My Thoughts on Photogrammetry & 3D Scanning:
Photogrammetry has come a long way since I first came across it when working for an Offshore Oil & Gas company in the mid 90’s. This company had a department dedicated to researching Photogrammetry and 3d Scanning for surveying existing Process Plant installations.
Fascinating stuff and it actually worked using predefined targets placed at strategic intervals on the existing plant.
The Aviation restoration companies have for a long time been using 3d scanning and photogrammetry. In fact, if I recall correctly the Smithsonian carried out a survey of the Ta152 which I believe was Photogrammtrey many moons ago. If you look closely at the following image you can see the red dot markers to help ascertain dimensional and positional data from the scans. If anyone out there has access to a copy of the survey results I sure would be interested in seeing them.
So not willing to fall behind on the latest technologies I endeavored to find out what has been happening with Photogrammetry and played about with some of the available software products. The software I looked at was 3DF Zephyr, Meshroom and Reality Capture. I had a lot of fun but as you may have noted in my previous post the laptop I was using was really not up to the task, nevertheless, I persevered with my research and attained a few good models which surprisingly worked very well.
I even went as far as designing a lightweight support mechanism for photographing fossils in the field. Often these are Sites of Special Scientific Interest (SSSI) in the UK, which is a conservation designation denoting a protected area. Essentially legislation for legal nature/geological conservation of land considered of special interest for their flora or fauna, geology or geomorphology.
Unfortunately, for many of these sites, the removal of fossils is frowned upon so the Fossil Pod was designed to facilitate taking photographs of the found objects…an adapted use for Tensegrity design.
It is early days in my research which I intend to continue to explore options for increasing dimensional accuracy using photogrammetry and obviate the limitations for shiny and reflective objects. I appreciate that the industry may be more interested in 3d laser scanning technologies which is essential for accuracy but I feel that photogrammetry has a lot to offer for presentation and grasping details when a 3d scanner is not available.
As for the software, I would recommend both the 3DF Zephyr and the Reality capture. I should note that all 3 software products do exceptional model generation from photographs however the Meshroom; though in early production; is much less forgiving and requires a very good dataset to work from whereas the others are more tolerant.
If you would like some inspiration for what photogrammetry can do check out this Youtube video from the Swedish Exhibition Agency.
Aviation CAD TechNotes 