Lost samll area - Githubissues

mapbox / tippecanoe

Build vector tilesets from large collections of GeoJSON features.

BSD 2-Clause "Simplified" License

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Lost samll area #966

Closed guyanf closed 1 year ago

guyanf commented 1 year ago

Hi guys: I have a polygon Geojson file, when I create tiles, some small areas were lost. Geojson file : geojson download

command: tippecanoe -Z 17 -z 20 -pC -pf -pk -pt -ab -Q --no-tiny-polygon-reduction -pS --buffer=30 --layer=lmwz --force -o ./data/lmwz_17_20.mbtiles ./data/lmwz_17_20.geojson

picture of Geojson: json_lost_small_area

picture of tiles:

tile_lost_small_area

How can I fix my command?

Thanks a lot. Thomas

e-n-f commented 1 year ago

I think this was a bug in Tippecanoe's polygon area calculations, which could in some circumstances overflow and choose the wrong winding order for a polygon. It has been fixed in the Felt version of Tippecanoe, https://github.com/felt/tippecanoe.

Mapbox:

Felt:

guyanf commented 1 year ago

@e-n-f Hi, thank you. All is OK.

Thomas