【Shader】Unity批量更换Shader

在Unity开发中，因为渲染管线问题，经常会遇到需要大量更改shader的问题，本篇文章讲述批量更换Shader的工具

一、原理：

• 拿到场景内、指定文件夹内所有模型或指定模型
• 编辑获取其Renderer上的所有材质球
• 记录原材质的颜色及贴图
• 更换新的shader
• 将颜色与贴图赋值给新的shader

二、代码

• 代码功能：（其他地方可自行更改）
  • 更换场景内所有物体的shader
  • 目标Shader为URP管线

using System;
using UnityEditor;
using UnityEngine;
using UnityEngine.SceneManagement;
using Object = UnityEngine.Object;

public class BathShaderTool : EditorWindow
{
    private Shader _targetShader;
    private int _selectedShaderIndex = 0;

    private static string[] _shaders = new string[]
    {
        // 可自定指定Shader名称
        //"Universal Render Pipeline/Lit",
    };

    private string _folderPath = "Assets/YourFolderPath"; // 指定你的文件夹路径

    [MenuItem("Tools/BathShaderTool")]
    public static void ShowWindow()
    {
        if (_shaders.Length == 0)
        {
            LoadAllShaders();
        }
        GetWindow<BathShaderTool>();
    }

    private void OnGUI()
    {
        GUILayout.Label("BathShader", EditorStyles.boldLabel);
        _folderPath = GUILayout.TextField(_folderPath);

        _selectedShaderIndex = EditorGUILayout.Popup("Target Shader", _selectedShaderIndex, _shaders);
        _targetShader = Shader.Find(_shaders[_selectedShaderIndex]);

        if (GUILayout.Button("设置场景中所有对象的shader"))
        {
            if (_targetShader != null)
            {
                SetShaderForAllObjectsInScene(_targetShader);
            }
            else
            {
                Debug.LogWarning("Please select a shader.");
            }
        }

        if (GUILayout.Button("设置文件夹中所有对象的shader"))
        {
            if (_targetShader != null)
            {
                SetShader<GameObject>("t:GameObject", _targetShader,
                    (mat, shader) => TraverseAndSetShader((GameObject)mat, shader));
            }
            else
            {
                Debug.LogWarning("Please select a shader.");
            }
        }

        if (GUILayout.Button("设置文件夹中所有材质球的shader"))
        {
            if (_targetShader != null)
            {
                SetShader<Material>("t:Material", _targetShader,
                    (mat, shader) => SetShaderForMat((Material)mat, shader));
            }
            else
            {
                Debug.LogWarning("Please select a shader.");
            }
        }
    }
    
    /// <summary>
    /// 设置场景中所有对象的Shader
    /// </summary>
    /// <param name="shader"></param>
    private void SetShaderForAllObjectsInScene(Shader shader)
    {
        GameObject[] allObjects = SceneManager.GetActiveScene().GetRootGameObjects();

        foreach (GameObject obj in allObjects)
        {
            TraverseAndSetShader(obj, shader);
        }

        Debug.Log("Shader has been set for all objects in the scene.");
    }

    /// <summary>
    /// 遍历对象
    /// </summary>
    /// <param name="obj"></param>
    /// <param name="shader"></param>
    private void TraverseAndSetShader(GameObject obj, Shader shader)
    {
        SetShaderForAllRenderers(obj, shader);

        foreach (Transform child in obj.transform)
        {
            TraverseAndSetShader(child.gameObject, shader);
        }
    }

    /// <summary>
    /// 遍历Renderer并设置Shader
    /// </summary>
    /// <param name="obj"></param>
    /// <param name="shader"></param>
    private void SetShaderForAllRenderers(GameObject obj, Shader shader)
    {
        Renderer[] renderers = obj.GetComponents<Renderer>();

        foreach (Renderer renderer in renderers)
        {
            if (renderer != null)
            {
                foreach (Material material in renderer.sharedMaterials)
                {
                    SetShaderForMat(material, shader);
                }
            }
        }
    }

    /// <summary>
    /// 设置材质球的Shader
    /// </summary>
    /// <param name="material"></param>
    /// <param name="shader"></param>
    private void SetShaderForMat(Material material, Shader shader)
    {
        if (material != null)
        {
            Color albedoColor = material.color;
            Texture albedoTexture = material.mainTexture;

            material.shader = shader;

            material.color = albedoColor;
            material.mainTexture = albedoTexture;
        }
    }
    
    /// <summary>
    /// 设置文件夹中所有指定类型的资源的Shader
    /// </summary>
    /// <param name="type"></param>
    /// <param name="shader"></param>
    /// <param name="action"></param>
    /// <typeparam name="T"></typeparam>
    private void SetShader<T>(string type,Shader shader,Action<object,Shader> action) where T : Object
    {
        string[] guids = AssetDatabase.FindAssets(type, new[] { _folderPath });
        foreach (string guid in guids)
        {
            string assetPath = AssetDatabase.GUIDToAssetPath(guid);
            T assetAt = AssetDatabase.LoadAssetAtPath<T>(assetPath);

            if (assetAt != null)
            {
                action?.Invoke(assetAt,shader);
                EditorUtility.SetDirty(assetAt);
            }
        }

        AssetDatabase.SaveAssets();
    }
    
    /// <summary>
    /// 加载所有Shader名称
    /// </summary>
    private static void LoadAllShaders()
    {
        var shaders = Resources.FindObjectsOfTypeAll<Shader>();
        _shaders = new string[shaders.Length];

        for (int i = 0; i < _shaders.Length; i++)
        {
            Debug.Log(shaders[i].name);
            _shaders[i] = shaders[i].name;
        }
    }
}