Vehicle physics in Godot 4 are nonexistent

None of the settings seem to create a functional vehicle on any level. Even with the default settings, the vehicle flips around, tires fall into the ground, and it’s overall completely broken.

Check the truck town demo here godot-demo-projects/3d/truck_town at master · godotengine/godot-demo-projects · GitHub which configures different vehicles with different values.

The demo is broken also. Although it’s for Godot 3, maybe that’s why converting it to Godot 4 breaks it, but it just seems like Godot 4 vehicle physics are terrible.

The demo linked is for Godot 4.x Download the zip https://github.com/godotengine/godot-demo-projects/archive/refs/heads/master.zip and extract it.

but it just seems like Godot 4 vehicle physics are terrible

okay :person_shrugging:

Download this directly: godot-demo-projects/3d/truck_town at master · godotengine/godot-demo-projects · GitHub the zip file isn’t for 4.x, the project in the link is though

and what else is terrible and unusable in godot engine? I’m just asking so that we don’t get left in the lurch here

:godot:

The vehicle physics is simplistic by design, see the documentation, it is general and won’t fit every project

It’s a great engine, I just can’t figure out the supposedly simplistic vehicle physics. The latest truck town demo seems to work correctly. I’ll try applying it to my own project. The settings for the vehicle nodes seem to be easy to mess up and break and the documentation doesn’t fully explain them.

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I just made an account to add my two cents. I have been using Godot for about a week and have next to no experience, so take what I have to say with a spoonful of salt

I started with Godot 3 since it was what I had installed a bit ago, and things worked well for vehicles.
I updated yesterday to Godot 4.2.2. Since I’m just getting started, why not?
Every imported vehicle project from 3 to 4 seems to have the center of gravity (or some other force???) off to one corner, causing the vehicle to rotate forever around that corner.
When I try to redo the project, it has the same issue, the vehicle rotates forever around a corner depending on values entered.
The vehicle body origin appears centered in everything else.
Recreating in Godot 3 still works fine.

I don’t know anything about the difference between Godot 3 and 4 (other than things seem to have been moved around in a variety of ways), but if I can’t figure this out soon I will just use 3.

Other than this hiccup Godot seems really cool so far!

I figured out something that works for my case.
I re-saved my mesh models so they are centered at the origin and the exact scale I want them to be. With this as my starting point, things behaved as they should. I think having a model with the origin at one corner, and scaling by 0.1 in Godot, the effective, center of gravity was ending up somewhere I could not locate it even if the origin of the mesh was appropriately indicated by the colored axis arrows. Previously, no amount of transforms in any direction seemed to help.

This doesn’t seem like a perfect solution, as I think you should be able to scale and move things within Godot to have the same effect, but exporting models like this isn’t too much extra heartache.