How do I stick an object to another without stopping it's movement (not like glue)

Questions & Answers
1

Hi, I’m trying to make an AR cube game where the cube is kind of like the planet but whenever I rotate the cube, a sphere on top will fall towards the gravity below but it still has to stick on the cube world.

Any idea on how to make it without sticking like glue?

2

One attempt would be to add a force always to the center of the cube.

using UnityEngine;
[RequireComponent(typeof(Rigidbody))]
public class PlanetGravity : MonoBehaviour {

    public Transform gravityCenter;
    public float gravityMultiplier;

    private Rigidbody rigidBody;
    void Awake()
    {
        rigidBody = GetComponent<Rigidbody>();
    }
    void FixedUpdate()
    {
        rigidBody.AddForce((gravityCenter.position - transform.position).normalized * gravityMultiplier);
    }
}

Just add this script to your sphere and drop the cube to the gravityCenter. You can also add a physics material to make it bounce a bit and play around with the gravityMultiplier value.