Ref : t3ssel8r

LandFacingUpward.cs

using UnityEngine;

public class LandFacingUpward: MonoBehaviour
{
	public LayerMask layerMask;
	public float maxDistance = 5;
	public Vector3 up = Vector3.up;
	public float Kp = 100;
	public float Kd = 20;
	
	Rigidbody rb;
	
	void Start(){
		rb = GetComponent<RigidBody>();
	}
	
	void FixedUpdate(){
		if (Physics.Raycast(rb.position, Physics.gravity, out RaycastHit hitInfo, maxDistance, layerMask)){
			Quaternion.FromToRotation(rb.rotation * up, hitInfo.normal).ToAngleAxis(out float angle, out Vector3 axis);
			Vector3 err = Mathf.Deg2Rad * angle * axis;
			rb.AddTorque(Kp * err - Kd 	* rb.angularVelocity, ForceMode.Acceleration);
		}
	}
}