Physics problem: Sphere not rolling on top of a rotating sphere

Unity Engine
1

I’m sure I’ve just overlooked something, but I can’t get a sphere working as it should on top of a rotating sphere/cylinder.
Instead of joining in the merry rotation (and gaining some momentum of its own) the ball on the top just sits still sliding on the rotating one, like they both would have zero friction. First I thought there was something wrong with my faux gravity script, but when I tried it with a bare minimum setup and with unity’s built-in gravity using default settings and it did the same thing.

The top ball has a rigid body with gravity and a sphere collider. The rotating sphere has just a sphere collider and this script:

function FixedUpdate () 
{
	transform.Rotate(0, Time.deltaTime * 140, 0);
}

I’ve tried messing with physics material frictions and angular velocity, but they didn’t help :frowning:

Here’s the bare minimum package and a web-player one so you can see what I’m talking about:
Web Player Link
525455–18579–$gravitytest.unitypackage (4.66 KB)

Any thoughts would be welcome

2

Ah, turns out I did overlook something. The solution was to use rigidbody with the lower sphere and rotate it by its MoveRotation.
Why I have trouble with this for ours and only find out the solution after minutes from posting, sorry everyone :stuck_out_tongue_winking_eye: