LiDAR Data to 3D Print
My journey from millions of points of data to a high-fidelity print
Geography has always been of interest to me. My dad’s first job out of college was with Rand McNally and we’d always have atlases & globes laying around the house. It taught me that understanding your location and the history behind it makes for better spacial awareness. This is why I wanted to explore topography when we were tasked this week with producing some kind of physical print.
I was inspired when RJ mentioned that a past student had printed a model of the Boulder Flat Irons. I wanted to take this idea and explore it further. I wanted to start from scratch.
After extensive Googling, I stumbled upon DEM and LiDAR data. LiDAR stands for Light Detection and Ranging and is a form of data that is collected typically via aircraft. The plane sends pulsed lasers back and forth from the surface of the Earth to measure variable distances. This process generates precise, three-dimensional information about the shape of the Earth and its surface characteristics. LiDAR systems are most often used by scientists and geographers to do things like produce more accurate shoreline maps, make digital elevation models (my use), to assist in emergency response operations, to monitor the wildlife in a certain area, and much more. The visualization of the data is something similar to what you see below; millions of little elevation points.
My use for these millions of data points was much more simple and juvenile. I wanted to pull this data, convert to a digital elevation map (DEM), and then using geography software, convert that DEM to an STL to be 3D printed. And make it as high-resolution as I could.
I discovered OpenTopography.com, a public high-resolution topography data website. It allows you to select a part of the world that has LiDAR data available, and download it to be used at your will. One thing that I learned quickly about LiDAR data, is there actually isn’t too much of it. Only small sections of the United States have been mapped and I had a place in mind I wanted to map out, the White Mountain region in Arizona. Sadly, this area was not available. I reached out to a cartographer who works for the Arizona State Land Department and she wrote me this kind email in response.
Unfortunately, by the time she responded, I had already completed my print. I’d love to explore this further though and try to map out the area as I had originally intended.
Anyways, I settled upon mapping the Kaibab Plateau; a region of Arizona just north of the Grand Canyon that has very detailed data available. The data was gathered in support of the ongoing studies of Northern Goshawk demographics.
I selected a region of data near Widfross Point, downloaded the LAS file, and begun my file conversion journey. I won’t bore you will ALL my errors, bugs, and workarounds, but I’ll tell you there were a lot of them. For a moment, I thought my quest for the highest resolution print possible would be a failure. A lot of the programs I needed to convert the files were PC-only programs. Here’s what I ended up using.
LAStools (LAS to DEM)
This was my first step. LAStools was only usable on PC, but I discovered this workaround using Homebrew, Wine, and my new-found knowledge of how to use the Mac Terminal. I thanked my lucky stars it worked. I successfully converted my file into a DEM.
QGIS (DEM to STL)
The next step was DEM to STL. I discovered a program called QGIS, a free and open-source geographic information system that allows the user to create, edit, visualize, analyze, and public geospatial information. The program itself seemed awesome, but I really didn’t get a chance to play around with it a whole bunch. Through the instruction of the internet, I installed a plugin, pretty self-explanatory, called “DEMto3D”. For the life of me, I couldn’t get it to work, and I had no idea why. I resorted to many other solutions, installing Blender, Python, Meshlab, and more. Trying everything to figure out how to I could convert this file. I was about to give up when I stumbled upon a hero who posted a blog instructing to have specific settings when exporting. It worked. I had my STL file.
Cura (STL to 3D Print)
I pulled the STL into Cura. For some reason, it was giving me a massive space below the top texture, but I just pushed the excess below the base plate. I scaled it down, and in order to keep fidelity, I printed it at the finest resolution. I was pretty happy with how it turned out. I’m going to refrain from upload my STL file to Sketchfab, as it ended up being a little over half a gigabyte.
My print took quite some time, but I still wanted to do more. I converted an area near my house in Boulder into an STL from OpenTopography, but was getting some issues with the conversion. I couldn’t figure out why and at this point I was getting a bit exhausted with fucking around with all these programs. But here’s the visualized data though of west Boulder and Mount Sanitas for wishful thinking. Next time!
Lessons Learned
Keep trying! I almost even installed bootcamp on my Mac just to get all those PC programs to work properly. I was happy I persisted and kept my original goal of high-fidelity. It might make a good Christmas gift down the line.
Data is pretty cool. There are so many tools out there to help you visualize it, you just need to find the right ones and use them properly! Data can be beautiful.
