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
parent 34b593f734
commit 5bdfb53566
125 changed files with 67608 additions and 29 deletions
@@ -0,0 +1,80 @@
+// This file is part of meshoptimizer library and is distributed under the terms of MIT License.
+// Copyright (C) 2016-2026, by Arseny Kapoulkine (arseny.kapoulkine@gmail.com)
+export type SimplifierFlags = 'LockBorder' | 'Sparse' | 'ErrorAbsolute' | 'Prune' | 'Regularize' | 'Permissive' | 'RegularizeLight' | 'PreserveFolds' | 'ErrorClamped';
+export type RemesherFlags = 'Thicken' | 'Shell' | 'Solve';
+
+/** @deprecated Use SimplifierFlags instead. */
+export type Flags = SimplifierFlags;
+
+export const MeshoptSimplifier: {
+	supported: boolean;
+	ready: Promise<void>;
+
+	compactMesh: (indices: Uint32Array) => [Uint32Array, number];
+	generatePositionRemap: (vertex_positions: Float32Array, vertex_positions_stride: number) => Uint32Array;
+
+	simplify: (
+		indices: Uint32Array,
+		vertex_positions: Float32Array,
+		vertex_positions_stride: number,
+		target_index_count: number,
+		target_error: number,
+		flags?: SimplifierFlags[]
+	) => [Uint32Array, number];
+
+	simplifyWithAttributes: (
+		indices: Uint32Array,
+		vertex_positions: Float32Array,
+		vertex_positions_stride: number,
+		vertex_attributes: Float32Array,
+		vertex_attributes_stride: number,
+		attribute_weights: number[],
+		vertex_lock: Uint8Array | null,
+		target_index_count: number,
+		target_error: number,
+		flags?: SimplifierFlags[]
+	) => [Uint32Array, number];
+
+	simplifyWithUpdate: (
+		indices: Uint32Array,
+		vertex_positions: Float32Array,
+		vertex_positions_stride: number,
+		vertex_attributes: Float32Array,
+		vertex_attributes_stride: number,
+		attribute_weights: number[],
+		vertex_lock: Uint8Array | null,
+		target_index_count: number,
+		target_error: number,
+		flags?: SimplifierFlags[]
+	) => [number, number];
+
+	simplifySloppy: (
+		indices: Uint32Array,
+		vertex_positions: Float32Array,
+		vertex_positions_stride: number,
+		vertex_lock: Uint8Array | null,
+		target_index_count: number,
+		target_error: number
+	) => [Uint32Array, number];
+
+	getScale: (vertex_positions: Float32Array, vertex_positions_stride: number) => number;
+
+	simplifyPoints: (
+		vertex_positions: Float32Array,
+		vertex_positions_stride: number,
+		target_vertex_count: number,
+		vertex_colors?: Float32Array,
+		vertex_colors_stride?: number,
+		color_weight?: number
+	) => Uint32Array;
+
+	simplifyPrune: (indices: Uint32Array, vertex_positions: Float32Array, vertex_positions_stride: number, target_error: number) => Uint32Array;
+
+	remesh: (
+		indices: Uint32Array,
+		vertex_positions: Float32Array,
+		vertex_positions_stride: number,
+		resolution: number,
+		flags?: RemesherFlags[]
+	) => Float32Array;
+};