Files
HelloVulkan/Engine/src/Renderer/Model.cpp
T
atdunbg 5bdfb53566 feat: LOD 网格分级——meshopt 解析期简化 + 按距离/级联选级
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)。
2026-09-24 20:53:19 +08:00

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//
// Created by atdunbg on 2026/9/21.
//
#include <Engine/Renderer/Model.h>
#include <Engine/Renderer/Material.h>
#include <Engine/Vulkan/Device.h>
#include <Engine/Vulkan/MemoryAllocator.h>
#include <Engine/Vulkan/DescriptorManager.h>
#include <Engine/Vulkan/Texture.h>
#include <Engine/Core/Log.h>
#include <assimp/Importer.hpp>
#include <assimp/scene.h>
#include <assimp/postprocess.h>
#include <meshoptimizer.h>
#include <filesystem>
#include <algorithm>
namespace Engine {
Model::Model(Device& device, MemoryAllocator& allocator,
DescriptorManager& descriptorManager,
vk::DescriptorSetLayout textureLayout,
const std::string& path)
: Model(device, allocator, descriptorManager, textureLayout)
{
// 同步便捷路径 = 两段式串行(等价异步收割后的主线程消费)
LoadModel(path);
}
// 空模型骨架:只建默认纹理;mesh/材质由 FromParsed 填充
Model::Model(Device& device, MemoryAllocator& allocator,
DescriptorManager& descriptorManager,
vk::DescriptorSetLayout textureLayout)
: m_Device(device)
, m_Allocator(allocator)
, m_DescriptorManager(descriptorManager)
, m_TextureLayout(textureLayout)
{
InitDefaultTextures();
}
Model::~Model() = default;
void Model::InitDefaultTextures()
{
// 各材质槽位的兜底纹理(1x1,开销可忽略):
// 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::Emissive] =
Texture::CreateSolidColor(m_Device, m_Allocator, 0, 0, 0);
m_DefaultTextures[Material::Ao] =
Texture::CreateSolidColor(m_Device, m_Allocator, 255, 255, 255, false);
}
Model::Model(Device& device, MemoryAllocator& allocator,
DescriptorManager& descriptorManager,
vk::DescriptorSetLayout textureLayout,
ProceduralTag, f32 halfSize, const std::array<u8, 3>& color)
: m_Device(device)
, m_Allocator(allocator)
, m_DescriptorManager(descriptorManager)
, m_TextureLayout(textureLayout)
{
// 纯色 1x1 贴图(albedo 兜底)
InitDefaultTextures();
auto tex = Texture::CreateSolidColor(device, allocator, color[0], color[1], color[2]);
// XZ 平面,法线 +Y,从上往下看 CCW 绕序
const f32 h = halfSize;
std::vector<Vertex> vertices = {
{{-h, 0.0f, -h}, {0, 1, 0}, {0.0f, 0.0f}},
{{-h, 0.0f, h}, {0, 1, 0}, {0.0f, 0.0f}},
{{ h, 0.0f, h}, {0, 1, 0}, {0.0f, 0.0f}},
{{ h, 0.0f, -h}, {0, 1, 0}, {0.0f, 0.0f}},
};
const std::vector<u32> indices = {0, 1, 2, 0, 2, 3};
const std::vector<std::vector<u32>> 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<Mesh>(
m_Device, m_Allocator, vertices, lodIndices, mat));
}
Scope<Model> Model::CreatePlane(Device& device, MemoryAllocator& allocator,
DescriptorManager& descriptorManager,
vk::DescriptorSetLayout textureLayout,
f32 halfSize, u8 r, u8 g, u8 b)
{
return Scope<Model>(new Model(device, allocator, descriptorManager,
textureLayout, ProceduralTag{},
halfSize, std::array<u8, 3>{r, g, b}));
}
ParsedModel Model::ParseFromDisk(const std::string& path)
{
ParsedModel out;
out.path = path;
// UV 翻转按格式区分:
// OBJ/FBX —— v 原点在底部,需翻到左上惯例(配合"v=0=图像顶"采样)
// glTF/GLB —— UV 本就是左上原点(v=0=图像顶),翻转会把所有
// 贴图上下颠倒(法线/MR 全反 = 塑料感元凶)
const std::string lower = [&] {
std::string s = path;
std::transform(s.begin(), s.end(), s.begin(),
[](unsigned char c) { return std::tolower(c); });
return s;
}();
out.isGltf = lower.size() >= 5 &&
(lower.rfind(".gltf") == lower.size() - 5 ||
lower.rfind(".glb") == lower.size() - 4);
Assimp::Importer importer;
const aiScene* scene = importer.ReadFile(path,
aiProcess_Triangulate |
(out.isGltf ? 0 : aiProcess_FlipUVs) |
aiProcess_GenSmoothNormals |
aiProcess_CalcTangentSpace | // 法线贴图 TBN
aiProcess_JoinIdenticalVertices);
if (!scene || (scene->mFlags & AI_SCENE_FLAGS_INCOMPLETE) || !scene->mRootNode) {
ENGINE_ERROR("Assimp error: {}", importer.GetErrorString());
return out; // meshes 空 = 无效
}
const std::filesystem::path modelDir =
std::filesystem::path(path).parent_path();
ProcessNode(scene->mRootNode, scene, out.meshes, modelDir, out.isGltf);
ENGINE_INFO("Model parsed: {} ({} meshes)", path, out.meshes.size());
return out;
}
Scope<Model> Model::FromParsed(Device& device, MemoryAllocator& allocator,
DescriptorManager& descriptorManager,
vk::DescriptorSetLayout textureLayout,
ParsedModel&& parsed)
{
if (!parsed.Valid()) {
ENGINE_ERROR("Model::FromParsed: invalid parsed model ({})", parsed.path);
return nullptr;
}
auto model = Scope<Model>(new Model(device, allocator,
descriptorManager, textureLayout));
model->m_ModelPath = parsed.path;
model->m_IsGltf = parsed.isGltf;
// 材质缓存去重 + 纹理上传 + mesh 缓冲(全部 GPU,主线程)
for (auto& pm : parsed.meshes) {
Material* mat = model->GetOrCreateMaterial(pm.texPaths.data(), pm.params);
model->m_Meshes.push_back(CreateScope<Mesh>(
device, allocator, pm.vertices, pm.lods, mat));
}
ENGINE_INFO("Model loaded: {} ({} meshes, {} textures)",
parsed.path, model->m_Meshes.size(), model->m_TextureCache.size());
return model;
}
void Model::LoadModel(const std::string& path)
{
// 同步路径:解析 + GPU 构建串行(与 FromParsed 相同的消费逻辑)
ParsedModel parsed = ParseFromDisk(path);
if (!parsed.Valid()) {
return;
}
m_ModelPath = parsed.path;
m_IsGltf = parsed.isGltf;
for (auto& pm : parsed.meshes) {
Material* mat = GetOrCreateMaterial(pm.texPaths.data(), pm.params);
m_Meshes.push_back(CreateScope<Mesh>(
m_Device, m_Allocator, pm.vertices, pm.lods, mat));
}
ENGINE_INFO("Model loaded: {} ({} meshes, {} textures)",
path, m_Meshes.size(), m_TextureCache.size());
}
void Model::ProcessNode(const aiNode* node, const aiScene* scene,
std::vector<ParsedMesh>& out,
const std::filesystem::path& modelDir, bool isGltf)
{
for (u32 i = 0; i < node->mNumMeshes; ++i) {
aiMesh* mesh = scene->mMeshes[node->mMeshes[i]];
out.push_back(ProcessMesh(mesh, scene, modelDir, isGltf));
}
for (u32 i = 0; i < node->mNumChildren; ++i) {
ProcessNode(node->mChildren[i], scene, out, modelDir, isGltf);
}
}
Texture* Model::GetOrLoadTexture(const std::string& rawPath, bool srgb)
{
// FBX/DCC 导出的路径常带反斜杠(Windows 语义),统一成正斜杠
std::string path = rawPath;
std::replace(path.begin(), path.end(), '\\', '/');
// 缓存键带 sRGB 语义:同一路径可能同时被颜色槽与数据槽引用
std::string key = (srgb ? "s:" : "l:") + path;
auto it = m_TextureCache.find(key);
if (it != m_TextureCache.end()) {
return it->second.get();
}
// 文件不存在则用兜底纹理
if (!std::filesystem::exists(path)) {
ENGINE_WARN("Texture not found, using default: {}", path);
return nullptr;
}
auto tex = CreateScope<Texture>(m_Device, m_Allocator, path, srgb);
Texture* ptr = tex.get();
m_TextureCache.emplace(key, std::move(tex));
return ptr;
}
Material* Model::GetOrCreateMaterial(const std::string paths[Material::kSlotCount],
const MaterialParams& params)
{
const std::string key = Material::MakeCacheKey(paths, params);
if (auto it = m_MaterialCache.find(key); it != m_MaterialCache.end()) {
return it->second.get();
}
// 每槽位解析纹理:空/缺失折到该槽位默认纹理
std::array<Texture*, Material::kSlotCount> textures{};
// 槽位 sRGB 语义:颜色图 true,数据图 false
const bool slotSrgb[Material::kSlotCount] = {true, false, false, true};
for (u32 slot = 0; slot < Material::kSlotCount; ++slot) {
Texture* tex = nullptr;
if (!paths[slot].empty()) {
tex = GetOrLoadTexture(paths[slot], slotSrgb[slot]);
}
textures[slot] = tex ? tex : m_DefaultTextures[slot].get();
}
auto mat = CreateScope<Material>(
m_Device, m_Allocator, m_DescriptorManager, m_TextureLayout,
textures, params);
Material* ptr = mat.get();
m_MaterialCache.emplace(key, std::move(mat));
return ptr;
}
ParsedMesh Model::ProcessMesh(const aiMesh* mesh, const aiScene* scene,
const std::filesystem::path& modelDir,
bool isGltf)
{
ParsedMesh out;
std::vector<Vertex>& vertices = out.vertices;
std::vector<u32> indices;
vertices.reserve(mesh->mNumVertices);
for (u32 i = 0; i < mesh->mNumVertices; ++i) {
Vertex vertex{};
vertex.position = {
mesh->mVertices[i].x,
mesh->mVertices[i].y,
mesh->mVertices[i].z
};
if (mesh->HasNormals()) {
vertex.normal = {
mesh->mNormals[i].x,
mesh->mNormals[i].y,
mesh->mNormals[i].z
};
}
if (mesh->mTextureCoords[0]) {
vertex.uv = {
mesh->mTextureCoords[0][i].x,
mesh->mTextureCoords[0][i].y
};
}
// 切线(法线贴图 TBN;无切线数据置零,shader 侧退回几何法线)
if (mesh->mTangents) {
vertex.tangent = {
mesh->mTangents[i].x,
mesh->mTangents[i].y,
mesh->mTangents[i].z
};
}
vertices.push_back(vertex);
}
for (u32 i = 0; i < mesh->mNumFaces; ++i) {
aiFace face = mesh->mFaces[i];
for (u32 j = 0; j < face.mNumIndices; ++j) {
indices.push_back(face.mIndices[j]);
}
}
// 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) {
const aiMaterial* material = scene->mMaterials[mesh->mMaterialIndex];
// glTF2 贴图在 assimp 5.x 的落点:MR 合图 → METALNESS(15)/
// DIFFUSE_ROUGHNESS(16)(同图双槽);baseColor → BASE_COLOR(12)。
// OBJ:map_Ns → SHININESS(独立 roughness 图)、map_Ka 常绑 AO。
// 先到先得,数组顺序即优先级
const std::pair<aiTextureType, u32> slots[] = {
{aiTextureType_DIFFUSE, Material::Albedo},
{aiTextureType_BASE_COLOR, Material::Albedo},
{aiTextureType_NORMALS, Material::Normal},
{aiTextureType_HEIGHT, Material::Normal}, // OBJ map_Bump 落点
{aiTextureType_METALNESS, Material::MetallicRoughness},
{aiTextureType_DIFFUSE_ROUGHNESS, Material::MetallicRoughness},
{aiTextureType_UNKNOWN, Material::MetallicRoughness},
{aiTextureType_SHININESS, Material::MetallicRoughness},
{aiTextureType_AMBIENT_OCCLUSION, Material::Ao},
{aiTextureType_LIGHTMAP, Material::Ao},
{aiTextureType_AMBIENT, Material::Ao},
{aiTextureType_EMISSIVE, Material::Emissive},
{aiTextureType_EMISSION_COLOR, Material::Emissive},
};
for (const auto& [type, slot] : slots) {
if (!texPaths[slot].empty()) continue; // 高优先级已命中
aiString path;
if (material->GetTexture(type, 0, &path) == AI_SUCCESS &&
path.length > 0) {
texPaths[slot] = (modelDir / path.C_Str()).string();
}
}
// 注:不做文件名探测/自动补槽——资产缺什么就是什么;
// 补槽是将来手动材质编辑的职责,加载期保持确定性
// 材质加载可见性:贴图槽缺失/路径解析错误会静默退化成默认
// 纹理(金属全没 → 塑料感),这里留下诊断锚点
ENGINE_INFO("Material '{}': albedo={} normal={} MR={} emissive={} ao={}",
material->GetName().C_Str(),
texPaths[Material::Albedo].empty() ? "<none>"
: texPaths[Material::Albedo],
texPaths[Material::Normal].empty() ? "<none>"
: texPaths[Material::Normal],
texPaths[Material::MetallicRoughness].empty() ? "<none>"
: texPaths[Material::MetallicRoughness],
texPaths[Material::Emissive].empty() ? "<none>"
: texPaths[Material::Emissive],
texPaths[Material::Ao].empty() ? "<none>"
: texPaths[Material::Ao]);
// 因子按工作流分支:
// glTF2:MR 合图(B=金属度语义),因子按声明(缺省 1/1)
// OBJ:specular 工作流无金属概念 → metallic=0;
// roughness 有独立贴图 → 因子 1(G 通道直达);
// 无贴图 → Blinn-Phong Ns 换算 R=sqrt(2/(Ns+2)),
// 补偿默认 MR 贴图 G=0.5 → 因子 = 2R
if (isGltf) {
ai_real metallic = 1.0f, roughness = 1.0f;
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);
} else {
f32 roughnessFactor = 1.0f;
if (texPaths[Material::MetallicRoughness].empty()) {
ai_real shininess = 10.0f;
material->Get(AI_MATKEY_SHININESS, shininess);
const f32 rough =
std::sqrt(2.0f / (static_cast<f32>(shininess) + 2.0f));
roughnessFactor = 2.0f * glm::clamp(rough, 0.05f, 1.0f);
}
params.factors = glm::vec4(0.0f, roughnessFactor, 0.0f, 0.0f);
}
}
// 材质创建延迟到 GPU 构建段(FromParsed):解析期只留引用
for (u32 slot = 0; slot < Material::kSlotCount; ++slot) {
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<u32> 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;
}
} // namespace Engine