ignore it I guess.

Quote
steer_local_matrix = no rotation - steer_joint

Not sure I get it. Does this mean that the origin of this reference system is such that steer_joint actually corresponds to chassis_steer ?
And are X,Y,Z axis of this reference are oriented as:

Is this what you mean ?

I'm no longer sure what front_upper, front_lower are, as they don't seem to be parallel to the steering axis ...

MaX.
Title: Re: Modding tools and documentation
Post by: HornetMaX on January 21, 2014, 04:53:03 pm
@neoraptor:

plenty of thing I don't understand yet (front_lower/upper, front_length, rear_upper/lower, rear_length).

In the .ggb file, the sliders control the rake angle, the swingarm pivot and the swingarm length correctly (pivot is useless tough, as min/max points are identical).

(https://drive.google.com/uc?export=view&id=0BzmU7Qoo77i1d0xmQXE5SmRDWHM)

MaX.

EDIT [MaX]: Ignore, that model is very wrong !
Title: Re: Modding tools and documentation
Post by: HornetMaX on January 22, 2014, 10:58:32 am
I think I've got it almost right now, I only miss this: are front_upper and front_lower the same point when front_length = 0 ? So front_lower (and fwheel) travel along the direction defined by the segment front_uppper .. front_lower ?

MaX.
Title: Re: Modding tools and documentation
Post by: PiBoSo on January 22, 2014, 12:06:27 pm
Quote from: HornetMaX on January 22, 2014, 10:58:32 am
I think I've got it almost right now, I only miss this: are front_upper and front_lower the same point when front_length = 0 ? So front_lower (and fwheel) travel along the direction defined by the segment front_uppper .. front_lower ?

MaX.


"front_lower" is the position of the bottom of the front suspensions in unsprung forks coordinates.
Title: Re: Modding tools and documentation
Post by: HornetMaX on January 22, 2014, 02:09:04 pm
Quote from: PiBoSo on January 22, 2014, 12:06:27 pm
Quote from: HornetMaX on January 22, 2014, 10:58:32 am
I think I've got it almost right now, I only miss this: are front_upper and front_lower the same point when front_length = 0 ? So front_lower (and fwheel) travel along the direction defined by the segment front_uppper .. front_lower ?

MaX.


"front_lower" is the position of the bottom of the front suspensions in unsprung forks coordinates.

Arghh ... guess a proper drawing would solve that for good. Anyway ...

So steer_joint and front_upper are in steer coords while front_lower and fWheel are in unsprung fork coords ?

And how do you position the unsprung part ? front_bottom (in chassis coords) must be laying on a line passing by front_upper (in chassis coords) and parallel to the steering axis ?

MaX

Title: Re: Modding tools and documentation
Post by: iVolution on January 22, 2014, 03:08:18 pm
Quote from: HornetMaX on January 22, 2014, 02:09:04 pm
Arghh ... guess a proper drawing would solve that for good. Anyway ...

So steer_joint and front_upper are in steer coords while front_lower and fWheel are in unsprung fork coords ?

And how do you position the unsprung part ? front_bottom (in chassis coords) must be laying on a line passing by front_upper (in chassis coords) and parallel to the steering axis ?

MaX

My brains hurts trying to understand what you just said  :o
Title: Re: Modding tools and documentation
Post by: HornetMaX on January 22, 2014, 03:21:25 pm
Quote from: iVolution on January 22, 2014, 03:08:18 pm
My brains hurts trying to understand what you just said  :o

Don't try then :)

TBH, it's pretty basic stuff, just hard to explain in words (and harder to backward-engineer with no doc).

MaX.
Title: Re: Modding tools and documentation
Post by: HornetMaX on January 29, 2014, 12:26:30 pm
@Piboso (or whoever knows): in the .geom file, what is "rear_length = 0.06" (for the 990) ? Changing it does not seem to have any visual impact in the showroom.

Max.