Hi, Only AutoCAD Map3D was a certain comprehension of what a CRS is. To my knowledge all other Autodesk Pilotdo not used any CRS. It is my honest opinion that AutoCAD Map is the worst attempt to make a GIS.
Nicolas Cadieux https://gitlab.com/njacadieux > Le 21 nov. 2021 à 13:52, Bernd Vogelgesang <bernd.vogelges...@gmx.de> a écrit > : > > > On 21.11.21 15:35, Nicolas Cadieux wrote: >> Hi, >> >> .dwg or dxf have no CRS. They can be in inches, feet, mm, cm, m... Usually >> meter in a local CRS like a local WGS84 UTM ZONE is used. You can usually >> find this in the metadata if available. >> >> Nicolas > I have no deep technical insight into dwg or dxf, but I am pretty sure that > those CAD-"products" are able to be produced with valid coordinates, fitting > to a common CRS. Most people using CAD-systems simply seem to be either too > stupid for that, or just do not care. > > One of the reasons, CAD-"data" is produced with a local reference system > instead with a normal CRS is, according to an CAD-operator I once asked about > this, that some CAD-systems just slow down to in-operability when using > real-world coordinates because of the huge numbers, compared to the small > coordinates in their own system. > > So, I would not even try to fix this, but instead ask those guys to stop > scratching their balls and better send you proper real-world data and tell > you which CRS they are in . The handling of this "data" is punishment enough > afterwords. > > Hope my dislike for this "technology" was not too obvious ;) > > Cheers, > > Bernd > > > >> >>> On 2021-11-21 9:07 a.m., Greg Troxel wrote: >>> Boaz Bar Ilan<boazpro...@gmail.com> writes: >>> >>>> i always have problem importing dwg or dxf . the layers dont fit the >>>> coardinations and even when i set the layers crs it doesnt work. >>> I am far from an expert, but recently tried to deal with a dwg. >>> >>> My impression is that they are almost always in local coordinates, and >>> the path to success is something like using GeoScience plugin to define >>> a local CRS based on control points where you know global coordinates >>> and local, and then to use that CRS for the data. >>> >>> I recently imported some "PNEZD" data (csv with point it, northing, >>> easting, vertical, and description, all in an unspecified local grid, >>> from a total station data collector) and used geoscience to align it >>> wtih RTK obsservations of a few points, and things fit quite well. >>> >>> How are you getting dwg? Are you using the proprietary dwg library with >>> gdal, or is there some open source path? >>> >>> _______________________________________________ >>> Qgis-user mailing list >>> Qgis-user@lists.osgeo.org >>> List info:https://lists.osgeo.org/mailman/listinfo/qgis-user >>> Unsubscribe:https://lists.osgeo.org/mailman/listinfo/qgis-user >> >> >> >> _______________________________________________ >> Qgis-user mailing list >> Qgis-user@lists.osgeo.org >> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user >> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
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