ml-agents/unity-environment/Assets/ML-Agents/Examples/SharedAssets/Scripts/CameraFollow.cs

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

namespace MLAgents
{

    public class CameraFollow : MonoBehaviour
    {

        public Transform target;
        Vector3 offset;

        // Use this for initialization
        void Start()
        {
            offset = gameObject.transform.position - target.position;
        }

        // Update is called once per frame
        void Update()
        {
            // gameObject.transform.position = target.position + offset;
            Vector3 newPosition = new Vector3(target.position.x + offset.x, transform.position.y,
                target.position.z + offset.z);
            gameObject.transform.position = newPosition;
        }
    }
}