//Sur le player
public class GravityBody : MonoBehaviour
{
    public GravityAttractor objAttractor;
    public bool useRbGravity;
    private Rigidbody rb;

    void Awake()
    {
        rb = GetComponent<Rigidbody>();
        rb.useGravity = useRbGravity;
        rb.constraints = RigidbodyConstraints.FreezeRotation;
    }

    void FixedUpdate()
    {
        if (objAttractor!= null) objAttractor.Attract(rb);
    }
}

//Sur les obj
public class GravityAttractor : MonoBehaviour
{
    public float gravity;
    public bool invertGravity;

    public void Attract(Rigidbody rb)
    {
        Vector3 direction = (transform.position - rb.position).normalized;

        if (invertGravity) direction = -direction;

        Vector3 gravityForce = direction * gravity;

        rb.AddForce(gravityForce, ForceMode.Acceleration);
    }
}