2nd/10_Wiki/Topics/Architecture/Procedural-Architecture-Systems.md

id, title, category, status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, verification_status, tags, raw_sources, last_reinforced, github_commit, tech_stack

id	title	category	status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	verification_status	tags	raw_sources	last_reinforced	github_commit	tech_stack
wiki-2026-0508-procedural-architecture-systems	Procedural Architecture Systems	10_Wiki/Topics	verified	self	PCG Architecture Procedural Generation Systems	none	A	0.85	applied	architecture pcg gamedev generation		2026-05-10	pending	language framework cpp unreal-houdini

Procedural Architecture Systems

매 한 줄

"매 building / city 매 hand-author 의 X — 매 rules + grammar + noise 매 generate". 매 No Man's Sky / Minecraft / Townscaper / Houdini 매 production-grade. 매 2026 LLM-driven layout 매 mainstream (e.g. Inworld + procedural blockout).

매 핵심

매 layers

• Macro: 매 city / region — Voronoi, road network, biome.
• Meso: 매 building footprint, lot subdivision (BSP, L-system).
• Micro: 매 facade grammar, room layout, props placement.

매 techniques

• Shape grammars: CGA Shape (Müller 2006) — 매 split, repeat, comp, replace ops.
• Wave Function Collapse: tile constraint solver — 매 Townscaper 매 famous.
• L-systems: 매 organic / fractal (street trees, ivy).
• Noise: Perlin / Simplex / Worley — 매 base terrain.
• Constraint propagation: 매 SAT/CSP for room layout.

매 응용

1. AAA open-world filler (Ubisoft, GTA city blocks).
2. Roguelike dungeon (Spelunky, Hades).
3. ArchViz mass modeling — Houdini PDG.
4. UGC (Roblox, Dreams) — runtime gen.

💻 패턴

Wave Function Collapse (Python)

import numpy as np, random

def wfc(tiles, adjacency, w, h):
    grid = [[set(tiles) for _ in range(w)] for _ in range(h)]
    while any(len(c) > 1 for row in grid for c in row):
        # pick lowest-entropy cell
        x, y = min(((i, j) for i, row in enumerate(grid)
                    for j, c in enumerate(row) if len(c) > 1),
                   key=lambda p: len(grid[p[0]][p[1]]))
        choice = random.choice(list(grid[x][y]))
        grid[x][y] = {choice}
        propagate(grid, adjacency, x, y)
    return [[next(iter(c)) for c in row] for row in grid]

Shape grammar (CGA-style)

def split_facade(rect, rules):
    # axiom: Facade -> Floor*
    floors = subdivide(rect, axis='y', sizes=[3.0, 3.0, 3.0])
    for f in floors:
        windows = subdivide(f, axis='x', sizes=[1.5]*5)
        for w in windows:
            emit_mesh('window_unit', w)

L-system street network

def lsystem(axiom, rules, depth):
    s = axiom
    for _ in range(depth):
        s = ''.join(rules.get(c, c) for c in s)
    return s

# F=forward, +=turn, [=push
streets = lsystem("F", {"F": "F[+F]F[-F]F"}, 4)

Noise-based terrain (GLSL)

float fbm(vec2 p) {
    float v = 0.0, a = 0.5;
    for (int i = 0; i < 6; i++) {
        v += a * snoise(p);
        p *= 2.0; a *= 0.5;
    }
    return v;
}

Houdini PDG-style chunked gen (pseudo)

# Chunk world into tiles, generate independently
for tile in tiles:
    seed = hash((tile.x, tile.z))
    rng = np.random.default_rng(seed)
    buildings = place_buildings(tile, rng)
    export(f"tile_{tile.x}_{tile.z}.usd", buildings)

LLM-augmented blockout (2026)

prompt = f"""Design a {style} village, 12 buildings.
Output JSON: [{{type, x, z, rotation, size}}]"""
plan = json.loads(claude.complete(prompt))
for b in plan:
    spawn_building(b['type'], (b['x'], b['z']), b['rotation'])

매 결정 기준

상황	Approach
매 grid-tile aesthetic	WFC
매 organic city	L-system + agent sim
매 facade detail	Shape grammar (CGA)
매 terrain	Noise + erosion sim
매 narrative-coherent	LLM-driven plan + procedural detail

기본값: 매 hybrid — LLM macro plan + procedural meso/micro.

🔗 Graph

• 부모: Procedural Generation
• Adjacent: Perlin Noise · CSP

🤖 LLM 활용

언제: 매 high-level layout / narrative coherence — LLM 매 plan, procedural 매 detail. 매 prompt-to-blockout (2026 Inworld, Promethean). 언제 X: 매 real-time per-frame gen — LLM latency 너무 김. 매 precompute / edge-cache.

❌ 안티패턴

• Pure noise: 매 visible repetition / no semantic. 매 layered noise + masking 필수.
• No seed control: 매 reproducibility 부재 — debugging hell.
• Monolithic gen: 매 entire world in one pass — chunked / streamable 필요.

🧪 검증 / 중복

• Verified (Müller — CGA Shape 2006; Gumin — WFC 2016; Houdini PDG docs 19.5+).
• 신뢰도 A.

🕓 Changelog

날짜	변경
2026-05-08	Phase 1
2026-05-10	Manual cleanup — full PCG architecture entry