On Mon, Sep 25, 2017 at 8:23 PM, Even Rouault <[email protected]> wrote: > > On lundi 25 septembre 2017 11:04:35 CEST Rich Shepard wrote: > > > On Mon, 25 Sep 2017, Markus Metz wrote: > > > > these multi-surfaces are in the layer with multi-polygons. OGR calls these > > > > geometries multi-surfaces. Investigating a bit more, I found > > > > curve-polygons within these multi-surfaces. Curve-polygons are in turn not > > > > ordinary polygons, but defined by curves, and v.in.ogr (most GIS software > > > > in general) does not support curves. > > > > > > Markus, > > > > > > Thanks for exploring the data files. Please suggest how I could extract > > > the useful polygons and attribute data. I know that agencies assume everyone > > > buys ESRI's software and they're not concerned with accommodating those of > > > us who do not. In the mid-1990s everyone used ESRI's export format (.e00) > > > and it was easy to write input filters for grass back then. > > > You could for example use ogr2ogr to convert the curve geometries to linear ones with > > > ogr2ogr -f sqlite out.db in.gdb -nlt CONVERT_TO_LINEAR > Thanks a lot for this suggestion! How are these curves converted to linear features, i.e. how does ogr2ogr decide on reasonable conversion parameters such as distance between vertices?
Regarding the dataset in question, it would be interesting to know what kind of information is provided with these multi-surfaces, if it is the same as in the multi-polygons or something different. A summary on the OpenFileGDB import issues: NHDmajor.gdb is available at ftp://www.ecy.wa.gov/gis_a/inlandWaters/NHD/NHDmajor.gdb.zip and contains 3 layers 1: NHD_MajorStreams (3D Measured Multi Line String) 2: NHD_MajorAreas (3D Multi Polygon) 3: NHD_MajorWaterbodies (3D Multi Polygon) all are imported just fine with v.in.ogr in=NHDmajor.gdb out=NHDmajor OGR layers are translated to GRASS layers, i.e. features of OGR layer 1: NHD_MajorStreams are in GRASS layer 1, features of OGR layer 2: NHD_MajorAreas are in GRASS layer 2, and features of OGR layer 3: NHD_MajorWaterbodies are in GRASS layer 3. Check with v.category input=NHDmajor option=report 2016WSDACropDistribution.gdb is available at https://agr.wa.gov/PestFert/NatResources/docs/2016WSDACropDistribution.gdb.zip and contains 2 layers 1: WSDACrop_2016 (Multi Polygon) 2: CropData (None) the second layer is, according to OGR, empty, so it might be better to skip it Importing 2016WSDACropDistribution.gdb with v.in.ogr in=2016WSDACropDistribution.gdb layer=WSDACrop_2016 out=2016WSDACropDistribution succeeds if multi-surface geometries are skipped by v.in.ogr (as of trunk r71508). Markus M
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