Hello everyone!
Can someone please share example settings for Chaos Modular Vehicle system in UE 5.6.1? Wheels, suspension, engine…
Im interested in following car types:
Just started exploring this system and stuck on trying to adjust parameters for simulation:(
This one didn’t go well.
Hello there @Heurex!
The best example I can think about with a full guide and a step by step approach, is the motorbike from the community guide. You can adapt it’s procedure and parameters to a bigger vehicle with four wheels:
A secondary guide for a SUV-like vehicle can also be found here. It does not cover all steps as deed as the bike guide, but the parameters used will be more useful for your intended target:
As well, please make sure to check all the related documentation to Chaos Vehicles in the community:
Hi, I’m fighting too with Chaos Modular. I tuck two screenshots to share with you my parameters for wheel and suspension. I’m now on 5.7 Preview 1 and some behaviors changed a lot. If you have any question, don’t doubt to ask it.
How’s working your Car? Do you have Sound? Have you found a way to get the engine RPM? The manual transmission is working properly in your car?
I hope we will share learned things about this plugin, best regards.
You can see this post explaining my experience with chaos modular here.
Here is what I am experimenting with its a 3 body setup PodRacer.
Hey! That’s so cool! Great job! I love it!
If you enter ShowDebug ModularVehicle on play. Do you have values > 0 on torque?
Throttle at 0.01 prduces instant change from IDLE to FULL RPM?
How did you make the sound? I’m testing Motosynth.
And the reactor fire? I’m thinking of using niagara for my car.
It’s really nice to see other people working with chaos modular vehicles and your project looks amazing!
Regards
Hey really thanks, i really enjoy dealing with this a lot.
I am using thruster sim module for this and it has a real smooth forces however i have similar issues on engine setups, think chasis module plays a big role over there with clutch ofc. However on the thruster didn’t see that issue on debug.
I found some transofmers scifi like warping sound on freesounds.org , the cue is basically doppler and modulator
but scripts for this run couple of stuff.
AudioEngine(Thrust),
AudioEngineDefault(Ambient)
AudioServo(Input Turns)
and the important one AudioSourceInertia (which is the this warping sound when thrusters get a high acceleration.)
I calculate acceleration by
This works however i made a better calculation literally getting distance delta and time travel and drive acceleration from there which is super good since its on game thread not on physics , visually audio wise its better
Also so far I changed vehicle setup to be more complex, testing multiplayer aspects of 3 body vehicles.
Ofc gameplay wise its not mario kart anymore but I think its pretty stable with the additions, and have snappy controls/ turns/ boosts. Also Pod racing is known as being the most dangerous sport in galaxy after all 
Still balancing it, since this is super nice on gamepad or analog keyboard but not so very good controls with digital keys, so will make it a bit worser turns lateral frictions to fit both worlds. It is almost the same in the multiplayer but phsyics constraints behave a bit differently so that the vehicle overall.
WOW! Thank you so much, for take your time to write and share all this. It’s extremely useful for me to see how other developers do the things. I’m just a newby in Unreal. I wrote my experience with CMV in this post
I will try the thruster component to see the differences. And analize all your message to try to understand as much a posible.
Best regards!
P.D. I don’t see transitions when you change the camera, aren’t you using GamePlay Camera System?
My pleasure, thank you too for sharing!
It’s about which forces in charge of what actually in the base, however ofcourse with networking, plus moving away from rigid body to a little bit further into actual chaos physics makes things more sophisticated but at the same time more interesting and actually something that is more fun.
I am making some additions here and there, looking what is actually being developed in the engine and how, so building some muscle power at the same time with building something not out of box but what Epic intends to be used for so I don’t have magic numbers to make it work but I rely on more feeling and behaviour of physics.
For cameras I have only 3 cameras, one 3rd preson is only with spring arm, 1st person directly onto head socket of our padavan, its kinda smooth (I don’t want it to be so smooth in first person however think i can do some easing on rotations X atleast). I don’t transition between for now, just enable disable cameras in an array , however since you mentioned think a transition something fast could be nice.
What about destruction possibilities with chaos destruction fracture in your vehicle geometry collections. I made some test videos to see the performance impact with high fractured bones.
If you don’t use a skeletal mesh with animation blueprint attached to it. In my case with Skeletal mesh I lost the ability to fracture the geometry collections. The animation is handled by the animation blueprint and when a part is broken, just get frozen. Like the wheels for example.
Right now I don’t have damage on bones enabled.
But any vehicle as you demonstrate can be choas destruction enabled, it’s a little bit about which parts (Fracture Bone Clusters) should be damaged.
In car case : outer shell, windows, body work is fine however if you want to go further it would be about the wheel geometry. Wheel geometry can be simply in majority of the games looses outer shell (Tire) however can be pushed further like loosing a wheel imo but would require some time to create nice fracture geometries on those wheels. That would make a good new era Carmageddon game.
In my case, similar but its harder, can be outer shell, additionally can be loss of power on thrusters with events, however since it should be balanced and since would effect gameplay negatively if this is a racing game. Can have penalties but not as punishment.
I have both skeletal meshes and GC, however right now there are some blockers in visual aspects thats why I implemented it since async phsyics and making a pod racer with ropes and stuff not looking the best cause of delays of ticking in different thread especially on network. However if we don’t care about that or we implement some other stuff on Niagara side to overcome sync issues everything can be done on the GC side as well. That time we wouldn’t have fighting systems with each other.
So its a bit of choice,
Geometry Collection fracture , Chaos owns transforms
Skeletal Mesh , Anim bp owns transforms, so when fracture happens chaos tries to write new transform, animation overwrites last position so the result is stuck positions. Simply they fight with each other and animation wins at that time. I didn’t try integrate those but will let you know when I do and as a gut feeling think it should be the best of both worlds, a nice hierarcy with base chaos with skeletal meshes, with outer fractureable gc following the base vehicles.
How is your hierarcy right now can you show?
Not sure, it should not jitter a lot with rewinding a lot especially in single player mode, there could be something wrong with the tick order that time. Sometimes if you are forcing transforms from GC to SKM or vice versa Skeletal mesh copying GC transform in wrong tick groups can cause that aswell, it will cause major desync.
On damaging side , in car case since its almost a single vehicle its possible to create layers of geometry collection.
For tires it can be 2 bones 1 geometry collection and for body inner chasis can be single bone, outer parts can be fractured many times. Root bone and inner chasis can have higher damage for breaking something very very high.
Upon collision or tire part removal it would still go, and it will effects its physics as it should be however think density of these parts can be lower to uneffect the overall stability of the vehicle.
In my pod its the same think can do something like that however it would require 3D modications anyway, think on your case too properly assemble the vehicle which is fine can be done, its just a bit time consuming.
Here below is some of my pure GC vehicles in multiplayer. With some custom arm components.
For me with the pods, its just about the rewind causing problems with niagara (for now) and sometimes with gc sockets (but there is workarounds for it, registering non simulated gc bodies with cluster solves it). Some devs feed velocity to niagara and compansate however its not super reliable especially vehicles with high velocity like a pod racer.
If we can mostly get rid of skeletal meshes its possible to do more accuracy with chaos ofcouse which will avoid frame syncing between game thread and last phsyics async. Since this brings the question you ask “What about fracture?”
When GC is the truth on async and if vehicle hits the hidden geometry collection either hit earlier or delayed. Since our eyes follow the skeletal mesh which is anyway delayed there would be some mismatch in fracture timing and placements. Can be ok in low speed however in high speeds would be visible.
Below is the difference on SKM Thruster and GC - Turquise is the skeletal mesh, difference is acceptable for now.
Here is my latest balancing and a proper camera integration to it . I feel pretty good about it but let me know what you think.
Looks fantastic!! On third person camera meanwhile I was watching, I though, I miss some camera roll and you just changed to first person camera, really great job, also the engine camera with sound responding clearly to location changes. As we said in Spain: Óle Tu! 
I also compiled ue5-main and detected one setting that directly affects the synch between phisycs and SKM. I’m on my Mac now and can’t check it but i remember its like PreRender or something like that in the GC settings.
In this video you can see how strong was the desynch in my case (the speedometer over the car perfectly show it). That’s why I was forced to use SKM.
I’m having a lot of problems because I’m a newbie in Unreal development and I just made a two months course. So I’m dealing with the “Why this is like this” and take my time to understand it and finally accept: Ok, have sense… Work with Unreal Engine can make you feel really powerful or really looser, all depends on if you know what are you doing or not…
Epic developers are doing a lot of changes in the CMV. I hope they will include all that in a nearly future release, specially the fix of torque.
Thats great if you find it, I am also tuning a lot.
Yeah this will take quite a while to develop for sure. There are many things being done in CMV, its good practice for me also to understand how it works, need more documentation and some advanced tutorials though, reading raw code sometimes helpfull sometimes doesn’t helps to me atleast.
I am making some poke arounds in engine too but trying to stay on plugin component side since its built that way to ease us building things on top, like different sim components etc.
As example this for sure will change how they behave so need to check it out, which makes sense tbh.
Another example is wheels thickness doesn’t effect anything atm, also that really effects the lateral slipping which should have a graph thats not implemented yet. I did that since I had a problem in lateral slips of vehicle in super low speeds and very high torques. Like the example of the loader truck (super powerfull but very slow and heavy) .
If you finish the damage and fracture side on the vehicle, can you share? I can take a look at it before I start doing it.
Edit :
This is where the magic happens with the wheels
https://github.com/cem-akkaya/UnrealEngine/blame/release/Engine/Source/Runtime/Experimental/ChaosVehicles/ChaosVehiclesCore/Private/SimModule/WheelModule.cpp
I just tweaked some stuff about lateral slips for trackion control + made a wheel not a drive wheel but just a follower so we don’t have to always have 4 wheels drive
Still I am just hack and slash mode, not proper changes possibly
This is how the crashes and bumps generally, have some stabilizers around it but maybe I can do a manager to handle those conditions gracefully, still thinking around how to penalty player. Either restart or maybe give some disadvantage on thrusters acceleration. However there is no fracture yet.
They updated the Chaos Modular Vehicle Examples with the use of mover plugin. You will found a test level with different surfaces to check the interaction with the car. Have you tried?
not sure which one to be honest mover , old chaos vehicles, new chaos modular vehicle with networked phsyics. BUT in the branch that I am working I have ChaosModularVehicles with networked component using base class AModularVehicleClusterPawn and examples with the same pawn classes.
They released a new version of Chaos Modular Vehicle Examples adding the Chaos mover, to demonstrate it.
Thats why in the demo map, there is a rectangular surface rotating like a Big Wheel to drive the car on it and see how the car reacts to the ground changes.
