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conorokane

Wilpena Pound, South Australia

by conorokane Nov 7, 2016
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Great work!!! Can you tell us what did you do to translate SRTM data into a printable model? I did it some time ago with an island in Europe but it wasn't strraightforward... Maybe that ELVIS system in Australia is easier...

I use a program called MicroDEM to extract the heightdata from SRTM GeoTiff files (basically view the elevation as a greyscale, then save the image). ELVIS data is high-resolution and has been cleaned up very well, however MicroDEM can't open it, so I run GDAL Translate on it to convert it to a format that MicroDEM can open. I then use the heightmap to displace a high-resolution plane in 3D Studio Max to make the printable model.

That's interesting, thank you for explanation. If I remember correctly, however, GeoTIFF has 8bit heightmap data, so only 256 possible levels of height. I don't like that so much. Does that sound true to you? For that reason I was thinking to write a small program to convert SRTM raw data in something like a STL file. I only have to find the spare time to do it.... :(

Yes that's correct, there's only 256 height levels, and this would be a problem in a 3D render or a video-game where you'd see the steps in the terrain, however when printed, this model is only 100 layers from the lowest height to the top of the mountains (printed at 0.1mm layers) so the height resolution of the image is more than double what the printer can produce. If this was printed at a much larger scale, or on a Resin/STL style printer then you might be able to reach the limits of the image resolution.

For scenes that have a greater height variation, a file format that supports 16-bit greyscale heightmaps would be better.

Here are some images of the raw mesh. You can certainly see the steps in the heightmap, particularly in the flat areas.

http://i.imgur.com/GrMtITZ.jpg

http://i.imgur.com/M9yrR4K.jpg

However they're still higher resolution than a 0.1mm printer so it's good enough. Also, I've added sand to the flat areas in this print, to give them more interesting texture.