diff --git a/App/main.cpp b/App/main.cpp
index 1f04c9e..67df9fe 100644
--- a/App/main.cpp
+++ b/App/main.cpp
@@ -28,289 +28,283 @@
 using namespace Engine;
 using namespace Engine::ECS;
 
-class SandboxApp final : public Application
+namespace
 {
-public:
-    SandboxApp()
-        : Application("HelloVulkan", 800, 600)
+    class SandboxApp final : public Application
     {
-    }
-
-protected:
-    // ---- 生命周期 ----
-
-    void OnInit() override
-    {
-        Scene& scene = GetScene();
-
-        // ImGui 叠加层（框架只做管线桥接，UI 内容全部在这里定义）
-        EnableImGui();
-
-        // 模型资产（AssetManager 负责加载/缓存/生命周期，返回句柄）
-        // SunTemple：FBX + DDS 压缩贴图（DdsLoader 验证场景）
-        const auto model = GetAssets().LoadModel("assets/models/viking_room/viking_room.obj");
-        const auto temple = GetAssets().LoadModel("assets/models/SunTemple/SunTemple.fbx");
-
-        m_Spinners.push_back(scene.CreateEntity("backpack"));
-        m_Spinners[0].AddComponent<MeshRendererComponent>(MeshRendererComponent{model});
-
-        // 地面：程序化纯色平面（半边长 15，中心 y=-2）
-        const auto ground = GetAssets().CreatePlane(15.0f, 140, 140, 145);
-
-        m_Ground = scene.CreateEntity("Ground");
-        m_Ground.GetComponent<TransformComponent>()
-                .SetPosition(glm::vec3(0.0f, -0.5f, 0.0f));   // dirty → 帧循环统一 Compose
-        m_Ground.AddComponent<MeshRendererComponent>(MeshRendererComponent{ground});
-
-        // 相机实体（primary = 当前渲染视角；位姿存实体 Transform）
-        m_Camera = scene.CreateEntity("MainCamera");
-        auto& camera = m_Camera.AddComponent<CameraComponent>();
-        camera.primary = true;
-        m_Camera.GetComponent<TransformComponent>()
-                 .SetPosition(glm::vec3(0.0f, 0.0f, 7.0f));
-
-        // 神庙实体 × 1（ FBX 单位较大，缩放到场景尺度）
+    public:
+        SandboxApp()
+            : Application("HelloVulkan", 800, 600)
         {
-            auto e = scene.CreateEntity("SunTemple");
-            e.GetComponent<TransformComponent>()
-             .SetScale(glm::vec3(0.05f));
-            e.AddComponent<MeshRendererComponent>(MeshRendererComponent{temple});
         }
 
-        // 灯光实体（第一个方向光 = 阴影光源）
-        m_KeyLight = scene.CreateEntity("KeyLight");
-        m_KeyLight.AddComponent<LightComponent>(
-            LightComponent{
-                .type = LightComponent::Type::Directional,
-                .direction = glm::vec3(-0.5f, -0.6f, -0.35f),
-                .color = glm::vec4(1.0f, 0.95f, 0.9f, 1.0f)
-            });
+    protected:
+        // ---- 生命周期 ----
 
-        scene.CreateEntity("FillLight")
-             .AddComponent<LightComponent>(
-                 LightComponent{
-                     .type = LightComponent::Type::Directional,
-                     .direction = glm::vec3(0.5f, -0.5f, 0.3f),
-                     .color = glm::vec4(0.3f, 0.5f, 1.0f, 0.8f)
-                 });
-
-        // 点光源（位置 = 实体 Transform，出生即有；无阴影，距离衰减）
-        auto fire = scene.CreateEntity("FirePitLight");
-        fire.GetComponent<TransformComponent>().SetPosition(glm::vec3(2.0f, 1.5f, 1.0f));
-        fire.AddComponent<LightComponent>(
-            LightComponent{
-                .type = LightComponent::Type::Point,
-                .color = glm::vec4(1.0f, 0.6f, 0.3f, 2.0f),   // 暖橙
-                .radius = 8.0f,
-            });
-
-        auto cool = scene.CreateEntity("CoolFillLight");
-        cool.GetComponent<TransformComponent>().SetPosition(glm::vec3(-2.5f, 2.0f, -2.0f));
-        cool.AddComponent<LightComponent>(
-            LightComponent{
-                .type = LightComponent::Type::Point,
-                .color = glm::vec4(0.3f, 0.5f, 1.0f, 1.2f),   // 冷蓝
-                .radius = 10.0f,
-            });
-    }
-
-    void OnUpdate(f32 deltaTime) override
-    {
-        // 暂停时冻结动画时钟（帧历史验证：暂停后 Temporal Diff
-        // 视图应在 2 帧内整屏变黑；相机移动同样会被 diff 捕捉到）
-        if (!m_PauseAnim)
+        void OnInit() override
         {
-            m_Time += deltaTime;
+            Scene& scene = GetScene();
+
+            // ImGui 叠加层（框架只做管线桥接，UI 内容全部在这里定义）
+            EnableImGui();
+
+            // 模型资产（PBR 验证场景：backpack 为旧式贴图资产，
+            // 退化为电介质因子路径——albedo+normal，metallic=0/roughness=0.5）
+            const auto model = GetAssets().LoadModel("assets/models/backpack/backpack.obj");
+
+            m_Spinners.push_back(scene.CreateEntity("backpack"));
+            m_Spinners[0].AddComponent<MeshRendererComponent>(MeshRendererComponent{model});
+
+            // 地面：程序化纯色平面（半边长 15，中心 y=-2）
+            const auto ground = GetAssets().CreatePlane(15.0f, 140, 140, 145);
+
+            m_Ground = scene.CreateEntity("Ground");
+            m_Ground.GetComponent<TransformComponent>()
+                    .SetPosition(glm::vec3(0.0f, -0.5f, 0.0f));   // dirty → 帧循环统一 Compose
+            m_Ground.AddComponent<MeshRendererComponent>(MeshRendererComponent{ground});
+
+            // 相机实体（primary = 当前渲染视角；位姿存实体 Transform）
+            m_Camera = scene.CreateEntity("MainCamera");
+            auto& camera = m_Camera.AddComponent<CameraComponent>();
+            camera.primary = true;
+            m_Camera.GetComponent<TransformComponent>()
+                    .SetPosition(glm::vec3(0.0f, 0.0f, 7.0f));
+
+            // 灯光实体（第一个方向光 = 阴影光源）
+            m_KeyLight = scene.CreateEntity("KeyLight");
+            m_KeyLight.AddComponent<LightComponent>(
+                LightComponent{
+                    .type = LightComponent::Type::Directional,
+                    .direction = glm::vec3(-0.5f, -0.6f, -0.35f),
+                    .color = glm::vec4(1.0f, 0.95f, 0.9f, 1.0f)
+                });
+
+            scene.CreateEntity("FillLight")
+                 .AddComponent<LightComponent>(
+                     LightComponent{
+                         .type = LightComponent::Type::Directional,
+                         .direction = glm::vec3(0.5f, -0.5f, 0.3f),
+                         .color = glm::vec4(0.3f, 0.5f, 1.0f, 0.8f)
+                     });
+
+            // 点光源（位置 = 实体 Transform，出生即有；无阴影，距离衰减）
+            auto fire = scene.CreateEntity("FirePitLight");
+            fire.GetComponent<TransformComponent>().SetPosition(glm::vec3(2.0f, 1.5f, 1.0f));
+            fire.AddComponent<LightComponent>(
+                LightComponent{
+                    .type = LightComponent::Type::Point,
+                    .color = glm::vec4(1.0f, 0.6f, 0.3f, 2.0f),   // 暖橙
+                    .radius = 8.0f,
+                });
+
+            auto cool = scene.CreateEntity("CoolFillLight");
+            cool.GetComponent<TransformComponent>().SetPosition(glm::vec3(-2.5f, 2.0f, -2.0f));
+            cool.AddComponent<LightComponent>(
+                LightComponent{
+                    .type = LightComponent::Type::Point,
+                    .color = glm::vec4(0.3f, 0.5f, 1.0f, 1.2f),   // 冷蓝
+                    .radius = 10.0f,
+                });
         }
 
-        // 相机（WASD/Space/Shift 移动；位姿读写实体 Transform）
-        m_Camera.GetComponent<CameraComponent>()
-                .camera.Update(GetWindow(),
-                               m_Camera.GetComponent<TransformComponent>(),
-                               deltaTime);
-
-        // 旋转动画：编辑 Transform 分量后 Compose 重算 world
-        for (size_t i = 0; i < m_Spinners.size(); ++i)
+        void OnUpdate(f32 deltaTime) override
         {
-            auto& t = m_Spinners[i].GetComponent<TransformComponent>();
-            t.SetRotation(glm::vec3(0.0f, m_Time * 60.0f + static_cast<f32>(i) * 40.0f, 0.0f));
-            t.SetScale(glm::vec3(0.5f));
-        }
-    }
-
-    // ---- 事件 ----
-
-    // ---- 叠加层 UI（唯一允许出现 ImGui 控件的地方）----
-
-    void OnRenderOverlay() override
-    {
-        ImGui::ShowDemoWindow();
-
-        ImGui::Begin("Scene Debug");
-
-        // 阴影光源方向：拖动滑条实时看影子变化
-        if (auto* light = m_KeyLight.TryGetComponent<LightComponent>())
-        {
-            ImGui::Text("Key Light (shadow caster)");
-            ImGui::SliderFloat3("direction",
-                                &light->direction.x, -1.0f, 1.0f);
-            if (ImGui::Button("reset"))
+            // 暂停时冻结动画时钟（帧历史验证：暂停后 Temporal Diff
+            // 视图应在 2 帧内整屏变黑；相机移动同样会被 diff 捕捉到）
+            if (!m_PauseAnim)
             {
-                light->direction = glm::vec3(-0.5f, -0.6f, -0.35f);
+                m_Time += deltaTime;
+            }
+
+            // 相机（WASD/Space/Shift 移动；位姿读写实体 Transform）
+            m_Camera.GetComponent<CameraComponent>()
+                    .camera.Update(GetWindow(),
+                                   m_Camera.GetComponent<TransformComponent>(),
+                                   deltaTime);
+
+            // 旋转动画：编辑 Transform 分量后 Compose 重算 world
+            for (size_t i = 0; i < m_Spinners.size(); ++i)
+            {
+                auto& t = m_Spinners[i].GetComponent<TransformComponent>();
+                t.SetRotation(glm::vec3(0.0f, m_Time * 60.0f + static_cast<f32>(i) * 40.0f, 0.0f));
+                t.SetScale(glm::vec3(0.5f));
             }
         }
 
-        // Tonemap + Bloom 参数（HDR 后处理输出端）
-        auto& renderer = GetRenderer();
-        ImGui::Separator();
-        ImGui::Text("Tonemap");
-        f32 exposure = renderer.GetExposure();
-        if (ImGui::SliderFloat("exposure", &exposure, 0.1f, 4.0f))
-        {
-            renderer.SetExposure(exposure);
-        }
-        bool aces = renderer.GetUseACES();
-        if (ImGui::Checkbox("ACES", &aces))
-        {
-            renderer.SetUseACES(aces);
-        }
+        // ---- 事件 ----
 
-        ImGui::Text("Bloom");
-        f32 threshold = renderer.GetBloomThreshold();
-        if (ImGui::SliderFloat("threshold", &threshold, 0.0f, 2.0f))
-        {
-            renderer.SetBloomThreshold(threshold);
-        }
-        f32 strength = renderer.GetBloomStrength();
-        if (ImGui::SliderFloat("strength", &strength, 0.0f, 2.0f))
-        {
-            renderer.SetBloomStrength(strength);
-        }
+        // ---- 叠加层 UI（唯一允许出现 ImGui 控件的地方）----
 
-        // 调试视图：帧历史差异（静止=黑，运动边缘发光=链路正确）
-        bool temporalDiff = renderer.GetShowTemporalDiff();
-        if (ImGui::Checkbox("Temporal Diff View", &temporalDiff))
+        void OnRenderOverlay() override
         {
-            renderer.SetShowTemporalDiff(temporalDiff);
-        }
-        ImGui::Checkbox("Pause Animation", &m_PauseAnim);
+            ImGui::ShowDemoWindow();
 
-        // Pass 级 GPU 耗时（RG timestamp）
-        ImGui::Separator();
-        ImGui::Text("GPU Timings");
-        ImGui::Text("instances: %u main / %u shadow",
-                    renderer.GetMainInstanceCount(),
-                    renderer.GetShadowInstanceCount());
-        const auto& names = renderer.GetPassNames();
-        const auto& times = renderer.GetPassGpuMs();
-        for (size_t i = 0; i < names.size() && i < times.size(); ++i)
-        {
-            ImGui::Text("  %-12s %.3f ms", names[i].c_str(), times[i]);
-        }
+            ImGui::Begin("Scene Debug");
 
-        // 帧率控制
-        auto& app = *this;
-        ImGui::Separator();
-        ImGui::Text("Frame");
-        bool vsync = app.GetVSync();
-        if (ImGui::Checkbox("VSync", &vsync))
-        {
-            app.SetVSync(vsync);
+            // 阴影光源方向：拖动滑条实时看影子变化
+            if (auto* light = m_KeyLight.TryGetComponent<LightComponent>())
+            {
+                ImGui::Text("Key Light (shadow caster)");
+                ImGui::SliderFloat3("direction",
+                                    &light->direction.x, -1.0f, 1.0f);
+                if (ImGui::Button("reset"))
+                {
+                    light->direction = glm::vec3(-0.5f, -0.6f, -0.35f);
+                }
+            }
+
+            // Tonemap + Bloom 参数（HDR 后处理输出端）
+            auto& renderer = GetRenderer();
+            ImGui::Separator();
+            ImGui::Text("Tonemap");
+            f32 exposure = renderer.GetExposure();
+            if (ImGui::SliderFloat("exposure", &exposure, 0.1f, 4.0f))
+            {
+                renderer.SetExposure(exposure);
+            }
+            bool aces = renderer.GetUseACES();
+            if (ImGui::Checkbox("ACES", &aces))
+            {
+                renderer.SetUseACES(aces);
+            }
+
+            ImGui::Text("Bloom");
+            f32 threshold = renderer.GetBloomThreshold();
+            if (ImGui::SliderFloat("threshold", &threshold, 0.0f, 2.0f))
+            {
+                renderer.SetBloomThreshold(threshold);
+            }
+            f32 strength = renderer.GetBloomStrength();
+            if (ImGui::SliderFloat("strength", &strength, 0.0f, 2.0f))
+            {
+                renderer.SetBloomStrength(strength);
+            }
+
+            // 调试视图：帧历史差异（静止=黑，运动边缘发光=链路正确）
+            bool temporalDiff = renderer.GetShowTemporalDiff();
+            if (ImGui::Checkbox("Temporal Diff View", &temporalDiff))
+            {
+                renderer.SetShowTemporalDiff(temporalDiff);
+            }
+            ImGui::Checkbox("Pause Animation", &m_PauseAnim);
+
+            // Pass 级 GPU 耗时（RG timestamp）
+            ImGui::Separator();
+            ImGui::Text("GPU Timings");
+            ImGui::Text("instances: %u main / %u shadow",
+                        renderer.GetMainInstanceCount(),
+                        renderer.GetShadowInstanceCount());
+            const auto& names = renderer.GetPassNames();
+            const auto& times = renderer.GetPassGpuMs();
+            for (size_t i = 0; i < names.size() && i < times.size(); ++i)
+            {
+                ImGui::Text("  %-12s %.3f ms", names[i].c_str(), times[i]);
+            }
+
+            // 帧率控制
+            auto& app = *this;
+            ImGui::Separator();
+            ImGui::Text("Frame");
+            bool vsync = app.GetVSync();
+            if (ImGui::Checkbox("VSync", &vsync))
+            {
+                app.SetVSync(vsync);
+                if (!vsync)
+                {
+                    const f32 target = app.GetTargetFps();
+                    app.SetTargetFps(target);
+                }
+            }
             if (!vsync)
             {
-                const f32 target = app.GetTargetFps();
-                app.SetTargetFps(target);
-            }
-        }
-        if (!vsync)
-        {
-            f32 target = app.GetTargetFps();
-            if (ImGui::SliderFloat("target fps", &target, 24.0f, 360.0f, "%.0f"))
-            {
-                app.SetTargetFps(target);
-            }
-        }
-
-        ImGui::Separator();
-        ImGui::Text("fps: %.1f  frame: %llu",
-                    1.0f / GetDeltaTime(),
-                    static_cast<unsigned long long>(GetFrameCount()));
-
-        ImGui::End();
-
-
-        // 自定义重载事件： 重载关闭事件模态框
-        {
-            if (m_ShowQuitConfirm)
-            {
-                ImGui::OpenPopup("Should quit?");
-                m_ShowQuitConfirm = false;
-            }
-
-            ImGui::SetNextWindowPos(
-                ImGui::GetMainViewport()->GetCenter(),
-                ImGuiCond_Appearing, ImVec2(0.5f, 0.5f));
-
-            if (ImGui::BeginPopupModal("Should quit?", nullptr,
-                                       ImGuiWindowFlags_AlwaysAutoResize))
-            {
-                ImGui::TextUnformatted("Quit the application?");
-                ImGui::Separator();
-                if (ImGui::Button("Yes", ImVec2(120, 0)))
+                f32 target = app.GetTargetFps();
+                if (ImGui::SliderFloat("target fps", &target, 24.0f, 360.0f, "%.0f"))
                 {
-                    m_QuitConfirmed = true;
-                    ImGui::CloseCurrentPopup();
+                    app.SetTargetFps(target);
                 }
-                ImGui::SameLine();
-                if (ImGui::Button("No", ImVec2(120, 0)))
-                {
-                    ImGui::CloseCurrentPopup();
-                }
-                ImGui::EndPopup();
             }
 
-            if (m_QuitConfirmed)
+            ImGui::Separator();
+            ImGui::Text("fps: %.1f  frame: %llu",
+                        1.0f / GetDeltaTime(),
+                        static_cast<unsigned long long>(GetFrameCount()));
+
+            ImGui::End();
+
+
+            // 自定义重载事件： 重载关闭事件模态框
             {
-                m_QuitConfirmed = false;
-                Close();
+                if (m_ShowQuitConfirm)
+                {
+                    ImGui::OpenPopup("Should quit?");
+                    m_ShowQuitConfirm = false;
+                }
+
+                ImGui::SetNextWindowPos(
+                    ImGui::GetMainViewport()->GetCenter(),
+                    ImGuiCond_Appearing, ImVec2(0.5f, 0.5f));
+
+                if (ImGui::BeginPopupModal("Should quit?", nullptr,
+                                           ImGuiWindowFlags_AlwaysAutoResize))
+                {
+                    ImGui::TextUnformatted("Quit the application?");
+                    ImGui::Separator();
+                    if (ImGui::Button("Yes", ImVec2(120, 0)))
+                    {
+                        m_QuitConfirmed = true;
+                        ImGui::CloseCurrentPopup();
+                    }
+                    ImGui::SameLine();
+                    if (ImGui::Button("No", ImVec2(120, 0)))
+                    {
+                        ImGui::CloseCurrentPopup();
+                    }
+                    ImGui::EndPopup();
+                }
+
+                if (m_QuitConfirmed)
+                {
+                    m_QuitConfirmed = false;
+                    Close();
+                }
             }
         }
-    }
 
-    void OnWindowClose(const Event& event) override
-    {
-        SetImGuiEnabled(true);
-        m_ShowQuitConfirm = true;
-    }
-
-    void OnKeyPress(const Event& event) override
-    {
-        if (event.key == GLFW_KEY_GRAVE_ACCENT)
+        void OnWindowClose(const Event& event) override
         {
-            SetImGuiEnabled(!GetImGuiEnabled());
+            SetImGuiEnabled(true);
+            m_ShowQuitConfirm = true;
         }
-        if (event.key == GLFW_KEY_F1)
+
+        void OnKeyPress(const Event& event) override
         {
-            STATS.PrintComparison();
+            if (event.key == GLFW_KEY_GRAVE_ACCENT)
+            {
+                SetImGuiEnabled(!GetImGuiEnabled());
+            }
+            if (event.key == GLFW_KEY_F1)
+            {
+                STATS.PrintComparison();
+            }
         }
-    }
 
 
-    void OnWindowResize(const Event& event) override
-    {
-        ENGINE_INFO("App: window resized to {}x{}", event.width, event.height);
-    }
+        void OnWindowResize(const Event& event) override
+        {
+            ENGINE_INFO("App: window resized to {}x{}", event.width, event.height);
+        }
 
-private:
-    bool m_ShowQuitConfirm = false;
-    bool m_QuitConfirmed = false;
-    EntityHandle m_Camera{}; // Scene::CreateEntity 之前为空
-    EntityHandle m_Ground{};
-    EntityHandle m_KeyLight{};
-    std::vector<EntityHandle> m_Spinners;
-    f32 m_Time = 0.0f;
-    bool m_PauseAnim = false;   // 冻结动画时钟（帧历史 diff 验证用）
-};
+    private:
+        bool m_ShowQuitConfirm = false;
+        bool m_QuitConfirmed = false;
+        EntityHandle m_Camera{}; // Scene::CreateEntity 之前为空
+        EntityHandle m_Ground{};
+        EntityHandle m_KeyLight{};
+        std::vector<EntityHandle> m_Spinners;
+        f32 m_Time = 0.0f;
+        bool m_PauseAnim = false;   // 冻结动画时钟（帧历史 diff 验证用）
+    };
+}
 
 int main()
 {
diff --git a/Engine/include/Engine/Core/Window.h b/Engine/include/Engine/Core/Window.h
index cb958a6..f71612e 100644
--- a/Engine/include/Engine/Core/Window.h
+++ b/Engine/include/Engine/Core/Window.h
@@ -44,7 +44,7 @@ namespace Engine {
             m_MouseCapture = std::move(mouse);
         }
 
-        vk::SurfaceKHR CreateSurface(vk::Instance instance);
+        vk::SurfaceKHR CreateSurface(vk::Instance instance) const;
         void DestroySurface(vk::Instance instance, vk::SurfaceKHR surface);
 
         u32 GetWidth() const { return m_Width; }
@@ -63,7 +63,7 @@ namespace Engine {
         // 输入事件系统
 
         bool IsKeyPressed(int key) const;
-        void GetMouseDelta(float& dx, float& dy);
+        void GetMouseDelta(float& dx, float& dy) const;
 
 
 
diff --git a/Engine/include/Engine/Renderer/Material.h b/Engine/include/Engine/Renderer/Material.h
index c394083..69f7c91 100644
--- a/Engine/include/Engine/Renderer/Material.h
+++ b/Engine/include/Engine/Renderer/Material.h
@@ -1,46 +1,58 @@
 //
 // Created by atdunbg on 2026/9/21.
 //
-// Material：着色材质 = 一组纹理槽 + 一个描述符集。
+// Material：PBR 材质 = 纹理槽组 + 因子参数 UBO + 一个描述符集。
 //
-// 槽位（binding = 槽位序号，与 simple_shader.frag 契约一致）：
-//   0 albedo（BaseColor，sRGB）  1 normal（切线空间法线，线性）
-//   2 specular（高光强度/颜色，线性）  3 emissive（自发光，sRGB）
+// 槽位（binding = 槽位序号，与 simple_shader.frag 契约一致，glTF
+// metallic-roughness 工作流）：
+//   0 albedo（BaseColor，sRGB）        1 normal（切线空间法线，线性）
+//   2 metallicRoughness（线性：G=粗糙度，B=金属度，glTF 约定）
+//   3 emissive（自发光，sRGB）         4 材质参数 UBO（fragment）
 //
-// 纹理非拥有（Model 的纹理缓存持有）；空槽由调用方传默认纹理
-//（白/平法线/黑/黑，Model 持有），shader 永远可以安全采样。
+// 纹理非拥有（Model 的纹理缓存持有）；缺槽由调用方传默认纹理。
+// 因子（metallicFactor/roughnessFactor）乘在 MR 贴图上——无 MR 图的
+// 旧资产退化为纯因子（电介质 + 常数粗糙度）。
 //
 
 #ifndef HELLOVULKAN_MATERIAL_H
 #define HELLOVULKAN_MATERIAL_H
 
 #include <Engine/Core/Types.h>
+#include <glm/glm.hpp>
 #include <vulkan/vulkan.hpp>
 #include <array>
 #include <string>
 
-namespace Engine
-{
+namespace Engine {
+
     class Device;
+    class MemoryAllocator;
     class DescriptorManager;
     class Texture;
+    class UniformBuffer;
 
-    class Material
-    {
+    // 材质因子（乘 MR 贴图；无贴图时即最终值）
+    struct MaterialParams {
+        glm::vec4 factors{0.0f, 0.5f, 0.0f, 0.0f};   // x=metallic y=roughness
+    };
+
+    class Material {
     public:
         // 槽位序号（与 binding 对齐）
         enum Slot : u32 {
             Albedo = 0,
             Normal = 1,
-            Specular = 2,
+            MetallicRoughness = 2,
             Emissive = 3,
-            kSlotCount = 4,
+            kSlotCount = 4,      // 纹理槽数
+            kParamsBinding = 4,  // 参数 UBO binding
         };
 
-        Material(Device& device,
+        Material(Device& device, MemoryAllocator& allocator,
                  DescriptorManager& descriptorManager,
                  vk::DescriptorSetLayout layout,
-                 const std::array<Texture*, kSlotCount>& textures);
+                 const std::array<Texture*, kSlotCount>& textures,
+                 const MaterialParams& params);
         ~Material();
 
         Material(const Material&) = delete;
@@ -49,12 +61,14 @@ namespace Engine
         vk::DescriptorSet GetDescriptorSet() const { return m_DescriptorSet; }
         Texture* GetTexture(Slot slot) const { return m_Textures[slot]; }
 
-        // 材质缓存键：同贴图组合共享一份（Model 层使用）
-        static std::string MakeCacheKey(const std::string paths[kSlotCount]);
+        // 材质缓存键：同贴图组合+同因子共享一份（Model 层使用）
+        static std::string MakeCacheKey(const std::string paths[kSlotCount],
+                                        const MaterialParams& params);
 
     private:
         std::array<Texture*, kSlotCount> m_Textures{};
         vk::DescriptorSet m_DescriptorSet;
+        Scope<UniformBuffer> m_ParamsBuffer;   // per-slot 参数 ring（创建时写死）
     };
 } // namespace Engine
 
diff --git a/Engine/include/Engine/Renderer/Model.h b/Engine/include/Engine/Renderer/Model.h
index 10c12b4..8ec168b 100644
--- a/Engine/include/Engine/Renderer/Model.h
+++ b/Engine/include/Engine/Renderer/Model.h
@@ -64,10 +64,11 @@ namespace Engine
 
         Texture* GetOrLoadTexture(const std::string& path, bool srgb);
 
-        // 材质缓存入口：同贴图组合共享同一 Material（一个描述符集），
+        // 材质缓存入口：同贴图组合+因子共享同一 Material（一个描述符集），
         // 槽位路径为空/文件缺失折到对应默认纹理。路径已做反斜杠归一化。
-        // paths 下标 = Material::Slot（albedo/normal/specular/emissive）
-        Material* GetOrCreateMaterial(const std::string paths[Material::kSlotCount]);
+        // paths 下标 = Material::Slot；params = metallic/roughness 因子
+        Material* GetOrCreateMaterial(const std::string paths[Material::kSlotCount],
+                                      const MaterialParams& params);
 
         Device& m_Device;
         MemoryAllocator& m_Allocator;
diff --git a/Engine/include/Engine/Renderer/Renderer.h b/Engine/include/Engine/Renderer/Renderer.h
index ed12c3f..feb32d5 100644
--- a/Engine/include/Engine/Renderer/Renderer.h
+++ b/Engine/include/Engine/Renderer/Renderer.h
@@ -49,7 +49,7 @@ namespace Engine {
 
     class Renderer {
     public:
-        Renderer(Window& window);
+        explicit Renderer(Window& window);
         ~Renderer();
 
         Renderer(const Renderer&) = delete;
diff --git a/Engine/include/Engine/Vulkan/CommandManager.h b/Engine/include/Engine/Vulkan/CommandManager.h
index 559bb7a..a60a985 100644
--- a/Engine/include/Engine/Vulkan/CommandManager.h
+++ b/Engine/include/Engine/Vulkan/CommandManager.h
@@ -28,10 +28,10 @@ namespace Engine {
         CommandManager& operator=(const CommandManager&) = delete;
 
         // 开始录制指定帧槽位的命令缓冲
-        vk::CommandBuffer BeginFrame(u32 frameSlot);
+        vk::CommandBuffer BeginFrame(u32 frameSlot) const;
 
         // 结束录制
-        void EndFrame(u32 frameSlot);
+        void EndFrame(u32 frameSlot) const;
 
         vk::CommandBuffer GetBuffer(u32 frameSlot) const { return m_Buffers[frameSlot]; }
 
diff --git a/Engine/include/Engine/Vulkan/DescriptorManager.h b/Engine/include/Engine/Vulkan/DescriptorManager.h
index 28d19dc..1141cd4 100644
--- a/Engine/include/Engine/Vulkan/DescriptorManager.h
+++ b/Engine/include/Engine/Vulkan/DescriptorManager.h
@@ -28,21 +28,21 @@ namespace Engine {
         DescriptorManager(const DescriptorManager&) = delete;
         DescriptorManager& operator=(const DescriptorManager&) = delete;
 
-        vk::DescriptorSetLayout CreateLayout(const std::vector<DescriptorBinding>& bindings);
+        vk::DescriptorSetLayout CreateLayout(const std::vector<DescriptorBinding>& bindings) const;
 
         vk::DescriptorSet AllocateDescriptorSet(vk::DescriptorSetLayout layout);
 
         void UpdateUniformBuffer(vk::DescriptorSet set, u32 binding,
-                                 vk::Buffer buffer, u64 size);
+                                 vk::Buffer buffer, u64 size) const;
         void UpdateStorageBuffer(vk::DescriptorSet set, u32 binding,
-                                 vk::Buffer buffer, u64 size);
+                                 vk::Buffer buffer, u64 size) const;
 
         void UpdateTexture(vk::DescriptorSet set, u32 binding,
-                           vk::Sampler sampler, vk::ImageView view);
+                           vk::Sampler sampler, vk::ImageView view) const;
 
         // 单个 set layout 的旧接口（保留）
         vk::PipelineLayout CreatePipelineLayout(vk::DescriptorSetLayout layout,
-                                                 u32 pushConstantSize);
+                                                 u32 pushConstantSize) const;
 
         // 多 set layout 的新接口。
         // push constant range 按程序级 vertex|fragment 声明（与
@@ -50,7 +50,7 @@ namespace Engine {
         // push 调用点必须带同样的双 stage（VUID-01796）
         vk::PipelineLayout CreatePipelineLayout(
             const std::vector<vk::DescriptorSetLayout>& layouts,
-            u32 pushConstantSize);
+            u32 pushConstantSize) const;
 
     private:
         Device& m_Device;
@@ -64,7 +64,7 @@ namespace Engine {
         // 每块的容量（set 数；各类型描述符数同值）
         static constexpr u32 kChunkSets = 4096;
 
-        vk::DescriptorPool CreateChunk();
+        vk::DescriptorPool CreateChunk() const;
     };
 
 } // namespace Engine
diff --git a/Engine/include/Engine/Vulkan/ShaderManager.h b/Engine/include/Engine/Vulkan/ShaderManager.h
index d3b8cd6..f37fc46 100644
--- a/Engine/include/Engine/Vulkan/ShaderManager.h
+++ b/Engine/include/Engine/Vulkan/ShaderManager.h
@@ -39,12 +39,12 @@ namespace Engine {
         ShaderObject CreateFromSPIRV(const std::vector<u32>& spirv,
                                       vk::ShaderStageFlagBits stage,
                                       const std::vector<vk::DescriptorSetLayout>& layouts = {},
-                                      u32 pushConstantSize = 0);
+                                      u32 pushConstantSize = 0) const;
 
-        void Destroy(const ShaderObject& shader);
+        void Destroy(const ShaderObject& shader) const;
 
     private:
-        std::vector<u32> ReadSPIRV(const std::string& path);
+        static std::vector<u32> ReadSPIRV(const std::string& path);
 
         Device& m_Device;
     };
diff --git a/Engine/include/Engine/Vulkan/SyncManager.h b/Engine/include/Engine/Vulkan/SyncManager.h
index 356502d..e1fee6f 100644
--- a/Engine/include/Engine/Vulkan/SyncManager.h
+++ b/Engine/include/Engine/Vulkan/SyncManager.h
@@ -35,8 +35,8 @@ namespace Engine {
         vk::Fence GetFrameFence(u32 frameIndex) const { return m_FrameFences[frameIndex]; }
 
         // 等待并重置这一帧的 Fence
-        void WaitFence(u32 frameIndex);      // 只等，不 reset
-        void ResetFence(u32 frameIndex);     // 只 reset
+        void WaitFence(u32 frameIndex) const;      // 只等，不 reset
+        void ResetFence(u32 frameIndex) const;     // 只 reset
 
     private:
         Device& m_Device;
diff --git a/Engine/include/Engine/Vulkan/UniformBuffer.h b/Engine/include/Engine/Vulkan/UniformBuffer.h
index c3c89c9..d8fa848 100644
--- a/Engine/include/Engine/Vulkan/UniformBuffer.h
+++ b/Engine/include/Engine/Vulkan/UniformBuffer.h
@@ -39,7 +39,7 @@ namespace Engine {
         u64 GetSize() const { return m_Size; }
 
         // 写入指定帧槽位的 UBO（仅在该槽位 fence 确认完成后调用）
-        void Update(u32 frameSlot, const void* data, u64 size);
+        void Update(u32 frameSlot, const void* data, u64 size) const;
 
     private:
         std::vector<Scope<Buffer>> m_Buffers;
diff --git a/Engine/src/Core/Stats.cpp b/Engine/src/Core/Stats.cpp
index bc97caf..2837565 100644
--- a/Engine/src/Core/Stats.cpp
+++ b/Engine/src/Core/Stats.cpp
@@ -18,7 +18,7 @@ namespace Engine
 
     // ============ 资源计数 ============
 
-    void Stats::AddTexture(u64 bytes)
+    void Stats::AddTexture(const u64 bytes)
     {
         std::lock_guard lock(m_Mutex);
         m_TextureCount++;
@@ -27,7 +27,7 @@ namespace Engine
         m_TotalAllocation += bytes;
     }
 
-    void Stats::RemoveTexture(u64 bytes)
+    void Stats::RemoveTexture(const u64 bytes)
     {
         std::lock_guard lock(m_Mutex);
         if (m_TextureCount > 0) m_TextureCount--;
@@ -36,27 +36,27 @@ namespace Engine
         m_TotalDeallocation += bytes;
     }
 
-    void Stats::AddMesh(u64 vertexBytes, u64 indexBytes)
+    void Stats::AddMesh(const u64 vertexBytes, const u64 indexBytes)
     {
         std::lock_guard lock(m_Mutex);
         m_MeshCount++;
-        u64 total = vertexBytes + indexBytes;
+        const u64 total = vertexBytes + indexBytes;
         m_MeshBytes += total;
         m_FrameAllocation += total;
         m_TotalAllocation += total;
     }
 
-    void Stats::RemoveMesh(u64 vertexBytes, u64 indexBytes)
+    void Stats::RemoveMesh(const u64 vertexBytes, const u64 indexBytes)
     {
         std::lock_guard lock(m_Mutex);
         if (m_MeshCount > 0) m_MeshCount--;
-        u64 total = vertexBytes + indexBytes;
+        const u64 total = vertexBytes + indexBytes;
         if (m_MeshBytes >= total) m_MeshBytes -= total;
         m_FrameDeallocation += total;
         m_TotalDeallocation += total;
     }
 
-    void Stats::AddBuffer(u64 bytes)
+    void Stats::AddBuffer(const u64 bytes)
     {
         std::lock_guard lock(m_Mutex);
         m_BufferCount++;
@@ -65,7 +65,7 @@ namespace Engine
         m_TotalAllocation += bytes;
     }
 
-    void Stats::RemoveBuffer(u64 bytes)
+    void Stats::RemoveBuffer(const u64 bytes)
     {
         std::lock_guard lock(m_Mutex);
         if (m_BufferCount > 0) m_BufferCount--;
@@ -74,25 +74,25 @@ namespace Engine
         m_TotalDeallocation += bytes;
     }
 
-    void Stats::AddMemoryBlock(u64 bytes)
+    void Stats::AddMemoryBlock(const u64 bytes)
     {
         std::lock_guard lock(m_Mutex);
         m_MemoryBlockBytes += bytes;
     }
 
-    void Stats::RemoveMemoryBlock(u64 bytes)
+    void Stats::RemoveMemoryBlock(const u64 bytes)
     {
         std::lock_guard lock(m_Mutex);
         if (m_MemoryBlockBytes >= bytes) m_MemoryBlockBytes -= bytes;
     }
 
-    void Stats::AddMemoryUsed(u64 bytes)
+    void Stats::AddMemoryUsed(const u64 bytes)
     {
         std::lock_guard lock(m_Mutex);
         m_MemoryUsedBytes += bytes;
     }
 
-    void Stats::RemoveMemoryUsed(u64 bytes)
+    void Stats::RemoveMemoryUsed(const u64 bytes)
     {
         std::lock_guard lock(m_Mutex);
         if (m_MemoryUsedBytes >= bytes) m_MemoryUsedBytes -= bytes;
@@ -111,14 +111,14 @@ namespace Engine
     {
     }
 
-    void Stats::AddAllocation(u64 bytes)
+    void Stats::AddAllocation(const u64 bytes)
     {
         std::lock_guard lock(m_Mutex);
         m_FrameAllocation += bytes;
         m_TotalAllocation += bytes;
     }
 
-    void Stats::AddDeallocation(u64 bytes)
+    void Stats::AddDeallocation(const u64 bytes)
     {
         std::lock_guard lock(m_Mutex);
         m_FrameDeallocation += bytes;
@@ -206,13 +206,13 @@ namespace Engine
 
     // ============ 打印 ============
 
-    static double MB(u64 bytes) { return bytes / (1024.0 * 1024.0); }
+    static double MB(const u64 bytes) { return bytes / (1024.0 * 1024.0); }
 
     void Stats::Print() const
     {
         std::lock_guard lock(m_Mutex);
 
-        auto proc = ReadProcessMemory();
+        const auto proc = ReadProcessMemory();
 
         ENGINE_INFO("========== Resource Stats ==========");
         ENGINE_INFO("Textures:   {:>4}  ({:.2f} MB)", m_TextureCount, MB(m_TextureBytes));
diff --git a/Engine/src/Core/Window.cpp b/Engine/src/Core/Window.cpp
index 849815c..8001e56 100644
--- a/Engine/src/Core/Window.cpp
+++ b/Engine/src/Core/Window.cpp
@@ -156,7 +156,7 @@ namespace Engine
         glfwPollEvents();
     }
 
-    vk::SurfaceKHR Window::CreateSurface(vk::Instance instance)
+    vk::SurfaceKHR Window::CreateSurface(const vk::Instance instance) const
     {
         VkSurfaceKHR surface;
         if (glfwCreateWindowSurface(instance, m_Window, nullptr, &surface) != VK_SUCCESS)
@@ -167,7 +167,7 @@ namespace Engine
         return surface;
     }
 
-    void Window::DestroySurface(vk::Instance instance, vk::SurfaceKHR surface)
+    void Window::DestroySurface(const vk::Instance instance, const vk::SurfaceKHR surface)
     {
         instance.destroySurfaceKHR(surface);
     }
@@ -184,14 +184,14 @@ namespace Engine
         glfwGetFramebufferSize(m_Window, &width, &height);
     }
 
-    bool Window::IsKeyPressed(int key) const
+    bool Window::IsKeyPressed(const int key) const
     {
         // UI 捕获键盘时，轮询接口同样静默（相机等轮询型消费方）
         if (m_KeyboardCapture && m_KeyboardCapture()) return false;
         return glfwGetKey(m_Window, key) == GLFW_PRESS;
     }
 
-    void Window::GetMouseDelta(float& dx, float& dy)
+    void Window::GetMouseDelta(float& dx, float& dy) const
     {
         double mx, my;
         glfwGetCursorPos(m_Window, &mx, &my);
diff --git a/Engine/src/Renderer/Material.cpp b/Engine/src/Renderer/Material.cpp
index 2646584..d186530 100644
--- a/Engine/src/Renderer/Material.cpp
+++ b/Engine/src/Renderer/Material.cpp
@@ -7,14 +7,17 @@
 #include <Engine/Vulkan/MemoryAllocator.h>
 #include <Engine/Vulkan/DescriptorManager.h>
 #include <Engine/Vulkan/Texture.h>
+#include <Engine/Vulkan/UniformBuffer.h>
+#include <Engine/Core/FrameContext.h>
 #include <Engine/Core/Log.h>
 
 namespace Engine
 {
-    Material::Material(Device& device,
+    Material::Material(Device& device, MemoryAllocator& allocator,
                        DescriptorManager& descriptorManager,
                        vk::DescriptorSetLayout layout,
-                       const std::array<Texture*, kSlotCount>& textures)
+                       const std::array<Texture*, kSlotCount>& textures,
+                       const MaterialParams& params)
     : m_Textures(textures)
     {
         m_DescriptorSet = descriptorManager.AllocateDescriptorSet(layout);
@@ -25,18 +28,31 @@ namespace Engine
                 m_Textures[slot]->GetSampler(),
                 m_Textures[slot]->GetView());
         }
+
+        // 材质参数：per-slot ring，创建时写死（参数静态，无每帧更新）
+        m_ParamsBuffer = CreateScope<UniformBuffer>(
+            device, allocator, sizeof(MaterialParams), kMaxFramesInFlight);
+        for (u32 slot = 0; slot < kMaxFramesInFlight; ++slot) {
+            m_ParamsBuffer->Update(slot, &params, sizeof(params));
+            descriptorManager.UpdateUniformBuffer(
+                m_DescriptorSet, kParamsBinding,
+                m_ParamsBuffer->Get(slot), m_ParamsBuffer->GetSize());
+        }
     }
 
 
     Material::~Material() = default;
 
-    std::string Material::MakeCacheKey(const std::string paths[kSlotCount])
+    std::string Material::MakeCacheKey(const std::string paths[kSlotCount],
+                                       const MaterialParams& params)
     {
         std::string key;
         for (u32 slot = 0; slot < kSlotCount; ++slot) {
-            if (slot) key += '\n';
             key += paths[slot];
+            key += '\n';
         }
+        key += "f:" + std::to_string(params.factors.x) +
+               "," + std::to_string(params.factors.y);
         return key;
     }
 } // namespace Engine
diff --git a/Engine/src/Renderer/Model.cpp b/Engine/src/Renderer/Model.cpp
index ff54636..3a2a2ee 100644
--- a/Engine/src/Renderer/Model.cpp
+++ b/Engine/src/Renderer/Model.cpp
@@ -38,13 +38,13 @@ Model::~Model() = default;
 void Model::InitDefaultTextures()
 {
     // 各材质槽位的兜底纹理（1x1，开销可忽略）：
-    //   albedo 白（受光） / normal 平法线 (0.5,0.5,1) / specular 黑 / emissive 黑
+    //   albedo 白 / MR 平参数（roughness 0.5, metallic 0）/ emissive 黑
     m_DefaultTextures[Material::Albedo] =
         Texture::CreateSolidColor(m_Device, m_Allocator, 255, 255, 255);
+    m_DefaultTextures[Material::MetallicRoughness] =
+        Texture::CreateSolidColor(m_Device, m_Allocator, 0, 128, 0, false);
     m_DefaultTextures[Material::Normal] =
         Texture::CreateSolidColor(m_Device, m_Allocator, 128, 128, 255, false);
-    m_DefaultTextures[Material::Specular] =
-        Texture::CreateSolidColor(m_Device, m_Allocator, 0, 0, 0, false);
     m_DefaultTextures[Material::Emissive] =
         Texture::CreateSolidColor(m_Device, m_Allocator, 0, 0, 0);
 }
@@ -74,7 +74,7 @@ Model::Model(Device& device, MemoryAllocator& allocator,
 
     // 材质/纹理生命周期随模型（缓存持有）
     std::string paths[Material::kSlotCount] = {"", "", "", ""};
-    Material* mat = GetOrCreateMaterial(paths);   // 全默认材质
+    Material* mat = GetOrCreateMaterial(paths, MaterialParams{});   // 全默认材质
 
     m_Meshes.push_back(CreateScope<Mesh>(
         m_Device, m_Allocator, vertices, indices, mat));
@@ -148,9 +148,10 @@ Texture* Model::GetOrLoadTexture(const std::string& rawPath, bool srgb)
     return ptr;
 }
 
-Material* Model::GetOrCreateMaterial(const std::string paths[Material::kSlotCount])
+Material* Model::GetOrCreateMaterial(const std::string paths[Material::kSlotCount],
+                                     const MaterialParams& params)
 {
-    const std::string key = Material::MakeCacheKey(paths);
+    const std::string key = Material::MakeCacheKey(paths, params);
     if (auto it = m_MaterialCache.find(key); it != m_MaterialCache.end()) {
         return it->second.get();
     }
@@ -169,7 +170,8 @@ Material* Model::GetOrCreateMaterial(const std::string paths[Material::kSlotCoun
     }
 
     auto mat = CreateScope<Material>(
-        m_Device, m_DescriptorManager, m_TextureLayout, textures);
+        m_Device, m_Allocator, m_DescriptorManager, m_TextureLayout,
+        textures, params);
     Material* ptr = mat.get();
     m_MaterialCache.emplace(key, std::move(mat));
     return ptr;
@@ -225,18 +227,20 @@ Scope<Mesh> Model::ProcessMesh(aiMesh* mesh, const aiScene* scene)
         }
     }
 
-    // 读取材质纹理路径（4 槽：albedo/normal/specular/emissive）
+    // 读取材质纹理路径（PBR metallic-roughness 槽位）+ 金属度/粗糙度因子
     std::string texPaths[Material::kSlotCount];
+    MaterialParams params;
 
     if (mesh->mMaterialIndex >= 0) {
         aiMaterial* material = scene->mMaterials[mesh->mMaterialIndex];
         const std::filesystem::path modelDir =
             std::filesystem::path(m_ModelPath).parent_path();
 
+        // glTF 的 metallicRoughness 贴图落在 aiTextureType_UNKNOWN
         const std::pair<aiTextureType, u32> slots[] = {
             {aiTextureType_DIFFUSE,  Material::Albedo},
             {aiTextureType_NORMALS,  Material::Normal},
-            {aiTextureType_SPECULAR, Material::Specular},
+            {aiTextureType_UNKNOWN,  Material::MetallicRoughness},
             {aiTextureType_EMISSIVE, Material::Emissive},
         };
 
@@ -247,10 +251,17 @@ Scope<Mesh> Model::ProcessMesh(aiMesh* mesh, const aiScene* scene)
                 texPaths[slot] = (modelDir / path.C_Str()).string();
             }
         }
+
+        // PBR 因子（glTF2 材质属性；旧资产无此键 → 默认电介质 0/0.5）
+        ai_real metallic = 0.0f, roughness = 0.5f;
+        material->Get(AI_MATKEY_METALLIC_FACTOR, metallic);
+        material->Get(AI_MATKEY_ROUGHNESS_FACTOR, roughness);
+        params.factors = glm::vec4(static_cast<f32>(metallic),
+                                   static_cast<f32>(roughness), 0.0f, 0.0f);
     }
 
-    // 材质缓存：同贴图组合 → 同一 Material（一个描述符集），mesh 数 ≠ 集数
-    Material* mat = GetOrCreateMaterial(texPaths);
+    // 材质缓存：同贴图组合+因子 → 同一 Material（一个描述符集）
+    Material* mat = GetOrCreateMaterial(texPaths, params);
 
     return CreateScope<Mesh>(
         m_Device, m_Allocator, vertices, indices, mat);
diff --git a/Engine/src/Renderer/Passes/SceneGpu.cpp b/Engine/src/Renderer/Passes/SceneGpu.cpp
index 9923efb..5c354c3 100644
--- a/Engine/src/Renderer/Passes/SceneGpu.cpp
+++ b/Engine/src/Renderer/Passes/SceneGpu.cpp
@@ -32,14 +32,17 @@ namespace Engine::Passes
         };
         uboSetLayout = descriptors.CreateLayout(uboBindings);
 
-        // Set 1: 材质纹理槽（binding = Material::Slot：0 albedo / 1 normal /
-        // 2 specular / 3 emissive）
+        // Set 1: PBR 材质纹理槽（binding = Material::Slot：0 albedo /
+        // 1 normal / 2 metallicRoughness / 3 emissive）+ 参数 UBO（binding 4）
         std::vector<DescriptorBinding> texBindings;
         for (u32 slot = 0; slot < Material::kSlotCount; ++slot) {
             texBindings.push_back(
                 {slot, vk::DescriptorType::eCombinedImageSampler,
                  vk::ShaderStageFlagBits::eFragment});
         }
+        texBindings.push_back(
+            {Material::kParamsBinding, vk::DescriptorType::eUniformBuffer,
+             vk::ShaderStageFlagBits::eFragment});
         textureSetLayout = descriptors.CreateLayout(texBindings);
 
         // Set 2: CSM 级联阴影图（fragment 采样，binding = 级联序号）
diff --git a/Engine/src/Vulkan/Buffer.cpp b/Engine/src/Vulkan/Buffer.cpp
index e188efa..056a740 100644
--- a/Engine/src/Vulkan/Buffer.cpp
+++ b/Engine/src/Vulkan/Buffer.cpp
@@ -14,9 +14,9 @@
 namespace Engine {
 
     Buffer::Buffer(Device& device, MemoryAllocator& allocator,
-               vk::DeviceSize size, vk::BufferUsageFlags usage,
-               vk::MemoryPropertyFlags memProps)
-    : m_Device(device), m_Allocator(allocator) , m_Size(size)
+               const vk::DeviceSize size, const vk::BufferUsageFlags usage,
+               const vk::MemoryPropertyFlags memProps)
+    : m_Device(device), m_Size(size) , m_Allocator(allocator)
     {
         // VMA 惯用法：创建 + 分配 + 绑定一步完成；
         // HOST_VISIBLE 时持久映射，MappedPtr 直接可用
@@ -33,7 +33,7 @@ namespace Engine {
         STATS.RemoveBuffer(m_Size);
     }
 
-    void Buffer::Upload(const void* data, vk::DeviceSize size, vk::DeviceSize offset)
+    void Buffer::Upload(const void* data, const vk::DeviceSize size, const vk::DeviceSize offset) const
     {
         if (!m_MappedPtr) {
             ENGINE_ERROR("Buffer::Upload: buffer is not host visible");
diff --git a/Engine/src/Vulkan/CommandManager.cpp b/Engine/src/Vulkan/CommandManager.cpp
index 910149a..eb5865c 100644
--- a/Engine/src/Vulkan/CommandManager.cpp
+++ b/Engine/src/Vulkan/CommandManager.cpp
@@ -35,9 +35,9 @@ namespace Engine {
         m_Device.GetDevice().destroyCommandPool(m_Pool);
     }
 
-    vk::CommandBuffer CommandManager::BeginFrame(u32 frameSlot)
+    vk::CommandBuffer CommandManager::BeginFrame(const u32 frameSlot) const
     {
-        auto cmd = m_Buffers[frameSlot];
+        const auto cmd = m_Buffers[frameSlot];
         cmd.reset();
 
         vk::CommandBufferBeginInfo beginInfo;
@@ -47,7 +47,7 @@ namespace Engine {
         return cmd;
     }
 
-    void CommandManager::EndFrame(u32 frameSlot)
+    void CommandManager::EndFrame(const u32 frameSlot) const
     {
         m_Buffers[frameSlot].end();
     }
diff --git a/Engine/src/Vulkan/DescriptorManager.cpp b/Engine/src/Vulkan/DescriptorManager.cpp
index a62bae5..7e8706d 100644
--- a/Engine/src/Vulkan/DescriptorManager.cpp
+++ b/Engine/src/Vulkan/DescriptorManager.cpp
@@ -18,12 +18,12 @@ namespace Engine
 
     DescriptorManager::~DescriptorManager()
     {
-        for (auto pool : m_Pools) {
+        for (const auto pool : m_Pools) {
             m_Device.GetDevice().destroyDescriptorPool(pool);
         }
     }
 
-    vk::DescriptorPool DescriptorManager::CreateChunk()
+    vk::DescriptorPool DescriptorManager::CreateChunk() const
     {
         std::array<vk::DescriptorPoolSize, 3> poolSizes = {
             vk::DescriptorPoolSize(vk::DescriptorType::eUniformBuffer, kChunkSets),
@@ -39,7 +39,7 @@ namespace Engine
         return m_Device.GetDevice().createDescriptorPool(poolInfo);
     }
 
-    vk::DescriptorSetLayout DescriptorManager::CreateLayout(const std::vector<DescriptorBinding>& bindings)
+    vk::DescriptorSetLayout DescriptorManager::CreateLayout(const std::vector<DescriptorBinding>& bindings) const
     {
         std::vector<vk::DescriptorSetLayoutBinding> vkBindings;
         for (auto& b : bindings)
@@ -80,8 +80,8 @@ namespace Engine
         }
     }
 
-    void DescriptorManager::UpdateUniformBuffer(vk::DescriptorSet set, u32 binding,
-                                                vk::Buffer buffer, u64 size)
+    void DescriptorManager::UpdateUniformBuffer(const vk::DescriptorSet set, const u32 binding,
+                                                const vk::Buffer buffer, const u64 size) const
     {
         vk::DescriptorBufferInfo bufferInfo;
         bufferInfo.setBuffer(buffer).setOffset(0).setRange(size);
@@ -97,8 +97,8 @@ namespace Engine
         m_Device.GetDevice().updateDescriptorSets(write, {});
     }
 
-    void DescriptorManager::UpdateStorageBuffer(vk::DescriptorSet set, u32 binding,
-                                                vk::Buffer buffer, u64 size)
+    void DescriptorManager::UpdateStorageBuffer(const vk::DescriptorSet set, const u32 binding,
+                                                const vk::Buffer buffer, const u64 size) const
     {
         vk::DescriptorBufferInfo bufferInfo;
         bufferInfo.setBuffer(buffer).setOffset(0).setRange(size);
@@ -114,8 +114,8 @@ namespace Engine
         m_Device.GetDevice().updateDescriptorSets(write, {});
     }
 
-    void DescriptorManager::UpdateTexture(vk::DescriptorSet set, u32 binding,
-                                          vk::Sampler sampler, vk::ImageView view)
+    void DescriptorManager::UpdateTexture(const vk::DescriptorSet set, const u32 binding,
+                                          const vk::Sampler sampler, const vk::ImageView view) const
     {
         vk::DescriptorImageInfo imageInfo;
         imageInfo.setSampler(sampler)
@@ -134,7 +134,7 @@ namespace Engine
     }
 
     vk::PipelineLayout DescriptorManager::CreatePipelineLayout(vk::DescriptorSetLayout layout,
-                                                               const u32 pushConstantSize)
+                                                               const u32 pushConstantSize) const
     {
         vk::PipelineLayoutCreateInfo info;
         info.setSetLayouts(layout);
@@ -154,7 +154,7 @@ namespace Engine
     }
 
     vk::PipelineLayout DescriptorManager::CreatePipelineLayout(const std::vector<vk::DescriptorSetLayout>& layouts,
-                                                               u32 pushConstantSize)
+                                                               const u32 pushConstantSize) const
     {
         vk::PipelineLayoutCreateInfo info;
         info.setSetLayouts(layouts);
diff --git a/Engine/src/Vulkan/ShaderManager.cpp b/Engine/src/Vulkan/ShaderManager.cpp
index 7f8627b..03b8bdb 100644
--- a/Engine/src/Vulkan/ShaderManager.cpp
+++ b/Engine/src/Vulkan/ShaderManager.cpp
@@ -21,11 +21,11 @@ ShaderManager::~ShaderManager()
 }
 
 ShaderObject ShaderManager::CreateFromFile(const std::string& spvPath,
-                                            vk::ShaderStageFlagBits stage,
+                                            const vk::ShaderStageFlagBits stage,
                                             const std::vector<vk::DescriptorSetLayout>& layouts,
-                                            u32 pushConstantSize)
+                                            const u32 pushConstantSize)
 {
-    auto spirv = ReadSPIRV(spvPath);
+    const auto spirv = ReadSPIRV(spvPath);
     if (spirv.empty()) {
         ENGINE_ERROR("Failed to read SPIR-V: {}", spvPath);
         return { nullptr, stage };
@@ -34,9 +34,9 @@ ShaderObject ShaderManager::CreateFromFile(const std::string& spvPath,
 }
 
 ShaderObject ShaderManager::CreateFromSPIRV(const std::vector<u32>& spirv,
-                                             vk::ShaderStageFlagBits stage,
+                                             const vk::ShaderStageFlagBits stage,
                                              const std::vector<vk::DescriptorSetLayout>& layouts,
-                                             u32 pushConstantSize)
+                                             const u32 pushConstantSize) const
 {
     vk::ShaderStageFlags nextStage = {};
     if (stage == vk::ShaderStageFlagBits::eVertex) {
@@ -70,7 +70,7 @@ ShaderObject ShaderManager::CreateFromSPIRV(const std::vector<u32>& spirv,
 
     vk::ShaderEXT shader;
     try {
-        auto result = m_Device.GetDevice().createShadersEXT(createInfo);
+        const auto result = m_Device.GetDevice().createShadersEXT(createInfo);
         shader = result.value[0];
     }
     catch (const vk::SystemError& e) {
@@ -81,7 +81,7 @@ ShaderObject ShaderManager::CreateFromSPIRV(const std::vector<u32>& spirv,
     return { shader, stage };
 }
 
-void ShaderManager::Destroy(const ShaderObject& shader)
+void ShaderManager::Destroy(const ShaderObject& shader) const
 {
     if (shader.Handle) {
         m_Device.GetDevice().destroyShaderEXT(shader.Handle);
@@ -96,7 +96,7 @@ std::vector<u32> ShaderManager::ReadSPIRV(const std::string& path)
         return {};
     }
 
-    size_t size = file.tellg();
+    const size_t size = file.tellg();
     std::vector<u32> buffer(size / sizeof(u32));
     file.seekg(0);
     file.read(reinterpret_cast<char*>(buffer.data()), size);
diff --git a/Engine/src/Vulkan/SyncManager.cpp b/Engine/src/Vulkan/SyncManager.cpp
index a0c22af..5c2d264 100644
--- a/Engine/src/Vulkan/SyncManager.cpp
+++ b/Engine/src/Vulkan/SyncManager.cpp
@@ -14,7 +14,7 @@ namespace Engine {
     SyncManager::SyncManager(Device& device, u32 maxFramesInFlight, u32 imageCount)
         : m_Device(device)
     {
-        vk::SemaphoreCreateInfo semInfo;
+        const vk::SemaphoreCreateInfo semInfo;
 
         // 每帧一个 ImageAvailable
         m_ImageAvailable.resize(maxFramesInFlight);
@@ -48,7 +48,7 @@ namespace Engine {
         for (auto s : m_RenderFinished) vkDevice.destroySemaphore(s);
     }
 
-    void SyncManager::WaitFence(u32 frameIndex)
+    void SyncManager::WaitFence(const u32 frameIndex) const
     {
         auto result = m_Device.GetDevice().waitForFences(
             m_FrameFences[frameIndex], VK_TRUE, std::numeric_limits<u64>::max());
@@ -57,7 +57,7 @@ namespace Engine {
         }
     }
 
-    void SyncManager::ResetFence(u32 frameIndex)
+    void SyncManager::ResetFence(const u32 frameIndex) const
     {
         m_Device.GetDevice().resetFences(m_FrameFences[frameIndex]);
     }
diff --git a/Engine/src/Vulkan/Texture.cpp b/Engine/src/Vulkan/Texture.cpp
index f59a3cf..6610250 100644
--- a/Engine/src/Vulkan/Texture.cpp
+++ b/Engine/src/Vulkan/Texture.cpp
@@ -219,7 +219,7 @@ namespace Engine
     // DDS → Vulkan 格式映射。sRGB 语义由贴图槽位决定（渲染侧职责）：
     //   颜色图（BaseColor/Emissive）→ SRGB 变体
     //   数据图（Normal/Specular 等线性槽位）→ UNORM
-    vk::Format ToVkFormat(Assets::Dds::DdsFormat f, bool srgb)
+    vk::Format ToVkFormat(const Assets::Dds::DdsFormat f, const bool srgb)
     {
         using DF = Assets::Dds::DdsFormat;
         switch (f) {
@@ -279,9 +279,10 @@ namespace Engine
         std::vector<vk::DeviceSize> offsets(m_MipLevels);
         {
             vk::DeviceSize off = 0;
+            auto* dst = static_cast<u8*>(stagingAlloc.MappedPtr);
             for (u32 mip = 0; mip < m_MipLevels; ++mip) {
                 offsets[mip] = off;
-                std::memcpy(stagingAlloc.MappedPtr + off,
+                std::memcpy(dst + off,
                             data.Mips[mip].data(), data.Mips[mip].size());
                 off += data.Mips[mip].size();
             }
diff --git a/Engine/src/Vulkan/UniformBuffer.cpp b/Engine/src/Vulkan/UniformBuffer.cpp
index cbb2ccc..7a84451 100644
--- a/Engine/src/Vulkan/UniformBuffer.cpp
+++ b/Engine/src/Vulkan/UniformBuffer.cpp
@@ -26,7 +26,7 @@ namespace Engine {
         ENGINE_INFO("UniformBuffer created: {} bytes x {} frames", size, frameCount);
     }
 
-    void UniformBuffer::Update(u32 frameSlot, const void* data, u64 size)
+    void UniformBuffer::Update(const u32 frameSlot, const void* data, const u64 size) const
     {
         m_Buffers[frameSlot]->Upload(data, size);
     }
diff --git a/shaders/simple_shader.frag b/shaders/simple_shader.frag
index f45fd24..2975c61 100644
--- a/shaders/simple_shader.frag
+++ b/shaders/simple_shader.frag
@@ -1,6 +1,7 @@
 #version 450
 
 const int MAX_LIGHTS = 4;
+const float PI = 3.14159265359;
 
 struct Light {
     vec4 color;       // rgb = 颜色，a = 强度
@@ -35,18 +36,20 @@ layout(set = 0, binding = 0) uniform UniformBufferObject {
 // 材质纹理槽（binding = Material::Slot）
 layout(set = 1, binding = 0) uniform sampler2D albedoMap;
 layout(set = 1, binding = 1) uniform sampler2D normalMap;
-layout(set = 1, binding = 2) uniform sampler2D specularMap;
+layout(set = 1, binding = 2) uniform sampler2D metallicRoughnessMap;  // G=粗糙度 B=金属度
 layout(set = 1, binding = 3) uniform sampler2D emissiveMap;
+layout(set = 1, binding = 4) uniform MaterialParams {
+    vec4 factors;   // x = metallic 因子，y = roughness 因子
+} matParams;
 
 layout(set = 2, binding = 0) uniform sampler2D shadowMap0;   // CSM 级联 0（最近）
 layout(set = 2, binding = 1) uniform sampler2D shadowMap1;   // 级联 1
 layout(set = 2, binding = 2) uniform sampler2D shadowMap2;   // 级联 2（最远）
 
-// 第 0 盏灯（KeyLight）的 CSM 阴影因子：0.3 影中 / 1.0 受光。
+// 第 0 盏方向光（KeyLight）的 CSM 阴影因子：0.3 影中 / 1.0 受光。
 // 级联按视图深度选择；采样器均 clamp-to-border 白色：
 // 光视锥外自动 1.0（无阴影），省出界分支。
 float ShadowFactor(vec3 N, float viewDepth) {
-    // 级联选择：第一个 viewDepth < split 的级联
     int cascade = 2;
     for (int i = 0; i < 3; ++i) {
         if (viewDepth < ubo.cascadeSplits[i]) { cascade = i; break; }
@@ -54,7 +57,6 @@ float ShadowFactor(vec3 N, float viewDepth) {
 
     vec4 ls = ubo.lightSpace[cascade] * vec4(fragWorldPos, 1.0);
     vec3 proj = ls.xyz / ls.w;
-    // NDC [-1,1] → UV [0,1]（ortho 的 w=1）
     vec2 uv = proj.xy * 0.5 + 0.5;
 
     float closest;
@@ -62,7 +64,6 @@ float ShadowFactor(vec3 N, float viewDepth) {
     else if (cascade == 1) closest = texture(shadowMap1, uv).r;
     else                   closest = texture(shadowMap2, uv).r;
 
-    // 斜率缩放 bias：掠射面用更大的 bias 压 acne
     vec3 L = normalize(-ubo.lights[0].direction.xyz);
     float bias = max(0.004 * (1.0 - dot(N, L)), 0.0012);
 
@@ -83,15 +84,39 @@ vec3 MappedNormal(vec3 geomN, vec3 T, vec2 uv) {
     return normalize(nT * sampled.x + B * sampled.y + N * sampled.z);
 }
 
+// ---- Cook-Torrance BRDF 各项 ----
+float DistributionGGX(float NdotH, float roughness) {
+    float a = roughness * roughness;
+    float a2 = a * a;
+    float d = NdotH * NdotH * (a2 - 1.0) + 1.0;
+    return a2 / (PI * d * d);
+}
+
+float GeometrySmith(float NdotV, float NdotL, float roughness) {
+    float r = roughness + 1.0;
+    float k = (r * r) / 8.0;   // 解析光源用此 k（IBL 才用 IBL 版本）
+    float gv = NdotV / (NdotV * (1.0 - k) + k);
+    float gl = NdotL / (NdotL * (1.0 - k) + k);
+    return gv * gl;
+}
+
+vec3 FresnelSchlick(float cosTheta, vec3 F0) {
+    return F0 + (1.0 - F0) * pow(clamp(1.0 - cosTheta, 0.0, 1.0), 5.0);
+}
+
 void main() {
     vec3 albedo = texture(albedoMap, fragUV).rgb;
-    float specIntensity = texture(specularMap, fragUV).r;
+    vec4 mr = texture(metallicRoughnessMap, fragUV);
+    float roughness = clamp(mr.g * matParams.factors.y, 0.045, 1.0);
+    float metallic  = clamp(mr.b * matParams.factors.x, 0.0, 1.0);
     vec3 emissive = texture(emissiveMap, fragUV).rgb;
 
     vec3 N = MappedNormal(normalize(fragNormal), fragTangent, fragUV);
     vec3 V = normalize(ubo.cameraPos.xyz - fragWorldPos);
+    float NdotV = max(dot(N, V), 1e-4);
+    vec3 F0 = mix(vec3(0.04), albedo, metallic);   // 电介质基准反射率 4%
 
-    vec3 result = ubo.ambientColor.rgb * albedo;
+    vec3 Lo = vec3(0.0);
 
     for (int i = 0; i < MAX_LIGHTS; ++i) {
         // 按类型分支：方向光无衰减；点光方向指向光源 + 平方距离衰减
@@ -100,32 +125,45 @@ void main() {
         if (ubo.lights[i].params.x > 0.5) {
             vec3 toLight = ubo.lights[i].position.xyz - fragWorldPos;
             float d = length(toLight);
-            if (d >= ubo.lights[i].params.y) continue;   // 衰减半径外，跳过
+            if (d >= ubo.lights[i].params.y) continue;
             L = toLight / d;
             float a = clamp(1.0 - (d * d) /
                             (ubo.lights[i].params.y * ubo.lights[i].params.y),
                             0.0, 1.0);
-            atten = a * a;   // 平方衰减，边缘更柔和
+            atten = a * a;
         } else {
             L = normalize(-ubo.lights[i].direction.xyz);
         }
 
-        float diff = max(dot(N, L), 0.0);
-        // Blinn-Phong 高光（半程向量；specular 图做强度系数）
-        vec3 H = normalize(L + V);
-        float spec = pow(max(dot(N, H), 0.0), 32.0) * specIntensity;
+        vec3 radiance = ubo.lights[i].color.rgb * ubo.lights[i].color.a * atten;
+        float NdotL = max(dot(N, L), 0.0);
+        if (NdotL <= 0.0) continue;
+
+        // Cook-Torrance 镜面项
+        vec3 H = normalize(V + L);
+        float NdotH = max(dot(N, H), 0.0);
+        float NdotH2 = max(dot(H, V), 0.0);
+        float D = DistributionGGX(NdotH, roughness);
+        float G = GeometrySmith(NdotV, NdotL, roughness);
+        vec3  F = FresnelSchlick(NdotH2, F0);
+
+        vec3 kS = F;
+        vec3 kD = (1.0 - kS) * (1.0 - metallic);   // 金属不参与漫反射
+        vec3 specular = (D * G * F) /
+                        max(4.0 * NdotV * NdotL, 1e-4);
 
         // 阴影只来自第 0 盏方向光（CSM）
         float shade = (i == 0 && ubo.lights[0].params.x < 0.5)
             ? ShadowFactor(N, fragViewDepth) : 1.0;
 
-        result += ubo.lights[i].color.rgb * ubo.lights[i].color.a *
-                  (albedo * diff + vec3(spec)) * atten * shade;
+        Lo += (kD * albedo / PI + specular) * radiance * NdotL * shade;
     }
 
-    // 自发光不经光照/阴影直接叠加
-    result += emissive;
+    // 环境光：无 IBL 的简化版（半球常数）；后续 IBL 替换
+    vec3 ambient = ubo.ambientColor.rgb * albedo;
 
-    outColor = vec4(result, 1.0);
+    vec3 color = ambient + Lo + emissive;
+
+    outColor = vec4(color, 1.0);
     outVelocity = fragVelocity;
 }