“Photogrammetry is a method for creating 3D models of objects by taking a series (usually hundreds) of photographs,” writes New Mexico-based maker William Grassie in his article titled “Quadcopter Photogrammetry,” which appears in our newest issue, MAKE Volume 37. The concept of photogrammetry has been around for a long time, but with the proliferation of digital photos and advances in software, what is possible has been elevated. Grassie informs, “The software takes all of the photographs and compares them to find matching points. Then the software uses these points to calculate depth.”
The article tells the story of how Grassie was able to combine his love of R/C aircraft with photogrammetry techniques to help in the restoration of historic buildings in Old Havana, Cuba. Prior to integrating quadcopters into the process, when taking the 360 shots of a building, Grassie writes:
I found that anything above the field of view would inevitably show up in the data as black holes rather than a solid 3D model. I started thinking of different ways to get a complete view of the building. One obvious method would be to rent a hydraulic lift, but that could be costly and impractical in tight spaces. Helicopters might work but would also be cost-prohibitive. Then it hit me: I could use multirotor R/C aircraft to photograph the inaccessible areas. My passion for photography and the R/C world came together in a beautiful way.
In the article, Grassie also shares the specs of his own setup, as well as seven photogrammetry tips. Read the article on page 42 of MAKE Volume 37, as well as here online.
In an effort to help folks who are interested in getting started with their own quadcopters, Grassie has also created a blog called UAV-3D. Below is a collection of some of the interesting videos from his site.
Time-lapse of the complete build of the multirotor used in Grassie’s photogrammetry project:
The results of Grassie’s first attempt at aerial photogrammetry using a GoPro Hero 3:
One of Grassie’s first experiences in photogrammetry, animated in 3D, of the Hotel Santa Isabel in Havana: