## 3 Materials and Methods
### Documentation and 3D Scanning Phase
The displacement map generation is performed within Autodesk Mudbox, and the process requires a source model (high resolution) that contains the sculpted details to be extracted as a reusable displacement map. The source models have been generated using the 3D scanned dataset, and it is important to note that this model does not require UV texture coordinates. This research made use of the Autodesk Mudbox Ray Casting technique to extract the displacement maps by recording the distance (as a pixel value) between the source and target model, based on ray casting along the surface normal of the target surface. To improve the accuracy of the maps generated based on the 3D scanned ornaments of the fragmented disk, the methodology makes use of the vector displacement map technique. A vector displacement map is a 2D image that records both the height and the directional information of individual points as 32-bit floating-point color information. The file can store the distance at which a vertex will be displaced (based on the pixel value in the image map) and the direction of the vertex displacement. Vector displacement maps have a main advantage over the ray casting extraction method of not producing any artifacts when applied to another surface. To extract the details from the 3D model acquired using the structured light scanning solution, we have opted for the technique known in the literature as the _\"Vector displacement map\"_. This technique has evolved from the technique known as the _\"Displacement map\"_, and was developed in the Pixar animation studio for the RenderMan Software solution to allow the creation of details on the surface of 3D models. Other researchers have proposed algorithms that allow the use of video cards to generate these textures that allow for the movement of the geometry of the 3D model [43]. The resulting 3D scanned model has been imported to 3 ds Max to facilitate the extraction of each individual ornament. The authors have proposed the following workflow that can be used to enable the extraction of ornaments, as vector displacement map tools that can be rapidly used to reapply the ornament onto the surfaces of other 3D models. The extraction and processing of the 3D scanned ornaments methodology proposed by the authors (presented in Figure 3) makes use of a two-step process. The methodology makes use of two 3D computer graphics software (3 ds Max and Mudbox) from Autodesk, but the workflow steps can be followed with other software solutions such as, Zbrush, Modo, or other commercial 3D modeling software packages, or free open-source software such as Blender. If other software solutions are used, the methodology requires a few adjustments, but it follows the same steps. For this case study, we have chosen 3 ds Max and Mudbox, as the two software are interconnected, and as 3 ds Max has good interoperability with computer-aided design software such as CATIA, the software that is used to define the accurate 3D model of the support of the reconstructed embossed disk based on the measured dimensions of the 3D scan dataset. The 3D model acquired by using structured light scanning was exported in two different file formats to facilitate the ease of work when using these files. The file format OBJ is suited for Digital Content Creation software such as 3 ds Max, while the STL file format is more suited for engineering analysis for computer-aided design software solutions such as CATIA V5. The first ornament extracted is represented by the aurochs, which is located in the central register of the disk. The extraction involved the selection and removal of the 3D scanned mesh that is not associated with the ornament; this step is illustrated in Figure 5.  
The aurochs' ornament has several perforated holes on its surface, which is due to the corrosion process of the iron. The corrosion of the ornament was stopped because of the physical conservation process applied to the fragments when the fragments were arranged on their current support.