How To: Turn a 3D Scan Into a Bust
Alec is here to walk you through the process of 3D scanning, preparing and 3D printing a custom bust of a person to display at work or at home!
This is a project I’ve been wanting to put together for a long time that I finally figured out the right workflow to make it a fairly quick and easy process to get from scan to 3D print. We carry 3D scanners that have some variance in the objects they are intended be used to scan; the Matter and Form or BQ Ciclop are intended for scanning small, action figure sized objects, or the 3D Sense scanner is for large objects or people. That being said, we don’t have a lot of prints around the office that utilize 3D scanners as the basis model, so I came up with a project that needed one: a 3D printed organization chart.
MatterHackers has grown significantly since I’ve started; teams have expanded, departments have formed, we even have a second office now. With so many new people, it made sense to me to have a visual representation of just how many people work here and have everyone all in one place.
The first step was figuring out how I wanted to mount these on the wall. I wanted these to be semi-permanent, but also be able to move them around as teams expand and people move around, which meant using any mounting tape was out of the question, but picture hanging command strips fit the bill perfectly. From there I made sure that whatever base I had the busts on needed to have a flat back large enough to fit one on there. Which meant of the two test models I made using an existing scan of myself, the one with the square base was the way to go (although how cool is that Greco-Roman bust).
Designing the Base
With a base in mind, I set out to use MatterControl 2.0 to make things a little easier to change the text from person to person. Using the align, text, and fit to bounds tools I was able to create a base that I could change things on the fly and update them in the future without having to start from scratch.
Making the Cutaway
To make the busts have that familiar cutout in the back of the torso, I used Fusion360 to create a template cutaway. First I made an extrusion with an arc in the shape I wanted to cut away from the back of the torso, and then a second extrusion from the front (and symmetrical) to cut away from the right and left sides of the bust. I also wanted to make sure the bust had a base flat and parallel with the z=0 plane, so I added a flat extrusion from the front as well. None of the radii of the extrusion are specific or need to be a particular shape, I just made them contour in a way I wanted.
Once I had that figured out, it was time to start scanning. What I’ve found to be the best procedure to get good scans is find a chair with a low back, leave about two feet of space around the chair, and get a 6ft USB extension cable. When I started scanning someone from too far away with the Sense scanner, the focal point was locked in too close and I’d lose part of their back and neck, too close and I’d lose their nose or ponytail; it’s a fine line to get the scan just right.
Cleaning Up the Scans
As you may have noticed, this scan didn’t come out perfectly and there’s a reason for that: the way the Sense scanner and most 3D scanners work relies on matte finishes, so anything glossy usually throws off an accurate scan. Cheeks and hair are usually shiny and turn into deep canyons when the software tries to makes sense of the data it gathered. Every scan is going to need some clean up, so from here we will head into Meshmixer and do a bit of sculpting.
When I’m cleaning up a scan, the only two tools I use are Draw+ and BubbleSmooth. Select BubbleSmooth as your secondary brush so you can hold Shift and instantly jump between your primary (Draw+) and secondary. Use the Draw+ sculpting tool to pull surfaces out and “fill in” material and BubbleSmooth to flatten them out and “remove” material. It’s easy to change the surface geometry too quickly, resulting in weird antenna coming out of the scan, so keep the strength and density to low values of X and Y, respectively. Control+Z will be your friend here.
Subtract the Cutaway
Once you’re cleaned up the mesh, you can drop it into NetFabb to subtract the cutaway piece from the bust. I select the cutaway piece and center it to the origin, click confirm, then select the 3D scan and center it to origin separately and confirm. Then I move the scan up in Z until the bottom of the scan is just barely inside the cutaway, to ensure a flat bottom. Once it’s all placed correctly, I use boolean and subtract the cutaway from the scan, leaving behind just the bust I want to keep.
Putting it All Together
With that finished, I can import the bust into MatterControl and figure out where to place the head on top of the box, to make sure there’s enough space to have the back of the base as the furthest point in Y to make sure it can attach to the wall. Using the align tool, I can move the bust to be exactly on top of the base, then create a small connector piece that I can subtract from the bust and base so I can easily swap parts out depending on if people get new titles or if they print their bust in a different color.
And there we go! It’s still an ongoing process scanning everyone in the office, cleaning up their models, and printing them in their filament of choice, but it’s a welcome addition for the many blank canvases we have around the office.