Create a fractal landscape by combining different frequencies of Perlin noise

noiseland.cs

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

public class noiseland : MonoBehaviour {

  public int numRows=10, numCols=10;
  public float minX=-1, maxX=1, minY=-1, maxY=1;

  float height(float x, float y)
    {
    x -= minX;
    y -= minY;
    float h = 0;
    float f = 1, s = 1;
    for (int i=0; i < 8; i++)
        {
        h += s * Mathf.PerlinNoise(f*x, f*y);
        f *= 2f;
        s /= 3f;
        }
    return h;
    }

  void Start ()
    {
    int index;
    Vector3[] myVerts = new Vector3[numRows*numCols];
    index = 0;
    for (int j=0; j < numRows; j++)
        for (int i=0; i < numCols; i++)
            {
            float x = Mathf.Lerp(minX,maxX,i/(numCols-1f));
            float y = Mathf.Lerp(minY,maxY,j/(numRows-1f));
            myVerts[index] = new Vector3(x,height(x,y),y);
            index++;
            }
    int[] myTris = new int[(numRows-1)*(numCols-1)*2*3];
    index = 0;
    for (int j=0; j < numRows-1; j++)
        for (int i=0; i < numCols-1; i++)
            {
            myTris[index++] = i + j*numCols;
            myTris[index++] = i + (j+1)*numCols;
            myTris[index++] = (i+1) + j*numCols;
            myTris[index++] = i + (j+1)*numCols;
            myTris[index++] = (i+1) + (j+1)*numCols;
            myTris[index++] = (i+1) + j*numCols;
            }
    Mesh myMesh = gameObject.GetComponent<MeshFilter>().mesh;
    myMesh.Clear();
    myMesh.vertices = myVerts;
    myMesh.triangles = myTris;
    myMesh.RecalculateNormals();
    }
	
  void Update ()
    {
    }
}