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Create TIN from contours - what FOSS software?

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#16
Hans van der Maarel

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Sounds interesting, but I couldn't find out yet how you got it done with Global Mapper. I have a similar problem here. Downloaded some E00 files from the British Antarctic Survey into Global Mapper. They show fine there and I also can export them to DXF and see that they contain all altitude information.
Problem here is: SiteTopo can only load very limited amounts of data and crashes with most contour line files from Antarctica. Therefore I would be very interested to know how you converted your lines to a TIN (in the long run I need to get an elevation GeoTiff).


  • Import the data in Global Mapper. Obviously it has to be 3D data.
  • Open the "Overlay Control Center", that's the 4th button from the left, or Tools -> Control Center
  • Right click on the layer name and pick the option "Create Elevation Grid from 3D Data". Go through the options there and make sure it does what you want to do (specifically, you'll want to tick the box that says "Save Triangulation Network (TIN) as a Vector Layer".
  • Hit OK and off it goes.

This will, incidentally, also create an elevation raster, which you could export to GeoTIFF.
Hans van der Maarel - Cartotalk Editor
Red Geographics
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#17
Simmer

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Worked like a dream, thank you! :)

But now I have another problem: The elevation contour lines start at 50 or 100m, so that there is basically nothing at sealevel. Lucky I am that there is also some coastline data in the same format which I could use for the 0m elevation line.

I loaded the elevation countours and the coastline into Global Mapper when creating a new 3D mesh the coastlines are being ignored.

After some search I found out why: The coastlines are missing an altitude attribute called CNT00HGT. You will find this in the elevation file I posted before but won't find it in the coastline file attached.
In the past hours I tried to find out if there are any programs that can add this height attribute the the coastlines but couldn't find any. I also tried it with an Editor but the E00 files I got here are so many and they are so complex that this would take weeks counting in the errors I would have to fix from my editing.

Any ideas?

Bests,
Simmer

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