2. Digital bodies¶

RESEARCH & IDEATION¶

3D scanning is a process of analyzing an object from the real world, to collect all the data in order to recreate its shape and appearance, digitally. Thanks to this process, the object can become a 3D model, which could help you as a base for the 3D project you are about to develop, but it can also be useful to reconstruct, analyze, or simulate ideas.

Laser 3D scanning

Laser 3D scanning is certainly the most common and used 3D scanning technique. Digitally capturing the shape of the object using laser light to get a digital representation of the real object. These 3D scanners are able to measure really fine details and capture free-form shapes to generate highly accurate point clouds.

This laser scanning technique is perfect for measurement and inspection of complex geometries. It allows getting measurements and data from where it is impractical with traditional methods!

A scanner using laser light is a little bit like a camera: it can only capture what is in its field of view. With this process, a laser dot or line is projected on an object from the device and a sensor measures the distance to the surface of this object.

By processing this data, it can be converted into a triangulated mesh, and then a CAD model.

Photogrammetry

Photogrammetry is a science of making a measurement from photographs! It seems pretty simple, no? This method uses the parallax obtained between several pictures, taken from different points of view. Photogrammetry can be used to record complex 2D and 3D motion fields. It imitates the stereoscopy of the binocular human vision, and it is used to get all information of existing physical objects. Indeed, this process collects the data regarding the shape, the volume, and the depth of the subject that you are trying to scan.

This is the method used to turn several pictures into an accurate 3D design. It won’t allow you to get the most accurate result, but by using good photogrammetry software you could actually reach a satisfying result!

Structured Light Scanning

With this Structured Light Scanning method, one of the camera positions used in previous scanning methods is actually replaced by a projector that projects different light patterns on the surface of an object. The way the objects distorts these patterns is recorded, allowing to create the 3D scan.

The structured light scanning process is used in facial or environment recognition technologies.

You can read more here

REFERENCES & INSPIRATION¶

1. Women abstract body is a piece of digital artwork by Magda Ziemak which was uploaded on January 15th, 2014
1. Desconstruction the female body - Jake Stollery
1. Body layers is a painting by Magda Ziemak which was uploaded on January 15th, 2014.

TOOLS¶

[Polycamera]
[Slicer for Fusion 360]
[MeshMixer]
[Cura Ultimaker]
[Lasser Cut]

PROCESS AND WORKFLOW¶

STEP 1 - SCANNING¶

There are different ways to scan a body in 3D, this time I will be using photogrammetry with the Polycam application that is available for both iPhone and Android, it is quite easy to use. I show you how below.

Don't forget that the more photos you take of the object, the more accurate the 3D model will be.

The application itself allows you to export in many formats.

I chose to export it in Stl format.

14 ene de 2024 by grecia20bello on Sketchfab

PROBLEMS AND TIPS¶

In my first attempt to scan, the model came out with many objects since the room where I was had many elements that the application recognized as part of the body. Likewise, the number of photos that were taken is 315.

Tip: Occupy a background preferably white walls and wear contrasting clothing, in the following example I dressed in black. Likewise, the number of photos was 518.

STEP 2 - WORK WITH THE MESH¶

CUT¶

After exporting the 3D model to STL, I proceeded to use the MESHMIXER program and cut out the parts of the body that I did not want.

SMOOTH SURFACE¶

Then select the entire model and choose the reduce option, thus eliminating details that we will not use. This will smooth the surface.

EDIT AND PATTERN TYPE¶

This tool is used to add patterns to the mesh of our 3D model, but the first time I used it this happened.

This happened because the model was very small, about 2mm. Then adjust the scale to fit the Meshmixer work surface.

After fixing the scale I was able to correctly visualize the different patterns that meshmixer offers us, here are some examples that were my favorites.

EDGES¶

This example highlights the curves but at the same time provides a grid, according to some examples that I saw they also tend to use this function to create splints.

I also uploaded it to SketchFab so you can zoom in.

EDGES BODY by grecia20bello on Sketchfab

RANDOM PRIMITIVE SURFACES¶

This option allows us to create balls around the surface of the mesh with a random organization.

I also uploaded it to SketchFab so you can zoom in.

RANDOM PRIMITIVE SURFACES BODY by grecia20bello on Sketchfab

LATTICE BODY¶

As its name says, grid structure.

I also uploaded it to SketchFab so you can zoom in.

LATTICE BODY by grecia20bello on Sketchfab

FINAL MODEL¶

To assemble the structure with laser cutting, I decided to alize the mesh to preserve the curves. The only step left would be to make it solid.

It can be achieved with the EDIT, MAKE SOLID function.

I also uploaded it to SketchFab so you can zoom in.

BODY by grecia20bello on Sketchfab

STEP 3 - SLICER¶

I did the slicer area using the Slicer for Fusion 360 program, this allows us to generate the 2D DXF cutting files to be able to cut them with the laser cutter.

To occupy it, the following parameters must be taken into account.

Size and thickness of the material to be cut
Size of the 3D model (it may not have the appropriate scale when you export it)
Assembly feasibility (later I show examples that would not be viable.)

CUTTING PATTERNS¶

Before starting I adjust the size of the model as in the following figure.

STACKED¶

Although this option gives us very defined shapes and quite a few details, it consumes a lot of material, but it is still a very beautiful model.

CURVE¶

The curved model, despite retaining details in the shape, has blue pieces that do not fit together to form part of a single body.

FOLDED¶

I found this example very interesting since we can generate many shapes from a single fold of material.

RADIAL SLICES¶

It is not so viable since the blue piece has nowhere to fit and be all part of a single body.

INTERLOCKED SLICES¶

This was the final model that I chose to generate the DXF files.

The configuration used is A2 size material plates with a thickness of 3mm.

This generated 4 files for cutting.

STEP 4 - LASER CUT¶

I will explain using the RDWorks software commonly used for Chinese brand laser cutters.

In the area of laser cutting it is very important to know what material we are cutting in order to configure the speed and power of the laser.

Before setting up, check the capacity and power of the machine, such as speed limits and laser power. Tip: First do a test with a small piece of the material you are going to cut to be more precise with the adjustments.

We have blue and red lines. Each color represents the following data:

Speed
Minimum laser power
Maximum laser power
Priority (according to the order, the red or the blue will begin to cut.)

SETTINGS¶

This case is occurring with an example of a 100W laser cutting machine.

For this color set the following data in:

Speed = 120 mm/s since the red lines are only light engravings and are not cuts.
Power range from 10 to 15 W, if I increase the power to around 50 W it could transfer the material but I only want a slight engraving.
Priority: 1, this is because first I want the engravings of the parts to be generated, they are the indications so that I know what part number it is.

For the color Blue, set the following data to:

Speed = 70 mm/s since the blue lines are only the cutting lines, so I need the laser path to be slower so that it has time to penetrate the material.
Power range from 30 to 50 W, as I will be cutting cardboard they will be sufficient values to transfer.
Priority: 2, I require that the blue pieces be the last so that they already have the engravings made before being cut completely.

Tip: The engraving is done first because if we did it after the piece has been cut it could happen that the cut piece moves mm and our engraving remains moved.

The software still gives us an approximate time of 3 minutes.