2d Terrain Generation With Perlin Noise.

Questions & Answers
1

I am trying to generate a simple random map with different biomes, parts, Every time I generate a world with this it just fills the grid with the same block.
Heres the code:

using UnityEngine;
using System.Collections;

public class TerrainGen : MonoBehaviour {

	public GameObject[] floorWater;
	public GameObject[] floorSand;
	public GameObject[] floorStone;
	public GameObject[] floorGrass;
	public GameObject[] floorDirt;

	public int mapWidth;
	public int mapHeight;

	private Transform Board;
	private float seed;

	void generateTerrain()
	{
		Board = new GameObject ("Board").transform;

		for (int x = 0; x < mapWidth; x++) 
		{
			for (int y = 0; y < mapHeight; y++) 
			{
				seed = Random.Range (0, 0.9f);
				float biome = Mathf.PerlinNoise (x, y)+seed;

				GameObject toInstantiate;
				GameObject instantiate;

				if (biome >= 0 || biome < 0.2) 
				{
					toInstantiate = floorWater [Random.Range (0, floorWater.Length)];
					instantiate = Instantiate (toInstantiate, new Vector3 (x, y, 0f), Quaternion.identity) as GameObject;
					instantiate.transform.SetParent (Board);
				}

				if (biome >= 0.2 || biome < 0.4) 
				{
					toInstantiate = floorSand [Random.Range (0, floorSand.Length)];
					instantiate = Instantiate (toInstantiate, new Vector3 (x, y, 0f), Quaternion.identity) as GameObject;
					instantiate.transform.SetParent (Board);
				}

				if (biome >= 0.4 || biome < 0.6) 
				{
					toInstantiate = floorDirt [Random.Range (0, floorDirt.Length)];
					instantiate = Instantiate (toInstantiate, new Vector3 (x, y, 0f), Quaternion.identity) as GameObject;
					instantiate.transform.SetParent (Board);
				}

				if (biome >= 0.6 || biome < 0.8) 
				{
					toInstantiate = floorGrass [Random.Range (0, floorGrass.Length)];
					instantiate = Instantiate (toInstantiate, new Vector3 (x, y, 0f), Quaternion.identity) as GameObject;
					instantiate.transform.SetParent (Board);
				}

				if (biome >= 0.8) 
				{
					toInstantiate = floorStone [Random.Range (0, floorStone.Length)];
					instantiate = Instantiate (toInstantiate, new Vector3 (x, y, 0f), Quaternion.identity) as GameObject;
					instantiate.transform.SetParent (Board);
				}
			}
		}
	}

	void Start () 
	{
		generateTerrain ();
	}
	

	void Update () 
	{
	
	}
}

Any help would be appreciated. Thanks.

2

Perlin noise doesn’t work for exact integer numbers due to the way it looks up it’s semi-random numbers to calculate it’s output. Try using a float instead and adding an arbitrary float as an offset.