Создание текстуры из 4 кусоков

TextureCreator.cs

using UnityEngine;
using System.Collections;
using UnityEditor;
using System.IO;

public class TextureCreator : Editor {

	[MenuItem("TEXTURE/Create Texture")]
	static void CreateTexture(){
		
		Texture2D texture = new Texture2D(1024,1024);

		Texture2D tex1 = (Texture2D)AssetDatabase.LoadAssetAtPath("Assets/1.jpg", typeof(Texture2D));
		Texture2D tex2 = (Texture2D)AssetDatabase.LoadAssetAtPath("Assets/2.jpg", typeof(Texture2D));
		Texture2D tex3 = (Texture2D)AssetDatabase.LoadAssetAtPath("Assets/3.jpg", typeof(Texture2D));
		Texture2D tex4 = (Texture2D)AssetDatabase.LoadAssetAtPath("Assets/4.jpg", typeof(Texture2D));

		DrawPixels(tex1, Postition.TopLeft, ref texture);
		DrawPixels(tex2, Postition.TopRight, ref texture);
		DrawPixels(tex3, Postition.BottomLeft, ref texture);
		DrawPixels(tex4, Postition.BottomRight, ref texture);
		
		byte[] pngData = texture.EncodeToPNG();
		if(pngData != null){
			File.WriteAllBytes("Assets/texture.png", pngData);
			Debug.Log ("TEXTURE CREATED");
		}

		AssetDatabase.Refresh();
		pngData = null;
	}

	enum Postition{
		TopLeft, TopRight, BottomLeft, BottomRight
	}

	static void DrawPixels (Texture2D tex, Postition pos, ref Texture2D result){

		int width = tex.width;
		int height = tex.height;
		int startX = 0;
		int startY = 0;

		switch (pos)
		{
		case Postition.TopLeft:
			height *= 2;
			startY = height/2;
			break;
		case Postition.TopRight:
			width *= 2;
			height *= 2;
			startX = width/2;
			startY = height/2;
			break;
		case Postition.BottomLeft:
			break;
		case Postition.BottomRight:
			width *= 2;
			startX = width/2;
			break;
		}

		for (int y = startY, GY = 0 ; y < height; ++y, ++GY)
			for (int x = startX, GX = 0; x < width; ++x, ++GX)
				result.SetPixel(x, y, tex.GetPixel(GX, GY));
	}
}