以下.cs需要放置在名称为 Editor 的文件夹下
EditorFlipMeshNormals.cs

#if UNITY_EDITORusing UnityEditor;
using UnityEngine;/// <summary>
/// 在 Hierarchy 视图对象的快捷菜单中增加 Flip Mesh Normals(反转网格法线)项
/// </summary>
public class EditorFlipMeshNormals : Editor {/// <summary> 翻转网格的法线 </summary>private static void FlipMeshNormals (Mesh mesh) {int[] triangles = mesh.triangles;for (int i = 0, len = triangles.Length; i < len; i += 3) {// 交换三角形的首尾索引int t = triangles[i];triangles[i] = triangles[i + 2];triangles[i + 2] = t;}mesh.triangles = triangles;}/// <summary> 翻转多个游戏对象网格的法线 </summary>private static void FlipMeshNormals (GameObject[] gameObjects) {for (int i = 0, len = gameObjects.Length; i < len; i++) {GameObject go = gameObjects[i];Mesh mesh = null;SkinnedMeshRenderer skinnedMeshRenderer = go.GetComponent<SkinnedMeshRenderer>();if (skinnedMeshRenderer) {mesh = skinnedMeshRenderer.sharedMesh;} else {MeshFilter meshFilter = go.GetComponent<MeshFilter>();if (meshFilter) {mesh = meshFilter.sharedMesh;}}if (mesh) {string path = AssetDatabase.GetAssetPath(mesh);// 是否为 Assets 文件夹下的资源(Assets 文件夹下的资源才能编辑，避免编辑到 Unity 的内置资源的网格)bool isAssetFolder = path.IndexOf("Assets/") > -1;if (isAssetFolder) {FlipMeshNormals(mesh);}}}}/// <summary> 验证所选择的游戏对象有网格时菜单才可用(不计算子级) </summary>[MenuItem("GameObject/Flip Mesh Normals", true)]private static bool ValidateFlipMeshNormalsOnGameObject () {bool isEnableMenuItem = false;GameObject[] gameObjects = Selection.gameObjects;for (int i = 0, len = gameObjects.Length; i < len; i++) {GameObject go = gameObjects[i];Mesh mesh = null;SkinnedMeshRenderer skinnedMeshRenderer = go.GetComponent<SkinnedMeshRenderer>();if (skinnedMeshRenderer) {mesh = skinnedMeshRenderer.sharedMesh;} else {MeshFilter meshFilter = go.GetComponent<MeshFilter>();if (meshFilter) {mesh = meshFilter.sharedMesh;}}if (mesh) {string path = AssetDatabase.GetAssetPath(mesh);// 是否为 Assets 文件夹下的资源(Assets 文件夹下的资源才能编辑，避免编辑到 Unity 的内置资源的网格)bool isAssetFolder = path.IndexOf("Assets/") > -1;if (isAssetFolder) {isEnableMenuItem = true;break;}}}return isEnableMenuItem;}[MenuItem("GameObject/Flip Mesh Normals", false, 11)]private static void FlipMeshNormalsOnGameObject () {FlipMeshNormals(Selection.gameObjects);}}
#endif