## 3 Materials and Methods
### Documentation and 3D Scanning Phase  
The 3D scanning phase has been conducted directly within the National Museum of Transylvanian History from Cluj-Napoca, Romania, using the equipment available within the 3D scan laboratory of Technical University of Cluj-Napoca [40]. Within the laboratory, there are a wide variety of 3D scanning equipment, such as laser scanners, structured light scanners, terrestrial laser scanners, and coordinate measuring machines equipped with 3D scanning accessories, as well as photogrammetry equipment. Displacement mapping techniques generated from 3D scan datasets have been previously applied to cultural heritage. The idea of coding a dense mesh with fine details and mapping them on a simplified version mesh has been pursued since early computer graphics applications. The researchers [PERSON] et al. have used displacement mapping techniques to optimize mesh models generated with 3D scanners [41]. The proposed framework makes use of the displacement mapping technique, but they are not intended to be used as simplified mesh versions; instead they are used to store the fine details of the 3D scan dataset as stencil tools to facilitate the 3D reconstruction of fragmented cultural heritage objects and monuments. The digitization process made use of a structured light scanning solution to record both the 3D shapes and the color texture of the Dacian embossed disks at a high resolution. We have opted for 3D scanning with the Creaform GoScan 50 [42], as it provides trueness and precision that ensures that the ornaments are acquired at their true scale with minimum deviations. The scanner has been developed by Creaform in partnership with AMETEK, as a flexible and rapid 3D scanning solution that is designed to address a wide range of professional needs, starting from industrial applications up to cultural heritage, while providing a portable handheld solution. The scanner makes use of 3D positioning targets, but it can also be used with ease for various cultural heritage digitization tasks, as it can use both targets, geometry, and texture as positioning references. The structured light scanner has a large field of view, with a scanning area of 380 \(\times\) 380 mm, and is recommended for objects with a size of between 300 and 3000 mm, making it the perfect solution, considering the size of the fragmented Dacian embossed disks from Piatra Rosie. The resulting 3D model is presented in Figure 3, along with close-ups of the most important ornaments. Figure 3: (**a**) A close-up photography of the physically realigned fragments; (**b**) 3D scan of the physically realigned fragments. The framework can make use of any 3D scanning equipment that is available, for the case study of the fragmented embossed disk. This was also processed using photogrammetry and laser scanning, but the most accurate and detailed meshes were obtained using the GolScan 50. Having 3D scanned the fragmented embossed disk ornaments, the raw dataset of each ornament has been processed using the following proposed ornament vector displacement map workflow (Figure 4). For this case study, an Autodesk Mudbox software solution was used, as it integrates an operation that enables vector displacement map creation. Other software solutions that enable vector displacement map creation can be used, such as Zbrush, Modo, and even free and open-source Blender. The vector displacement map can be processed within MATLAB. We have chosen Mudbox, as it offers better file interoperability than other similar software solutions. The interoperability from Mudbox is enabled by using Autodesk 3 ds Max, which can be linked to Mudbox, offers a wide variety of file formats to be imported, and integrates topology modifiers to ensure that the 3D mesh has no associated 3D modeling problems. Figure 4: The proposed ornament vector displacement map creation workflow from the proposed framework, along with the illustrated steps for the aurocks ornament case study. The ornament extraction process is based on ray casting methodology.