Garment Notation Language: Formal descriptive language for clothing construction

Source: Hacker News

GNL — Garment Notation Language

A formal descriptive language for clothing construction.

Try the live viewer

Dance has Labanotation. Music has staff notation. Architecture has plan/section/elevation conventions. GNL brings the same rigor to garments — a generative descriptive language where a valid expression is sufficient to construct a garment without ambiguity.

Core Concepts

• Body-anchored — the body is the coordinate system, using anatomical landmarks (@shoulder.L) and regions (%torso.front)
• Topological — garments are surfaces with boundaries and openings
• Constructive — descriptions encode build order, not just final form
• Composable — complex garments are compositions of simpler elements

Quick Example

S(sleeve.cap, {front.armhole, back.armhole}, serged)
>> S(front.side, back.side, serged)
>> F(hem, 2.5cm, in)

GARMENT t_shirt [SYM] {
  FABRIC: M(160gsm, fluid, biaxial:15%, 1.0, knit.jersey)

  front  = P(%torso.front, contour, 1.15)
  back   = P(%torso.back, contour, 1.15)
  sleeve = P(%arm[0..0.4], contour, 1.2)

  neck = O(@neck, circle, body+8cm)
  hem  = O(@hip, circle, body+10cm)

  BUILD:
    S(front.shoulder, back.shoulder, serged)
    >> S(sleeve.cap, {front.armhole, back.armhole}, serged)
    >> S(front.side, back.side, serged)
    >> F(hem, 2.5cm, in)
}

Grammar

The language is formally defined as a PEG grammar targeting Peggy. The generated parser produces a richly‑typed AST which is adapted to the renderer’s internal format at runtime.

npm install          # install Peggy (dev dependency only)
npm run generate     # regenerate viewer/src/gnl-parser.js from grammar/gnl.peg
npm test             # run parse + adapter tests against all examples

Viewer

The repo includes a live viewer that parses GNL and renders both assembled garment views and flat pattern pieces.

Assembled View

Write GNL on the left, see the full garment on the right — with stitch lines, dimension callouts, and construction details.

Pattern Pieces

Toggle to “Pieces” to see the individual flat pattern pieces with shape outlines, grain lines, and dimensions.

Korosteleva Dataset Converter

The repo includes a converter that transforms garment templates from the Korosteleva NeurIPS 2021 dataset (2D panel geometry as JSON) into GNL.

# Auto-downloads 21 templates from GitHub on first run, converts all
node converter/convert.js

Four example templates (tee, skirt, pants, dress) are also available directly in the viewer — select from the “Korosteleva Dataset” section of the examples dropdown. A GNL/JSON toggle lets you compare the raw geometric input with the converted semantic output.

See the converter README for details on the mapping approach.

Documentation

• Full Specification — the complete v0.2 spec

Status

v0.2 — Draft. Includes grain parameter, directional ease, princess seams (EDGE), lining (LAYER), and component composition (USE/ATTACH). A starting point that will need refinement through use, critique, and input from garment‑makers, pattern‑drafters, and computational designers.

License

All rights reserved.