AutoCAD Civil 3D General Discussion

AutoCAD Civil 3D General Discussion

*Expert Elite*
Posts: 2,253
Registered: ‎09-04-2006
Message 11 of 14 (245 Views)

Re: Export to DEM

09-18-2013 08:25 AM in reply to: eladkcem

I experienced the same behaviors described in this thread. I submitted a support request and the behavior was confirmed.


After several exchanges with support the issue is being escalated. Here is the final reply I received:


I   am sorry that the DEM files created in Civil 3D do not work correctly when   importing to ESRI products. Having spent the better part of the last 12 years   relying on software to do my work, I know how frustrating it is when   something does not turn out as expected.
  So you are aware, I have been able to recreate in ArcGIS what you have   described. Meaning that no matter what grid size I export to DEM, it comes in   to GIS as a small piece of the surface. This held true all the way down to a   1' grid DEM. I was able to get the whole surface in and correctly located   with a 1' grid DEM. This means that the solution is to create a DEM with a 1'   grid spacing. Ideal or not, it does work, and gives you the desired results   inside ESRI. Note: When preparing to export the DEM, I do have to select   another Coordinate System because the USGS DEM file format does not support   the selected [assigned] Coordinate System. I select from the Projected list   NAD83/Arizona Central.
  All of that said, no matter what size I choose to create the grid, when I   import said DEM back in to Civil 3D, it comes in as the entire surface, and   is located correctly. When I bring in the DEM files to MAP, they also come in   as complete surfaces, even from 5' and larger grids. I even cut the surface   down into 3 rectangular shapes [thinking maybe the surface shape may be   causing some of the grief] and even the smaller pieces came in as partial,   except when created from a 1' grid. Why is the 1' grid working where the rest   do not when imported to GIS? That is impossible to say, because again, the   issue can only be recreated in an external program. Please see the attached   image. It is a screen capture of the 1' grid DEM described above imported   into GIS.
  From here the best I can do is escalate the case to the Development team.   They will then contact ESRI, and have to come up with a solution between   them. When an issue is escalated to our development team, they have to   perform their own research as to what might be causing the issue as well as   how to fix it. Their schedule is regulated by service pack and new release   timeframes, and the priority for fixing issues is determined by how the fix   impacts other functionality, and the business case for fixing the issue. Here   in Product Support, we are not informed of Development's schedule for fixing   issues such as this one.
  I have added the 1' DEM file I created from your surface data to the FTP. The   file is a little under 800mb. This will save you the time it takes to create   it from C3D. The FTP remains active for up to 30 days, but I would recommend   grabbing it sooner rather than later.
  Because there is a provided workaround, and this case is being escalated to   the Development team, all of the steps moving forward are out of my hands. I will be archiving the case now.


Neil Wilson (a.k.a. neilw)
Infrastructure Suite/C3D 2013, LDT 2004, Power Civil v8i SS1
WIN 7 64 PRO
HP Pavillion h8xt, i7 2600, 12 GB
RADEON 6450, 1 GB
Valued Contributor
Posts: 96
Registered: ‎05-27-2013
Message 12 of 14 (225 Views)

Re: Export to DEM

09-19-2013 07:04 PM in reply to: eladkcem

Don't know how helpful this post will be, considering that it's already been escalated up to the dev team, but I've never had any problems like this when exporting from C3D to ArcGis. I use the metric system all the time; maybe the issue is related with the use of feet? And like mentioned above, I also use the geotif format. I also have issues with the other formats that can be used.

Posts: 3
Registered: ‎11-08-2012
Message 13 of 14 (185 Views)

Re: Export to DEM

09-29-2013 02:42 PM in reply to: Neilw

I have been trying to solve this same riddle for quite some time.  I found a web page that provided an answer at  I proceeded though the steps until I get to the 1st bullet under step 3.  When I try to import the XML file back up pops a dialog box (see Attached).  I accept the default, since there doesn't seem to be anyway to edit it, and import the XML anyway.  When I measure distances from 2 identical locations between files I get the same number giving me the thought that I have not converted units at all. When all is done I am still unable to open in any independent USGS DEM viewers.  I have used 3rd party software to create TINs from XYZ points in a text file to eventually create a DEM that can be opened in the independent USGS DEM viewers but have sacrificed accuracy in the transformation.  To be able to go from C3d to a DEM usable outside of C3d would be the best.

*Expert Elite*
Posts: 1,661
Registered: ‎06-03-2011
Message 14 of 14 (174 Views)

Re: Export to DEM

09-30-2013 04:56 AM in reply to: doogie1959

doogie1959 wrote:

To be able to go from C3d to a DEM usable outside of C3d would be the best.

What happens when you run the _SURFACEEXPORTTODEM command?

You should have both .DEM and Geotiff output: try 'em, then load in Microdem, for instance.

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