replace crawler

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;
+
+    private Vector3 dirToGo;
+    // Start is called before the first frame update
+    void Awake()
+    {
+        rb = GetComponent<Rigidbody>();
+    }
+
+    // Update is called once per frame
+    void Update()
+    {
+        dirToGo = target.position - transform.position;
+        dirToGo.y = 0;
+        transform.rotation = Quaternion.LookRotation(dirToGo);
+    }
+
+    void FixedUpdate()
+    {
+        rb.AddForce(dirToGo.normalized * walkSpeed * Time.fixedDeltaTime, ForceMode.VelocityChange);
+    }
+}

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

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