mapbox / mapbox/tippecanoe

Multipolygon missing holes

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Description

I took some data and constructed a geojson and used tippecannoe to convert it into vector tiles and visualize it in deckgl. However the holes are missing

here is the result without anything and with the --use-source-polygon-winding tag
![use source polygon winding](https://user-images.githubusercontent.com/66239914/108972816-a6d87700-76be-11eb-97a3-c2db155ec39b.PNG)

here is the result when i used the --reverse-source-polygon-winding tag (the white dots the results, because they are too small)
![reverse source polygon winding](https://user-images.githubusercontent.com/66239914/108972914-c1125500-76be-11eb-90d4-51aab6113f8c.PNG)

here is what that patch should look like as shown using the geojson-vt debug website: http://mapbox.github.io/geojson-vt/debug/
![correct2](https://user-images.githubusercontent.com/66239914/108973148-ff0f7900-76be-11eb-8bb9-57f193cf4d4e.PNG)

and I double checked that part of my geojson with https://geojsonlint.com/
![correct](https://user-images.githubusercontent.com/66239914/108973270-1fd7ce80-76bf-11eb-8adb-800680d3b7aa.PNG)

I have use the geojson_rewind library for python before dumping the geojson

the command I am currently using to generate the mbtiles is:
tippecanoe -z 5 -ae -pf -pk -pg -ps -pS -pn -pt --use-source-polygon-winding --force --read-parallel -o /data/test/{filename}.mbtiles /data/test/{filename}.geojson'

the geojson is attached in the zip file below
[S_NWC_CT_HIMA08_20S55N-80E150E-NR_20210206T000000Z.zip](https://github.com/mapbox/tippecanoe/files/6034549/S_NWC_CT_HIMA08_20S55N-80E150E-NR_20210206T000000Z.zip)

please help thank you

Contributor guide

Open the contributing guide

Research direction

Start by reproducing the reported command with the attached S_NWC_CT_HIMA08_20S55N-80E150E-NR_20210206T000000Z.zip GeoJSON and compare the output with the geojson-vt debug result. Investigate tippecanoe's multipolygon handling with --use-source-polygon-winding and --reverse-source-polygon-winding. Done means the generated vector tiles preserve the polygon holes for this input.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp, python
Domain
computer-graphics, data
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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