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mbloch / mapshaper

Tools for editing Shapefile, GeoJSON, TopoJSON and CSV files
http://mapshaper.org
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Bug? Multipolygon holes filled by style property fill #492

Open robintschoetschel opened 3 years ago

robintschoetschel commented 3 years ago

Hi there,

thanks for creating this awesome software. Discovering it allowed me to develop a new hobby!

maybe this is an error in use, but I can't seem to be figuring out a fix. I am drawing a map that uses multipolygons to render lakes (from OSM). But in my rendering mapshaper seems to fill in the holes (ie. islands) with the same fill color as the actual multipolygon area? See in the attached screenshot.

The outlines are drawn by the pdf/svg renderer, they appear in the mapshaper gui at less zoom, but disapper when zooming in. Yet, they demonstrate that the multipolygon information is present in the shapefile, and it's a matter of filling/not filling the right elements of the multipolygon shape.

Thank you for your help! Screenshot 2021-06-23 at 11 40 23

mbloch commented 3 years ago

Hi, can you send some sample data that exhibits this behavior, to help me debug it? You could drop the file in a comment here or email it to me directly. thanks :)

robintschoetschel commented 3 years ago

I've sent you an email with a link to a file somewhat smaller than the one I was originally working with. The behaviour reproduces on my end.

maylanng commented 1 year ago

Hi @mbloch , was there a resolution to this possible bug?

mbloch commented 1 year ago

@maylanng It seems that I didn't follow up on this bug report... I also didn't find a sample file in my email history from Robin, to help me reproduce this rendering bug. If you encountered this issue, could you send me a file?

maylanng commented 1 year ago

Thabks! Here's the file QPF168hr_Day1-7_latest.zip

mbloch commented 1 year ago

The original bug report was related to rendering glitches in the GUI affecting multipolygons with holes. As far as I can see, the QPF168hr_Day1-7_latest shapefile is getting rendered correctly in the GUI. The polygons in this file are nested and overlapping, so I added an opacity to help me visualize the polygons using this command: -style fill=black opacity=0.1. The map image looks correct to me, and is stable as I zoom and pan: image

Here's a zoomed-in detail: image

If you think that mapshaper is rendering this layer incorrectly, please attach a screenshot or give me instructions for reproducing the problem.

Cheers, Matt