This week I covered 3D scanning. 3D scanning is The process of analysing a real-world object or environment to collect data on its shape and its appearance, and making a 3D model. This process can be used for a number of things including:
- industrial design
- reverse engineering
- prototyping
- robotic mapping
- Orthotics, prosthetics, dental implants
- quality control/inspection
- digitization of cultural artifacts
- production of movies, video games, virtual reality
- augmented reality
- motion capture
- gesture recognition
It can be single or multiple scans and consists of a polygon mesh or point cloud of geometric samples on the surface of the subject .
Contact scanners
Contact 3D scanners probe the subject through physical touch, while the object is in contact with or resting on a precision flat surface plate, ground and polished to a specific maximum of surface roughness. Where the object to be scanned is not flat or can not rest firmly on a flat surface, it is supported and held firmly in place by a fixture
Non contact scanning
Non contact scanners rely on detecting reflected ambient radiation. The visible light radiation is most common as its readily available ambient radiation. Other types of radiation, such as infrared could also be used. Passive methods can be very cheap, because in most cases they do not need particular hardware but simple digital cameras.
Sterio
Stereoscopic systems usually employ two video cameras, slightly apart, looking at the same scene. By analysing the slight differences between the images seen by each camera, it is possible to determine the distance at each point in the images. This method is based on the same principles driving human stereoscopic vision.
We went to look at some scanners. These ones were non-contact and relied on you shooting a laser at the object at a certain angle from the handle, and the laser will bounce back giving the fixed arm the details to map it out.
There was also a 360degree rotary scanner, this would have the object placed on its plate. the object will be rotated while the object turns giving it a full view of the object.
This came in hand with one of my other modules, the Fixperts project. I needed to scan in a moulded handle to modify it for manufacture. This was what I was working with:
To make things more simpler i decided to remove the bottom ring of the design. it helps as it makes it smaller, to fit on the rotarty scanner, and its unnecessary to scan in easy objects like circles when you can cut them down.
And here was my scanning result. It came out perfectly and was more accurate than what I imagined. There was one bit that had trouble that was the inner side of the loop but only took a little bit to seal it up. we can then use this design in our fixperts project to manipulate for manufacture
I also learn about a few apps including Qlone and Polycam. These apps allow you to scan objects in through your phone. Qlone allows you to print a Qr code that you place on a flat surface. you would then place the object in the middle od the Qr code, when you rase the camera in the app it will overlay a dome that is split into many segments.
You would then angle your phone through all the sections uncovering the object.
After you will get a 3D model. It isn’t the most accurate scan but is definitely fun to play around with.
Polycam, the other app, uses in a different way. You sit your item in front of you and keep still. The app will know that point and then will let you record which then you will angle the phone around the object, it is taking loads of photos and each photo is using the previous photos to reference of, building the data of a whole object. 
And this was the result. these also aren’t as accurate but are still fun. Polycam also offers LiDAR which is a specific hardware on some iPhones and will be more accurate but not as accessible.