A 3D EMERGENT SAGA demo: The Brimsworth Marketplace — fictional cobblestone Sunday market with 24 stalls + 200+ shoppers and an AGENTIC ECONOMY (real supply, demand, prices). 3 acts: morning bell / market rush / closing chimes. ACT 3 climax: the BREAD CRISIS — Vellum's bakery is the last with bread; donation cart of free apples + kids' choir serenades the market. Like Howl's Moving Castle market scenes meet Notting Hill.
Built with:three.js r0.160 (single file)24 stalls × agentic economy (supply/demand/prices) + 200 shopperslocalStorage Marketplace Saga + shared world state + live news ticker
#threejs#emergent-saga#autoplay
## What this is
A 3D recreation of The Brimsworth Marketplace, a fictional cobblestone Sunday market with 24 stalls, 200+ shoppers, and a REAL AGENTIC ECONOMY. Each stall has supply (limited stock), demand (shopper desire), and price (rises with demand, falls with surplus). Shoppers have budgets + wishlists; vendors have profit goals. As shoppers buy, the stall pile meshes physically shrink, and sold-out red flags raise. 24 stalls arranged in 2 facing rows of 12 around a central fountain and bell tower. 28 director cameras cycle. 236 named entities (24 vendors + 8 town officials + 134 shoppers + 30 name pool + 40 porters). The story is a 3-act emergent narrative. ACT 1 (morning bell): vendors set up stalls, opening pricing. ACT 2 (rising market rush): shoppers haggle, bartering brain panels visible, prices fluctuate, two stalls run out of bread, one stall has surplus apples and slashes price. ACT 3 (climax minute 5-7): the BREAD CRISIS — every stall sold out except Master Vellum's bakery; line forms; Vellum announces last loaves. Denouement: the apple-surplus vendor donates extra to a kids' choir who serenades the market. The AGENTIC PLAN TREE PANEL shows nested vendor goal→sub-goal→action AND shopper goal→wishlist→step→haggle hierarchy. NEURAL ATTENTION GLYPHS render attention channels (looking, gauging, queue tension).
The marketplace *remembers AND broadcasts*. localStorage saves `marketplace_saga_v1` (cycle, act, prices, stock, drama meter) AND reads/writes SHARED WORLD STATE `megaverse_world_state_v1` — rain visibly reduces walking speed by 40%. LIVE NEWS TICKER pushes 8+ beats per cycle; reads foreign multiverse beats; alternates sources. Crossover chyron reads `bake_off_3paths_v1` (Vellum's other appearance!), `eternal_brew_v1`, `multilayer_books_v1`. Each ten-minute reseed runs a new market day.
You don't play it. You watch a real economy unfold. And it broadcasts to every other demo.
## Why this is mind-blowing
The chyron is the secret weapon: "Cycle 4, Act III, minute 5:13 — Vellum's bakery has 4 loaves left. Mrs. Pemberton finishes her haggle (12¢ off — Vellum smiles). The Whitford twins arrive with a donation cart of 200 apples. The kids' choir starts 'When the Lantern Swings.' 73% of shoppers stop walking to listen. Bytes the cat opens one eye." That single line stitches three vendors AND a moment of community uplift in one beat — Master Vellum on the baker-oven close camera with the last 4 loaves visible (drama ladder rung 7 of 8 "bread crisis", recurring cast vellum +1, plan tree shows "secure supply for tomorrow" branch updating, news ticker push: "Vellum's last loaves go to grandmothers and children"), Mrs. Pemberton on the haggle-close camera with her coin purse open and a satisfied tilt of her head (recurring cast pemberton +1, attention glyph from Pemberton to Vellum thick), and the Whitford twins on the choir-arrival close camera with the donation cart wheels squeaking and 200 apples piled high (drama ladder rung 8 of 8 "community uplift", recurring cast whitford +1, news ticker push: "Whitford grandkids donate 200 apples; choir sings"). The mid-cycle twist is the heart: at minute 5, the Whitford twin grandkids spawn a donation cart at the market's edge AND the kids' choir spawns at the bell tower AND ~55% of shoppers freeze in place to listen. Walking speed drops, market pauses, attention glyphs all rotate to face the choir. Tip jars overflow — vendors signal Pemberton with a wink. Multiply that by 236 named entities each with their own brain panels and plan trees, an AGENTIC ECONOMY where supply/demand/prices visibly affect mesh size and behavior, NEURAL ATTENTION GLYPHS visible at all times, SHARED WORLD STATE where rain affects walking speed, a LIVE NEWS TICKER pushing 8+ beats per cycle, an explicit 3-act narrative with bread-crisis climax, and a community-uplift mid-cycle twist that genuinely earns its emergent-saga scope, and you've got a Howl's-Moving-Castle-meets-Notting-Hill stream that nobody else has built. ALL FICTIONAL.
Prompt
Build a single-file HTML page that recreates "a fictional cozy cobblestone Sunday marketplace with a real agentic economy and a 3-act bread-crisis narrative" as a continuous 3D autoplay world with AGENTIC PLAN TREES + NEURAL ATTENTION GLYPHS + SHARED WORLD STATE + LIVE NEWS TICKER.
CONCEPT: BRIMSWORTH MARKETPLACE — Howl's-Moving-Castle-meets-Notting-Hill tone.
Hard constraints:
- One HTML file, < 200KB.
- three.js r0.160.0 from unpkg, IIFE strict, reseed every ~10 min.
- First body line: <!-- ROUND20_SAGA v1 -->
- localStorage `marketplace_saga_v1`.
All R16+R17+R18+R19 spec retained. R20 NEW:
1. AGENTIC PLAN TREE PANEL — vendor + shopper plans
2. NEURAL ATTENTION GLYPHS — ATTN channel
3. SHARED WORLD STATE — rain affects walking speed
4. LIVE NEWS TICKER — push/read megaverse_news_v1
5. 3-ACT NARRATIVE — bread crisis climax
6. 25+ director cameras
7. 200+ named (here 236)
8. MID-CYCLE TWIST at 5min — donation cart + kids' choir
Tone: COZY market. ALL FICTIONAL.
Paste this into Claude, Cursor, or Copilot. Change one thing that matters to you.
What I learned shipping it
How to simulate a real agentic economy (supply/demand/prices) with visible mesh shrinkage as stock sells
How to make weather affect agent behavior (rain → 40% walking speed reduction)
How to do a community-uplift mid-cycle twist (donation cart + kids' choir) instead of a generic plot twist