2. Digital bodies¶

Research & Ideation¶

Activity Description:¶

3D scanning process: I used the Polycam mobile app to scan a mannequin. In the process, I captured approximately 100 images from different angles, which generated a 3D model of the mannequin. Once the model was generated in the app, I made some adjustments: I removed the base of the model and adjusted the dimensions so that the silhouette was accurate. The application allowed me to export the final model in STL format to use in the following steps. I also tried another tool called AR Code, which allowed me to explore a different scanning technique. This app generates a QR code that, when scanned, shows the 3D model directly on the device.
Repair and manipulation of the 3D model: After exporting the model in STL format from Polycam, I imported it into Fusion 360 for further modifications. The first step was to cut the model, leaving me with only the torso of the mannequin. Next, I filled in some gaps that were in the mesh and adjusted the model to secure it correctly at the origin coordinates. Afterwards, I exported this new adjusted 3D model to continue with the next step: preparation for laser cutting.
Preparation for laser cutting: I loaded the fitted model into Slicer for Fusion 360 software (although it should be mentioned that this software is deprecated). Here I experimented with various configurations until I obtained an optimal design that suited my needs. I defined the dimensions of the material I would work with: cardboard 1m x 0.75m x 4mm thick. This material would serve as a canvas for the pieces that would be cut in the laser cutter.

Before making the final cut, I did a series of tests to calculate the kerf, that is, the material that is lost due to the thickness of the laser beam. To do this, I created a rectangle with 10 divisions of 1 cm each (i.e. a total length of 100 mm). After making the test laser cut, I measured the length of the rectangle again, which came out to 97.8 mm. With these values, I was able to calculate the kerf using the following formula:

Ker f = (Original size - After cut size)/ Division number

Ker f = (100mm-97.8mm)/10= 0.22mm

Thus, the kerf was 0.22 mm, which was enough to adjust the parameters in the cutting software.

Laser cutting: I used the CAMFive Laser Cutting Recorder CFL-CMA1080K laser cutter, which has a working area of 1.00 x 0.80m. After adjusting the laser speed and power parameters for my cardboard material, I loaded the exported file in DXF format from Slicer for Fusion 360. I also exported a PDF version to better visualize the pieces. I used SmartCarve software to upload the DXF file and prepare it for cutting, exporting the file in the format required by the laser machine.
Assembly and documentation: Once I had all the pieces cut, I proceeded to assemble the mannequin. I took all the pieces to a well-lit area and used a tripod to capture each step of assembly through photographs. I relied on the step-by-step assembly feature offered by Slicer for Fusion 360, which made the process much easier by clearly showing me how to put the pieces together, very similar to Lego assembly tutorials.
Creation of videos and final documentation: With the photos and videos obtained, I generated a timelapse of the laser cutting process and a stop motion video of the assembly, using FFMPEG to edit and create both videos. Finally, I compiled all the images and documents necessary to complete the documentation, including the 3D 5files in STL format, the 2D files in DXF and PDF, and the final images of the assembled mannequin.