Sadly this does not work for me… As my car is in the air the wheels are spinning but as it touch the ground everthing freeze.
Hi PaulBlythe,
Very nice investigation on c++ side, in fact the problem seem really related to sleeping physics.
On this, i second Geodav in the fact it seem more likely is epic will have to fix it.
Because i suppose just a few people will compile themselve Unreal to get Chaos vehicle working on older computers.
About the press W trick’s, it work until the vehicle stop, and unfortunately the vehicle dont move right a way after.
Hi Syenar,
Very nice investigation on blueprint side, i have follow your recommendation and it work almost fine since.
I guess is more accessible temporary solution for majority of person, while waiting epic fix it in next iteration of UE5.
Additionally, it is need to wake the physic not only on throttle but also on steering and brake and so on, to prevent the vehicle to fall in sleep as soon he dont move.
pasted it before FBodyInstance* TargetInstance = GetBodyInstance();
no effect
I also have a custom constraint vehicle I tried in UE5 and it sounds we both are having the same issue where the angle constraints aren’t staying locked and the wheel axle basically bends. Is that what you are getting?
Did you ever try chaos physics in UE4.26 ? I’m wondering if this is in all chaos physics implementations or just the UE5 chaos physics.
Thanks
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@Syenar… your fix worked perfectly, thank you! 
I’m not sure if this helps anyone,
But I created a child BP (which has the ‘stuck in the air’ problem) of the default provided AWheeledVehiclePawn, and the skeletal mesh had SimulatePhysics on FALSE. I set it to TRUE on the editor, and the child instance I placed in the world started behaving correctly (fell to the floor and I could control it)
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ok this won’t let me go as i’m a vehicle idiot (ex mechanic) while trawling the forum i found a thread with tips on improving UE5 performance, after changing the setting i tried the advance vehicle template again and it worked great (first try) so here’s the settings i changed
Dynamic Global Illumination Method: None (instead of Lumen)
Reflection Method: Screen Space (instead of Lumen)
Shadow Map Method: Shadow Maps (instead of Virtual Shadow Maps (Beta))
hope this helps.
In my case the torque curve was not set in the engine setup, which resulted in a vehicle that did not move.
Once I applied a curve under “Engine Setup” everything started to move.
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So, guys. Is Chaos Vehicle any good in long run? Usable for production?
hard to say since its just a hobby for me, but you will need uptodate hardware (GPU) my GTX960 just doesn’t do it, apart from that i can get basic wheeled vehicles to work with tweaking.
On mac pro m1 this problem still there in UE5.1. Tested with Yaw input and Set Drive Torque.
"I think I found it! Chaos uses raycasting: link(https://youtu.be/Wc6lUXOhRO0?si=WS-fm32kZ7tv9ccx&t=317), and I think you can’t raycast with a GTX 1080 (I have almost the same PC as you), but you can with an RTX. I’ve tried to find a way to raycast with a GTX (some articles talk about it), but I’m not sure.
Thank you for your comment, it led me in the right direction."