Vellum surveys worlds that don't exist and drafts them as atlas
charts. Give it a number, called a seed, and it builds an entire world
from scratch.
First it raises land out of noise: noise layered at several
scales, then pushed and pulled out of shape so the features wander and swirl
instead of repeating in a regular pattern. That distortion is what gives
coastlines their ragged, believable look instead of round, featureless blobs.
Next it runs water downhill until every river finds its way to the sea.
A simple climate of temperature and rainfall decides where forests, deserts, and
tundra grow.
Towns settle where any founder would, near sheltered harbors,
river mouths, and good soil, and roads thread between them by the easiest route,
sharing corridors. Borders follow the lay of the land, tracing ridgelines and
rivers, and carve it into quarrelsome realms. Place names are drawn from ten
invented languages, one per culture.
Then Vellum sits down at the drafting table and draws the maps:
parchment texture, hatched mountain ranges, a compass rose, a sea serpent, a
title cartouche. All of it is reproducible: the same seed always draws exactly
the same world, identical SVG, right down to the last coastline.
Under the hood: a zero-dependency TypeScript engine, using
domain-warped gradient
noise for terrain, priority-flood
hydrology so every river drains to the sea, a
Whittaker-style climate model,
Dijkstra
least-cost roads, and a single seed feeding fork-labeled random streams for
full reproducibility.
Draw your own: read the
README.
