CSV to Vector Tiles: Encoding polygons in Tippecanoe (or some other software)

Question

I want to generate .pdf vector tiles from polygon features. From what I've found out, tippecanoe seems to be the way to go. Like so (found here):

tippecanoe --no-feature-limit --no-tile-size-limit --no-tile-compression --output-to-directory directory layerName.json

I'm pondering the optimal workflow. My data is provided in a database from which I can easily build CSV. Tippecanoe can read CSV but apparently for point features only. However, I need polygons. I could generate the input as a geocsv as specified here with the geometries provided in some way, e. g. as WKT (polygon examples from here).

id   name      attr1     attr2    geom
1    garden1   green     round    POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))
2    garden2   emerald   edgy     POLYGON ((35 10, 45 45, 15 40, 10 20, 35 10), (20 30, 35 35, 30 20, 20 30))

There is a file geojson.cpp in the tippecanoe Github but it doesn't look like it's using this specification and I can't find any documentation for it. So I wonder if there's a way to build vector tiles in tippecanoe (or any other software) without taking the detour of generating GeoJSON first.

Answer 1

Still not sure if that's the optimal workflow to get from CSV to MVT but I ended up using GeoJSON as an intermediate step. This can be done easily with GDAL/ogr2ogr:

CSV (geometry saved in column named geom, in WKT format):

id   name      attr1     attr2    geom
1    garden1   green     round    POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))
2    garden2   emerald   edgy     POLYGON ((35 10, 45 45, 15 40, 10 20, 35 10), (20 30, 35 35, 30 20, 20 30))

CSV → GeoJSON:

ogr2ogr -f GeoJSON output1.json input.csv -oo GEOM_POSSIBLE_NAMES="geom" -oo KEEP_GEOM_COLUMNS=NO

GeoJSON → PBF: (with tippecanoe or, alternatively, with GDAL; the directory of the second output is called output2_directory in my examples)

tippecanoe --zg --output-to-directory output2_directory output1.json
ogr2ogr -f MVT output2_directory output1.json -dsco FORMAT=DIRECTORY -dsco COMPRESS=NO