Unity图片转换为法线贴图

using UnityEngine;using System.IO;using UnityEditor;public class NormalTexture : MonoBehaviour{public Texture2D tex1;private int W;private int H;void Start(){int W = tex1.width;int H = tex1.height;Texture2D tex2 = new Texture2D(W,H);for (int i = 1; i < W-1; i++)for (int j = 1; j < H-1; j++){//转换可修改算法，实现更加优质的贴图Color c;c = tex1.GetPixel(i-1, j);float left = (c.r + c.g + c.b) / 3;c = tex1.GetPixel(i+1,j);float right = (c.r + c.g + c.b) / 3;c = tex1.GetPixel(i, j + 1);float top = (c.r + c.g + c.b) / 3;c = tex1.GetPixel(i, j - 1);float bottom = (c.r + c.g + c.b) / 3;float u = left - right;float v = top - bottom;Vector3 ve3_U = new Vector3(1,0,u);Vector3 ve3_V = new Vector3(0,1,v);Vector3 N = Vector3.Cross(ve3_U, ve3_V).normalized;float r = N.x * 0.5f + 0.5f;float g = N.y * 0.5f + 0.5f;float b = N.z * 0.5f + 0.5f;tex2.SetPixel(i, j, new Color(r, g, b));}tex2.Apply(false);byte[] arr = tex2.EncodeToPNG();using(FileStream fs = new FileStream(Application.dataPath + "/MyTexture.png", FileMode.OpenOrCreate)){fs.Write(arr, 0, arr.Length);}Debug.Log("法线贴图创建完毕");AssetDatabase.Refresh();}}