注释以后有空再写吧，加班到现在还没吃饭呢

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEditor;
using System.IO;
using System.Text.RegularExpressions;

/// <summary>
/// 根据材质球上的主贴图名字进行改为同名的其他后缀的贴图，并且加上法线贴图
/// </summary>
public class Replace
{

    [MenuItem("Tools/replace")]
    public static void Rename()
    {
        Object[] m_objects = Selection.GetFiltered(typeof(Object), SelectionMode.DeepAssets);//选择的所以对象  

        foreach (Object item in m_objects)
        {
            string path = AssetDatabase.GetAssetPath(item);

            Debug.Log("材质球的位置：");
            Debug.Log(path);

            if (Path.GetExtension(path) != "")//判断路径是否为空  
            {
                if (item.GetType() == typeof(Material))
                {
                    Material m = (Material)item;

                    path = AssetDatabase.GetAssetPath(m.mainTexture);
                    Debug.Log("材质球上主贴图的位置：");
                    Debug.Log(path);

                    string[] strs = path.Split('.');
                    string afterpath = strs[0] + ".jpg";

                    Debug.Log("材质球上主贴图相应后缀的位置：");
                    Debug.Log(afterpath);

                    if (AssetDatabase.LoadAssetAtPath<Texture>(afterpath))
                        m.mainTexture = AssetDatabase.LoadAssetAtPath<Texture>(afterpath);


                    string strNormalMap = strs[0] + "_NRM.jpg";

                    Texture texturebump = AssetDatabase.LoadAssetAtPath<Texture>(strNormalMap);

                    if (texturebump != null)
                        m.SetTexture("_BumpMap", texturebump);
                }

            }

        }

        AssetDatabase.SaveAssets();
        AssetDatabase.Refresh();

        Debug.Log("Complete!");
    }

}