Create a fractal landscape mesh in Unity3D, using midpoint subdivision

fractalland.cs

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

public class fractalland : MonoBehaviour {

    Vector3[][] newArray(int size)
        {
        Vector3[][] v = new Vector3[size][];
        for (int i=0; i < size; i++)
            v[i] = new Vector3[size];
        return v;
        }

    float heightOffset(float yscale)
        {
        return (Random.Range(-yscale,yscale) + Random.Range(-yscale,yscale) + Random.Range(-yscale,yscale))/3f;
        }

    void Start ()
        {
        Vector3[][] verts0;
        int size = 2, size0, i, j;
        float yscale = 10f;
        Vector3[][] verts = newArray(2);
        verts[0][0] = new Vector3(-10,0,-10);
        verts[1][0] = new Vector3(10,0,-10);
        verts[0][1] = new Vector3(-10,0,10);
        verts[1][1] = new Vector3(10,0,10);
        for (int level=0; level < 3; level++)
            {
            verts0 = verts;
            size0 = size;
            size = size * 2 - 1;
            verts = newArray(size);
            yscale /= 1.8f;
            for (i=0; i < size0; i++)
                for (j=0; j < size0; j++)
                    {
                    verts[i*2][j*2] = verts0[i][j];
                    }
            for (j=0; j < size0; j++)
                for (i=0; i < size0-1; i++)
                    {
                    Vector3 v = (verts0[i][j] + verts0[i+1][j])/2;
                    v.y += heightOffset(yscale);
                    verts[i*2+1][j*2] = v;
                    }
            for (i=0; i < size0; i++)
                for (j=0; j < size0-1; j++)
                    {
                    Vector3 v = (verts0[i][j] + verts0[i][j+1])/2;
                    v.y += heightOffset(yscale);
                    verts[i*2][j*2+1] = v;
                    }
            for (i=0; i < size0-1; i++)
                for (j=0; j < size0-1; j++)
                    {
                    Vector3 v = (verts0[i][j] + verts0[i+1][j] + verts0[i][j+1] + verts0[i+1][j+1])/4;
                    v.y += heightOffset(yscale);
                    verts[i*2+1][j*2+1] = v;
                    }
            }
        Vector3[] myVerts = new Vector3[size*size];
        for (i=0; i < size; i++)
            for (j=0; j < size; j++)
                {
                myVerts[i+j*size] = verts[i][j];
                }
        int[] myTris = new int[(size-1)*(size-1)*2*3];
        int index = 0;
        for (j=0; j < size-1; j++)
            for (i=0; i < size-1; i++)
                {
                myTris[index++] = i + j*size;
                myTris[index++] = i + (j+1)*size;
                myTris[index++] = (i+1) + j*size;
                myTris[index++] = i + (j+1)*size;
                myTris[index++] = (i+1) + (j+1)*size;
                myTris[index++] = (i+1) + j*size;
                }
        Mesh myMesh = gameObject.GetComponent<MeshFilter>().mesh;
        myMesh.Clear();
        myMesh.vertices = myVerts;
        myMesh.triangles = myTris;
	    myMesh.RecalculateNormals();
        }
	
    void Update ()
        {
        }
}