Router for 3D building game mechanics in Three.js. Use when creating survival games, sandbox builders, base builders, or any game with player-constructed structures. Routes to 9 specialized skills for performance, physics, multiplayer, terrain, decay, UX, platform support, and design reference. Start here for building mechanics projects.
Resources
2Install
npx skillscat add bbeierle12/skill-mcp-claude/building-router Install via the SkillsCat registry.
The building-router skill directs developers to appropriate specialized modules for constructing 3D structures in Three.js, handling performance, physics, networking, terrain, decay, UX, platform support, and design reference. It resolves the challenge of selecting and integrating the correct mechanics for survival, sandbox, or base‑building games, and should be used when starting a project that requires player‑built structures.
Building Mechanics Router
Routes to 9 specialized skills based on game requirements.
Routing Protocol
- Classify — Single/multiplayer + scale + core features
- Match — Apply signal matching rules below
- Combine — Most games need 3-5 skills together
- Load — Read matched SKILL.md files before implementation
Quick Route
Tier 1: Core Mechanics
| Need | Skill | Signals |
|---|---|---|
| Spatial queries, collision | performance-at-scale |
slow, lag, optimize, spatial, collision, thousands |
| Stability, damage, collapse | structural-physics |
stability, collapse, support, damage, Fortnite, Rust, Valheim |
| Network sync, prediction | multiplayer-building |
network, multiplayer, sync, server, latency, authoritative |
Tier 2: Enhanced Features
| Need | Skill | Signals |
|---|---|---|
| Slopes, foundations, anchoring | terrain-integration |
slope, terrain, foundation, ground, pillar, heightmap |
| Timer decay, Tool Cupboard | decay-upkeep |
decay, upkeep, maintenance, tool cupboard, abandoned |
| Blueprints, undo/redo, preview | builder-ux |
blueprint, prefab, undo, redo, ghost, preview, selection |
Tier 3: Platform & Reference
| Need | Skill | Signals |
|---|---|---|
| Touch, VR, accessibility | platform-building |
mobile, touch, VR, hand tracking, colorblind |
| Design analysis, trade-offs | case-studies-reference |
how does Fortnite/Rust do, compare games, trade-offs |
Signal Priority
When multiple signals present:
- Multiplayer explicit →
multiplayer-buildingrequired - Scale indicator → >1000 pieces triggers
performance-at-scale - Persistence → Long-running servers trigger
decay-upkeep - Platform constraint → Mobile/VR triggers
platform-building - Default →
structural-physicsalways relevant for building games
Common Combinations
Full Survival (Rust-style, 6 skills)
performance-at-scale → spatial indexing
structural-physics → stability + damage
multiplayer-building → networking
terrain-integration → foundations on slopes
decay-upkeep → Tool Cupboard + upkeep
builder-ux → blueprints + undoBattle Royale Building (2 skills)
performance-at-scale → fast collision
multiplayer-building → low-latency syncSingle-Player Builder (3-4 skills)
structural-physics → stability + damage
terrain-integration → natural terrain
builder-ux → blueprints + undo
performance-at-scale → if >1000 piecesPersistent Server (4 skills)
multiplayer-building → networking
structural-physics → stability
decay-upkeep → automatic cleanup
performance-at-scale → entity managementDecision Table
| Mode | Scale | Terrain | Skills |
|---|---|---|---|
| Single | <1K | Grid | physics + ux |
| Single | <1K | Natural | physics + terrain + ux |
| Single | >1K | Any | performance + physics + ux |
| Multi | Fast | Any | performance + multiplayer |
| Multi | Survival | Any | performance + physics + multiplayer + decay |
| Multi | Persistent | Any | performance + physics + multiplayer + decay + ux |
Integration Order
When combining skills, wire in this sequence:
- Spatial index → Query foundation for all other systems
- Validator → Uses spatial for neighbor/support detection
- Damage → Uses spatial for cascade radius
- Network → Broadcasts all state changes
- Client prediction → Uses local spatial + validator
Fallback
- No scale stated → Ask: "How many pieces expected?"
- Unclear mode → Ask: "Single-player or multiplayer?"
- Generic "building game" → Start with
structural-physics+builder-ux
Reference
See references/integration-guide.md for complete wiring patterns and code examples.