Combination of noiseland.cs & noisetex.cs - creates landscape geometry and a texture to apply to the geometry

noiseland2.cs

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

public class noiseland2 : MonoBehaviour {

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

  public int tex_width=256;
  public int tex_height=256;
  private Texture2D tex;
  private Color32[] colors;

  void Start ()
    {
    generateGeometry();
    generateTexture();
    }

  void generateTexture()
    {
    tex = new Texture2D(tex_width,tex_height);
    colors = new Color32[tex_width*tex_height];
    GetComponent<Renderer>().material.mainTexture = tex;
    int index = 0;
    for (int j=0; j < tex_height; j++)
        for (int i=0; i < tex_width; i++)
            {
            float x = Mathf.Lerp(minX,maxX,i/(tex_width-1f));
            float y = Mathf.Lerp(minY,maxY,j/(tex_height-1f));
            float h = height(x,y);
            if (h < 0.5)
                colors[index] = Color.blue;
            else if (h < 0.8)
                colors[index] = Random.ColorHSV(0.3f,0.35f,0.7f,1f,0.8f,0.9f);
            else if (h < 0.95)
                colors[index] = Random.ColorHSV(0.15f,0.2f,0.7f,0.8f,0.5f,0.75f);
            else
                colors[index] = Random.ColorHSV(0f,1f,0f,0.1f,0.9f,1f);
            index++;
            }
    tex.SetPixels32(colors);
    tex.Apply();
    }

  void generateGeometry()
    {
    int index;
    Vector3[] myVerts = new Vector3[numRows*numCols];
    Vector2[] myUV = new Vector2[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));
            float u = Mathf.Lerp(0,1,i/(numCols-1f));
            float v = Mathf.Lerp(0,1,j/(numRows-1f));
            myVerts[index] = new Vector3(x,height(x,y),y);
            myUV[index] = new Vector2(u,v);
            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.uv = myUV;
    myMesh.triangles = myTris;
    myMesh.RecalculateNormals();
    }

  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;
    }

}