com.misaki.hdrp-toon/Editor/NormalBaker/SmoothNormalBakerWindow.cs

using System.IO;
using UnityEditor;
using UnityEditor.UIElements;
using UnityEngine;
using UnityEngine.UIElements;

namespace Unity.Toonshader.Editor
{
    public class SmoothNormalBakerWindow : EditorWindow
    {
        [MenuItem("Tools/UTS/Smooth Normal Baker")]
        public static void ShowWindow()
        {
            var window = GetWindow<SmoothNormalBakerWindow>("Smooth Normal Baker");
            window.ShowUtility();
        }

        public void CreateGUI()
        {
            var objectField = new ObjectField("Input Object")
            {
                allowSceneObjects = false,
                objectType = typeof(Mesh)
            };

            var directBakeToggle = new Toggle("Direct Bake");

            var bakeButton = new Button()
            {
                text = "Bake"
            };

            bakeButton.clicked += () =>
            {
                if (objectField.value is not GameObject inputObject)
                {
                    return;
                }

                var outputObject = inputObject;
                if (!directBakeToggle.value)
                {
                    var saveLocation = EditorUtility.OpenFolderPanel("Save location", "", "");

                    if (!Directory.Exists(saveLocation))
                    {
                        return;
                    }

                    var inputMeshLocation = AssetDatabase.GetAssetPath(inputObject);
                    var outputMeshLocation = Path.Combine(saveLocation, $"{Path.GetFileNameWithoutExtension(inputMeshLocation)}_UtsSmoothedNormal{Path.GetExtension(inputMeshLocation)}");

                    if (!File.Exists(outputMeshLocation))
                    {
                        AssetDatabase.CopyAsset(inputMeshLocation, outputMeshLocation);
                        AssetDatabase.ImportAsset(outputMeshLocation);
                    }

                    outputObject = AssetDatabase.LoadAssetAtPath<GameObject>(outputMeshLocation);
                }

                var originalMesh = UTSNormalBakerHelper.GetMesh(inputObject);
                var smoothedMesh = UTSNormalBakerHelper.GetMesh(outputObject);

                foreach (var item in originalMesh)
                {
                    var m = item.Value;
                    UTSNormalBakerHelper.ComputeSmoothedNormalByJob(smoothedMesh[item.Key], m);
                }
            };

            rootVisualElement.Add(objectField);
            rootVisualElement.Add(directBakeToggle);
            rootVisualElement.Add(bakeButton);
        }
    }
}