Create Terrain From Digital Elevation

  • August 21, 2012
  • 1,662 Downloads
  • 5 Likes
  • Blender 2.6x
  • Render: Blender Internal
  • Creator: BMF
  • License: CC-0
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Description:

This is a tutorial that will teach you how to create Blender terrain models from digital elevation data downloaded from the Internet.

The URLs to download the free software is included in the tutorial. The software you will need is:

  1. MicroDEM: This free application loads digital elevation data and converts it a gray scale heightmap to be used as the texture in Blender for the displacement modifier. You need this application to complete the tutorial.

  2. GoogleEarth and the srtm41.kmz file: This is optional, but I cover how to use it in the tutorial. This allows you to download the elevation data collected by the Shuttle Radar Topography Mission (SRTM) worldwide. Although it is low resolution data, I find it very useful.

I use actual digital elevation data to create Blender terrains for mountains, volcanos, canyons, deserts, river valleys, beaches, coves, battlefields and other historic palces, and many other uses. ANT is a very good tool in Blender and I use it. However, when you want to create specific terrain models or ones with high resolution without a lot of effort, then digital elevation data is what I prefer.

Using GIMP, Photoshop, or other imaging software, you can, with some practice, edit the heightmaps to add, modify, and delete terrain to meet your needs. Also, you can paint in flat areas to create roads, paths, streams, rivers, etc. But it does take some practice to select the proper gray scales for the desired terrain features.

The tutorial will take you step by step from downloading the elevation data for Mount Saint Helens in Washington State, to loading the data in MicroDEM, converting it to a heightmap, and then using that heightmap in Blender to create a model of Mt. St. Helens.

The preview to the left shows two techniques covered in the tutorial.

The first technique is represented by the red arrows and uses elevation data downloaded from the Internet. In the upper left is the elevation data opened in MicroDEM. The red arrow points to the image on the right that is the data converted to a gray scale heightmap. The red arrow pointing down from the heightmap shows the result you will get in Blender.

The second technique is represented by the yellow arrow in the preview to the left. Using GoogleEarth with the srtm41.kmz file installed select the area to be modeled and download the srtm data directly from GoogleEarth. After processing in MicroDEM, the yellow arrow points to the Blender terrain model of that same area in GoogleEarth.

If you know how to use the displacement modifier, then once you download the digital elevation data file, it will take no more than 5-10 minutes to create a detailed terrain model of actual terrain. If you are new to Blender, then it might take a little longer.

As noted, the software needed is free.

There are four easy steps:

  1. Download the digital elevation data file either directly from the Internet or via GoogleEarth.

  2. Open the file in the MicroDEM software application.

  3. Convert the data to a gray scale heightmap and save it as a GeoTiff file.

  4. Use the GeoTiff file as the texture image in Blender for use in the displace modifier.

Additionally, I show you how to download elevation terrain data for most of the world using GoogleEarth and give you an example of what it will look like in Blender.

GoogleEarth is free and the kmz file that provides access to the SRTM (Shuttle Radar Topography Mission) elevation data is also free and is a no-brainer to install.

It’s simple, it’s easy, and it’s all free.

Once you have the software installed (the GoogleEarth technique is optional), the tutorial shouldn’t take more than about 20 minutes from downloading the data file to producing the Blender model. Once you’ve done it two or three times, I’d be surprised if it took you more than 5-10 minutes after you downloaded your elevation data.

And note that MicroDEM will allow you to merge multiple elevation data files (of the same format) to create terrain models of larger areas.

Comments:

  • InfameDavid profile picture
    InfameDavid

    great topographic resourse... thanks for share!

    Edited August 21, 2012
  • williamsakai profile picture
    williamsakai

    Thanks for nice tutorial!

    Written August 22, 2012
  • formfollowsfunction profile picture
    formfollowsfunction

    Thank you very much!

    Written August 22, 2012
  • greco profile picture
    greco

    nice tutorial

    Written August 22, 2012
  • Jeff2207 profile picture
    Jeff2207

    Very useful, thanks.

    Written August 23, 2012
  • prof-2004 profile picture
    prof-2004

    Woah... just what i needed. Great tut!!!

    ;)

    Ty

    Written August 23, 2012
  • sleepwalker profile picture
    sleepwalker

    This is a technique I've been trying to figure out for a long, long time. Thank you oh so much.

    Written August 23, 2012
  • mramshaw profile picture
    mramshaw

    Works very nicely, thanks for posting this.

    I had problems with formats other than GeoTiff so I'd stick with GeoTiff as a format, MicroDEM happily chews through other types but then puts up an error message at the end (Usually I restart MicroDEM at this point, the problem generally seems to be memory corruption).

    Written September 07, 2012
  • BMF profile picture
    BMF

    Martian, It could be a memory problem since MicroDEM appears to be a project developed at Annopolis by the faculty. In other words, it could have bugs in the code.

    However, I found that if I don't install it in the default directories (i.e., C:/microdem and C:/mapdata) the program throws errors and/or doesn't give expected results. I also found that it is more reliable when you create a working directory on C:/. I use C:/DEM Working. Once I have created my heightmaps there, I move the results to my Blender models directory and finish the project.

    Although MicroDEM will allow you to install it in other directories, which I've tried, it has only worked properly for me when installed at the C:/ root.

    Also, as I mentioned, not all DEM formats are the same. They have evolved over time and MicroDEM will not open some of the older formats. Unfortunately, it's impossible to tell the difference between them unless you open them up in a text editor and know exactly what you are looking for. That's not useful for the average user.

    Also, one commercial application used its own DEM file proprietary format which can only be opened in that application. You can tell just by looking at the file. I run across the older/proprietary .dem formats all the time. But there are very good digital elevations in the other formats so I can usually find a format for the area in which I'm interested.

    A way around the older .dem formats is to open them in another free geospatial application (there are at least four others but they are not as easy to use as MicroDEM for generating heightmaps) that can read it properly and then save it to another format, such as GeoTiff, that MicroDEM can open.

    It requires a couple of extra steps, but it works.

    I've experimented with a number of other digital elevation formats in MicroDEM and haven't experienced any problems yet.

    Also, you can get some improvement in resolution of your terrain in Blender if you increase the resolution of the heightmap in GIMP or Photoshop (better results if you use one of the third party applications such a Blowup 2 by Alien Skin or the PS plug-in by OnOne). and tinker with the contrast.

    Written September 08, 2012
  • mramshaw profile picture
    mramshaw

    Thanks for the feedback, I should have said that DEMs are no problem, it's non-GeoTiff options via the Google Earth route that are my problem (I think these are either ARC ASCII or ARC GRID but in either case they cause me problems that I have not had when working with GeoTiff).

    I did try sharpening as a way of increasing Contrast, not a good idea as it tends to affect edges in a destructive way. I have a developer version of Gimp that will process in 16 bits or even 32 bits, but the normal Gimp uses 8 bits. Something to keep in mind as all of this Geo software usually uses 16 bits for greater precision. Not much of an issue for textures but definitely an issue for height maps.

    Written September 09, 2012
  • BMF profile picture
    BMF

    The SRTM elevation files are .arc format. When opening in MicroDEM, you need to select the ARC ASCII format to create the initial map which you then convert to the gray scale heightmap.

    Then again, maybe I don't understand the problem you are having.

    I import the .arc files all the time into MicroDEM with no problem.

    If you didn't install MicoDEM in the default C: root directory then all bets are off. I've never gotten MicroDEM to work properly if I try to install to anywhere other than the default.

    I'll have to look into the 8/16 bit issue. I haven't noticed any problems in Photoshop CS6 or CS6 just importing the GeoTiff files, adjusting contrast and sharpening and then saving the heightmaps to a jpeg format. I've also tried png format but there isn't any difference that I can tell.

    While I have GIMP and the GIMP Normal plug-in installed and I use it occasionally, I use Photoshop for 98% of my image modification work.

    Personally, I think their capabilities are very similar, but I'm much more familiar with PS.

    I'll do some experimenting to see if I see the same problems and/or if I find a way to achieve better results.

    Thanks for the tips and suggestions.

    Written September 10, 2012
  • Atom profile picture
    Atom

    Note: There is no BLEND file for download, only a PDF.

    Written October 09, 2012
  • BMF profile picture
    BMF

    ATOM, There isn't supposed to be a blend file included. It's a tutorial on how to create realistic terrain by converting digital elevation maps (DEM) to height maps using MicroDEM (free), and then using the height maps as displacement textures for your blender terrain.

    I provided the links to a source DEM file and for MicroDEM so you could experience the entire process from downloading a DEM file to converting into a blender terrain.

    Including a blender file would have significantly increased the size of the tutorial.

    Written November 07, 2012
  • undzie profile picture
    undzie

    thank you :)

    Written February 21, 2013
  • BMF profile picture
    BMF

    You are welcome. There are many useful terrains you can create with this technique. Additionally, you will learn how height maps work and that you can create your own with GIMP by just using black, white, and shades of gray.

    Written February 22, 2013
  • gaztec profile picture
    gaztec

    Wow so cool and useful thanks.

    Written July 01, 2013
  • BMF profile picture
    BMF

    Glad you liked the tutorial.

    Written July 01, 2013
  • DigDug profile picture
    DigDug

    Another method is to import the Google earth map right in Sketch up and export it as an OBJ or 3dxf. then import it into Blender. This works for those of us who have macs and MicroDEM isn't for us.

    Written September 14, 2013
  • BMF profile picture
    BMF

    Great point. I'll give it a try as I'm always looking for simpler/faster ways of doing things in Blender.

    Thanks for the tip.

    BMF

    Edited September 15, 2013
  • blend2cap profile picture
    blend2cap

    I'm the 1000 downloader

    Written May 14, 2015
  • ralphgauer profile picture
    ralphgauer

    Thanks. MicroDem download is now at: http://www.usna.edu/Users/oceano/pguth/website/microdem/microdemdown.htm

    Written August 30, 2015
  • reidh profile picture
    reidh

    Really Great so fa. Thanks For MicroDEM from Prof. Guth

    Written November 03, 2017