ml-agents/Project/Assets/ML-Agents/Examples/PushBlock/Scripts/SimpleNPC.cs

// using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class SimpleNPC : MonoBehaviour
{

    public Transform target;

    private Rigidbody rb;

    public float walkSpeed = 1;
    // public ForceMode walkForceMode;
    private Vector3 dirToGo;

    // private Vector3 m_StartingPos;
    // Start is called before the first frame update
    void Awake()
    {
        rb = GetComponent<Rigidbody>();
        // m_StartingPos = transform.position;
    }

    // Update is called once per frame
    void Update()
    {
    }

    void FixedUpdate()
    {
        dirToGo = target.position - transform.position;
        dirToGo.y = 0;
        rb.rotation = Quaternion.LookRotation(dirToGo);
        // rb.AddForce(dirToGo.normalized * walkSpeed * Time.fixedDeltaTime, walkForceMode);
        // rb.MovePosition(rb.transform.TransformDirection(Vector3.forward * walkSpeed * Time.deltaTime));
        // rb.MovePosition(rb.transform.TransformVector() (Vector3.forward * walkSpeed * Time.deltaTime));
        rb.MovePosition(transform.position + transform.forward * walkSpeed * Time.deltaTime);
    }

    public void SetRandomWalkSpeed()
    {
        walkSpeed = Random.Range(6f, 7f);
    }
}