ポリゴンを出力するチュートリアルをちょっとだけ改造したメモ。[tutorial](http://catlikecoding.com/unity/tutorials/procedural-grid/)

TriPolygonGenerate.cs

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

[RequireComponent(typeof(MeshFilter), typeof(MeshRenderer))]
public class CubeTest : MonoBehaviour {
    public int xSize, ySize;
	void Awake(){
	   StartCoroutine( this.Generate() );
	}

    Vector3[] vertices;
    IEnumerator Generate(){
        var wait = new WaitForSeconds(0.05f);
        
        Mesh mesh;
        GetComponent<MeshFilter>().mesh = mesh = new Mesh();
        mesh.name = "Procedural Grid";        
        
        // 頂点情報
        this.vertices = new Vector3[ (this.xSize + 1 ) * ( this.ySize + 1 )];
        // UV情報
        Vector2[] uv = new Vector2[vertices.Length];

		Vector4[] tangents = new Vector4[vertices.Length];
		Vector4 tangent = new Vector4(1f, 0f, 0f, -1f); // [Thus w should always be 1 or -1.](http://docs.unity3d.com/ja/current/ScriptReference/Mesh-tangents.html)
        
		for (int i = 0, y = 0; y <= this.ySize; y++) {
			for (int x = 0; x <= this.xSize; x++, i++) {
				this.vertices[i] = new Vector3(x, y); // モデル座標空間における値
                //uv[i] = new Vector2(x / xSize, y / ySize);
                uv[i] = new Vector2((float)x / xSize, (float)y / ySize);
                //yield return wait;
                tangents[i] = tangent;
			}
		}
        
        // 頂点を入れる
        mesh.vertices = vertices;
        // uv情報を入れる
        mesh.uv = uv;

        mesh.tangents = tangents;

        int[] triangles = new int[ xSize * ySize * 6 ];
        for( int y = 0,count = 0, total = 0; y < this.ySize; y ++, total ++ ){
            for(int x = 0; x < this.xSize; x++, count += 6, total ++ ){
                this.DrawTriCorrectLocation (ref triangles, count, total);
                mesh.triangles = triangles; // 代入すると描画される
                yield return wait;
                this.DrawTriInversion (ref triangles, count, total);
                mesh.triangles = triangles;
                yield return wait;
                Debug.Log("Draw" + x + ":" + y);                
            }
        }
        mesh.RecalculateNormals();
    }
    void DrawTriCorrectLocation(ref int[] triangles, int count, int total  ){
		triangles[ count + 0] = total;
		triangles[ count + 1] = total + xSize + 1;
		triangles[ count + 2] = total + 1;
    }    
    void DrawTriInversion( ref int[] triangles, int count, int total ){
		triangles[ count + 3 ] = total + 1;
		triangles[ count + 4 ] = total + xSize + 1;
		triangles[ count + 5 ] = total + xSize + 2;        
    }
    
    void OnDrawGizmos(){
        if( this.vertices == null ) return;
        
        Gizmos.color = Color.black;
        for( int i = 0; i < this.vertices.Length; i++ ){
            Gizmos.DrawSphere( this.vertices[i] + this.transform.position, 0.1f ); // モデル座標空間における位置に自身の位置を合算させる。
        }
    }
    
}