Question Rigidbody player won't turn properly

My character turn 90,180,270 and 360 degrees wheel, but when moving diagonally it moves a few degrees left or right...

Code (CSharp):

1. public class PlayerController : MonoBehaviour
2. {
3.     //Move the rigidbody
4.     //Face the input direction
5.     //Rotate based on input
6.  
7.    
8.     Rigidbody m_Rigidbody;
9.     public float m_Speed = 5f;
10.     public float rotationSpeed = 15;
11.  
12.     void Start()
13.     {
14.         //Fetch the Rigidbody from the GameObject with this script attached
15.         m_Rigidbody = GetComponent<Rigidbody>();
16.     }
17.  
18.     void FixedUpdate()
19.     {
20.         //Store user input as a movement vector
21.         Vector3 m_Input = new Vector3(Input.GetAxisRaw("Horizontal"), 0, Input.GetAxisRaw("Vertical")).normalized;
22.         //Vector3 inputDir = m_Input.normalized;
23.         //Apply the movement vector to the current position, which is
24.         //multiplied by deltaTime and speed for a smooth MovePosition
25.         m_Rigidbody.MovePosition(transform.position + m_Input * Time.deltaTime * m_Speed);
26.         //Input.y = 0;
27.         RotateToward(m_Input);
28.        
29.     }
30.  
31.     private void RotateToward(Vector3 m_Input)
32.     {
33.         //(m_Input.magnitude == 0) {return;}
34.         //if(Mathf.Approximately(m_Input.sqrMagnitude, 0))
35.         //{
36.         //    return;
37.         //}
38.         //if (Mathf.Approximately(m_Input.magnitude, 0) == true)
39.         //    return;
40.         //Quaternion rotation = Quaternion.LookRotation(m_Input);
41.         //transform.rotation = Quaternion.RotateTowards(transform.rotation, rotation, rotationSpeed);
42.        if (m_Input.magnitude >= 0.1f)
43.         {
44.             transform.rotation = Quaternion.Lerp(transform.rotation, Quaternion.LookRotation(m_Input), rotationSpeed * Time.deltaTime);
45.         }

 

Two problems:

1. You're using Quaternion.Lerp incorrectly. Your third parameter makes no sense. Lerp expects a 3rd parameter that moves over time from 0 to 1.
2. If this is a rigidbody you should not set transform.rotation directly. Instead, use m_Rigidbody.MoveRotation()

 

Thanks for help. I'm trying to learn it but I really don't understand... I'm looking for it a days...