public float heightScale = 20f;
public float detailScale = 20f;

float seed;
// Use this for initialization
void Start()
{

    //if (instance == null)
     //   instance = this;



    for (int x = 0; x < mapSizeX; x++)
    {
        for (int z = 0; z < mapSizeZ; z++)
        {
            int y = (int)(Mathf.PerlinNoise((x + seed) / detailScale, (z + seed) / detailScale) * heightScale);

            GameObject g = Instantiate(grass) as GameObject;
            g.transform.position = new Vector3(x, y , z);
            g.transform.SetParent(this.transform);







        }
    }

}`