feat: 透明窗口 + 实例预算扩容（修复斜光阴影静默截断）

透明窗口：SceneSettings 加 ClearColor/DrawSkybox，随 FrameSceneData
每帧下发到 SkyboxPass（替换硬编码清屏色）；GLFW 透明帧缓冲已开，
tonemap 预乘 alpha 直通已有，链路全通。TAA alpha 时域混合为已知边界。

实例预算：kMaxInstances 16384 → 65536（四视图共享预算，100 实体
斜光时需求 16.4k 超限，cascade 2 实例被静默丢弃 = 用户看到的
"拖灯光方向部分背包阴影消失"）。截断状态每帧落遥测 + ImGui 红字
（原 warn-once 对动态穿越阈值的场景等于没有告警）。

App/main.cpp

@@ -22,13 +22,13 @@
 
 #include <glm/glm.hpp>
 #include <glm/gtc/matrix_transform.hpp>
+#include <glm/gtc/type_ptr.hpp>
 
 #include <GLFW/glfw3.h>
 
 #include <atomic>
 #include <thread>
 
-
 using namespace Engine;
 using namespace Engine::ECS;
 
@@ -88,7 +88,7 @@ namespace
             const auto model = GetAssets().LoadModel("assets/models/backpack/backpack.obj");
             // const auto model = GetAssets().LoadModel("assets/models/pocket_watch_4k.gltf/pocket_watch_4k.gltf");
 
-            int countSize = 2;
+            int countSize = 10;
             for (int i = 0; i < countSize; i ++)
             {
                 for (int j = 0; j < countSize; j ++)
@@ -316,23 +316,31 @@ namespace
             {
                 // 动态环境切换（Assets 层加载 → Renderer 换绑；缓存去重）
                 ImGui::Text("Environment (IBL)");
-                int envIdx = m_EnvIndex;
+                bool& DrawSkybox = GetScene().GetSettings().DrawSkybox;
-                if (ImGui::Combo("env", &envIdx, kEnvNames, kEnvCount))
+                ImGui::Checkbox("DrawSkybox", &DrawSkybox);
+                if (DrawSkybox)
                 {
-                    // 异步：解码后台线程，完成后 OnUpdate 里换绑
+                    int envIdx = m_EnvIndex;
-                    m_EnvIndex = envIdx;
+                    if (ImGui::Combo("env", &envIdx, kEnvNames, kEnvCount))
-                    RequestEnvironment(envIdx);
+                    {
-                }
+                        // 异步：解码后台线程，完成后 OnUpdate 里换绑
-                ImGui::Text(m_EnvLoadBusy ? "(decoding...)" :
+                        m_EnvIndex = envIdx;
-                            "(switch = compute pre-integrate, ms-level)");
+                        RequestEnvironment(envIdx);
+                    }
+                    ImGui::Text(m_EnvLoadBusy ? "(decoding...)" :
+                                "(switch = compute pre-integrate, ms-level)");
 
-                // 调试视图：单看某个 pass 的中间输出（类 UE pass debug）
+                    // 调试视图：单看某个 pass 的中间输出（类 UE pass debug）
-                const auto& viewNames = renderer.GetDebugViewNames();
+                    const auto& viewNames = renderer.GetDebugViewNames();
-                int view = renderer.GetDebugView();
+                    int view = renderer.GetDebugView();
-                if (ImGui::Combo("Debug View", &view, viewNames.data(),
+                    if (ImGui::Combo("Debug View", &view, viewNames.data(),
-                                 static_cast<int>(viewNames.size())))
+                                     static_cast<int>(viewNames.size())))
+                    {
+                        renderer.SetDebugView(view);
+                    }
+                }else
                 {
-                    renderer.SetDebugView(view);
+                    ImGui::ColorEdit4("ClearColor", glm::value_ptr(GetScene().GetSettings().ClearColor));
                 }
             }
 
@@ -343,6 +351,10 @@ namespace
                 ImGui::Text("instances: %u main / %u shadow",
                             renderer.GetMainInstanceCount(),
                             renderer.GetShadowInstanceCount());
+                if (renderer.GetInstancesTruncated()) {
+                    ImGui::TextColored(ImVec4(1.0f, 0.3f, 0.3f, 1.0f),
+                        "TRUNCATED: instance buffer full!");
+                }
                 const auto& names = renderer.GetPassNames();
                 const auto& times = renderer.GetPassGpuMs();
                 for (size_t i = 0; i < names.size() && i < times.size(); ++i)

Engine/include/Engine/ECS/Scene.h

@@ -41,7 +41,9 @@ namespace Engine::ECS {
 
         // ---- 场景级设置 ----
         struct Settings {
-            glm::vec4 ambientColor{0.07f, 0.07f, 0.09f, 0.0f};
+            glm::vec4 ClearColor = {0.1, 0.1, 0.1, 1.0};
+            glm::vec4 AmbientColor{0.07f, 0.07f, 0.09f, 0.0f};
+            bool DrawSkybox = true;
         };
         Settings& GetSettings() { return m_Settings; }
 

Engine/include/Engine/Renderer/Renderer.h

@@ -109,6 +109,7 @@ namespace Engine {
         // 双视图剔除后的实例数（遥测）
         u32 GetMainInstanceCount() const;
         u32 GetShadowInstanceCount() const;
+        bool GetInstancesTruncated() const;   // 实例预算溢出（遥测红字）
 
         // 垂直同步开关（present mode 切换会重建 swapchain），
         // 只应在帧 UI 构建段调用（Render 之前）

Engine/include/Engine/Renderer/SceneTypes.h

@@ -33,7 +33,11 @@ namespace Engine {
     };
 
     constexpr u32 kMaxLights = 4;
-    constexpr u32 kMaxInstances = 16384;          // 实例 SSBO 容量（矩阵数）
+    // 实例 SSBO 容量（矩阵数）。四视图（main + 3 级联）共享同一预算：
+    // 需求 = Σ各视图剔除后实例数，大场景斜光时阴影实例可膨胀到主视图
+    // 的 2-3 倍。65536 = 4MB/槽位，覆盖 ~800 实体 × 79 mesh 全级联；
+    // 再往上就该上 LOD / GPU culling，而不是继续加预算
+    constexpr u32 kMaxInstances = 65536;
     constexpr u32 kMaxCascades = 3;               // CSM 级联数
     constexpr u32 kCascadeRes = 1024;             // 每级联阴影图边长
 
@@ -69,6 +73,9 @@ namespace Engine {
     struct FrameSceneData {
         UniformBufferObject ubo{};
 
+        glm::vec4 ClearColor{0.1, 0.1, 0.1, 1.0};
+        bool DrawSkybox = true;
+
         // 天空盒反投影矩阵：inverse(projNoJitter × mat4(mat3(view)))
         //（视图去平移只留旋转 → 反投影结果即世界方向；Skybox pass push）
         glm::mat4 skyInvVP{1.0f};
@@ -90,6 +97,10 @@ namespace Engine {
         bool bloomEnabled = true;     // BloomPass 子 pass 空转 + tonemap 强度归零
         int  debugView = 0;           // Passes::DebugView 枚举（tonemap 路由上屏）
 
+        // 实例预算溢出（kMaxInstances）：本轮收集有实例被静默丢弃——
+        // 必须遥测可见，"只告警一次"的大场景截断等于没有告警
+        bool instancesTruncated = false;
+
         f32 collectMs = 0.0f;   // 收集+剔除 CPU 耗时（遥测）
     };
 

Engine/src/Renderer/Passes/SkyboxPass.cpp

@@ -94,9 +94,10 @@ namespace Engine::Passes
             ZoneScopedN("Skybox");
             const vk::CommandBuffer cmd = ctx.cmd;
 
+            const glm::vec4& cc = m_Frame.ClearColor;
             vk::ClearValue clear;
             clear.color = vk::ClearColorValue(
-                std::array<float, 4>{0.1f, 0.1f, 0.1f, 1.0f});
+                std::array<float, 4>{cc.r, cc.g, cc.b, cc.a});
 
             vk::RenderingAttachmentInfo color;
             color.setImageView(ctx.View(m_HDRColor))
@@ -112,13 +113,13 @@ namespace Engine::Passes
 
             cmd.beginRendering(renderingInfo);
 
-            if (m_Env) {
+            if (m_Env && m_Frame.DrawSkybox) {
                 // 无环境贴图：只清屏（Forward loadOp=Load 依赖这里先写）
-                std::array<vk::ShaderStageFlagBits, 2> stages = {
+                const std::array<vk::ShaderStageFlagBits, 2> stages = {
                     vk::ShaderStageFlagBits::eVertex,
                     vk::ShaderStageFlagBits::eFragment
                 };
-                std::array<vk::ShaderEXT, 2> shaders = {m_Vert, m_Frag};
+                const std::array<vk::ShaderEXT, 2> shaders = {m_Vert, m_Frag};
                 cmd.bindShadersEXT(stages, shaders);
 
                 cmd.bindDescriptorSets(vk::PipelineBindPoint::eGraphics,
@@ -149,12 +150,12 @@ namespace Engine::Passes
                 cmd.setVertexInputEXT({}, {});
 
                 cmd.setRasterizationSamplesEXT(vk::SampleCountFlagBits::e1);
-                vk::SampleMask sampleMask = 0xFFFFFFFF;
+                constexpr vk::SampleMask sampleMask = 0xFFFFFFFF;
                 cmd.setSampleMaskEXT(vk::SampleCountFlagBits::e1, sampleMask);
                 cmd.setAlphaToCoverageEnableEXT(VK_FALSE);
                 cmd.setAlphaToOneEnableEXT(VK_FALSE);
 
-                vk::Viewport viewport(0.0f, 0.0f,
+                const vk::Viewport viewport(0.0f, 0.0f,
                                       static_cast<float>(ctx.extent.width),
                                       static_cast<float>(ctx.extent.height),
                                       0.0f, 1.0f);
@@ -170,8 +171,8 @@ namespace Engine::Passes
                              .setDstAlphaBlendFactor(vk::BlendFactor::eZero)
                              .setAlphaBlendOp(vk::BlendOp::eAdd);
                 // ArrayProxyNoTemporaries 拒绝临时量：具名局部变量传入
-                vk::Bool32 blendEnable = VK_FALSE;
+                constexpr vk::Bool32 blendEnable = VK_FALSE;
-                vk::ColorComponentFlags colorWriteMask =
+                constexpr vk::ColorComponentFlags colorWriteMask =
                     vk::ColorComponentFlagBits::eR |
                     vk::ColorComponentFlagBits::eG |
                     vk::ColorComponentFlagBits::eB |

Engine/src/Renderer/Renderer.cpp

@@ -215,6 +215,11 @@ namespace Engine
         return m_SceneRenderer->GetMainInstanceCount();
     }
 
+    bool Renderer::GetInstancesTruncated() const
+    {
+        return m_SceneRenderer->Frame().instancesTruncated;
+    }
+
     u32 Renderer::GetShadowInstanceCount() const
     {
         return m_SceneRenderer->GetShadowInstanceCount();

Engine/src/Renderer/SceneRenderer.cpp

@@ -166,9 +166,11 @@ namespace Engine
             ubo.proj[2][1] += jy * 2.0f / static_cast<f32>(targetExtent.height);
         }
 
-        ubo.ambientColor = scene.GetSettings().ambientColor;
+        ubo.ambientColor = scene.GetSettings().AmbientColor;
 
         // ---- 运行时开关/调试视图落帧（各 pass 与 frag 只读契约字段）----
+        m_Frame.ClearColor = scene.GetSettings().ClearColor;
+        m_Frame.DrawSkybox = scene.GetSettings().DrawSkybox;
         m_Frame.shadowsEnabled = m_ShadowsEnabled;
         m_Frame.taaEnabled = m_TAAEnabled;
         m_Frame.bloomEnabled = m_BloomEnabled;
@@ -363,11 +365,13 @@ namespace Engine
         m_LastProjNoJitter = ubo.projNoJitter;
         ++m_FrameIndex;
 
+        // 截断状态每帧落遥测（ImGui 可见）——"只告警一次"的日志对
+        // 大场景不够：预算是动态穿越的，用户必须实时看到截断发生
+        m_Frame.instancesTruncated = instanceTruncated;
         if (instanceTruncated && !m_TruncationWarned) {
-            // 只告警一次（每帧告警会刷屏）
             m_TruncationWarned = true;
-            ENGINE_WARN("GPUDriven: instance buffer full ({}), entities truncated",
+            ENGINE_WARN("GPUDriven: instance buffer full ({}), entities truncated "
-                        kMaxInstances);
+                        "(见 Scene Debug 面板红字)", kMaxInstances);
         }
 
         m_Frame.collectMs = std::chrono::duration<f32, std::milli>(