Have you ever wanted to have a small model of your own head? With the amazing advancements in both 3D printing and 3D scanning technology, it is now easier than ever to achieve great quality 3D scans of small objects and print them yourself on any 3D printer.
The Tech Behind the Idea
For our summer camps this year we were very fortunately lent a demonstration MakerBot 2 printer – a high end consumer printer from MakerBot. Whilst we use lots of 3D printers at our camps, and have used several different types over the years, they have generally been either kits or other low-end models. The MakerBot 2 is in a different league, with all the premium features such as WiFi, a built-in camera, filament run out detection, a very rigid frame and amazing print resolution, the result of all these being great final print quality and a very reliable machine.
We decided to combine it with some very accessible 3D scanning technology that can now be used by anyone who has what is now quite an old piece of hardware – an Xbox Kinect sensor. These are readily available online for as low as £6 - a cheap price tag for something that has a surprising amount of tech and computer science behind it.
Fundamentally, the Kinect is an infrared depth sensor, combined with a normal camera. This, combined with the right software and enough computing power, enables the Kinect to ‘see’ in 3D, and take 3D photographs.
The Process from 3D Scanning to 3D Printing
Scanning our Summer Camp Tutors
On to the process – to generate a 3D scan, you need a setup where you can use the Kinect to take lots of different pictures of the thing you want to scan from lots of different angles, without the item you are scanning moving or changing shape. In our case, we wanted to scan our Summer camp tutors – luckily a standard office chair and a few crates to stand the Kinect on worked perfectly.
Using the first piece of software, KScan3D (freely available online), you take around 20-30 3D photos of the subject whilst they slowly rotate in the chair. The key is keeping as still as possible – any movement will reduce the quality of the scan and might result in two noses! We did have a few issues with some hairstyles confusing the sensor as they were a bit see-through from certain angles – a hat or even a bucket on the head is the key here to getting these scans to work well.
Once the data has been captured, the initial ‘meshing’ is done within the KScan software. The program has a process to auto-align all of the scans together, by intelligently finding similar features between images and using them to move and scale each individual mesh so they line up. This works well for an initial pass, but there is no substitute for fine tuning – 5-10 minutes tweaking the mesh alignment by hand is key to getting a great looking result. Once the alignment is complete, the meshes are combined and can be saved into a 3D file format.
Tweaking the Mesh
The first operation is visual – have a good look around the model and select and remove blobs or areas of mesh that should not be printed. Next, we can use Blender’s great automated tools to fill any remaining holes in our model, left over from areas that we missed during the scanning process.
Finally, if you really want the perfect model, you can use the manual modelling and sculpting tools to cleanup the main parts of the model, such as hair, areas under overhangs that the camera couldn’t see (under the chin, nose, ears) and so on. Once you are happy with the model, it can be exported ready for printing on the MakerBot.
Printing the Models
The final stage is the ‘slicing’ – this is where a specialised program slices the model into layers that the printer will then create one at a time, and generate the tool path for the printer. This is a very complicated file, that works out exactly where the head of the printer will move to draw out each layer. The MakerBot Replicator 2 has a dedicated slicing program, MakerBot Print, that they developed especially for their printers and is guaranteed to give great printing results every time.
Transfer the file to the printer (you can even do it wirelessly if you have the MakerBot!) and in a few hours, your very own head model will be complete. You could even use Blender to sculpt the model onto a body or another model and make your very own action figure – one of our Game Design tutors even added some of the heads to a 3D game as enemies and weapons!
Repeat these steps enough times and you end up with your very own 3D printed head army – ready to take over the world (or just attach to your keys).
You can start building your own 3D printer and printing your own models at one of our 3D printing camps for all skill levels. Or take a look on a different challenge at one of our other engineering & computer science camps.