# VR as a 3D Modelling Tool in Engineering Design Applications
## 3 Results
### Research Study: VR 3D Modelling Results
#### 3.2.2 Questionnaire after Modelling  
After the user testing of 3D modelling in VR, participants were given a questionnaire consisting of 5-scale rating questions and open questions. First, they were asked to respond to questions about how much they agreed with statements about the use of VR technology. As can be seen in Figure 10, they largely agree that a freeform model can be created faster with VR modelling than with a desktop modeller. All but one participant disagreed with the statement that VR enables the same modelling options as a desktop modeller. They had difficulties deciding whether the VR is accurate or not, but in general, they feel that it is more of an inaccurate tool. They agree that VR modelling is intuitive and that the spatial perception of the product in VR is clearer. Figure 10: Participants’ opinions on modelling using VR technology after the study. \begin{table}
\begin{tabular}{p{113.8 pt} p{284.5 pt}} \hline \hline
**VR Modelling Phases** & **Researchers’ Observations** \\ \hline Imported images & Importing alone was easy and none of the participants complained about it. They all said it was intuitive. \\ \hline Sketches/projected sketches & Placing the sketches in the coordinate system was reasonably quick, but scaling the images caused problems for the participants. \\ \hline Surfaces & Creating the surface patch was quick but fitting the surface to the curves was time consuming and required some extra work. \\ \hline Geometry matching & The VR process does not allow for exact positioning on planar views (e.g., top view, side view), therefore, the alignment of the geometry must be done from a 3D perspective, which caused issues with geometry fitting to the reference images. \\ \hline Surface transition & At this point, participants have prepared half of the surface model for mirroring on the right plane. They had difficulties creating a suitable surface model with an appropriate amount of vertices to achieve symmetry and frequently needed help with the controls. \\ \hline Solid body & All participants succeeded in creating a fully enclosed surface model, which enabled the conversion of the model into a solid body. This step requires some additional work for model conversion in desktop tools. However, some participants did not succeed in creating the model with the right geometry and proportions. \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Researchers’ observations during the modelling steps. In the questionnaire, participants were also asked to describe their experience in VR regarding 3D modelling, to state and argument their opinion if they would rather use VR than traditional (desktop) modelling and if they find one to be easier than the other (Table 6). The answers in the table below are given in their original form. When describing their 3D modelling experience in VR, few participants compared it to the modelling using the desktop tools. They argue that the freeform surface modelling is easier in VR: \"VR enables very fast and intuitive surface modelling.\" (P3) and \"Modelling is similar to Solidworks, more free forming (better ability to create free forms), maybe some control points are missing. It's easier to move around the model.\" (P4). Participant P6 gave a more detailed description highlighting specific modelling activities which are better in one tool than in the other: \"VR modelling is pretty simple, maybe some functions are missing (closing the surfaces, extrude,...). Certain functions, e.g., freeform modelling was easier in the VR environment than in SolidWorks because it is easier to move the points in 3D space. Positioning is easier in SolidWorks because we can choose the view which we want, in VR we have to position it manually. In SolidWorks modeller scaling of the images is also easier, because we can perform it in a way that we 'drag' the point and mark the dimensions of the model.