Hi,

Just speculating as I do not know how simplification works but I imagine that 
only more complex shapes are being simplified. I also imagine that this 
simplification depends on the zoom level and depends on the total number of 
vertices in a shape therefore some island would not be filled in. I would 
expect multipolygons to exhibit this simplification faster than the polygon 
equivalents because they are more complex.  Depending on how files are being 
exported, some may be exported as polygons or multipolygons depending on file 
formats. This may be what is happening with the FIX Geometries. I imagine 
multiSurface may be treated as a mesh by QGIS??? Meshes have been introduced 
later in QGIS and I suspect it may not use the simplification.  This is pure 
speculation on my part.  

Bug reporting is done here.

https://www.qgis.org/en/site/getinvolved/development/bugreporting.html 

Nicolas

> Le 27 déc. 2019 à 14:43, malcolm <[email protected]> a écrit :
> 
> 
> Maybe a bug report, if so please advise where to submit.
> 
> With simplification turned on, some complex polygons with holes inside get 
> filled when zoomed out. It does not happen to all the holes, only some of 
> them. The fill goes away when zoomed way in say at 1:600 (feet) for some, or 
> 1:50 for others. The layer is a Polygon(MultiPolygon) from Postgres. A view 
> created from this layer (union of many polygons) that gets created as 
> Polygon(MultiSurface) does not suffer from this error.
> 
> A temp layer created from FIX Geometries does not exhibit this error, but 
> when exported to PostGIS and added back to QGIS the error returns.
> 
> -- 
> Malcolm T Meyer
> _______________________________________________
> Qgis-user mailing list
> [email protected]
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
_______________________________________________
Qgis-user mailing list
[email protected]
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Reply via email to