3D Building Mechanics

Complete building system for Three.js games with performance optimization, structural physics, and multiplayer networking.

Quick Start

import { SpatialHashGrid } from './scripts/spatial-hash-grid.js';
import { HeuristicValidator } from './scripts/heuristic-validator.js';

// Spatial indexing for fast queries
const spatialIndex = new SpatialHashGrid(10);
spatialIndex.insert(piece, piece.position);
const nearby = spatialIndex.queryRadius(position, 15);

// Structural validation (Rust/Valheim style)
const validator = new HeuristicValidator({ mode: 'heuristic' });
validator.addPiece(piece);
const canPlace = validator.validatePlacement(newPiece);

Reference Files

Read these for detailed implementation guidance:

• references/performance-at-scale.md - Spatial partitioning, chunk loading, instancing, LOD
• references/structural-physics-advanced.md - Arcade vs heuristic vs realistic physics
• references/multiplayer-networking.md - Authority models, delta sync, conflict resolution

Scripts

Performance (references/performance-at-scale.md)

• scripts/spatial-hash-grid.js - O(1) queries for uniform distribution
• scripts/octree.js - Adaptive queries for clustered bases
• scripts/chunk-manager.js - World streaming for large maps
• scripts/performance-profiler.js - Benchmarking utilities

Structural Physics (references/structural-physics-advanced.md)

• scripts/heuristic-validator.js - Fast validation (Fortnite/Rust/Valheim modes)
• scripts/stability-optimizer.js - Caching and batch updates
• scripts/damage-propagation.js - Damage states, cascading collapse
• scripts/physics-engine-lite.js - Optional realistic physics

Multiplayer (references/multiplayer-networking.md)

• scripts/delta-compression.js - Only send changed state
• scripts/client-prediction.js - Optimistic placement with rollback
• scripts/conflict-resolver.js - Handle simultaneous builds
• scripts/building-network-manager.js - Complete server/client system

Key Patterns

Spatial Indexing Selection

Pieces	Distribution	Use
<1,000	Any	Array
1-5k	Uniform	SpatialHashGrid
1-5k	Clustered	Octree
5k+	Any	ChunkManager + Octree

Physics Mode Selection

• Arcade (Fortnite): Connectivity only, instant collapse, best for combat
• Heuristic (Rust/Valheim): Stability %, predictable, best for survival
• Realistic: Full stress/strain, expensive, best for engineering sims

Multiplayer Pattern

Server-authoritative with client prediction. Use delta compression for sync.