# Influence of Material on the Density of a Point Cloud Created Using a Structured-Light 3D Scanner
## 3 Materials and Methods
### Description of the Equipment Used  
The Artec Eva Lite (Figure 3) handheld structured-light 3D scanner from Artec 3D, which has been operating on the market since 2007, was used to scan all materials (activities A4, A8, and A12). This type of 3D scanner was chosen due to the principle of data acquisition. \"Eva\" works on the principle of photogrammetry. It is this method that is significantly more widespread than laser scanning due to the purchase price of both devices [6]. When comparing the Artec Eva Lite with most other 3D scanners on the market, it is clear that the price/performance ratio is the best for this type of 3D scanner, which is why it was the choice for this research. Examples of prices are as follows. The price of a used Artec Eva 3D scanner with an accuracy of 0.1 mm is USD 15,000. A comparable handheld scanner with laser technology and 20 mm accuracy costs USD 53,710. The examples of prices are indicative and obtained as of 6 January 2024 and can be found in [37].  
As the word \"Lite\" in the name suggests, this is a cheaper and less demanding version of the Artec Eva scanner. This needs to be taken into account, as the results of data collection from two seemingly identical scanners can be very different. Although the Artec Eva Lite has the same accuracy as its full version, it cannot capture the optical texture and color of the object, and, thus, has a lower resolution. This also means that, unlike the full version, it focuses only on the geometry and the shape of the object, and not on its color and texture; however, even these factors could affect the quality of the scans [38].  
Undoubtedly, the advantage of the simplified version is also the fact that, thanks to the scanning of only simple object geometry, we collect and then work with a much smaller volume of data, and, thus, the Lite version is less demanding in terms of power consumption and the required minimum computer power. While the Lite version can capture up to 2 million dots per second, the full version is able to capture up to 18 million dots per second.  
The Artec Eva Lite scanner uses structured light technology for data collection. The device has a total of 12 LED light sources, which are used to project a special light pattern on the object. In Figure 4, where this pattern is projected onto the wall, it can be seen that these are alternate rows of smaller and larger points, which are placed in regular rows, but in an irregular order.  
The shape of the scanned object distorts this light pattern; the scanner can capture this distorted shape using three cameras to create a point cloud corresponding to the actual shape of the object. It is important to maintain the working distance, which is about 0.4-1 m.  
From the principle of structured light technology, it is assumed that some materials may be more or less problematic to scan with this technology if, for example, structured light passes through them or is reflected at a different angle than the object's shape [39].  
Notebook  
A Dell Precision M3800 notebook (Figure 3) with a fourth-generation Intel(r) Core-i7-4702 HQ quad-core processor, NVIDIA Quadro K1100M graphics card, and 8 GB of RAM was used for scanning and subsequent work with the acquired data. It is also equipped with a touch screen and a fast SSD disk. Windows 10 is installed on the laptop.  
Artec Studio 12 Professional  
MeshLab  
We used the software Meshlab 2022.02 (www.meshlab.net, accessed on 3 October 2022) to create polygon meshes from the raw data in the form of a point cloud. At the same time, we diagnosed (determining the number of points in a specified area) the models that were also used in this research.