Vehicle 'Arcade physics' with Chaos physics?

Development Programming & Scripting Blueprint
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Hi,

I’m rather new to game-development. First dabbled a bit with Godot, but it was/is too heavy with having to program nearly everything, which resulted in progressing at a snails pace and even not getting any further. So I switched to Unreal Engine, first time dipping my toes in it with 4.26/4.27 (Chaos).
Since I’m in the very beginnings of my game, it’s better for me to use UE5.1 and fiddle with all the new stuff, instead of learning the things that will be obsolete/deprecated after awhile.

So I’m focusing on the Chaos physics, and my programming skills are just so-so, I want to be able to get the majority done with the properties provided and blueprints.

It was easy to set up the Chaos physics and control to get the car moving. Plenty of documentation and tutorials about that. I’m no car-mechanic either and there are so many properties that I get lost in them.
I want to create an arcade-racer like Split Second: Velocity (although most are from in Godot, here you can see what I’m trying to develop). So I generally need my cars to be ‘planted’ to the ground, certainly not tip over, gain speed quickly and maintaining most of it even during turning, but also be able to put into a drift a control it easily.

I’ve already done some basic stuff, like increasing the Friction Force Multiplier of front and rear wheels, (which helped getting up to speed more quickly), changed the center of mass on the Z-axis to a negative value (keeping the car more grounded and not so prone to rolling over, although it still can). Also trying to get more drift by setting the center of mass more to the back of the car, but that also gives various results.

What properties should I look at, to get more ‘arcade-physics’ out of the Chaos physics?
In the Vehicle Movement Component details, I also see something of ‘Arcade control’, divided into ‘Torque control’, ‘Target Rotation Control’ and ’ Stabalize Control’. Can that help to get more arcadey physics?
Will using exaggerated values help or just make things more difficult down the road? (no pun intended :sweat_smile: )

Btw, I hope I’m in the right section of the forum for these questions.

Cheers

1 Like
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Hi eyeEmotion,

Thanks for sharing your Youtube channel. Welcome to the Forums!

Great questions, I would love to see a extensive breakdown of all these ‘knobs and switches’ that drive Chaos Vehicles. But I’m not aware of any yet.

It would be a bit like deciphering hieroglyphics for me, but looking at the C++ code that drives these settings could be one aspect in getting a better understanding.

Lowering the center of mass for stability was a good idea.

Another idea is to enable the debug/telemetry data.

This is tangential, but I’d love to see something like a ‘Chaos Vehicles Tuners Club’ where people share their vehicles/settings and there is some standardized race tracks to test the vehicles on.

It still feels like ‘early days’ for Chaos Vehicles. (In 5.1 the plugin is tagged as ‘Experimental’…) So I’m expecting better tutorials/documentation as the systems solidify.

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Hi Astrotronic,

I have a feeling Chaos Vehicles has most things covered. I’m coming accross different solutions and sometimes opposite opinions on the matter. Raycasts seem to be popular for arcade physics. They refer to the suspensions I guess. But then I see that the Chaos wheels are by default Raycast.
This seems to be a popular reference: https://www.youtube.com/watch?v=LG1CtlFRmpU , where I do understand the logic, but nobody is showing ‘me’ how to do it. That’s the main problem: everybody is showing stuff, but vague about how to actually apply it and show how it’s done, like other tutorials are done.
I’m not scared of learning these things, but it’s hard to learn if they don’t show you the information. Every link I click, it’s more explanation without showing anything. Very frustrating for someone who’s new to the syntax and blueprints.
I’ve also come accross a blueprint site where you can copy them, but they don’t work as they are from UE 5.0 and it seems UE5.1 doesn’t have things like ‘Chaos Wheeled Vehicle Component’ anymore. And I also don’t like to just copy/past things, as I won’t learn anything by doing that. I rather have a step by step tutorial that explains what and why they are doing the things they are doing.

As much information I’ve already found about it, Chaos seems to have it all implemented, so it would be ridiculous for me to “reinvent the wheel”. Lower center of mass, raycast suspension, friction wheels, velocity/torque, … . This is all in Chaos, I just need to find a way to manipulate to what I need.
I’ve found some old official tutorials, but some of those properties don’t exist anymore (https://www.youtube.com/watch?v=6vFZ9alQKqI). The ‘Lat Stiff’ and ‘Long Stiff’ values are gone, and I think they are replaced with the ‘Lateral Slip graph’, but I can’t find anything on how to set that up.
Actually, most properties I try to google, I come up empty handed.

I’ve tried the ‘Arcade Control’ section in the ‘Vehicle Movement Component’. My hunch was atleast right and they seem make it easier to set the physics up to have a more arcade handling. The only one I’ve figured out up till now is the ‘Stabilize Control’ section. By the visual debugs, I’ve figured out that these create an opposite force to what the Chaos physics are creating, to make sure the car isn’t sliding too easily ‘Position Hold XY’ (which I had to lower a lot from the default value) or coming of the ground too easily ‘Altitude Hold Z’ (which I had increase a lot from the default value, yet with the default gravity of -980, still had that floaty balloon feel when jumping from higher to lower ground).
The ‘Stabilize Control’ has made the handling better and if I use the handbrake, it will drift… but just a bit. It still loses speed and it’s still a short sim-like drift with little control over it. So I know I need forward and/or lateral velocity for it (as explained by some youtube video’s). Which I think might be what the ‘Torque Control’ and ‘Target Rotation Control’ under ‘Arcade Control’ are for, but experimenting with them as yielded nothing so far, even with the visual debugs on I don’t have a qlue.

Then I saw you can disable ‘Mechanical Sim’, which makes the car not move at all. Probably so I can make it move through custom BluePrint code(?). Not that I currently know how to set that up. I first found something about ‘Simple Wheeled Vehicle Component’, but that doesn’t appear to exist in UE5.1 either anymore. Seems like everything is converted to Chaos.

Seems like the major problem is that important information isn’t available. Information that is known, people seem to keep for themselves and are very vaque about. So basically, nowhere is concrete information to be found, just the “magic numbers” excuse. With so many arcade-racers made (in UE), I find it hard to believe it’s this difficult to find information or help about the subject.
It constantly feels like 2 steps forward, 5 steps back.

A bit off-topic, but how can I find the topics where I’m part of? Either where I’m the topic-starter or a replier?

Cheers.

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Thanks for sharing your learnings. (That’s the best we can do at this stage)

After the plugin gets out of ‘Experimental’ I’d expect to see an updated tutorial series like the one you linked.

To see topics: Try clicking Home → Your Name → Interactions tab → Activity Tab

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Hi,

I’m trying to get a sphere to roll, but with the purpose of controlling a car. Apparently, such a method is used to get more of an arcade control to the cars. So maybe that way I can disable the Mechanical Sim and keep the rest of the Chaos Vehicle.

No problem getting a sphere to roll forward and backward, or even left or right (with add force or torque). Problem is that left and right are achieved with applying that torque or force, while I need to it to rotate the direction of the forward/backward force/torque.

All the tutorials I find for controlling a sphere, they use all the directions to apply force/torque. I tried the link in this thread also, but doesn’t work for me either.

I’m trying to achieve something like this:
Building an arcade racer: Part 2
Problem for me is:

  1. It’s in Unity
  2. It’s in programming language and since I’m new to this all, not good at converting (unknown) code Blueprints.
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I experience the same problems as you are: mainly a lack of useful information to find.
I’m an UE beginner, though i have lots of programming experience, i am only using BluePrints right now.
Meanwhile i have 3 UE versions installed and tried out vehicles in all version (PhysX and Chaos). It appears to be difficult to even make the same car(behavior) in the different editor versions… and seeing by the lack of good videos and/or tutorials, i am not alone having that problem.
It is a struggle with different settings (in different editor versions) and physical materials (and what more) to make a car do what you want (or even get close to what you want).
Car Physics for games

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Yeah, I’m surprised that most tutorials don’t go beyond the basic setup. And others that just want to sell their Blueprint setup.
Which is quite hard to believe, since there are so many racing games made in Unreal.

I’m still working with the UE5.1 Chaos Vehicle, but switched off those arcade controls, as I don’t know what they do and by using a Lateral SlipGraph for the rear wheels I got here: Unreal 5 Conversion - Switchboard Studios Documentation , together with increased gravity (3000) and low center of mass, it’s a stable car now.
Although, still not what I want, as maintaining a drift is really hard. But atleast now I can test the length of my track and the speed of the car.

I’m actually surprised, with such a common and popular game-engine, beyond the popular tutorials, there really isn’t much to no help from others. With Godot, there were atleast some people that tried to help as much as they could. With Unreal, you seem to only get help if it’s for views or for monetary gain.

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For me at least, it feels like there is some hidden traction control setting for the whole car. Even after setting high traction values, car slows down too much when turning. I tried changing a lot of settings that may affect this, but its still there.

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Do you have anything (video/image) to show your problem and settings? I’m no expert, but I can compare with my settings to see if any significant difference shows up.

I do have my Torque up to 1500 to not be affected too much by hills and turns. And my RPM goes up to almost 6000.