[Qgis-user] Styling polygon borders: preventing double rendering between polygons

[chris hermansen]

Jorge and List,

On Thu, Jun 11, 2020 at 7:13 AM Jorge Gustavo Rocha <jgr at geomaster.pt>
wrote:

> Thank you for the feedback, Karl and Christoph.
>
> Your work around is valid. It is possible to transform the polygons into
> lines and then render them correctly.
>
> It would be nice to have an option to render only once adjacent polygons,
> with a a common border.
>

In my experience, this is one of many kinds of "cartographic  boundary
weirdness" that would be nice to have, conceptually speaking anyway.

Another is an international boundary that disappears when the ocean is on
one side and land is on the other (the border between Spain and Portugal
symbolized as an international border, but Portugal's and Spain's
coastlines symbolized as shoreline).

Or provincial / state boundaries disappear when one country is on one side
and one is on the other (the border between Portalegre and Castel Branco
shows as provincial border, but the border between Portalegre and
Extremadura shows as national border).

And of course as you say, in no case should the border be symbolized twice.

Regardless of whether the process of this symbolization is manual or
automatic, there is obviously a process of converting polygons to lines,
removal of duplicate lines, then analyzing the entities to the left and
right to determine how to symbolize the line according to some
pre-configured list of priorities.

-- 
Chris Hermansen · clhermansen "at" gmail "dot" com

C'est ma façon de parler.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/qgis-user/attachments/20200611/b3f21e1d/attachment.html>