Tiny World Builder

Run

open tiny-world-builder.html
# or serve it
python3 -m http.server 8000

Controls

Action	Input
Place	click a cell
Erase	E then click, or pick the eraser
Orbit	drag
Zoom	scroll wheel
Stack/enhance item	click the same object tool on an existing object (max 8)
Switch tool	1–9, then letter shortcuts shown in the toolbar
Toggle camera	P or I (perspective ⇄ ortho)
Reset to preset	R
Clear to grass	C

Tools

Grass · Path · Dirt · Water · House · Tree · Fence · Rock · Bridge · Crop · Corn · Wheat · Pumpkin · Carrot · Sunflower · Tuft · Erase.

Terrain/object rules are normalized by the renderer: crops force dirt underneath, bridges force water, and ordinary objects do not float on water. Paths, shorelines, water foam, bridges, fences, castle walls, houses, and rocks are adjacency-aware — placing a neighbor re-renders surrounding cells so roads join, rivers get banks, bridge direction updates, fence walls connect, house clusters form L/T/+/square buildings, and rock cells grow into craggy outcrops.

Architecture

Single <script> block, ~1600 lines of vanilla JS, organised by section comments (// -------- xyz --------). The model is split cleanly:

• world[x][z] — intent: { terrain, kind, floors } per cell.
• cellMeshes['x,z'] — rendered Three.js groups for each cell.
• setCell(x, z, opts) — single mutation entry point. Updates world, rebuilds the cell's tile/object meshes, and re-renders any neighbors that care about adjacency (fence/house clusters).

House clusters use BFS (bfsHouseCluster) plus tryComposite (L/T/+) and trySquare to decide whether a group of house cells should render as a unified structure or stretched rectangles.

A shared dropAnims queue ease-outs new tiles/objects into place. Other per-frame animations (tree sway, crop bob, smoke origin) check obj.userData.landing so they yield while a piece is still falling in.

See AGENTS.md for guidance on extending the codebase.

Files

tiny-world-builder.html          the app
tiny-world-builder BACKUP.html   byte-identical snapshot from 2026-05-09
README.md                        this file
AGENTS.md                        guidance for AI coding agents