Hi,

  *   The main question is why...
Those who have written the DXF driver (Frank Warmerdam, Alan Thomas, Even 
Rouault...) may know why but I guess that that their client did not have 
multipoints in their data, or they were not willing to pay for something that 
they do not need. Multipoints are not so common in GIS. Open Source tends to 
work so that a developer writes something that is good enough for their own, or 
their customers' needs. Then they put the results available for others, who may 
find the code usable.

-Jukka Rahkonen-

Lähettäjä: Michał Kowalczuk <michkowalc...@gmail.com>
Lähetetty: torstai 16. tammikuuta 2025 10.11
Vastaanottaja: Rahkonen Jukka <jukka.rahko...@maanmittauslaitos.fi>
Kopio: gdal-dev@lists.osgeo.org
Aihe: Re: [gdal-dev] DXF MLTIPOINT

Thank you, Jukka.
I saw this post. The main question is why the DXF driver implementation can 
explode MultiPolylines and MultiPolygons (which is more complex) and MultiPoint 
not?

Michał Kowalczuk

czw., 16 sty 2025 o 08:24 Rahkonen Jukka 
<jukka.rahko...@maanmittauslaitos.fi<mailto:jukka.rahko...@maanmittauslaitos.fi>>
 napisał(a):
Hi,

By this gis.stackexchange answer 
https://gis.stackexchange.com/questions/336804/export-to-dxf-from-multipoint-z-geometry-in-postgresql-using-ogr2ogr
 the main issue is in the DXF format that does not support MultiPoints. Try the 
workaround and explode your multipoints.
About why it is allowed to create a geometry type that is not supported by the 
driver, I do not know if the validity of the geometry type is checked 
https://gdal.org/en/stable/api/python/raster_api.html#osgeo.gdal.Dataset.CreateLayer
 of if it up to user to know that, or if DXF is a special case.

-Jukka Rahkonen-

Lähettäjä: gdal-dev 
<gdal-dev-boun...@lists.osgeo.org<mailto:gdal-dev-boun...@lists.osgeo.org>> 
Puolesta Michal Kowalczuk via gdal-dev
Lähetetty: torstai 16. tammikuuta 2025 8.56
Vastaanottaja: gdal-dev@lists.osgeo.org<mailto:gdal-dev@lists.osgeo.org>
Aihe: [gdal-dev] DXF MLTIPOINT


HUOM! Viesti on saapunut ulkopuolisesta osoitteesta. Älä avaa viestin linkkejä 
tai liitteitä, jos et tunnista lähettäjää.

Hi,
Does anyone know why DXF driver supports writing MutiLine and Multipolygon 
(make automatic conversion) but MultiPoint is not...?
If so, why layer creation (GDALDatasetCreateLayer) with this geometry type 
(wkbMultiPoint... family) is allowed and the error occurs only when creating a 
feature on a layer (OGR_L_CreateFeature)?

CPLError: No known way to write feature with geometry 'Multi Point'.

The DXF driver documentation is silent about this type of geometry...

Regards,
Michał Kowalczuk
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