I'm trying to model the great lakes bathymetric data for a cnc. I'm using Qgis to handle the conversion

The Geotiff was obtained from https://www.ngdc.noaa.gov/mgg/greatlakes/erie.html

using the raster calculator I removed the elevation above 0 ("erie@1" <= 0)*"erie@1"

which gave me Land elevation removed

I've tried using DEMto3d plugin to generate the stl file, but I can't get it to look like the raster in qgis

I have tried increasing the exaggeration factor in the plugin (demto3d) to 10 and even used the raster calculator to exaggerate the the raster file before converting. "erie@1"*100

Any suggestions?

  • i can't seem to get a model (it crashes qgis, but I know this plugin DOES work if you get the settings just right). Have you tried reducing the vertical exaggeration (using raster calc) a lot? Also, you tried the invert terrain option? Also, there are several formats available (e.g. floating point, integer), have you tried one of the other formats?
    – Steven Kay
    May 10, 2017 at 19:24
  • also, if you did manage to produce an stl, can you add a screenshot of what it looks like as a mesh (e.g. from blender or meshlab)?
    – Steven Kay
    May 10, 2017 at 21:02
  • 1
    I previously answered a question related to STL and DEMto3D plugin here: gis.stackexchange.com/a/229242/63384. Check the settings based on this link according to your case, and I hope it can help you solve the issue.
    – ahmadhanb
    May 11, 2017 at 0:56

1 Answer 1


Appreciate the help. I played withe settings in DEMto3D. I was able to get my desired effect. It turned out to be a post qgis error on my part. I was reducing all 3 axis by the same percentages in my CAD software.

After making my z independent, I retained the detail. I also ended up using raster calc to exaggerate the original data by erie1@1*300 and another exaggeration factor of 5 in the DEMto3D

enter image description here.

  • user3049898, did you need to convert all values to positive before the conversion to STL in DEMto3D (i.e., the lowest point in your bathymetry is 0 and the flat area around the lake is in effect an elevated plateau)? I had read that the plugin requires positive values.
    – Dan
    Jun 20, 2019 at 18:03
  • I found that's best to set the lowest point at 1. It just makes it easier when manipulating it in your cad software. Jun 25, 2019 at 0:02
  • Thank you for the tip, will give that a try.
    – Dan
    Jun 25, 2019 at 0:10

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