convert

Convert 3D city models between CityJSON, CityJSONSeq, FlatCityBuf, OBJ and CityParquet in the browser and on the command line. Drop a file (or paste a URL), pick the output format, levels of detail and attributes, and download the result. Nothing is uploaded: the conversion runs locally in DuckDB-Wasm with the cityjson DuckDB extension.

Experimental. The extension is under active development; verify results before relying on them. Everything is held in memory, so very large files may not fit.

Command line and library

@cityjson/cjconv is the same conversion as a CLI and Node library:

cjconv delft.city.jsonl delft.fcb --lod 2.2
cjconv info delft.city.jsonl

Development

A pnpm workspace: packages/core (@cityjson/cjconv-core), packages/cjconv (@cityjson/cjconv, the CLI) and apps/web (this website). Requires Vite+ (vp).

vp install
vp exec --filter @cityjson/cjconv-web playwright install chromium   # once, for the browser smoke test
vp run dev                                        # http://localhost:5173/
vp check && vp test                               # lint, types, unit, integration, CLI and browser tests
vp run -r build                                   # pack the npm packages, build the website

Design and architecture: docs/idea.md and docs/cli.md. Working conventions: CLAUDE.md.

Releases

The npm packages are published by the Publish to npm workflow (run it from main, choosing a patch, minor or major bump). The release workflow then creates the matching GitHub release.

Branches

• develop: day-to-day work, push freely. CI runs on every push.
• main: releases. Updated only by merging develop; every push deploys to GitHub Pages.

Data

The test fixture is a subset of the 3DBAG Delft tile (CC BY 4.0).

License

MIT. The vendored DuckDB extensions and duckdb-wasm carry their own (MIT) licenses.