Introduction: Project7_3D_scanning

By sambourgault.com
About: PhD student at University of California, Santa Barbara, in the Expressive Computation Lab (https://ecl.mat.ucsb.edu/).

This week's assignment aimed to scan a 3d object from the real world, clean the mesh and print it. I really wanted to make a mask integrating nails and that could fit my face. So I 3d scanned my head and clean that mesh in order to make a suiting face garment.

It ended up looking somewhere between a mask against patriarchy and a BDSM accessory.. ;)

Supplies

Creality Ender 3 Pro Printer

Filament

iPad with TrueDepth Camera

MeshMixer

Blender

Rhino

Nails

Step 1: Scanning

The first step involved trying out some 3D scanning applications available on the 2019 iPad Pro. I tested the free app Display.land. It seemed to work better for large spaces rather than small objects or human features.

I then tried out Scandy Pro. The free version only allows you to take one scan per day so I invested 2.49$/week to extend this capability. It was worth it. The results of Scandy Pro were pretty impressive.

The original meshes were missing some parts but they had captured the essential features in order to fit a mask.

Step 2: Alignment in MeshLab

In MeshLab, I used the alignment function in order to create a combination of my two best captures. I worked well.

Then I tried the VCG Surface Reconstruction filter. It crashed a few times until I found the best resolution so I can create a mesh out of it. The resulting mesh was okay, but lost some resolution compared to the original captures.

Step 3: Cleanup in MeshMixer

I decided to switch gear and tried to clean up one of my 3d scans using MeshMixer instead. I found this approach very convenient as it focuses on direct manipulation operations rather than filters.

I followed this tutorial in order to clean my mesh, which involved these steps:

1. aligning correctly in space by editing transform. Edit > Transform

2. removing extra unconnected bits. Edit > Separate Shells > Delete the unwanted shells in the popup menu

3. selecting and closing holes. Select > Erase and Fill

4. making a solid out of the surface mesh. Edit > Make Solid

5. using the sculpt mode to soften the mesh. Sculpt > Brush > Smooth

I found that workflow very intuitive given my prior experience in 3d modeling and sculpting in Blender. It enables the user to have full control over the modifications applied to the mesh.

Step 4: Retopology in Blender

To create the mask I started by a retopology in Blender. This technique enabled me to trace the surface that would be in contact with my face.

Step 5: Modeling Mask in Blender

The second steps in Blender was to create the outer layer of the mask. I copied the inner surface into a new object and started manipulating the vertices in order to reshape then the way I wanted the outer mask to look like. Then, I connected both parts and applied a subdivision surface modifier in order to smooth the whole thing.

Note that I extruded a small portion of the inner part in order for the wearer to bite on and secure the mask in place. Note also that I actually performed the boolean operation necessary for the holes for the nails in Rhino. For some reason, the boolean operation in Blender was not working properly, leaving weird artifacts on the surface.

Step 6: Printing

The final step consisted of printing the mask. It was pretty straightforward and printed very well. I tried the Tree support offered in Cura as an experimental feature for the first time and was amazed by how supportive it is during the print and how easy it is to remove from the model afterward. Also, the amount of wasted material was significantly lower with the tree support, which made me happy.