First we use 123D Catch to capture a nice model of whoever we want to create a bobblehead of.
Then we use Meshmixer to clean up the capture and cut out a cylindrical cavity I made with 123D Design for the spring to attach to the inside bottom of the head. We'll only 3D print the head part and reuse an existing body.
Each of these apps can be found for free at 123dapp.com
Step 1: Create a 3D model of your head using 123D Catch
Creating a 3D model with 123D Catch can be easy. Basically you shoot a sequence of overlapping photographs as you move around the person. For example, I'll shoot 20 photos or so in small increments in a full 360 degree loop to ensure I get full coverage. I may shoot some additional top-down angles to get the top of the head.
It can take some practice/redos, to capture a good model of a person's head. Sometimes I have to reshoot them a second or third time.
The biggest challenge is having the subject remain perfectly still.
Here are some tips for capturing a live person's head:
Things to tell your subject when shooting photos:
• Sit down (to eliminate balance movement).
• Close jaw to avoid subtle face movements.
• Comfortably focus eyes on a distant point.
• Blink between shots.
• Channel their inner mannequin
Things you can do:
•Shoot sharp, well framed photographs, oh but quickly!
•Put pieces of masking tape around the chest, shoulders, neck, and back of head. (These features help 123D Catch reconstruct the model)
•Frame your subject from just below the chest and up. The more context the better the model will come out.
•If you see your model move their face, even slightly, just start over and tell them the above points.
Some other things to be aware of:
Photo Coverage: Catch must be able to “see” everything that you want to create a Capture of. Make sure you take enough photographs. Don’t have too much space in between shots. When shooting a person I try balance this and shoot the least amount of photos to eliminate the chance of them moving. Typically 20-25 in a loop framing their chest upwards, making sure to get under their chin. Then, 5-10 from top-down angle to get the top of the head.
Blurry Photos: Blurry photos will confuse 123D Catch
Lighting: Poorly lit scenes will cause problems for 123D Catch, as well as irregular lighting (like strong back-lighting).
Good Job, Gabe! Yours came out great!
Step 2: Import the head capture into the amazing MeshMixer.
1. Export your capture as an OBJ with the texture from 123D Catch. You can do this either from the Desktop PC version or find your project in your account on 123dapp.com. Just log in and you can download the OBJ mesh package zipped up in the "Downloads" section for that project.
2. Launch MeshMixer and from the menu, choose "Import Textured".
3. Find the OBJ of the capture for import.
Note: If your mesh imports and you don't see the texture, click the "Shaders" bucket on the left panel and drag the shader that looks like an earth onto the model.
4. You may press the "T" key to Transform your model right side up if it isn't (Also available in the "Edit" bucket).
5. Once upright, press the "A" key or click "Accept" for the reorientation
Gabe, you can stop holding still!!
Step 3: Clean up the head capture.
First, learn the how to navigate inside of Meshmixer:
Orbit: Alt + left click drag
Zoom: Alt + right click drag
Pan: Alt + scroll wheel click drag
Note: You can change the navigation controls to 123D if you want from the menu....View...Navigation Mode...123D.
In MeshMixer, pressing "S" enters you into the Select tool. This is a common tool for anyone who works in MeshMixer so get used to how it works.
-When in "Select" tool, you can paint select or laser select.
-Paint select: Mouse over part of the mesh and you will see a circle follow your mouse on the surface. Click and drag on top of the model to paint with this. Adjust the brush size with the scroll wheel.
-Laser select can take some practice getting used to but is pretty clever. In Select tool, click off of the model and drag a straight line across your model. One side of the line is selected. Great way to select a group faster than paint selecting it, eh?
-Esc always clears the selection. (ESC is your friend in Meshmixer)
1. Now, draw a laser selection through the model, just below the chin, cutting off the neck and below (key "S" if you are not in "select" tool.
If you zoom into the selection (selected part is orange), you will see it is jagged based on the resolution of the triangles in your mesh. Meshmixer can smooth this out.
2. From the side panel, choose "Modify....Smooth Boundary" (or shortcut "B"). Then, click "Accept" to see the smoothed selection. This will allow us to delete one side and have a smooth edge.
TIP!: Press the "W" key to toggle on/off the Wireframe visibility.
3. Lastly, from the side bar, click "Edit...Discard" (or simply use "X" hotkey) to delete the selected geometry.
I didn't get good coverage on top of Gabe's head, so there is some missing/stray geometry. I use a similar select-delete method to clean up the top of his head. Just get rid of the parts we don't need and in the next step we'll heal them...
Step 4: Heal the mesh holes
To invoke the Inspector too, click the "Analysis" bucket from the left panel, then click "Inspector" from the Analysis options.
The Inspector tool identifies the issues with pins pointing to the mesh issue. You can click the end of the pin to simply fix it (or click Auto Repair All to fix all issues at once).
For the next step I like to use remesh on the bottom to make the mesh more dense where we will cut out the cavity for the springs to go into. It helps retain the texture and make a clean cutout.
To do this:
1. Use the Select tool to select the parts of the mesh you want to remesh. Here it is just the bottom of the head that was filled in.
2. Click "Edit...Remesh"
3. Drag the Remesh slider to the right to increase the mesh density.
Step 5: Cut out the cavity on the bottom.
For this I use the 123D Design web app to create an assembly of two cylinders that we will use as the cut out piece. Essentially its a cylinder with a diameter of 2cm and height of 1cm. Then I assemble another cylinder on top of that (centered) with a diameter of 1 cm and height of 1 cm (See sketch).
I won't detail how to do this within 123D Design, its pretty intuitive. I attached the cutout model to this step for convenience and here is a link to the model as well:
This cutout piece is made with scale in mind (which is important for when we 3D print it, so we'll use this cutout piece as reference to scale the head model to.
Back in Meshmixer...
1. Click "File...Import", then choose "Append" in the dialog that pops up to add it to the MeshMixer workspace as a new separate object.
2. If asked, click "Yes" to shift position.
The cutout piece is imported and is at the scale we want the bobblehead to print. We'll want to scale and position the head and make sure not to scale the cutout piece. You can switch between the active object by clicking on the object (head or cutout) OR, show the objects browser to select them there.
3. (optional) Click "View Objects Browser" See that you can select one or the other to make it active.
4. Rotate the cutout piece rightside up by using the Transform too. Click "T", then use the rotation manipulator and the snapping angles to snap it 90 degrees, with the small cylinder on top. Then click "Accept" in the upper left corner.
5. Next, make the head object active by clicking on it (or use the Object Browser).
6. Scale the head up and move it into place, so the cutout is poking just through the bottom. Use "Transform" here again. The middle white box in the manipulator will scale the object.
(Note: I had to make the bottom of the cylinder assembly cutout extend on the bottom to properly pop out the bottom of the head. To do this, select the bottom faces with Select mode, then Transform them downwards.
ALAS, now make the cut!!
7. Select, in order while pressing Shift to multiselect, the head model, then select the cutout piece (easiest to do this in the Objects Browser while pressing Shift to multiselect).
8. From the Edit bucket on the left panel, choose "Boolean Difference"
9. The model will temporarily change color so you can inspect the cut. Lastly click "Accept" to finish the operation and the texture returns.
Step 6: 3D print your model in color
Export your model as an OBJ which will include the textures:
1. Click "File...Export"
2. Choose the filetype as OBJ
3. Click Save.
3D printing in color is supported by several vendors, including iMaterialise and Shapeways(www.shapeways.com). It is a full color sandstone material.
Here is a link on using this service:
Shapeways prefers the VRML or X3D format. You can export an X3D format from Meshlab, which is free here:
Also, you can export a VRML 2 format (WRL) from Autodesk Max. Simply import the OBJ, then export choosing the VRML filetype. I attached a screenshot of the settings I used that work.
3D printing in color is still in the early stages in terms of accessible file formats and best practices, so if you have any issues, feel free to reach out to me and I may be able to help out.
I made a test print with a rigid black material on an Objet to see how it fit before sending for the color print. You can see the texture adds quite a bit of realism since there is more details not captured in the geometry.
I will post Gabe's print when its finished, I'm trying it out on the Mcor color printer, which uses paper for material.
Step 7: Assemble!
-Existing bobblehead body (I simply ripped the head off of a Hunter Pence SF giants bobblehead
-A 3/4 inch spring (from your local hardware store)
-Your 3D print of the head.
1. I measured how long the spring needed to be and snipped it accordingly. The head should just hover over the shoulders so it will bobble without hitting the body.
2. With the glue gun, apply liberally to the inner part of the head where it is cut out, then push the spring into the glue and wait for it to harden.
3. Apply some glue to the neck of the body and fit the spring over it. Hold until it is dry.
4. Show all of your family and friends what you've made!!