QGIS: exporting contours to DXF with height values

This might be useful for anyone in who needs to go from analysis (GIS) to construction and CAD (landscape architecture, planning etc).

[@donodony3868]

Great music man, chill and no effensive, really appretiate

[@moizzasaeed5132]

Your tutorial was very helpful, I had bit of a trouble with it understanding and fixing the units

[@maunoaho1689]

Thanks! it really helped me. I just have to add one trivial step in AutoCAD (applies to BricsCAD as well): When you export anything from QGIS (or ArcGIS) to DXF the units in DXF will be inches. This is ridiculous and the first thing in CAD is to change the units to meters. If you skip this and use the DXF file anwhere all the measures and thus also the CRS will be wrong since CAD programs think they are really inches which they never were. If you create a DXF from scratch it will be unitless and usually understood as millimeters.

[@tombuckland4236]

this explains so much

[@moizzasaeed5132]

do we change the units manually or through units tab? can you explain units a bit more please

[@maunoaho1689]

@@moizzasaeed5132 I was speaking about drawing units. Although the AutoCAD I used was configured to ISO i.e. metric drawing units it will consider unitless DXFs having inch as drawing unit. I have not used any specific unit table.

[@maunoaho1689]

@@moizzasaeed5132 Sorry, I misread your question. I' m not using units tab. Since I have originally learnt AutoCAD DOS version 9 in late 80's prefer commands and just enter "units" and select meters.

[@ticoyderek]

In case anyone is interested, the reverse process (DXF->SHP) can be done with Civil 3D using the MAPEXPORT command and specifying to the elevation attributes in the DATA tab. Greetings from Mexico.

[@luminaryaurorae]

I keep coming back to this one, every time - two kung fu steps - blam! yes :) my brain is going

[@theoalliot632]

Thank's! But when I open the DXF in Autocad, all my curves are on Z=0 ... Do you know where it might come from?

[@svvine5803]

I have the same problem. No height values when I import it into my other software. Did you find a fix?

[@robnewell9531]

I had that issue and figured out the fix. On the export to DXF there is Geometry options area. Expand Geometry area and change it from Automatic to Polygons, and then make sure the "Include Z-Dimension" box is checked. Worked for me.

[@praddyban]

@@robnewell9531 Whoa! That little step was the final piece of the puzzle I was looking for! Thank you for posting that!

[@malcolmafonso1353]

@@robnewell9531 this solution saved the day. Thank you.

[@seafravil]

​@@robnewell9531thanks for the info

[@hondaf20b6]

@Quoc Dang once I complete the "import loaded vector" command and my elevation values are gone in the new "contours_vector" layer which probably causes my QGIS to crash the 2d to 3d step.... I have tried both QGIS with GRASS 3.10 and 3.12. Both fail.... Any ideas how to fix this?

[@Math.C.T]

I was struggling with this so much, finally got how to do it. Unfortunately when I click "View output" in 2D to 3D nothing happens and I'm stuck again. Anyone can help?

[@Kangage]

your USGS wrong

[@iStrider]

You are a national hero

[@rickwentworth6842]

I have a large area of contours in a geodatabase and I am trying to only select a small portion of contours to export as DXF. Is there a way to only select contours within a particular area? So far, QGIS selects only those contours that are completely within the selection polygon. I want to select the contours that my polygon touches. Any help would be great.

[@wesleymarinho8475]

Dude, you saved me with it. Thank you very much

[@lemonbomb9972]

after the 2D -> 3D fanction has successfully finished i press "view output" but the layer wont appear, any ideas ?

[@jannydaggs1715]

I had the same issue

[@Math.C.T]

Any solutions?

[@joebrennan648]

As far as I'm aware, GRASS plugin is no longer available through QGIS? Any ideas what to do?

[@quocdang7024]

I'm not aware of this, I haven't upgraded to the latest QGIS. Have you tried posting your question over here gis.stackexchange.com/ ?

[@iHaveContrl]

Joe. GRASS is still available dude. I'm using QGIS version 2.18.9 with GRASS 7.2.1, they are the latest at the moment. I uninstalled my old QGIS version first; I went to GRASS website and installed the GRASS package in a separate directory planet.qgis.org/planet/tag/grass/ and then installed QGIS version 2.18.9 after. When I run the software, I run with the QGIS desktop 2.18.9 with GRASS 7.2.1, then you should be able to search the plugin GRASS7. (or maybe you should be able to search GRASS7 if you are using the latest QGIS version, idk, I just did the long way to hope everything work ok...)

[@benwalters3825]

I recently downloaded qgis and it came with qgis with grass as separate install and I had no idea what it was for until this video ,

[@ticoyderek]

It helped me to download the old version 2.14

[@ActionEcology]

It would be great if you could update this for 2021 now that QGIS has GRASS kinda built in. Thanks!

[@jackierosales3697]

I dont get the option save as, I dont know if this is because its the new QGIS but I cant save it after that.

[@MS-xk1ne]

Open Mapset is greyed out for me so I am unable to click on it. What do you need to do for you to be able to access it? I can't create a new Mapset as this is greyed out also. :/ I have looked online and can't seem to find anything trouble shooting this.

[@rikschoeman6636]

hey, After choosing for import vector with the Grass tool, you have to choose for a loaded layer. How do you make this layer? or Where you make this layer?

[@seyramaguadze6025]

I keep getting "Finished with error". When I get to V to 3D.. and I don't get an output file??

[@antonioandrearq]

I know this is an old post but were can i find tutorial from the begining to make contour lines from a specific site location and extract those curve to CAD. It is possible to extract existent building and roads from surroundings?

[@ninjapancakes9435]

Extremely Helpful!!!!! Thanks

[@rbcadigeotecnologias6960]

Very good, thankyou!

[@1x3lol1x3]

Hi if is it the other way around like i have the DXF and i want to upload it to qgis?

[@ticoyderek]

¡Muchas gracias!

[@evintini8363]

great tutorial, thanks! I am following all steps but when converting to 3d vectors the Column with height values field has only one option (cat) although the attribute table includes the elevation column. Any ideas?

[@alexr4926]

did u find the answer ?

[@ashrafkutty5183]

i got the dxf file out put but the contour limit size is very small in open cad.I think may it should be scaled multiple of thousands.some one could advise me?

[@bowtechbob6]

Awesome! Thank You!

[@benwalters3825]

very useful , cheers !!!!!!!

[@renueenergia9617]

thanks

[@alialhameedi990]

Thank you so much

[@iHaveContrl]

I got an error "Unable to open Data source": (FIXED) When I tried to do the import vector thingy, choice loaded layer (.shp) and when I clicked the "Run", i got an error saying "Unable to open Data source" I'm using QGIS version 2.18.9 with GRASS 7.2.1, they are the latest atm so shouldn't be a problem... is it because of the .shp file?

[@iHaveContrl]

Through an hour investigation, the .shp file you use in QGIS can only be used from a directory of all English letters without any special characters, or an error "Unable to open Data source" will occur, kinda stupid really. I fixed it by moving all my .shp files to my desktop and re-imported into QGIS.

[@pinkivyagr4481]

sir how do we get contour text in cad from qgis

[@benwalters3825]

Hi , I just realised i have a bit of a problem , when I go to convert 2d contour to 3d by attributes- when I look for which attribute to get the elevation data, I am only given 4 options when attribute table contains many more columns including the one i need named "elevation"

[@benwalters3825]

p.s. I just found out what my problem was - elevation column was classed as "string", to fix this I had to make new column and do function see this link - gis.stackexchange.com/questions/75021/convert-string-to-integer-in-qgis-tables/75032

[@JMSculptureDesigns]

please, can you make please a tutorial on how to grab elevations from google earth /and contours from qgis/ into revit, your tutorial is very good but for me it's too complicated...PLEASE i'm trying to import elevations terrain into revit since 2 weeks everyday but revit doesn't no recognize any dwg or dxf, so please HELP me, i never seen in my life something so difficult...please sir help me or show me how to the simple way or a good way explained please, thank you

[@glennkam8797]

Can you please show how to compute volume from Google Earth into QGIS?

[@maxbloki]

How can I change xy scale? scale factor is just right for z, but xy scale is too small!!!

[@quocdang7024]

What program is it too small in, Autocad?

[@maxbloki]

When I export from Qgis the dxf file and then import it into autocad z scale is right, but xy are not!!! thei are too small!!!

[@properrhino]

Massimiliano Blocher I’m facing the same problem, Maybe the solution is in QGIS csr settings . Could you figure out the solution?

[@TheForge10]

Went to find GRASS in the plugins , its not listed.

[@despoinamountogiannaki4832]

hi, same problem, did you find it somehow?

[@iancorrea8472]

same problem i cant find grass in the plugins

[@despoinamountogiannaki4832]

​@@iancorrea8472 there is seperate app in the latest qgis

[@ticoyderek]

It helped me to download the old version 2.14

[@ognjenkralj4012]

My Z is always 0. How to fix it?

[@svvine5803]

I have the same problem. No height values when I import it into my other software. Did you find a fix?

[@ognjenkralj4012]

@@svvine5803 No, i still have that problem.

[@nedpadilah]

thanks