Unityプロジェクト内に存在するすべてのマテリアルのシェーダーキーワードをShaderVariantCollectionへ登録するツール (Unity2022 / URP14.0.10)

ShaderKeywordCollector.cs

namespace MyTool
{
    using System;
    using UnityEditor;
    using UnityEngine;
    using System.Linq;
    using UnityEngine.Rendering;

    public class ShaderKeywordCollector : EditorWindow
    {
        [SerializeField] private ShaderVariantCollection shaderVariantCollection;
        private Vector2 _scrollPosition;
        private Material[] _materials = { };
        private int _materialCount;

        [MenuItem("Window/Shader Keyword Collector")]
        public static void ShowWindow()
        {
            GetWindow<ShaderKeywordCollector>("Shader Keyword Collector");
        }

        void OnGUI()
        {
            GUILayout.Label("Shader Keyword Collector", EditorStyles.boldLabel);
            
            // ShaderVariantCollection登録フィールド
            shaderVariantCollection = EditorGUILayout.ObjectField("Shader Variant Collection", shaderVariantCollection,
                typeof(ShaderVariantCollection), false) as ShaderVariantCollection;
            
            // キーワード取得
            EditorGUI.BeginDisabledGroup(shaderVariantCollection == null);
            if (GUILayout.Button("Collect Keywords"))
            {
                Execute();
            }
            EditorGUI.EndDisabledGroup();

            GUILayout.Space(16);
            GUILayout.Label($"Collected Materials ({_materialCount})", EditorStyles.boldLabel);

            EditorGUI.indentLevel++;
            _scrollPosition = EditorGUILayout.BeginScrollView(_scrollPosition);
            DrawCollectedMaterial();
            EditorGUI.indentLevel--;
            
            EditorGUILayout.EndScrollView();
        }

        private void DrawCollectedMaterial()
        {
            if (_materials == null)
            {
                return;
            }

            foreach (var material in _materials)
            {
                if (material == null)
                {
                    continue;
                }

                var shader = material.shader;
                if (shader == null)
                {
                    continue;
                }

                EditorGUILayout.ObjectField(material, typeof(Material));
            }
        }

        private void Execute()
        {
            if (shaderVariantCollection == null)
            {
                Debug.LogError("Please assign a Shader Variant Collection.");
                return;
            }

            shaderVariantCollection.Clear();
            _materials = Resources.FindObjectsOfTypeAll<Material>()
                .Where(IsCollectTarget)
                .ToArray();
            _materialCount = _materials.Length;
            
            foreach (var material in _materials)
            {
                if (material.shader == null) continue;

                AddMaterialVariant(shaderVariantCollection, material);
            }

            EditorUtility.SetDirty(shaderVariantCollection);
            AssetDatabase.SaveAssets();

            Debug.Log("Shader keywords collected and added to the Shader Variant Collection.");
        }

        /// <summary>
        /// 登録対象のマテリアルか判別
        /// </summary>
        private static bool IsCollectTarget(Material material)
        {
            if (material == null)
            {
                return false;
            }

            if (material.hideFlags == HideFlags.DontSave)
            {
                return false;
            }

            var shader = material.shader;
            if (shader == null)
            {
                return false;
            }

            if (shader.hideFlags == HideFlags.DontSave)
            {
                return false;
            }

            if (shader.name.StartsWith("Hidden/"))
            {
                return false;
            }

            return true;
        }

        /// <summary>
        /// ShaderVariantCollectionへマテリアルのシェーダーキーワードを登録
        /// </summary>
        private static void AddMaterialVariant(ShaderVariantCollection collection, Material material)
        {
            Shader shader = material.shader;
            if (material.shader == null) return;

            int subShaderCount = shader.subshaderCount;
            int passCount = shader.passCount;
            for (uint subShaderIndex = 0; subShaderIndex < subShaderCount; subShaderIndex++)
            {
                for (uint passIndex = 0; passIndex < passCount; passIndex++)
                {
                    AddPassVariant(collection, shader, passIndex, material.shaderKeywords);
                }
            }
        }

        /// <summary>
        /// ShaderVariantCollectionへのVariant登録
        /// </summary>
        private static void AddPassVariant(ShaderVariantCollection collection, Shader shader, uint passIndex,
            string[] keywords)
        {
            var variant = new ShaderVariantCollection.ShaderVariant
            {
                shader = shader,
                passType = GetLightModePassType(shader, (int)passIndex),
                keywords = keywords
            };
            collection.Add(variant);
        }

        /// <summary>
        /// PassTypeの取得
        /// </summary>
        private static PassType GetLightModePassType(Shader shader, int passIndex)
        {
            // ShaderのLightModeパスタグの値を利用して、PassTypeを判別
            // PassTypeについては https://docs.unity3d.com/ja/2019.4/ScriptReference/Rendering.PassType.html を参照
            ShaderTagId lightModeTag = shader.FindPassTagValue(passIndex, new ShaderTagId("LightMode"));
            bool success = Enum.TryParse<PassType>(lightModeTag.name, true, out PassType passType);
            if (success)
            {
                return passType;
            }

            switch (lightModeTag.name)
            {
                case "SRPDefaultUnlit":
                case "": // URPでは、LightModeパスタグが指定されていない場合は SRPDefaultUnlit として扱われる
                    return PassType.ScriptableRenderPipelineDefaultUnlit;
                default:
                    return PassType.ScriptableRenderPipeline;
            }
        }
    }
}