## 3 Results and Discussions
### Three-Dimensional Scanning of Sample 1  
For mode A of 3D scanning (see Table 2) S1, the scanning factors were found to be insignificant. Almost the same percent contributions (PCRs) were demonstrated from both watertightness and simplification, as can be seen in Table 3. Of the main effects plot in Figure 5, 50% and MW were identified to be the optimal levels of simplification and watertightness as volumetric error was found to be the lowest at these levels. Figure 5: Main effects plot for volumetric error (Mode A). However, the error PCR was found to be the highest when compared to other PCRs for scanning factors. Therefore, a review of the interaction plots is direly needed to reveal the cause of this huge error PCR. It should be clarified here that two kinds of errors were investigated in this work. The first error investigated was the volumetric error, also called the 3D scanning error. Volumetric error may also referred to as empirical error. However, the error associated with the PCR is a statistical error that is calculated using crucial values from an ANOVA, Table 3. In an interaction plot, colorful lines usually belong to one factor, i.e., simplification in relation to another factor, i.e., watertightness, as shown in Figure 6. These lines cross each other at an angle which defines the severity index (SI) of the interaction. If the lines were parallel, the SI will be zero, representing zero interaction between the factors. Likewise, an SI of 100% implies that interaction occurs between the factors when the two lines intersect each other at a 90-degree angle. Normally, two lines intersect each other at an angular value between 0 and 90 degrees, indicating the presence or absence of interaction between the factors. If an SI value were found to be near zero percent, the interaction may be classified as a mild interaction between the factors. A severe interaction is usually present if the SI value reaches 100%. The interaction may be classified as moderate if the SI value lies between zero and one hundred percent. From the interaction plot in Figure 6, the severity index (SI) values were found to be between 70% to 89% for all possible interactions, depicting a severe degree of interaction for mode A of the 3D scanning. Moreover, a severe interaction means that the levels of the two factors i.e., simplification and watertightness, do not affect the response parameter, i.e., the volumetric error in the 3D scanning independently for mode A of 3D scanning. In fact, there exists a combined  
Figure 6: Interaction plots for volumetric error (Mode A). \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Source** & **DF** & **Adj SS** & **Adj MS** & **F-Value** & **\(p\)-Value** & **PCR** \\ \hline Simplification & 2 & 18.87 & 9.43 & 0.5 & 0.64 & 12.30 \\ Watertightness & 3 & 17.94 & 5.98 & 0.3 & 0.82 & 11.69 \\ Error & 6 & 116.6 & 19.43 & & & 76.00 \\ Total & 11 & 153.40 & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: ANOVA for volumetric error (Mode A). effect between the levels of simplification and watertightness that affects the quality of the 3D scanning. A high SI value is usually considered the cause of the highest error PCR and the non-significance of factors. Hence, combined effects on the 3D scanning error among the levels of watertightness and simplification cause the increased value of the error PCR. When S1 was scanned three dimensionally with mode B, all the factors were found to be insignificant from the ANOVA for the 3D texture scan and sharpness selected in the absence of smoothness for the simple box sample, as shown in Table S1 of the Supplementary File. A MW watertightness and a simplification of 70% were the two levels of simplification and watertightness which resulted in the minimum volumetric error of the 3D scanning the simple box (i.e., S1), as can be seen from the main effects plot in Figure S2 of the Supplementary File. The PCR for simplification was found to be higher than that of the watertightness.