This year I was commissioned to make a personalized action figure with the face of a man who loves (and who luckily looks a lot like) Superman. Only recently, since the introduction of free 3D scanning apps and software, can this be a weekend garage project without needing access to a space-age FabLab!
In this tutorial, I'm making a new head for this large action figure using 3D scanning, 3D printing and hand painting.
You will need:
123D Catch: a free phone app that creates a 3D scan from a collection of pictures.
ReMake: a desktop software that creates also a 3D model from a collection of photos, and lets you edit the resulting 3D mesh for better resolution. (It's free as long as you're exporting to Fusion 360!)
Fusion 360: a cloud based CAD program that works for combining, sizing, and prepping the model for 3D printing. (Free for students and educators, reasonably priced for everyone else)
I recommend these tools
Step 1: 3D scan
The Human's Head
If using either 123D Catch or Remake, you'll take around 30-40 pictures of the subject at different angles. The result will be a 3D mesh.
To get the most detail, make sure that all angles of the person are well lit. It may take 2-3 tries to get a good scan, but it's worth it. If the resulting grey mesh is recognizable as the person, it's ready. Learn from my mistakes and have the person make an exaggerated heroic expression while 3D scanning.
The Action Figure's Head (optional)
This step is helpful to know where and how the head attaches to the body, but it's not necessary. I scanned this head because I wanted to use superman's luscious hair.
Detach the head from the body as carefully as you can. My figure's head is rubber, so I took a thin knife and made a vertical cut at the base of the neck, then stretched it off.
Step 2: bring the scan into CAD
Instructions for Fusion 360
1. Export 3D mesh in Quads
Fusion operates in quads (4 pointed polygons rather than the conventional triangles.) You will not be able to convert your mesh into a solid body if it's in triangles.
If using Remake, export the scan to the Fusion 360 setting. This will give you a .obj file in quads.
2. Model attachment features
Open a new file in F360 and model the features that will attach the head to the neck. (Pay careful attention to the measurements!) In my case, it was a ring that snaps onto the neck. This model will act as the scale when you bring the head scan in.
3. Upload Mesh as new file
Use the upload icon in the left data panel shaped like a cloud with an arrow inside. (I'm not sure why, but when I import mesh into an existing file, I can't convert it to a t-spline. If you know why, please comment!)
4. Convert to solid body (stay with me here)
The date is December 2016. Fusion 360 pushes new updates and features every month. In the near future it's quite possible for there to be an easier way to convert a mesh to solid body. However, this is the best way given the tools F360 has now.
Go into the sculpt environment, and select the mesh body. Select the "utilities" menu and click "convert."
Make sure the operation is "new body" and click "okay."
Go back to the utilities menu, and click "repair body." Select the head, then press the icon next to "auto repair." (it may take a few minutes) Click "okay."
Go again to utilities - "convert," make sure the selection filter is on t-spline. Select the t-spline body from the left browser. Make the operation "new body." click "okay."
If successful, you should see 3 bodies in the left browser. A mesh body, a t-spline body, and a solid body.
4. Size head to attachment features*
Drag the (now solid) head file from the data panel on the left into the file with the attachment features. Scale and rotate the head until it matches the size and orientation of the attachment features. Use the "combine bodies" tool to make 1 body.
5. Export as STL
Right click on the body in the "browser" tree to the left. Select "Save as STL." Default settings are fine.
*4.5. If you want to combine the human and figure head, repeat step 3 and 4 on any additional scan and bring them into the same file. Orient the two heads so that they are the same size and the facial features are aligned. Cut away features from each head that you don't want to include. Use the "combine bodies" tool to make them one body.
Step 3: 3D Print
Instructions will vary based on your 3D printer and loading software, however the basic steps are usually the same.
- Bring STL file into 3D printing software
- Orient to get the best resolution on key spots. (mine is upside down because I wanted the neck attachment geometry to be the most accurate)
- Define wall thickness. I used a thicker wall than the standard because I planned to sand some extra detail into the features.
- Print! This one took around 8 hours
Step 4: sand, fill and paint
Sand and fill
Automotive primer is perfect for finishing 3D prints, it fills in the texture and is wet-sandable. You can work the surface to a perfect finish (even if you mess up :)
Go back and forth between coating with filler/primer and smoothing with sandpaper until the 3D printed linear texture is completely gone. If you are unsatisfied with the level of detail in the features (like I was) use a narrow sanding bit on a dremel to etch in details like the nostrils and ear cavity.
Mix the skin tone
Using a few cheap craft acrylic paints, mess around with small samples in simple proportions. One part this, two parts that, one toothpick dab of red. Try and match the (dry!!) color to the skin tone of the original figure's head.
Once you're happy with the color, grab an empty container (see travel mouthwash bottle below) and mix in a batch. Begin with your formula, then tweak as needed to get the whole bottle of paint the desired color.
A cheap craft foam brush does just fine If used correctly. The goal is to avoid visible brush strokes.
Load the brush by dabbing the tip into a thin layer of your premixed skin colored paint.
Quickly put down a thin translucent layer using fast light strokes back and forth.
Let dry completely!
- Repeat until you can't see the primer. (about 5-7 coats)
If you want to go the extra mile, paint the skin of the action figure body with your leftover skin tone paint.
Facial features - Don't Be Scared!
Painting features like eyes and lips can be terrifying, but I promise it's much easier here than drawing a face on paper. The reason why 2D faces are hard is because it's freehand. It's far too easy to draw an eye at the wrong angle or the wrong size and mess up the whole picture. Here, there is a real proportioned 3D scan of a face. Practically a coloring book that you just have to fill in. You'll do great, just remember, "Keep it light 'til it's right!"
Work slowly and with many pictures of the original person at hand. You can always paint over mistakes with skin tone.
Start with a light brown color to gesture in the eyebrows, nose definitions, and ear detail. Move to darker colors as you become more confident.
Eyes and lips
Using a liner brush, paint in the whites of the eyes, layer with eye color, pupal dot, then a nice cartoon-like highlight. Line the eye carefully according to the person's lash thickness/density.
Mix tiny amounts of red and brown into the skin tone paint until it matches the person's lip color. Fill in the shape paying attention to where the lips end harshly, and where they blend into the skin color.
Paint the hair a solid color. If you want to add in some highlights, or salt and pepper, localize those details around the forehead and sideburns.
Lastly, I referenced contouring makeup tutorials to add some extra definition.
Attach the finished head to the action figure make someone's day! :)