[gdal-dev] openFileGDB driver - polygons with bezier curves not exporting correctly

[obrl soil]

Even, thanks so much for the rapid fix. I'll test it out once the
OSGeo4W gdal-dev version updates.

Regards
Lauren

On Mon, Dec 4, 2017 at 10:42 PM, Even Rouault
<even.rouault at spatialys.com> wrote:
>> I have been provided with a polygon layer in ESRI FileGDB format
>
>> (created in ArcMap v10.3 at least, maybe 10.4 or 10.4.1). The polygons
>
>> in the layer have been digitised using a mix of straight line segments
>
>> and bezier curves / true arcs, which I've verified in ArcMap by
>
>> looking at the geometry in edit mode.
>
>>
>
>
>
> Lauren,
>
>
>
> Bezier curves have no equivalent representation in Single Feature modelling,
> so they are linearized as small straight segments. Up to now, 100
> intermediate points were used, which in a case like your dataset was indeed
> excessive. I've tweaked the logic in trunk to be smarter (taking into
> account the angular difference between the start and end tangents, and the
> relative length of those tangents vs the direct distance), and now the
> resulting GPKG from the conversion is 9 MB, with after a quick visual check
> is nearly rendered the same as the previous brute force version
>
>
>
> https://trac.osgeo.org/gdal/changeset/40941
>
>
>
> Regarding layer geometry types, given that there will be a mix of
> MultiPolygon and MultiSurface (MultiSurface due to the polygons with
> circular portion), and that this cannot be anticipated before reading the
> layer content, you may want to either add "-nlt MULTISURFACE" (that will
> keep the circular portion as such), or "-nlt MULTIPOLYGON") (to linearize
> everything). On your sample dataset, the difference of size is neglectable:
> 9064448 for the output of -nlt MYLTISURFACE vs 9080832 for the output of
> -nlt MULTIPOLYGON.
>
>
>
> Even
>
>
>
> --
>
> Spatialys - Geospatial professional services
>
> http://www.spatialys.com