Requirements for lane assist and how it works

[mfizz]

I'm just wondering on a Passat, and others on the same platform like the superb, I have heard many saying that have just the camera in the windscreen is sufficient enough to have active lane assist even though you may not have it coded from factory.

Is this true? Do I just need the camera there and there is no motor function on the steering wheel or does it steer the car by braking?

[MikeBz]

It steers using the steering rack, so the wheel turns.

According to this it does just use a single camera.