## 2 Materials and Methods  
The GoSCAN SPARK, developed by Creaform, is a compact and portable 3D scanner that offers precise measurement and scanning capabilities. It is specifically designed for a wide range of applications, including creating 3D models for the textile industry, product development, quality control, reverse engineering, and heritage preservation. With its advanced features and versatility, it provides an efficient solution for object reconstruction and measurement necessities. The GoSCAN SPARK is a handheld 3D scanner that utilizes structured light technology to capture precise and detailed 3D scans of objects. It offers measurement accuracy as low as 0.05 mm and scanning resolution as low as 0.1 mm. Being user-friendly, the scanner is easy to handle, making it suitable for scanning complex objects. Additionally, it uses advanced technology to rapidly generate high-quality 3D scans of objects and surfaces [21; 22; 23; 24; 25; 26; 27]. The GoSCAN SPARK scanner does not require the surface of the indoor sports shoes to be pulverized with special spray for antireflection, compared to other types of laser scanners that require this preliminary operation. This scanner utilizes 3D hand scanning and reverse engineering technology, along with prototyping technology, to quickly measure and analyze the geometric data of sports shoes designed for indoor use/matches. This process involves analyzing the shape and appearance of real-world objects or environments to create three-dimensional digital models. The 3D hand scanning of sports shoes presented in this paper was performed on the outer surface of the shoe because a different approach is required for inner scanning, which will be presented in a future paper. Considering manual scanning with a 3D scanner with structured light for scanning several objects, as in the case of the present work (shoes used in indoor sports), scanning errors may occur. The GoSCAN 3D SPARK shown in Figure 1 is an optical device that projects white light strips onto scanned objects (in this case shoes used in indoor sports) and then registers the distortion of the lines by means of three cameras on the entire light strip, creating a surface formed by a cloud of points [28]. Figure 1: HandySCAN GoSCAN SPARK 3D [28]. The necessary steps to build a 3D model of scanned sports footwear using a hand-held 3D scanner are scanning the point cloud and real-time processing as a mesh in the VXelements software [29]. VXelements is a software application developed by Creaform, specifically designed for the acquisition and processing of 3D scan data from various scanning devices [30; 31]. The processing of the point cloud resulting from the scanning of the sports shoes analyzed in this paper was performed using VXelements software by reducing the noise and the number of points using filtering algorithms from different assemblies and subassemblies in the case of products made from multiple 3D scans [32]. Structured light scanners use trigonometric triangulation, but instead of using laser light, these systems use a projector to display a series of linear patterns on an object such as the footwear intended for indoor sports [33]. Then, by examining each line in the pattern, it calculates the distance from the scanner to the surface of the sports shoe analyzed in this paper [34]. Figure 2 shows the principle of scanning indoor sports footwear using a 3D hand scanner with structured light [35]. Figure 3 presents model A and B of the footwear used for indoor sport (handball) which went through the 3D scanning process. In the case of the GoSCAN SPARK scanner that was used for the scanning of the two models of shoes used for indoor sports, it is not necessary to spray the contact surface of the  
Figure 3: Sports footwear for indoor sports (handball): (**A**) footwear type A used for indoor sports (handball); (**B**) footwear type B used for indoor sports (handball). Figure 2: Principle of structured light for a HandySCAN 3D [35].