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Pedro P. Palazzo

GIS vs DWG Coordinates mess

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If anyone can give me a hint on what I am doing wrong?

I have a DWG file which I want to georeference in UTM. The CAD file's metric coordinates, as imported into VW, match VW's metric coordinates (considering the particular UTM zone and hemisphere I'm using). I then georeference this layer without transforming geometry, and export it as a shapefile. I open QGIS, set the coordinate system to the same I was using in VW, and import the shapefile. Mess #1: the coordinates in QGIS turn out completely different from those in the VW file, and a site in the southern hemisphere ends up in the North Sea!

Now I get a shapefile generated in ArcMap, which opens with the correct coordinates in QGIS. I set VW's coordinate system to match that of the GIS, and import the shapefile. Mess #2: the coordinates again turn out all wrong.

Is this behavior somehow supposed to make sense?

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Just a quick thought... when you set the GIS coordinates in VW, are you setting it for the specific design layers? Setting the Georeferencing in Document Prefs does NOT automatically apply that to the design layers.

You probably already know that... just a thought.

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Yes? My current results are:

-Exporting shapefile from Mess #2 (which was in WGS84) back into GIS: coordinates are right again. Reimporting this shapefile back into VW will only line up with the previous import if I manually set the layer to WGS84. Using the shapefile's .prj (even if it was set to WGS84 to begin with) will not line up.

-georeferencing my CAD layer from Mess #1 will not line it up with the shapefile's coordinates, whether I transform the geometry or not.

I can see some consistency in the shapefile import/export behavior, but I can't seem to understand why Vectorworks will not use the UTM metric coordinates when positioning the shapefiles. That is, if I have a shapefile projected in UTM/WGS84, GIS will correctly give me *both* the metric coordinates for my current zone/hemisphere *and* the latitude/longitude. On the other hand, Vectorworks' coordinate system, which is only metric as far as I can see, does not match the actual UTM metric coordinates at all.

A concrete example: I have a point with UTM coordinates 211,800 x 8,274,000 in the 23S zone. In the CAD file I imported first, this point has proper coordinates x=211,800, y=8,274,000, and so it is imported into VW with the same coordinates. When I import the same point from a shapefile (which was displaing the correct coordinates in GIS), however, VW shows this point as being near x=(-5,909,088) and y=(-1,725,144). I suppose this is relative to a "world origin" at latitude=0 and longitude=0, however it is very counterintuitive.

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hi

i have had this problem before. i am in the uk and generally use OSGB36 co-ordinates. i came across this problem when someone sent me WGS84 co-ordinates and i tried to put them into VW, and it put things in the wrong place. the way i got round it was to convert WGS84 to OSGB36.

someone may be able to shed some light on why this is.........

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VW has always had problems with georeferenced coordinates as well as UTM my guess is that they are not using fully complaint WGS-84 G1150 datum parameters.

I guess if VW would have implemented a tool with Esri similar to ArcGIS for AutoCAD all these shapefile import/export would be transparent to us users...

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I have suffered this project georeferencing settings that are not included in the design layers which I dont get the rationale for this crazy concept? I am doing a georeferenced project EVERYTHING has to be georeferenced! HELLO VW?

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