Floating Origin Script

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

public class FloatingOrigin : MonoBehaviour {

    [Header("Settings")]
    [Tooltip("When Target's position reaches this magnitude/distance, Target and Scene Root transforms will be moved.")]
    public float _threshold = 1000f;

    [Header("References")]
    [Tooltip("This Transform we will use to calculate the distance from origin. It will be moved back to near origin.")]
    public Transform _target;

    void Awake() {
        if (_target == null)
            _target = Camera.main.transform;
    }

    void LateUpdate() {
        Vector3 targetPos = _target.position;
        targetPos.y = 0f;

        if (targetPos.magnitude > _threshold) {
            foreach (GameObject rootGO in SceneManager.GetActiveScene().GetRootGameObjects()) {
                rootGO.transform.position -= targetPos;
            }
        }
    }
}