I’ve been looking at the new chaos car plugin and wanted to see what it’s like. I follow the UE4 Chaos Docs but it doesn’t work. When I set the wheels collision to kinematic, the car no longer falls. Also, I have a steer input set to 1 on every frame, and the wheels don’t turn at all. I have followed the docs, and YT tutorials (multiple times), and it ends up all the same. The car never moves, no input works, nada.
What’s up with that?
I started following the docs and tuts at 10am, its 2:30am haha. I need some insight.
I’m having the exact same issue. Beating my head against the wall. Followed tutorial and docs, and the car just sits there, frozen in space. Wheels don’t move either when throttle input is given.
(Specifically the step at 16:50 (create an external torque curve) was something I initially skipped, assuming the curve drawn in the blueprint details would suffice. But after hitting that create external button and saving it as a separate asset, my car was able to drive
In particular, I used the 4.26 Chaos Preview 2 build from the Epic launcher, and activated the Chaos Vehicle plugin in my project. I also made a new test vehicle from scratch in Blender (just 4 cylinders and a simple boxy body) instead of a pre-rigged PhysX vehicle I had lying around (which didn’t move for reasons I could never determine). Not sure what I did differently, but going through all the steps from scratch more than once helped, after which I converted my existing PhysX project successfully.
Note that the Chaos Vehicle implementation (at least in blueprints) still has significant issues, so just treat this early preview version as a test playground to find and report bugs and get a taste of what’s to come.
If it’s any consolation, I find the vehicle movement looks/feels more natural than PhysX, and doesn’t seem to suffer from some of the weird bugs in PhysX (shooting off randomly into space)… so worth the wait even if you don’t get it working right away
I used to have a version that was working in the first preview of the 4.26, but aftrer update to preview 2 and preview 3, cars no longer move, they just stay static in the air, they don’t even drop to the ground, so it’s not like it’s the inputs, it’s like they don’t initialize at all
I feel like I will have to re-make it from a scratch just to see if it will work, but as it’s quite a bit of clicking, I’m still waiting to see if there are more updates, so that I don’t have to keep doing this
Personally I had the same problem and I activated the Simulate Physics option on the skeletal mesh of the vehicle blueprint and everything worked fine after.
Adding onto Pookemon - I had to add a Torque curve. I spent a day and a half debugging, re-importing, re-working physics bodies, double checking Simulate Physics was checked on for the skeletal physics mesh, trying everything to get the vehicle moving but only the torque curve got things working. If you think you’ve done everything right and it’s still not moving, definitely check/add the torque curve.
Also like Pookemon I am trying to figure out why reverse doesn’t work. It seems to also have to do with the torque curve, because I can only reverse when I give that curve negative values. At which point, I can no longer move forward. I feel like I’m missing something obvious here. The Input axes are clearly getting read correctly, print string shows 1 and -1 for forward/back. It’s something in the vehicle.
I appreciate the feedback and understand the frustration. I’m taking notes from this thread to add some additional info to the docs to avoid this happening in the future. Things like “make sure your vehicle is simulating physics” are simple things to check but can cause a lot of frustration if you don’t know what to look for.
I can’t give an ETA but I’ll be updating the docs in the near future to address some of the issues mentioned here. If you have any other feedback, please post it in this thread
While you’re taking requests, could you please add some documentation for the arcade control parameters? Namely, Torque Control, Target Rotation Control, and Stabilization Control. A very helpful scenario to document is how to keep a 2 wheeled vehicle (motorcycle, bicycle) upright and how each parameter of Torque/Target Rotation work in practice.
Just stopping by to explain how I solved my steering issue,
I converted a PhysX vehicle to Chaos and spent an entire day wondering why the steering wouldn’t work, turns out I missed the “Affected By Steering” checkbox addition to the Chaos Vehicle Wheel blueprint. Just set to true for your front wheel and you’re good to go. may be worth adding to the “How to Convert PhysX Vehicles to Chaos” docs considering it’s a change from physX? I don’t think it was mentioned
I have experienced this issue for two/three days working full time and finally found the solution. For some people it is maybe obvious, but I did not know there is a separate Unreal Engine 4.26 and 4.27 for the CHAOS physics. When adding a new engine version, you must scroll down and install the CHAOS version. If you try chaos vehicles on the ordinary version even with the plugin installed you do not get errors or anything, it will just not fall when the wheel physics type is set to kinematic.
