Generate Terrain

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

public class GenerateTerrain : MonoBehaviour {

	public int heightScale = 5;
	public float detailScale = 5.0f;
	List<GameObject> myRocks = new List<GameObject>();

	void Start ()
	{
		Mesh mesh = this.GetComponent<MeshFilter> ().mesh;
		Vector3[] vertices = mesh.vertices;
		for (int v = 0; v < vertices.Length; v++)
		{
			vertices [v].y = Mathf.PerlinNoise ((vertices [v].x + this.transform.position.x) / detailScale,
				                                (vertices [v].z + this.transform.position.z) / detailScale) * heightScale;

			if (vertices [v].y > 0.8)
			{
				GameObject newRock = RockPool.getRock ();
				if (newRock != null)
				{
					Vector3 rockPos = new Vector3 (vertices [v].x + this.transform.position.x,
						                           vertices [v].y + 0.5f, //Reduce on y axis if object is floating above terrain
												   vertices [v].z + this.transform.position.z);

					newRock.transform.position = rockPos;
					newRock.SetActive (true);
					myRocks.Add (newRock);
				}
			}

		}

		mesh.vertices = vertices;
		mesh.RecalculateBounds ();
		mesh.RecalculateNormals ();
		this.gameObject.AddComponent<MeshCollider> ();
	}


	void OnDestroy()
	{
		for (int i = 0; i < myRocks.Count; i++)
		{
			if (myRocks [i] != null)
				myRocks [i].SetActive (false);
		}
		myRocks.Clear ();
	}


	void Update ()
	{

	}
}