ticj

ticj is a lightweight browser tool for selecting CityJSON inputs for CJLoupe.

It supports two source types:

• FlatCityBuf .fcb files: reads the header and packed R-tree leaf nodes, renders a quadtree overlay, and builds CJLoupe URLs with compact feature byte ranges.
• FlatGeobuf .fgb tile indexes: reads tile polygons with tile_id, filepath, bounds, and feature_count, then opens the selected tile filepath or selected tile filepaths in CJLoupe.

For remote FlatGeobuf indexes, relative filepath values are resolved against the parent URL of the .fgb file.

Usage

bun install
bun run dev

Then open the URL printed by Vite.

With Nix:

nix develop
bun install
bun run dev

You can also run the flake apps directly:

nix run .#dev
nix run .#build

You can load remote FCB or FGB tile index URLs. Remote FCB files must support CORS and HTTP Range requests. Remote FGB tile indexes must support CORS.

To load an index on startup, pass it as a URL parameter:

https://example.com/ticj/?index=https%3A%2F%2Fexample.com%2Ftile_index.fgb

Build a CityJSONL tile index

bun run index:tiles -- ./seq ./tile_index.fgb --overwrite

With Nix:

nix run . -- ./seq ./tile_index.fgb --overwrite

The indexer is a Node.js script that uses the existing flatgeobuf package, so it does not require GDAL/OGR.