[Qgis-user] Autotrace working?

[Martin Dobias]

Hi Andreas

On Wed, Jun 22, 2016 at 12:42 PM, Neumann, Andreas <a.neumann at carto.net> wrote:
> Hi all,
>
> Thank you all for your ideas.
>
> Meanwhile I found the problem: it doesn't seem to work with data containing
> circular arcs (CurvePolygon, CompoundCurve, etc.). If I load data without
> circular arcs it works fine.

Oh right - the circular arcs are not currently considered in tracing.


> Saber/Martin: could you estimate how much effort it would be to also support
> these geometry types?

A simple solution should be fairly easy, and I can do that within the
bugfixing work, but it would involve segmentation of circular arcs
(for tracing we need to compute intersections of all geometries with
GEOS). A more elaborate solution for the future could be to either use
some heuristics to reconstruct the arcs or do not include arcs in
intersection computation or handle arcs completely separately.

Would it be sufficient solution for you if the segmentation of arcs
was in place?


> I could provide sample data with circular arcs (Geopackage, GML or Postgis
> dump).

That would be useful - thanks!

Cheers
Martin