In this episode of the basic turntable photogrammetry series, I will give an overview of the setup used to photograph the walnut shell that will be reconstructed through photogrammetry.
Video Transcript
Hello everyone! In this episode of the basic turntable photogrammetry series, I will give an overview of the setup used to photograph the walnut shell that will be reconstructed through photogrammetry.
As mentioned in the series overview, the objects used are deliberately non professional. The goal is to demonstrate the basic elements of photogrammetry, some of the common issues you might encounter, and how to solve them, without needing expensive equipment, at least in the beginning.
I placed the walnut shell on a support made of three long wooden sticks, which rest on a rotating base, with the idea of suspending it in the air, so to speak.
This setup has two advantages. First, it allows for photographing the object from the bottom as well. Second, the area occluded by the supports is very small and will be easy to remove, both in terms of geometry and textures.
To take the photographs, I used a non high end smartphone, keeping it steady with a desktop Light Ring and a flexible tripod, using the latter for low angle shots.
The Light Ring provides good general lighting for the object, although it is insufficient for the bottom part. So, I aimed a lamp at the base of the support to create bounce lighting for that area.
However, this introduced some greenish reflections, and the central lower part still remained slightly in shadow. I will show possible solutions for both of these issues throughout the series.
In a way, the small problems caused by this kind of setup turned out to be useful, as they allowed me to discuss various tools and techniques throughout the episodes. Let’s try to see the glass as half full!
I took the photos by manually rotating the turntable each time. Of course, there are motorized supports, but for this basic experiment, I didn’t want to rely on them.
In any case, I took photos from three different heights to capture the object from below, frontally, and from above. Before recording the episodes, I removed any blurry or poorly exposed photos, ending up with 146 usable images.
Alright, that’s it for this episode! In the next one, we’ll start getting familiar with Meshroom and photogrammetry! See you soon!