simplification-and-generalization SKILL.md skillA
simplification-and-generalization 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/simplification-and-generalization@git:20261026.79a684ePins git:20261026.79a684e 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/simplification-and-generalization/SKILL.md- Versions recorded
- 1
- Latest version
- git:20261026.79a684e, committed Oct 26, 2026
- Size
- 36,488 bytes
- Repository stars
- 24
- License
- GPL-3.0
How 28 map engines reduce geometry for the scale it is drawn at (Douglas-Peucker, Visvalingam ranks, snap-to-grid, 1-pixel filters, shared-arc simplification, per-zoom levels, dropping small features) and what they measured and reverted. Load it before choosing a simplification tolerance or algorithm in bake.ts, when a request spans several zoom levels and you must decide between one bake, several baked levels or a per-vertex rank, when adjacent polygons (admin areas, choropleths, land cover)…
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
# Simplification and generalisation: tolerance, topology and levels, decided at bake time Source geometry carries far more vertices than a screen can show. Every engine reduces it, and every engine had to answer the same questions: where the reduction runs (data source, tiler, render loop, export), in which coordinate space and with what tolerance, with which algorithm per geometry type, how to keep neighbouring polygons watertight, how many levels of detail to store, and which whole features to drop at a scale. General engines mostly answer at run time, because they cannot know the data or the zoom in advance, and their history is full of tolerances that collapsed polygons, simplifiers that broke shared borders, and caches that made things worse. A renderer here knows its data, its projection and its zoom range at bake time [1], so the reduction runs once in `bake.ts` and the renderer only selects what was baked. What carries over from the engines is the evidence about tolerances, topology, order of operations and the cost of extra levels. Per-engine detail, with all numbers: [references/engines.md](references/engines.md). …
Read the whole file at its exact version.
How to install
mdr add yuiseki/map-from-scratch/simplification-and-generalization@sha256:8fbd8346eff0efb0The line at the top of this page pins the label git:20261026.79a684e, 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_iinnsa23qehns6rg)
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Versions
The registry has recorded 1 version of this file, committed on Oct 26, 2026.
Audit of the latest version
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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_iinnsa23qehns6rg GET https://markdownregistry.com/api/v1/resolve?ref=yuiseki/map-from-scratch/simplification-and-generalization GET https://markdownregistry.com/api/v1/blob/8fbd8346eff0efb03ffaff30977acf0a40945b00722803ad0b67589b2b3783b3
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.