I append two images of the same shapefile which contains a single polygon with several "lakes". In SAGA it displays correctly with all the lakes as transparent but in QGIS the larger lakes contain the colour fill.

Is there something I'm not doing correctly in QGIS 2.6.1, or is there an option for changing the way it imports a polygon?

  • QGIS

QGIS polygon

  • SAGA

SAGA polygon

  • I would run Check Geometry Validity on the file in QGIS and see what pops up. It's come up a few times on here that a shapefile can have errors that one program will ignore but another won't. For instance if those two lakes are supposed to be holes that don't touch anything else, perhaps the shapefile has the coordinates for them listed in the wrong direction - meaning they'd read as shapes, not holes. Or there might be stacked vertices or some other invalid geometry about those two holes that QGIS doesn't like. Running it through ogr2ogr is also frequently suggested. – Chris W Jan 29 '15 at 21:46

If it may be a rendering problem, try unchecking the "Simplify geometry" in Layer properties > Rendering.

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