[Unity] A simple and fast LOD system

LOD.cs

// Update: not needed for Unity 5 since LOD groups are available in personal edition

//========================================
//==	Simple LOD system               ==
//==	File: LOD.cs	                ==
//==	By: Ivan Notaros - Nothke       ==
//==	Use and alter Freely	        ==
//========================================
 
//Description:
// Switches models according to distance from player

using UnityEngine;
using System.Collections;

public class LOD : MonoBehaviour
{
    [System.Serializable]
    public class LODLevel
    {
        public GameObject LODobject;
        public float LODin = 0;
        public float LODout = 100;
        [HideInInspector]
        public bool prevAppear;
    }

    public LODLevel[] LODlevels;

    public float LODmultiplier = 1; // multiplies LODin and LODout in all LODobjects, this is a quick way to make it configurable in game graphics settings
    public float checkRate = 1; // how often is the distance checked, in seconds

    public bool debug;

    Transform player;
    float distance;

    IEnumerator Start()
    {
        player = Utils.GetPlayer().transform; // Change this to whatever way you get the player position

        foreach (LODLevel ll in LODlevels)
        {
            ll.LODobject.renderer.enabled = false;
        }

        yield return new WaitForSeconds(Random.value);

        do
        {
            DoLOD();
            yield return new WaitForSeconds(checkRate);
        } while (true);
    }

    void DoLOD()
    {
        distance = Vector3.Distance(transform.position, player.position);

        foreach (LODLevel ll in LODlevels)
        {
            if (distance >= ll.LODin * LODmultiplier && distance < ll.LODout * LODmultiplier)
            {
                if (!ll.prevAppear)
                {
                    ll.LODobject.renderer.enabled = true;
                    ll.prevAppear = true;
                    if (debug) Debug.Log("LOD - " + ll.LODobject + " appears");
                }
            }
            else
            {
                if (ll.prevAppear)
                {
                    ll.LODobject.renderer.enabled = false;
                    ll.prevAppear = false;
                    if (debug) Debug.Log("LOD - " + ll.LODobject + " hidden");
                }
            }
        }
    }
}