From d9b1742327a16644a7becb49231aac9843eaa3f7 Mon Sep 17 00:00:00 2001 From: atdunbg Date: Thu, 24 Sep 2026 20:53:19 +0800 Subject: [PATCH] =?UTF-8?q?feat:=20LOD=20=E7=BD=91=E6=A0=BC=E5=88=86?= =?UTF-8?q?=E7=BA=A7=E2=80=94=E2=80=94meshopt=20=E8=A7=A3=E6=9E=90?= =?UTF-8?q?=E6=9C=9F=E7=AE=80=E5=8C=96=20+=20=E6=8C=89=E8=B7=9D=E7=A6=BB/?= =?UTF-8?q?=E7=BA=A7=E8=81=94=E9=80=89=E7=BA=A7?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit vendored meshoptimizer 1.2（submodule 环境故障改直接 vendor）。Mesh 多 LOD：各级索引连续拼进同一 index buffer（共享顶点，LodRange 区间 选择），解析期 meshopt_simplify 生成链（LOD0=原始，每级目标减半， 相对误差 1e-2，小网格复用上级）；都在 worker 线程，加载零额外卡顿。 SceneRenderer 按 (mesh, LOD) 聚合 batch（lookup key = 指针<<8|lod）： 主视图按屏占比近似 radius/dist 选级（阈值 10/20 倍半径）；阴影级联 按级联序降级（越远越简）。Draw 按 batch.lod 选索引区间。 A/B 对比（100 背包 10×10，RTX 5060 Laptop，vsync off）： - 纯背包：LOD 开 93-95 fps / 关 90-107 fps —— 无显著差异 - 加 SunTemple：LOD 开 52-56 / 关 51-55 —— 无显著差异 结论：当前场景瓶颈不在顶点数（5060 顶点吞吐富余），LOD 基础设施 保留（几何复杂资产/低端 GPU/更大场景生效），帧率问题转向 Tracy GPU 时间线定位真实瓶颈。 坑：LodRange 记录"LOD 不足复用最后一级"时 first 不得继续累加 （buffer 无重复数据，累加必越界——VUID-08798 抓的）。 --- Engine/CMakeLists.txt | 6 +++ Engine/include/Engine/Renderer/Mesh.h | 26 +++++++++--- Engine/include/Engine/Renderer/Model.h | 4 +- .../include/Engine/Renderer/SceneRenderer.h | 4 +- Engine/include/Engine/Renderer/SceneTypes.h | 4 +- Engine/src/Renderer/Mesh.cpp | 42 ++++++++++++++----- Engine/src/Renderer/Model.cpp | 37 ++++++++++++++-- Engine/src/Renderer/Passes/ForwardPass.cpp | 2 +- Engine/src/Renderer/Passes/ShadowPass.cpp | 2 +- Engine/src/Renderer/SceneRenderer.cpp | 27 +++++++++--- 10 files changed, 125 insertions(+), 29 deletions(-) diff --git a/Engine/CMakeLists.txt b/Engine/CMakeLists.txt index 108c165..44987a8 100644 --- a/Engine/CMakeLists.txt +++ b/Engine/CMakeLists.txt @@ -47,4 +47,10 @@ target_compile_definitions(Engine PUBLIC TRACY_ON_DEMAND) find_package(Threads REQUIRED) target_link_libraries(Engine PUBLIC Threads::Threads) +# meshoptimizer（vendored，LOD 网格简化；submodule 机制故障改为直接 vendor） +file(GLOB MESHOPT_SOURCES ${CMAKE_SOURCE_DIR}/Lib/meshoptimizer/src/*.cpp) +add_library(meshopt STATIC ${MESHOPT_SOURCES}) +target_include_directories(meshopt PUBLIC ${CMAKE_SOURCE_DIR}/Lib/meshoptimizer/src) +target_link_libraries(Engine PUBLIC meshopt) + target_compile_definitions(Engine PRIVATE VULKAN_HPP_DISPATCH_LOADER_DYNAMIC=1) \ No newline at end of file diff --git a/Engine/include/Engine/Renderer/Mesh.h b/Engine/include/Engine/Renderer/Mesh.h index dc26873..f26e068 100644 --- a/Engine/include/Engine/Renderer/Mesh.h +++ b/Engine/include/Engine/Renderer/Mesh.h @@ -18,13 +18,18 @@ namespace Engine class Buffer; class Material; + // LOD 级数：LOD0 = 原始网格，越高越简（解析期 meshopt_simplify 生成， + // 共享顶点数据，只换索引区间） + inline constexpr u32 kMeshLodCount = 3; + class Mesh { public: // material 非拥有指针：Model 的材质缓存拥有（同贴图共享一份） + // lods[0] 必须为原始索引（与 vertices 对应），各级简化链由解析期生成 Mesh(Device& device, MemoryAllocator& allocator, const std::vector& vertices, - const std::vector& indices, + const std::vector>& lods, Material* material); ~Mesh(); @@ -32,11 +37,16 @@ namespace Engine Mesh& operator=(const Mesh&) = delete; // instanceCount/firstInstance：GPUDriven 按 mesh 分 batch 后， - // 同 mesh 的 N 个实体一次 draw 完成，模型矩阵经实例索引取 - void Draw(vk::CommandBuffer cmd, u32 instanceCount = 1, u32 firstInstance = 0) const; + // 同 mesh 的 N 个实体一次 draw 完成，模型矩阵经实例索引取。 + // lod：索引区间选择（越界取最高级） + void Draw(vk::CommandBuffer cmd, u32 instanceCount = 1, + u32 firstInstance = 0, u32 lod = 0) const; Material* GetMaterial() const { return m_Material; } - u32 GetIndexCount() const { return m_IndexCount; } + u32 GetLodIndexCount(u32 lod) const + { + return m_Lods[lod < kMeshLodCount ? lod : kMeshLodCount - 1].indexCount; + } // 局部空间包围球（构造时从顶点算出），视锥剔除用 struct Bounds { @@ -46,10 +56,16 @@ namespace Engine const Bounds& GetBounds() const { return m_Bounds; } private: + // 同一 index buffer 内连续排布的各级索引区间 + struct LodRange { + u32 firstIndex = 0; + u32 indexCount = 0; + }; + Scope m_VertexBuffer; Scope m_IndexBuffer; + std::array m_Lods{}; Material* m_Material; - u32 m_IndexCount = 0; Bounds m_Bounds; u64 m_VertexBytes = 0; diff --git a/Engine/include/Engine/Renderer/Model.h b/Engine/include/Engine/Renderer/Model.h index b48645c..ad55e91 100644 --- a/Engine/include/Engine/Renderer/Model.h +++ b/Engine/include/Engine/Renderer/Model.h @@ -34,7 +34,9 @@ namespace Engine // worker 线程产出（ParseFromDisk），主线程消费（FromParsed）。 struct ParsedMesh { std::vector vertices; - std::vector indices; + // LOD 链（[0] = 原始索引，越往后越简）：解析期 meshopt_simplify + // 生成（worker 线程），消费端共享顶点只换索引 + std::vector> lods; std::array texPaths; MaterialParams params; }; diff --git a/Engine/include/Engine/Renderer/SceneRenderer.h b/Engine/include/Engine/Renderer/SceneRenderer.h index f38b825..5c0aaec 100644 --- a/Engine/include/Engine/Renderer/SceneRenderer.h +++ b/Engine/include/Engine/Renderer/SceneRenderer.h @@ -73,7 +73,9 @@ namespace Engine { // 时实例分散各处），扁平化成连续数组推迟到 appendView std::vector> batchWorlds; std::vector> batchPrevWorlds; - std::unordered_map lookup; + // key = (Mesh*, LOD)：同 mesh 不同 LOD 索引区间不同， + // 必须分开成 batch（低 8 位 LOD，高位指针，指针 8 字节对齐安全） + std::unordered_map lookup; void Clear() { diff --git a/Engine/include/Engine/Renderer/SceneTypes.h b/Engine/include/Engine/Renderer/SceneTypes.h index 03e6033..834f515 100644 --- a/Engine/include/Engine/Renderer/SceneTypes.h +++ b/Engine/include/Engine/Renderer/SceneTypes.h @@ -19,11 +19,13 @@ namespace Engine { class Mesh; - // GPUDriven：按 mesh 聚合的绘制批 + // GPUDriven：按 (mesh, LOD) 聚合的绘制批——同 mesh 不同 LOD 的实例 + // 索引区间不同，不能并成一次 draw struct InstanceBatch { Mesh* mesh; u32 first; // 在实例矩阵数组中的起始下标 u32 count; // 实例数 + u32 lod = 0; // 绘制用索引区间（Mesh::Draw） }; // 一个渲染视图的剔除结果（相机视图 / 光源视图各一份） diff --git a/Engine/src/Renderer/Mesh.cpp b/Engine/src/Renderer/Mesh.cpp index d97e2b3..8b0b07a 100644 --- a/Engine/src/Renderer/Mesh.cpp +++ b/Engine/src/Renderer/Mesh.cpp @@ -17,13 +17,13 @@ namespace Engine { Mesh::Mesh(Device& device, MemoryAllocator& allocator, const std::vector& vertices, - const std::vector& indices, + const std::vector>& lods, Material* material) : m_Material(material) { - if (vertices.empty() || indices.empty()) + if (vertices.empty() || lods.empty() || lods[0].empty()) { - ENGINE_ERROR("Mesh: empty vertices or indices"); + ENGINE_ERROR("Mesh: empty vertices or LOD0 indices"); return; } @@ -35,15 +35,31 @@ namespace Engine vk::MemoryPropertyFlagBits::eHostCoherent); m_VertexBuffer->Upload(vertices.data(), vbSize); - u64 ibSize = sizeof(u32) * indices.size(); + // 各级索引连续拼进同一 index buffer（共享顶点，只换索引区间） + std::vector allIndices; + for (const auto& idx : lods) { + allIndices.insert(allIndices.end(), idx.begin(), idx.end()); + } + + u64 ibSize = sizeof(u32) * allIndices.size(); m_IndexBuffer = CreateScope( device, allocator, ibSize, vk::BufferUsageFlagBits::eIndexBuffer, vk::MemoryPropertyFlagBits::eHostVisible | vk::MemoryPropertyFlagBits::eHostCoherent); - m_IndexBuffer->Upload(indices.data(), ibSize); + m_IndexBuffer->Upload(allIndices.data(), ibSize); - m_IndexCount = static_cast(indices.size()); + // 记录各级区间。LOD 不足的级复用最后一级的"已有区间" + //（first 不得继续累加——buffer 里没有重复数据，累加必越界） + u32 first = 0; + for (u32 lod = 0; lod < kMeshLodCount; ++lod) { + if (lod < lods.size()) { + m_Lods[lod] = {first, static_cast(lods[lod].size())}; + first += m_Lods[lod].indexCount; + } else { + m_Lods[lod] = m_Lods[lods.size() - 1]; + } + } // 局部空间包围球：顶点包围盒 → 中心 + 最大半径（视锥剔除用） { @@ -61,10 +77,12 @@ namespace Engine } } - ENGINE_INFO("Mesh created: {} vertices, {} indices", vertices.size(), indices.size()); + ENGINE_INFO("Mesh created: {} vertices, LOD0 {} indices", vertices.size(), lods[0].size()); m_VertexBytes = sizeof(Vertex) * vertices.size(); - m_IndexBytes = sizeof(u32) * indices.size(); + for (const auto& idx : lods) { + m_IndexBytes += sizeof(u32) * idx.size(); + } STATS.AddMesh(m_VertexBytes, m_IndexBytes); } @@ -73,10 +91,14 @@ namespace Engine STATS.RemoveMesh(m_VertexBytes, m_IndexBytes); } - void Mesh::Draw(vk::CommandBuffer cmd, u32 instanceCount, u32 firstInstance) const + void Mesh::Draw(vk::CommandBuffer cmd, u32 instanceCount, u32 firstInstance, + u32 lod) const { + const LodRange& range = + m_Lods[lod < kMeshLodCount ? lod : kMeshLodCount - 1]; cmd.bindVertexBuffers(0, m_VertexBuffer->Get(), {0}); cmd.bindIndexBuffer(m_IndexBuffer->Get(), 0, vk::IndexType::eUint32); - cmd.drawIndexed(m_IndexCount, instanceCount, 0, 0, firstInstance); + cmd.drawIndexed(range.indexCount, instanceCount, range.firstIndex, + 0, firstInstance); } } // namespace Engine diff --git a/Engine/src/Renderer/Model.cpp b/Engine/src/Renderer/Model.cpp index 5ec5ded..9be1986 100644 --- a/Engine/src/Renderer/Model.cpp +++ b/Engine/src/Renderer/Model.cpp @@ -14,6 +14,8 @@ #include #include +#include + #include #include @@ -81,13 +83,14 @@ Model::Model(Device& device, MemoryAllocator& allocator, {{ h, 0.0f, -h}, {0, 1, 0}, {0.0f, 0.0f}}, }; const std::vector indices = {0, 1, 2, 0, 2, 3}; + const std::vector> lodIndices = {indices}; // 材质/纹理生命周期随模型（缓存持有） std::string paths[Material::kSlotCount] = {"", "", "", ""}; Material* mat = GetOrCreateMaterial(paths, MaterialParams{}); // 全默认材质 m_Meshes.push_back(CreateScope( - m_Device, m_Allocator, vertices, indices, mat)); + m_Device, m_Allocator, vertices, lodIndices, mat)); } Scope Model::CreatePlane(Device& device, MemoryAllocator& allocator, @@ -158,7 +161,7 @@ Scope Model::FromParsed(Device& device, MemoryAllocator& allocator, for (auto& pm : parsed.meshes) { Material* mat = model->GetOrCreateMaterial(pm.texPaths.data(), pm.params); model->m_Meshes.push_back(CreateScope( - device, allocator, std::move(pm.vertices), std::move(pm.indices), mat)); + device, allocator, pm.vertices, pm.lods, mat)); } ENGINE_INFO("Model loaded: {} ({} meshes, {} textures)", parsed.path, model->m_Meshes.size(), model->m_TextureCache.size()); @@ -177,7 +180,7 @@ void Model::LoadModel(const std::string& path) for (auto& pm : parsed.meshes) { Material* mat = GetOrCreateMaterial(pm.texPaths.data(), pm.params); m_Meshes.push_back(CreateScope( - m_Device, m_Allocator, std::move(pm.vertices), std::move(pm.indices), mat)); + m_Device, m_Allocator, pm.vertices, pm.lods, mat)); } ENGINE_INFO("Model loaded: {} ({} meshes, {} textures)", path, m_Meshes.size(), m_TextureCache.size()); @@ -256,7 +259,7 @@ ParsedMesh Model::ProcessMesh(const aiMesh* mesh, const aiScene* scene, { ParsedMesh out; std::vector& vertices = out.vertices; - std::vector& indices = out.indices; + std::vector indices; vertices.reserve(mesh->mNumVertices); @@ -386,6 +389,32 @@ ParsedMesh Model::ProcessMesh(const aiMesh* mesh, const aiScene* scene, out.texPaths[slot] = std::move(texPaths[slot]); } out.params = params; + + // ---- LOD 链（解析期生成，worker 线程免费时间）：---- + // LOD0 = 原始；每级目标索引数减半，相对误差 1e-2。顶点共享， + // 简化只重排索引（meshopt_simplify 从 LOD0 单次起点逐级向下） + out.lods.push_back(std::move(indices)); + for (u32 lod = 1; lod < kMeshLodCount; ++lod) { + const size_t target = out.lods[0].size() >> lod; + // 太小的网格不简化：简化收益低于误差风险，直接复用上一级 + if (target < 96 || out.lods[0].size() < 192) { + out.lods.push_back(out.lods.back()); + continue; + } + std::vector dest(out.lods[0].size()); + float error = 0.0f; + const size_t count = meshopt_simplify( + dest.data(), + out.lods[0].data(), out.lods[0].size(), + &out.vertices[0].position.x, out.vertices.size(), sizeof(Vertex), + target, 1e-2f, 0, &error); + if (count == 0) { + out.lods.push_back(out.lods.back()); // 简化失败兜底 + continue; + } + dest.resize(count); + out.lods.push_back(std::move(dest)); + } return out; } diff --git a/Engine/src/Renderer/Passes/ForwardPass.cpp b/Engine/src/Renderer/Passes/ForwardPass.cpp index bea2844..e343912 100644 --- a/Engine/src/Renderer/Passes/ForwardPass.cpp +++ b/Engine/src/Renderer/Passes/ForwardPass.cpp @@ -139,7 +139,7 @@ namespace Engine::Passes cmd.bindDescriptorSets(vk::PipelineBindPoint::eGraphics, m_Gpu.forwardLayout, 1, batch.mesh->GetMaterial()->GetDescriptorSet(), {}); - batch.mesh->Draw(cmd, batch.count, batch.first); + batch.mesh->Draw(cmd, batch.count, batch.first, batch.lod); } cmd.endRendering(); diff --git a/Engine/src/Renderer/Passes/ShadowPass.cpp b/Engine/src/Renderer/Passes/ShadowPass.cpp index 7e2ecbc..3d7c2a9 100644 --- a/Engine/src/Renderer/Passes/ShadowPass.cpp +++ b/Engine/src/Renderer/Passes/ShadowPass.cpp @@ -101,7 +101,7 @@ namespace Engine::Passes &m_Frame.ubo.lightSpace[c]); for (const auto& batch : m_Frame.shadowCascades[c].batches) { - batch.mesh->Draw(cmd, batch.count, batch.first); + batch.mesh->Draw(cmd, batch.count, batch.first, batch.lod); } cmd.endRendering(); diff --git a/Engine/src/Renderer/SceneRenderer.cpp b/Engine/src/Renderer/SceneRenderer.cpp index 1416f23..31d23a0 100644 --- a/Engine/src/Renderer/SceneRenderer.cpp +++ b/Engine/src/Renderer/SceneRenderer.cpp @@ -297,7 +297,19 @@ namespace Engine glm::vec3(t.World() * glm::vec4(bounds.center, 1.0f)); const f32 worldRadius = bounds.radius * worldScale; - auto tryAppend = [&](ViewScratch& s, const Frustum& frustum) { + // LOD 选级：屏占比近似 = radius/距离（主视图按实例距离； + // 阈值 10/20 倍半径，可调） + const f32 dist = + glm::length(worldCenter - camTransform->GetPosition()); + u32 mainLod = 0; + if (dist >= worldRadius * 20.0f) { + mainLod = 2; + } else if (dist >= worldRadius * 10.0f) { + mainLod = 1; + } + + auto tryAppend = [&](ViewScratch& s, const Frustum& frustum, + u32 lod) { if (!frustum.IntersectsSphere(worldCenter, worldRadius)) { return; } @@ -309,10 +321,12 @@ namespace Engine // 单实体时两序号恰好恒等，多实体共享 mesh 后分叉 // → batches[worldsIdx] 越界）。batch.first（GPU // firstInstance 基址）才是 worlds 索引，语义别混 + const u64 key = + (reinterpret_cast(mesh.get()) << 8) | lod; const auto [it, inserted] = s.lookup.emplace( - mesh.get(), static_cast(s.result.batches.size())); + key, static_cast(s.result.batches.size())); if (inserted) { - s.result.batches.push_back({mesh.get(), 0, 0}); + s.result.batches.push_back({mesh.get(), 0, 0, lod}); s.batchWorlds.emplace_back(); s.batchPrevWorlds.emplace_back(); } @@ -326,9 +340,12 @@ namespace Engine ++totalInstances; }; - tryAppend(m_MainScratch, mainFrustum); + tryAppend(m_MainScratch, mainFrustum, mainLod); for (u32 c = 0; c < kMaxCascades; ++c) { - tryAppend(m_CascScratch[c], cascFrustum[c]); + // 级联降级：越远的级联覆盖范围越大，用越低的 LOD + //（阴影本来就是低频信息，误差可接受） + tryAppend(m_CascScratch[c], cascFrustum[c], + std::min(c, kMeshLodCount - 1)); } } });