AC Modding Questions Thread

[Cimmerian_Iter]

Hey I have a problem with my car and i don't really know where i should start to solve it.

When I steer a lot, sometime the front wheel will lift.

Does anyone knows what could be the problem? thanks

 

[Stereo]

Hey I have a problem with my car and i don't really know where i should start to solve it.

If you open the Suspension app and hit numpad 1 2 3 4, it should show locations of the physical wheels, that'll help figure out what could be happening.

 

[Ofitus21]

Hi! I have a few questions regarding the tyres.ini document, so hopefully a physics guru can help me out making sense of the parameters inside.

I found a really useful Excel sheets with explainations on each parameter, yet I still have the following doubts.
-Is D the Coefficient of Friction? (so Mu). I presume it does refer to the coefficient of friction and the curves that define it based on various effects (so camber, load, pressure...). I want to make sure this is the case
-When calculating the Rolling Resistance, in which velocity is a factor, Is that velocity introduced in m/s? Or is it km/h?
-On the "FRICTION_LIMIT_ANGLE", it says the value should be checked on the tyre devs app, but I'm not sure what app is that. In the telemetry app I do see Slip Angles, but I'd have to plot it against lateral forces to accurately compare it with the data we have in the team and see if it matches with the data I have from the real tyre. And the tyre apps show 2 lines but it doesn't seem to give any units for the axis, so I have no idea what I'm looking at (By the shape it looks like FY vs SA, but again, not sure if this is the case). Am I overthinking this and the process of dialing this value is much different?
-Would it make sense for the Flex Gain value to be negative? The data that I have for my tyre seems to indicate the slip angle at 2*FZ0 is lower than FZ0 (Thus Flex Gain would be negative), but all tyre models I've seen so far feature a positive value. Not sure if I'm missing something about how to calculate this parameter

That's all for now, I think I understand what is required for everything else
Best regards

 

[Cimmerian_Iter]

If you open the Suspension app and hit numpad 1 2 3 4, it should show locations of the physical wheels, that'll help figure out what could be happening.

Thank you, hubmass was the problem. Badly balanced the car weight which made one part lift up.


Another problem i have now is 3D related, the windshield is being shown from the front, but inside the cockpit it's like there is no windshield. If i try to press in custom showroom the windshield object from the cockpit it doesn't find the windshied object.

How can i solve this problem and make the windshield appear while in cockpit?

Thanks


Cockpit

Outside of the cockpit

 

[Denny370]

hello, do you happen to have the normal upside down?
or you have to understand in the hierarchy where you have the glass.

 

[Denny370]

...

 

[Vinz Clortho]

Noob here - How can I create SOL presets that I can select PRIOR to jumping into a race so that I don't have to configure weather settings on the starting line as the starting timer counts down? Surely thats not the only way to operate this app... right? The weather effects look great otherwise, thanks.

 

[Denny370]

It seems that all mods that have extended physics with CSP and FWD traction have a problem..
The car moves backwards slowly when stopped, or in the pause\settings menu, the car instead of standing still moves slowly backwards even if the wheels are not turning. It happens even more rarely that when you switch from the menu to the game, the wheels also turn and the car slides backwards as if it were on a downhill road with no brakes.
Replacing FWD in drivetrain.ini with any other drivetrain, RWD, AWD etc, the problem goes away.
Even eliminating the extended physics script the problem disappears.
Has anyone noticed the same problem or know of a solution?

 

[Denny370]

hi, does anyone know if there is the possibility of creating an AXLE suspension also at the front to simulate the front axles that some jeeps or tractors have?
if yes, how?...can you give an example...? thank you

 

[mike855]

Hello,
No that cause some bad things
Maybe with CSP Cosmic suspensions

 

[Denny370]

Hello,
No that cause some bad things
Maybe with CSP Cosmic suspensions

It's just that, having no references, I wouldn't know how to compile the scripts, I've seen examples of the cosmic csp suspension, but I don't know if exactly it's an axle or something else..

 

[A Casual Sim Racer]

I wish, I've heard Axle suspensions in the front are in the works. However, Ilja mentioned that they have encountered a lot of issues so far with the various ideas they have tried. I need the feature added to realistically implement front physics for a lot of pre-ww1 cars.

 

[mclarenf1papa]

I wish, I've heard Axle suspensions in the front are in the works. However, Ilja mentioned that they have encountered a lot of issues so far with the various ideas they have tried. I need the feature added to realistically implement front physics for a lot of pre-ww1 cars.

You can do essentially any suspension type using cosmic. Front axle no problem

 

[Denny370]

Hello, but there are no examples on how to implement cosmic suspensions, I mean clear and working examples, there is something but not clear and not working.. It would be nice to have clearer documents and examples to be able to start.. You know mods that have the cosmic suspension to see how it is implemented?

 

[Stereo]

I have a few unreleased cars that use cosmic, the main holdup from my end is not with simulating solid front axles, it's that there are other aspects that need to be fixed and it's unhelpful to say "don't use this part if you don't have csp 0.1.80" when that's patreon-only. Specifically it's a problem for strut cars and some display issues, but the strut thing is likely necessary to accurately do certain early cars. I know sliding-pillar suspension was a thing.

 

[mclarenf1papa]

Hello, but there are no examples on how to implement cosmic suspensions, I mean clear and working examples, there is something but not clear and not working.. It would be nice to have clearer documents and examples to be able to start.. You know mods that have the cosmic suspension to see how it is implemented?

The documentation on the wiki is quite extensive… if you do not find it useful then it might not be a good idea to try to use cosmic in the first place (as it is quite a bit more difficult than vanilla AC suspension).

 

[zagyvaakos]

Hello,
I am wondering if I could get (and how) the Slip Angles (FL, FR, RL, RR) from the game with python?
Or maybe any chance to get a CTE (or XTE - cross track error) data from the game? If not I would thanks for any help or advice how to get it.

Working on a Reinforcement Learning agent, for self driving (and maybe drifting or racing) but cant access to the data I need.

I am managed to get 'wheelSlip' data for all the wheels but Slip Angles shows zeros all the time no matter what I do.

- 'slipAngle1': 0.0, 'slipAngle2': 0.0, 'slipAngle3': 0.0, 'slipAngle4': 0.0, -

Guess the problem is the telemetry reader that I use from here:

OpenRacingHUD/scripts/assetto_corsa_telemetry_reader.py at master · dzosz/OpenRacingHUD

OpenRacingHUD. Contribute to dzosz/OpenRacingHUD development by creating an account on GitHub.

github.com

Thanks, A

 

[Denny370]

La documentazione sul wiki è piuttosto ampia... se non la trovi utile, potrebbe non essere una buona idea provare a usare cosmic in primo luogo (poiché è un po' più difficile della sospensione AC vanilla).

La documentazione sul wiki è piuttosto ampia... se non la trovi utile, potrebbe non essere una buona idea provare a usare cosmic in primo luogo (poiché è un po' più difficile della sospensione AC vanilla).

I have a few unreleased cars that use cosmic, the main holdup from my end is not with simulating solid front axles, it's that there are other aspects that need to be fixed and it's unhelpful to say "don't use this part if you don't have csp 0.1.80" when that's patreon-only. Specifically it's a problem for strut cars and some display issues, but the strut thing is likely necessary to accurately do certain early cars. I know sliding-pillar suspension was a thing.

@Stereo
I don't want to ask too much, and of course if you can't I understand it .... could you share me a working example of cosmic to simulate AXLE at the front and rear? ..., I don't even speak English and even translating something always gets distorted , and unfortunately I was not clear documentation on the wiki.
Probably if I were more capable in this topic I wouldn't have all these difficulties, but unfortunately I didn't get there..

 

[Denny370]

cosmic suspensions with csp are visible in CM showroom like KUNOS suspensions?

 

[Stereo]

Nope, CM showroom ignores them and if there is still AXLE/DWB code it'll draw the lines from those. The suspension dev app shows them ingame, same way as other types, but you probably need to view it in twilight & with the car stationary due to graphical issues.

Here's a front axle example

[FRONT]
TYPE=COSMIC
BASEY=-.55	 ; Distance of CG from the center of the wheel in meters. Front Wheel Radius+BASEY=front CoG. Actual CG height =(FWR+FBasey)+(RWR+Rbasey))/CG_LOCATION%
TRACK=1.665	 ; Track width in meters (from pivot 3D placement of the 3d model of a wheel)
HUB_MASS=35	 ; masse sospese anteriori
TOE_OUT=0.005					; Toe-out expressed as the length of the steering arm in meters
TOE_OUT_L=0.0004
BASE_R_OFFSET=0.0,0.0,0.0 ; coordinates added to right wheel position for asymmetry (offset from basey, track, etc.)
STATIC_CAMBER=0.0						; Static Camber in degrees. Actual camber relative to suspension geometry and movement, check values in game
BUMP_STOP_RATE=120000					; bump stop spring rate
PACKER_RANGE=0.31						; Total suspension movement range, before hitting packers

BODY_0_NAME=AXLE			; adding extra rigid objects to the simulation
BODY_0_MASS=110				; pre-existing rigid objects are named HUB_L, HUB_R, and CHASSIS
BODY_0_INERTIA=1.6, 0.1, 0.1
BODY_0_POS=0.8325, 0.0, 0.0

ENGINE_TORQUE_BODY=AXLE		; select where engine reaction torque applies (typically the body with the differential hard mounted to it. default is chassis)

J0=TOP_KINGPIN			; J0= line has to exist, its contents is a descriptive comment
J0_BODY_A=AXLE			; J0_BODY_A and BODY_B are the 2 objects this attaches to
J0_POS=0.198, 0.076, -0.010 ; .005		; default is body0 = CHASSIS, body1 = "this" (HUB_L on left, HUB_R on right)
J0_KP=1				; _KP=1 is the joint at the top of the kingpin, =0 is bottom.  Use on a joint where BODY_B=hub; tells the code which joints are WB_CAR_TOP and WB_CAR_BOTTOM for steering calculations

J1=BOTTOM_KINGPIN
J1_BODY_A=AXLE
J1_POS=0.1807, -0.076, 0.010
J1_KP=0

DJ0=TRAILING_LINK
DJ0_BODY_B=AXLE
DJ0_POS0=0.464,0.115, -0.805
DJ0_POS1=0.29,0.0,0.0

DJ1=TRAILING_LINK_U		; controls axle twist
DJ1_BODY_B=AXLE
DJ1_PARITY=0
DJ1_POS0=0.464,0.115,-0.805
DJ1_POS1=0.29,0.10,0.0

STEER_JOINT_0=STEER_LINK
STEER_JOINT_0_BODY_A=CHASSIS
STEER_JOINT_0_PARITY=1
STEER_JOINT_0_POS0=1.355, 0.22, 0.166
STEER_JOINT_0_POS1=0.1304, -0.033, 0.166

STEER_JOINT_1=TIE_ROD
STEER_JOINT_1_PARITY=0			; default -1, setting 0 or 1 makes this link part of left or right suspension.
STEER_JOINT_1_BODY_A=HUB_L			; linking wheel hub to wheel hub is possible
STEER_JOINT_1_BODY_B=HUB_R
STEER_JOINT_1_POS1=1.5346, -0.033, 0.166
STEER_JOINT_1_POS0=0.1304, -0.033, 0.166
STEER_JOINT_1_STEERVECTOR=0.0, 0.0, 0.0	; sets the direction this link moves when steered.  in this case it's 0 because it only changes length with toe, not with steering.

[FRONT_SPRING_0] ; vertical coil spring
RATE=70000; 52700
BODY_B=AXLE
PRELOAD=0.08
POS0=0.29,0.7,0.0
POS1=0.29,0.0,0.0

[FRONT_SPRING_1] ; lateral spring based on compliance
RATE=1200000
PULL_FORCE=TRUE  ; spring is symmetrical rather than the default of compression only
BODY_B=AXLE
POS0=1.201,0.115,-0.805
POS1=0.29,0.0,0.0

[FRONT_DAMPER_0] ; vertical damper
DAMP_BUMP=6000						; Damper wheel rate stifness in N sec/m in compression
DAMP_FAST_BUMP=850
DAMP_FAST_BUMPTHRESHOLD=0.075
DAMP_REBOUND=  12200						; Damper wheel rate stifness in N sec/m in rebound
DAMP_FAST_REBOUND= 4000
DAMP_FAST_REBOUNDTHRESHOLD=0.130
BODY_B=AXLE
POS0=0.29,0.5,0
POS1=0.29,0.0,0
MIN_LENGTH=0.355		; suspension travel is limited by this
MAX_LENGTH=0.575
END_RATE=1000000			; spring force of end limits
END_VTAPER=0.02			; speed at which rate tapers off
END_VMAX=0.10			; speed where end limit adds 0 force

[FRONT_DAMPER_1] ; lateral damping
DAMP_BUMP=69000
DAMP_FAST_BUMP=3000
DAMP_FAST_BUMPTHRESHOLD=0.6
DAMP_REBOUND=69000
DAMP_FAST_REBOUND=3000
DAMP_FAST_REBOUNDTHRESHOLD=0.6
BODY_B=AXLE
POS0=1.201,0.115,-0.805
POS1=0.29,0.0,0.0

[FRONT_DAMPER_2]  ; limiting steer lock for stability, only acts as hard bumpstop, no damping
DAMP_BUMP=0		; req'd for it to read the section
BODY_A=AXLE
POS0=0.1, 0.0, 0.34
POS1=0.1304, 0.0, 0.166
MAX_LENGTH=0.28

[FRONT_DAMPER_3] ; steering damper connecting axle to hub to prevent speed wobble
DAMP_BUMP=5000
DAMP_FAST_BUMP=1000
DAMP_FAST_BUMPTHRESHOLD=0.1
DAMP_REBOUND=5000				; Damper wheel rate stifness in N sec/m in rebound
DAMP_FAST_REBOUND=1000
DAMP_FAST_REBOUNDTHRESHOLD=0.1
BODY_A=AXLE
POS0=0.53, -0.033, 0.166
POS1=0.1304, -0.033, 0.166