No that one is does not have the wheel jumping bug fixed yet.
I thought I was going to get that fix this weekend but this it is a harder problem than thought.
I can get it to work by doing something that I do no really want to, I rather fix the problem correctly,
The problem has to do with the contact being calculated by the engine rather than by the vehicle code.
if it solve by the engine, the it will made one call for each body the tire is colliding with.
and that is what is wrong. in your case you have multiple meshes, example when the tire goes across two different meshes.
when the happen the solve does now how to discriminate these two contacts because they are both correct.
The way to discriminate one is by doing a convex ray cast and before the newton update, and save the closest bodies the tire should collide with, the use those bodies as a filter fro when the vehicle need to collide.
I did that but I found out that the function convex Ray Cast is busted when dealing with non uniform scale objects, and the tire are non uniform, so I have to have that fixed first.
Once this is fixed then I believe the vehicles will be completed.
Can you get the latest code and just try the vehicle tell me what do you think about.
For my side this is the most accurate to realistic vehicle model yet, I finally fond what was wrong with the tire model, and now behaves predictable. You can see wen driving the vehicle inertia.
also you can see the vehicle slip angle followed the tire sleep angle, with is the condition for stable driving. I have no try yet steady unstable drifting (drifting) but now that eth tire model behave in tune with the physics of real tire, I believe that should be possible.
I will try tat afet I get the jump bug fixed. Should be these week.
BTW the vehicle is a rear wheel drive car, and it is quiet drivable. so that tell me we are on the right track.
According to the book, rear wheel drive car are more stable and maneuverable that front wheel drive, but as you know, almost no one can get a rear wheel drive to drive stable. I about 95% of all video games, the use four wheel drive, and even eh ones that let you select the mode, they actually cheat, and apply tire force on all wheels, by only integrate the wheel you select as drivable. the rest is jut kinematic.
Only game like Forza, and Grand tourism do a realistic simulations, but the use Lagrangian Mechanic to derive a physics models for a type of vehicle which once is created it can no be changes easily.
Some time I thought of going that route, but that model is not really suitable for a general purposes physic engine, is more for a dedicated vehicle simulator, with a different solver for different vehicle time. I want to go the other way, I want a unified solve that take care of all the dynamics.
Please try the vehicle and let me know what you think.