Unity 5 - WheelColliders broken?

Hi all,

I’ve just upgraded to Unity 5 this morning and ported a copy of my current project into it. It’s a simple scene - several vehicles sitting in a town square. There is a large box collider composing the road surface and one of the vehicles has four wheel colliders, which worked fine in Unity 4.6 yesterday.

Upon running the scene today after playing with the new standard shader and updating my materials, the vehicle with wheel colliders just drops straight through the road, every time.

I’ve removed the wheel collider components and re-attached new ones, thinking the components have changed and need updating with Unity 5, but the same thing still happens. I haven’t changed anything with the scene other than the material shaders. The road surface box collider is still there and active. The wheel colliders are all attached and set up. The vehicle starts a small distance above the road, so it isn’t IN the road collider.

Is this a bug?

I BELIEVE THIS TO BE THE ANSWER FOR ALL who have problems with WheelColliders in the new 5.x PhysX3 engine.

It seems the document writers and programmers might have gotten together on that one an made sure that a prominent note was placed in the WheelCollider entry in the SCRIPTING MANUAL such as:

NEW PhysX3 engine and new wheelcollider physics… see Physics in Unity MANUAL

see RECAP in comment below… could be priceless time saving!

…and yes, I know they will say it is in the release notes of 5.x, but still as important as this is, such warning would have saved much time!!

Cancel that - problem sorted. For some reason, Unity 5’s WheelColliders weren’t happy with the GameObject hierarchy that I had them set up in. They’re now direct children of the rigidbody and seem to be working fine.

The default settings for the WheelColliders aren’t to be trusted, though. A spring value of 35000 and Damper of 4500 where creating some interesting behaviour, to say the least!