[Qgis-developer] Anti aliasing issues with no-border at adjacent polygons

[Andreas Neumann]

Hi,

I am forwarding this issue from the QGIS user mailing-list.

When you have adjacent polygons and render them with just fills and no
borders there are rendering artefacts (thin lines shining through from
the white background) coming from anti aliasing.

See http://hub.qgis.org/issues/10984
and the email-thread starting at
http://lists.osgeo.org/pipermail/qgis-user/2014-July/028603.html

I am pretty sure this is an issue of the qt-rendering library. Either
there is a rendering setting that helps to solve the issue or there is
probably not much we can do.

I am pretty sure the problem also disappears if you disable anti aliasing.

This issue was probably already discussed before?

I know that some rendering libraries, such as AGG solved this issue -
see http://www.antigrain.com/screenshots/ and search for "adjacent
polygons" in the text.

Any thoughts?

Andreas