hokay, so people have asked me to do a tutorial on downloading real world terrain (like Mt St Helens or Mt Shasta or you name it) like google has. Well, weeks of research and a few bottles of soda later, I got it. Many of the tutorials on this are unclear and none of them go into how to get it into Blender. We will be using DEMs from USGS and Terragen and 3DEM. There’s a simpler way to do it with Vue, but it’s not free. BTW this is not a formal tutorial (I dont like formality) :).
So What is a DEM?
A DEM is a Digital Elevation Map; it is elevation data.
How Long Will This Take Me?
It depends on how much land you would like to mess with. More land means more time. One chunk of land would be around 5-10 minutes once you’ve got this down.
What Do I Need?
- 3DEM - What we use to convert the DEM to a Terragen file.
- Terragen (old) - What we use to convert the Terragen file to an lwo.
- Windows - cuz its awesome (and cuz 3DEM only works on windows)
- Blender - cuz it pwns dawg
- A Brain - For me to eat
Will You Take me to Your Leader?
Sorry. I can’t do that. Ton said no.
What do I do Now?
Step 1: USGS Seamless
First we need to start by actually downloading the DEMs. Sorry no DEM fairy, this is all manual work. Do this by going to the seamless USGS website. Hit “View and Download United States Data.” You can also get international data, but it’s poor quality and they won’t always have something for you. To the right are all the tools, but only two of them are necessary. With the default tool, click and drag a box around the area to zoom into, keep a Google Maps tab open for area reference, and use landmarks to judge where you are going. I’ll get Mt Shasta. In all screenshots, because I’m too lazy to download Gadwin and because PrintScreen doesn’t capture the mouse, the mouse will be represented by a white circle.
Now zoom in more. It’s OK if it takes a while for each zoom, its slow.
This is at the top of California
Now you have a nice image of Mt Shasta, and you can see the erosion and detail quite nicely. Now we can start downloading. To the right, click on the Download Tab, then under Elevation, uncheck all then check 1/3" NED. The higher the denominator, the higher the resolution, but 1/9" NED is not available here.
Here you can also download sattelite images under Orthioimagery, but the quality isn’t to die for, and I don’t need it.
Now that we have our parameters set, let’s start downloading! To the left, hit the icon of the black mouse inside a dotted square (). For people getting international data, scroll down. Now draw a box around the desired location. If the box is green, you download area is small enough for download. Once it becomes red, it is too big.
This is good enough for me. Now when you let go a popup will appear, showing white boxes on the left, and random shtuff to the right. You may have more than one box, they are just chunks of the Earth. At the toip, hit “Modify Data Request”
In the new thingo, just wait a few seconds for the unneeded download parts to automatically collapse. Now, next to the checked box, click on the ArcGRID dropdown, change it to GeoTiff, this is necessary because 3DEM does not support ArcGRID.
Scroll down and hit “Save Changes & Return to Summary,” though you might want to change the “Maximum size (MB) per piece” to 250 for best quality :D. Now either you have more or less chunks of data. I went from 2 to 1, but for the sake of the people who have more than one peice, I’ve gone back and redrawn my download area (so now I has da 4 chunks). Now, next to the first chunk, click download. Another window will pop up.
Now go do something else, like stare at a wall (my favorite pastime), as the servers calculate your queue. When it’s done, download the zip file and unpack it, the servers are fast so the download should go quickly, 130 mb for me took 2 min. Create a new folder, and in the unpacked one, find the TIFF file and put it inot the new folder. Keep doing this until you have one folder full of TIFF files.
PS If you are downloading international data, you’ll want to switch to the icon with the arrow inside two squares, and in the dropdown select a “(World)” template. Why? Because the box dragging thing won’t always return a result, but this will, though there will usually be empty patches of no data in your queue.
Step 2: 3DEM - Multiple TIFFs
If you have one TIFF, go ahead and skip to Step 2: 3DEM - Single TIFF.
Now that you have these files, how will you get them into Blender? Well first we have to go through a few loopholes. Start up 3DEM, and in the opening dialog, hit the GeoTiff DEM bullet, then click OK. Now browse to the folder of TIFFs and select the first TIFF and click Open. 3DEM will to some cool stuff then you’ll have a shaded relief of that chunk of land.
Skip this part of the step for now (marked by the horizontal lines), if merging does not work properly (it says the maps are different projections) come back and do this part. Go to Operation>Change Projection>Convert to UTM Projection and hit NAD83, if not already on it, then clickity the OK. The reason for this is that if all the chunks have different projections, 3DEM can’t merge them later.
Now go ahead and go to File>Save USGS ASCII DEM and save it into a new folder. Call it ‘1’.
Go to File>Load Terrain model and do the same thing again, naming each new dem file .objectLastCreated + 1, until you have a folder of DEMs going from 1-numberofchunks, so for me it’s 1-4. You can go ahead and delete the old TIFFs to save space.
Now still in 3DEM, go to File>Load Terrain Model and hit the USGS DEM bullet then click OK. Now browse to the folder of all the DEMs you just created and select them all, then hit Open.
Then 3DEM will merge all of your maps together. Well why couldn’t we just multiselect the GeoTiffs and load those in, rather than converting them all to USGS DEM? Because 3DEM won’t let us select more than one TIFF file. Now 3DEM will automatically merge these files. You may have seams in some areas, but these can be fixed later in Blender with the sculpt tool by using Smooth or Flatten. In my case I have FAT seam through the middle of Mt Shasta, this can be fixed with some work, or I could go back and change the projections and hope it turns out better. This happened to me becuase merging did not work, the projections were different, so I had to convert all the projections to NAD83 first which screwed it up.
Now go to File>SaveTerragen Terrain>Entire Terrain, then save it somewhere :D. You can now delete the old DEMs if you like.
Step 2: 3DEM - Single TIFF
Sorry, we hate you because you’re let off easy, not having to do extra steps, so I can’t provide images to you in order to bring you down to our level of misery.
Open up 3DEM and hit the GeoTiff bullet, and click OK, then browse to find your Geotiff. Now go to File>SaveTerragen Terrain>Entire Terrain. Now ur done ya little easy ass worker. Now you have to go here: link
Step 3: Terragen
Start up Terragen. In the default Landscape window, click Open.
Go ahead to ‘Size’ and choose 513, 257, or 129, based on what you want. Now go to Export and go to Lightwave 3D Object(s) then hit Select File and Save.
Finally, save it somwhere. You are done in Terragen now (unless you want to add color settings then render top view Ortho full size for a UV map).
Step 4: Blendah
Open up the awesomeness that is Blender. Delete the default cubey. Now go to File>Import>LightWave(lwo) and look for the terrain file. Import it, and viola! You got a real world terrain! If you have ANY questions or comments please PM me or post below.
The method usingn Vue is a lot better and more reliable, you can check out this PDF: link then export from there, this it what I usually use, but for the sake of the general population, I used Terragen, which has a free version.
Here is the final product (after a bit of fixing up):
Then you can slap on a satellite image if you like.
PS If you are having lots of problems or want a full quality DEM (Terragen free version removes quality when you resize), then PM me and I’ll help you or I’ll convert the DEM to a .blend with Vue.