topic Re: Contour lines in AutoCAD in AutoCAD Forum

Contour lines in AutoCAD

Anonymous — Fri, 10 Mar 2017 04:15:52 GMT

I would like to bring USGS contour lines (10' intervals) into AutoCAD. How can I do this?

I have done it before, but in a convulted fashion. I believe I created a PDF file of the contour lines, then used a PDF to DXF conversion software to convert it to a AutoCAD file, and then imported and superimposed those lines onto my drawing.

Unfortunately, I don't seem to remember the exact conversion software, and think there must be an easier way.

How can I import USGS contour lines into AutoCAD 2017?

Re: Contour lines in AutoCAD

gotphish001 — Fri, 10 Mar 2017 13:16:58 GMT

I'm using ACA but the same should work for plain autocad. I've never used the USGS maps though since my workflow is just for prelim studies of a project so they don't need to be perfect. We then sub out to a consultant that does the more precise surveys. I use sketch up to make the contours and then export them as a dwg file that I can drop into autocad. I've compared my results with some surveys and they are pretty close. Here's a video explaining how. A suggested tip: when you grab the region in sketch up from the map, grab a much bigger area than you need like 50% bigger. When I don't do this I always end up having to go back and get a bigger swatch and start over. You can always trim off the extra contours that you don't need or whatever. Much easier to get rid of them than wishing you had another 15' of them.

https://www.youtube.com/watch?v=QBzq6xML1qU

Re: Contour lines in AutoCAD

john.vellek — Fri, 10 Mar 2017 16:56:58 GMT

Hi @Anonymous,

I see that you are visiting as a new member. Welcome to the Autodesk Community!

What format are the lines originally? If you can convert to PDF then use the PDFIMPORT inside of AutoCAD 2017 to convert the data back into vector geometry.

Please select the Accept as Solution button if my post solves your issue or answers your question.

Re: Contour lines in AutoCAD

Anonymous — Fri, 10 Mar 2017 17:37:20 GMT

The original format is a picture on a webpage (google maps superimposed with contours). I can make it a pdf but tried a couple converters and they don't convert the jpg data to vector data. I am not sure if I have tried the pdfimport function of AutoCAD 2017 though.

Re: Contour lines in AutoCAD

john.vellek — Fri, 10 Mar 2017 17:55:58 GMT

Hi @Anonymous,

Type ABOUT at the command line and tell me what version you have of AutoCAD. Currently I have 2017 Sp1 (service pack 1). Mine has the PDFIMPORT on the Insert tab.

Do you want to attach a file for me to try?

Re: Contour lines in AutoCAD

Anonymous — Sat, 11 Mar 2017 00:43:29 GMT

I tried PDF import (native in AutoCAD 2017) but that didn't work. Also 2 or 3 converters.

Here is the PDF file that contains the topo lines. I can use other sources too, this is just one example.

Re: Contour lines in AutoCAD

gotphish001 — Mon, 13 Mar 2017 13:04:38 GMT

You need an intern to just trace those contours with a spline.

Re: Contour lines in AutoCAD

john.vellek — Mon, 13 Mar 2017 20:55:18 GMT

HI @Anonymous,

The contours in the map you attached are raster based. This means AutoCAD (and your converters) are not able to convert the raster to vector information.

Since the lines are not very smooth, I doubt any converter will do any more than what you have already tried. Unfortunately, tracing is the solution here.

Please select the Accept as Solution button if my post solves your issue or answers your question.

Re: Contour lines in AutoCAD

john.vellek — Tue, 14 Mar 2017 22:15:01 GMT

HI @Anonymous,

Since your PDF had such poor raster quality a true raster to vector conversion isn't likely to happen. The beauty is that if your topo maps are similar in complexity and size to this one, tracing works well and is pretty quick. I did a trace on this image in about 4 minutes.

Please select the Accept as Solution button if my post solves your issue or answers your question.