# Enhanced and Combined Representations in Extended Reality through Creative Industries
## 3 Materials and Methods
### Implementation
#### 3.2.2 Instances from CT-Scans  
Generating the Instances  
In our attempt to democratize tomography through immersion technologies, we relied on the possibility offered by specialized software for the analysis of volumetric data. Specifically, we took advantage of the possibility of extracting a finite number of snapshots of the internal structure of the seven major fragments (A to G) of the Antikythera Mechanism. For each of the artifact fragments, starting from one edge of the bounding box, we selected the number (N = 100) of snapshots that we deemed necessary to provide end users with a complete picture of the internal structure of the fragments. The software, traversing the volumetric representation along a selected axis, produced the snapshots in image form (in.png file format with opacity, except fragment D) until they reached the edge of the bounding box (RQ1). The resolution of the images was set to full high definition (1920 \(\times\) 1080 pixels, apart from fragment D) (Table 2). Figure 2 depicts indicative instances for each fragment (A to G).  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Fragment** & **Format** & **Opacity** & **Resolution** & **Instances per Fragment** \\ \hline A &.png & yes & 1920 \(\times\) 1080 & 100 \\ B &.png & yes & 1920 \(\times\) 1080 & 100 \\ C &.png & yes & 1920 \(\times\) 1080 & 100 \\ D &.png & no & 648 \(\times\) 736 & 100 \\ E &.png & yes & 1920 \(\times\) 1080 & 100 \\ F &.png & yes & 1920 \(\times\) 1080 & 100 \\ G &.png & yes & 1920 \(\times\) 1080 & 100 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Details for the captured instances from the CT scans of the selected fragments of the Antikythera Mechanism.  
We investigated and tested two possible scenarios for the integration of the information from the tomographies in the virtual museum, namely (a) switching of the snapshots on a static surface and (b) switching of the snapshots on a moving surface. In the virtual museum for the Antikythera Mechanism, the first selection was applied (RQ2).  
Display on a Static Surface  
In the case of switching the sequence of snapshots (RQ1) to a static surface, we use a surface in the game engine that is permanently located at a fixed point. The content of the fixed surface is determined by the dynamic rotation of the content, which consists of the serial stack of images. The sense of perspective regarding the internal structure of the fragment results from the illusion that will be created for the user by the alternating images. Essentially, we rely on the basic principle of the art of animation to communicate the information of the scans in an easy-to-use and understandable way (RQ2).  
Display on a Moving Surface  
In the case of switching the sequence of snapshots on a moving surface, we use a surface in the game engine that is permanently in motion. The moving surface is moved along the axis on which the snapshots were taken, following the same displacement step. The content of the moving surface is determined by the dynamic rotation of the content, which consists of the serial stack of images. However, each distinct position on the surface corresponds to a single instance. The sense of perspective regarding the internal structure of the fragment is greatly enhanced by the simultaneous displacement of the viewing surface. It could be described as a movable projection screen.