As technologies improve and get more accessible, new possibilities are emerging—and solutions to many healthcare challenges are getting better. This is how the R&D team from Chabloz Orthopedie managed to create a one-of-a-kind, revolutionary prosthetic.
Why pay for something when you can do it for free (or more affordably)?
Of course, nothing is entirely free. Even if you are using free photogrammetry software, you probably still need to invest in a camera to take the pictures. And the question remains: why would you pay for something if there is a solution that lets you do it for essentially free? It really depends what you want or need!
Here are the top 7 things you need to consider when trying to decide between photogrammetry and 3D scanning.
1. The all-forgiving texturesA high-resolution texture can sometimes have a very positive effect on the perception of a mesh. This is, for instance. how the cinematic industry works (very high textures with relatively low poly meshes). High resolutions work great for visual applications. If you are working on reverse engineering or plan to send your scan to a 3D printer, however, chances are you will want all the mesh resolution you can get. Take this colored mesh for instance. It looks great with texture, but it is actually pretty limited in terms of geometry.
2. Hold still, very still!Another limitation for photogrammetry is that it requires the subject to be perfectly still. This is the reason why full body scanners require 20-30 cameras synchronized. Any slight movement will have devastating effect of the results:
3D scanning, on the other hand, is a lot less affected by movement as it only relies on a smaller area at the time. A handheld device also has a significantly smaller form factor, making it much easier to carry it and bring it directly onsite.
3. What’s the deal with texture?
When working with photogrammetry, you take a lot of pictures of the same objects from different angles. The software then identifies features (found in the texture) and matches them in the different pictures. Being able to match these features between images from different angles is what makes the 3D surfaces. This works very well on an object with a lot of texture (like a rock)—but will produce very poor results on an object with little texture (like a car door).
A 3D scanner works better with objects with little texture as it relies on recognizing its projected pattern. Texture might disturb detection of the light pattern making it more difficult for the scanner to work.
4. Like working with a blindfold…
Another great advantage of using a 3D scanner is to see what you are doing in real time. This lets you see the areas you’ve scanned and, more importantly, the areas you’ve missed.
It is always possible to add more images to a photoscan, but you will need to process the whole model every time to know and see if you have everything you need. Processing large scans with a lot of pictures can take a long time. This also makes the use of 3D scanning as process significantly faster than using photogrammetry.
5. What kind of accuracy can you expect?
It is possible to obtain great looking scans with photogrammetry—but getting good accuracy is more challenging and more random as a lot of parameters are simply not controlled. Cameras (even the good ones) are generally not optically calibrated for the purpose of 3D scanning. This can create important scaling errors in a 3D scan.
3D scanners (the good ones at least) will generally be calibrated for the purpose of scanning. They provide more of a controlled ecosystem making them more predictable hence the possibility to provide accuracy specifications.
6. The difference between interior and exterior…
Again, photogrammetry works great if you can get all around the subject and take a good number of pictures, but what if you are trying to scan the interior of something in more of a confined area? Think of trying to scan the inside of a car for instance. Getting the right number of pictures of all components from all angles will be nearly impossible making it practically unfeasible to scan the inside of object with this technology.
This is where having a 3D scanner with a small form factor will definitely be handy. As you can easily get it into, around or under things, scanning objects from all angles will be a lot more achievable.
7. How much time can you invest in onboarding and training?
This is something you hear a lot: “Oh, the things he can do with his equipment!” Many people have the preconceived notion of being competent or qualified with a device or system. This is a system that relies on its user to deliver great performance. When you know how to use it, it works pretty well. However, getting there can sometimes be painful. And if the system is to be used by more than one person, these new users also have to learn how all of its ins and outs.
A system that does not require any training or specific scanning knowledge is, therefore, a great bet. This is the case with good 3D scanners as they will prevent users from collecting bad-quality data and deliver great performances regardless of the way they are used.
Overall, when choosing between photogrammetry and 3D scanning, you really have to consider your needs and applications. In some cases, and for some applications, photogrammetry is definitely interesting but, just like about anything, it is not suited for everything.
Two thousand years ago, there was no social media, no selfies, no Snapchats. And definitely no 3D scanning! The best (and only!) way to capture a person’s portrait was to carve it in stone. These stone carvings inevitably lasted centuries, offering us a window to the past and how people looked like in ancient Greece or Egypt.
Who do we look like? Do we have an ancient doppelganger? This is precisely what the Musée de la Civilisation tried to answer coming up with the very interesting exhibit, “My 2000-year-old double.” The museum recruited around thirty people, using a contest, with specific facial characteristics. The faces of the selected lucky few were then cross-referenced with a large sculpture database provided by the Musée d'art et d'histoire de Genève and the Fondation Gandur pour l’Art. The team used a face-matching algorithm to find the closest match between the subjects and statues.
How does this connect to the peel 3d affordable scanner you might ask? It turns out the Musée de la Civilisation also bought its own scanner to scan the faces of all candidates. The plan was to immortalize these faces—not in stone, but with modern techniques. Naturally, that meant 3D scanning and 3D printing! The museum needed something quick and easy to use; the team members of the project had many faces to scan and were planning to use the scanner on their own.
peel 3d proved to be the perfect 3D scanning solution for their needs. Providing a great level of detail, it could capture a complete human face in seconds.
The software included with the 3D scanner also provided very useful tools allowing to clean, align, improve and fill areas where data was missing. The results were very impressive:
The museum is currently working on scanning other participants from around the world. The scans will then be prepared for 3D printing. The exhibit is scheduled to open at the end of October 2018 in Québec City. Stay tuned for more information!