I made collider with a mesh (json) and got a jittering Effect.
Another collider with a cube doesnt shows the effect.
Its not the code its the collider.
As you can see in my example, you can drive the car with arrow keys.
The left ramp has the mesh collider.
Hmm… Probably not much can be done about that. The code path for collision detection in Ammo.js is different when you use a mesh vs a standard primitive.
Out of interest, what happens when you create a wedge shape? I wonder if the car is sometimes going through the mesh as it’s so thin? https://www.easyfoam.co.uk/foamshapes/Btriangle.png
I have tried this with different meshes also very thick ones, with the same effect.