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jfukunaga981
619 Vistas, 5 Respuestas

Imported DXF not showing elevation

Hello,

 

I'm totally new to AutoCad. I am practicing a land surveying worflow, and it involves generating some AutoCad files in QGIS. When in QGIS, my generated contours have height or elevation values, but when I load the exported dxf and import into AutoCad, the model is flat, and everything reads as zero. 

 

Anything I seem to find in my searching only yields support of Civil 3D. The courseware I am watching is definitely AutoCad.

 

Any help on this will be hugely appreciated!

 

Best, Jeremy

Patchy
en respuesta a: jfukunaga981
pendean
en respuesta a: jfukunaga981


@jfukunaga981 wrote:

... The courseware I am watching is definitely AutoCad...


Ask the courseware providers/author/presenter for explanations is another solution since you forgot to share a link for the rest of us to watch what you are watching.

jfukunaga981
en respuesta a: Patchy

Thanks for the link. That is pretty much what I had done. Alas...

 

I am assuming there is no setting that turn elevation on and off for contours lines with elevation. I seem to have read that in the other forums for Civil 3D. Also wondering if anyone else can load the file I attached and confirm one way or the other.

 

Thanks again.

ChicagoLooper
en respuesta a: jfukunaga981

Hi @jfukunaga981 

<<....When in QGIS, my generated contours have height or elevation values....>>

 

What format are the contours before they're exported to dxf? Shapefile? I suspect they are shapefile. A contour shapefile will typically have elevation DATA and that's not the same as contours that are ELEVATED.

 

Assuming you have shapefile format, then what you refer to as elevation values are merely numbers contained in the shapefile's database file (dbf). Each individual contour line has:

  1. SHP: Geometry, the vector or the contour line itself.
  2. PRJ: A projection, a geospatial location which is the spot the vector goes to in modelspace.
  3. DBF: The a 'row' in the database file which contains information related to the vector.
  4. SHX: An index which MARRIES the geometry with a certain row in the dbf.

Elevated contours have a Z-value (elevation value) they're elevated and reside at XX feet (or meters) above mean sea level. If you rotate AutoCAD's view cube from TOP to FRONT, you'll see contours where some are higher than others because they're physically sitting at their proper elevation.

 

The contours in a shapefile are not elevated. They do, however, have data indicating their elevation. All shapefile contours, when considered as a group, will use the default Z=0 and sit exactly at sea level. If you use these contours to make a surface it would be flat, unless of course, you leverage the data and raise the contours to their proper elevation.  

 

The green contour lines in the image below began as a shapefile feature class. The shapefile was imported using MAPIMPORT from the Map3D toolset. This import procedure not only converts the vectors from shapefile format to plain vanilla AutoCAD format, it will also 'raise' the contours to their elevation. It raises them using the ALTER PROPERTIES feature because the property ELEVATON, as displayed in the Properties Palette, is altered (or changed) from Z=0 to Z=the ELEVATION stored in the database file.

101.PNG

 

To watch a video that used the Map3D Toolset to generate the green contours above, click >>HERE<<.

BTW, if you're currently dealing with land surveying and plan to stick with it, you can (should) visit the Civil3D forum. you'll get better responses from more qualified forum participants.

 

Chicagolooper

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Pointdump
en respuesta a: jfukunaga981

Hi Jeremy,
It's not possible to get any elevation values from your DXF, except by manually changing the Z of each contour in Properties. If you started with a shapefile in QGIS, then the workflow suggested by @Patchy is the easiest way.
Even if you had elevated contours, Vanilla AutoCAD will limit what you can do with them. Civil 3D is best for working with surfaces.
Dave

Dave Stoll
Las Vegas, Nevada

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