polygon-triangulation SKILL.md skillA
polygon-triangulation from yuiseki/map-from-scratch is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add yuiseki/map-from-scratch/polygon-triangulation@git:20261027.231c915Pins git:20261027.231c915 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- yuiseki/map-from-scratch
- Path
.agents/skills/polygon-triangulation/SKILL.md- Versions recorded
- 2
- Latest version
- git:20261027.231c915, committed Oct 27, 2026
- First version recorded
- Oct 26, 2026
- Size
- 27,442 bytes
- Repository stars
- 24
- License
- GPL-3.0
How 33 map engines turn polygons into GPU triangles (earcut at bake or run time, stencil fill instead, ring and hole hygiene, clipping huge polygons, index layout, globe subdivision) and what they tried and reverted. Load it when a map-from-scratch renderer must fill polygons, before writing the triangulation step of bake.ts, when fills show spikes, missing or filled holes, flooded land, slivers or outlines along tile edges, or when choosing between baked triangles, stencil fill and shipping…
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Polygon triangulation: what to bake, what to check, what to skip A filled polygon reaches the GPU either as triangles or as a stencil trick. Triangles need a triangulator that is fast but fragile on real data (duplicate points, touching rings, wrong winding, thousands of holes, rings the size of a continent), and an index buffer whose size and layout cost bytes. Engines spent years on this: they swapped triangulators, capped holes, moved work between threads, shipped pre-built triangles and stopped shipping them. Most of their run-time machinery exists because a general engine cannot trust or pre-process its input. A renderer here can, because it triangulates once in `bake.ts` [1][2]. What still matters is what the engines learnt about input that breaks triangulation, about layout, and about when not to triangulate at all. Per-engine detail, with all numbers: [references/engines.md](references/engines.md). ## Where this repo stands - earcut is the only run-time dependency allowed, vendored at 3.2.4 in `vendor/earcut` [1][4]. Triangulation belongs in `bake.ts` [2]. - `tools/geo.ts` `triangulatePolygon(rings)` drops a repeated closing …
Read the whole file at its exact version.
How to install
mdr add yuiseki/map-from-scratch/polygon-triangulation@sha256:38a18bd811ae0f91The line at the top of this page pins the label git:20261027.231c915, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_ydisjcfwovndjfba)
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Versions
The registry has recorded 2 versions of this file, between Oct 26, 2026 and Oct 27, 2026, more than one a day.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261027.231c915 latest | 2026-10-27 | 231c915 | 27,442 B | A | view · diff |
| git:20261026.79a684e | 2026-10-26 | 79a684e | 27,439 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (27442 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
yuiseki/map-from-scratch · 24 stars · license GPL-3.0 · pushed 2026-11-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_ydisjcfwovndjfba GET https://markdownregistry.com/api/v1/resolve?ref=yuiseki/map-from-scratch/polygon-triangulation GET https://markdownregistry.com/api/v1/blob/38a18bd811ae0f91e972d25bff4abb43e1a9ea6beb2875937addf4a86c061511
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.