# VR as a 3D Modelling Tool in Engineering Design Applications
## 1 Introduction
### Background and Objectives
Another study showed that with using VRparticipants could better perceive the fit of user interface elements and estimate the model dimensions with a lower relative error than in desktop interface on PC screen [15]. VR also offers advantages in fields such as programming of industrial robots [21]. By immersing individuals in a virtual world where they may observe and interact with robots in 3D collaborative or distant locations, VR allows for more natural and intuitive interactions. This can improve situational awareness and make interaction simpler [22]. Alongside the improved spatial perception of the objects, virtual environments can enhance the communication between the dislocated participants as they enable speech and gesturing while at the same time viewing the product in true scale 3D environment when compared to the regular video conferencing tools [23]. [PERSON] et al. [24] investigated the application of VR collaboration in a globally distributed manufacturing company. They found that the greatest issue was the transfer of the models from CAD to VR environment. The interaction design of VR systems was highlighted as an important factor for manufacturing companies to widely adopt and benefit from the latest advancements of VR technologies. In addition, VR and AR technologies have high potential and play an important role in education and training of mechanical and design engineers. Researchers have discovered that studying with the support of MR technology can significantly improve the student's abilities in geometric analysis and creativity [25]. However, the learning theories on design are often not considered by developers of VR and AR applications, which makes it difficult to incorporate them in the study process [26; 27]. Besides the application of VR for viewing and discussing proposed design solutions, this technology can also support earlier stages of design. According to [PERSON] et al. [28] the product development process consists of the following phases: planning and ideation, concept development, embodiment design, detail design, testing and refinement and production ramp-up. Engineers use various tools that can assist them with different tasks during development, with the aim to speed up the process. When the product concept is created, it is commonly represented in the form of sketches. These sketches serve as a starting point for the product embodiment, which can be formed as physical or virtual prototypes [29]. With the rapid development of tools and technologies, virtual prototypes created using 3D modelling in CAD software have become the most common way for design representation [30]. They enable engineers to easily share and modify their designs using dedicated desktop CAD tools. However, CAD on a screen cannot always meet all the requirements regarding the functional and ergonomic validations of complex 3D models [20]. In recent years, CAD modelling tools were developed and adapted to support the use of VR headset technology. [PERSON] and [PERSON] [31] classified design functions that can be supported by VR into early phases, co-design, 3D modelling, virtual assembly and prototyping, product evaluation and educational purposes. [PERSON] and [PERSON] [3] discussed the usability of VR tools and their capabilities for early design phases. They listed several challenges: for the detailed design phase the transfer from 3D VR to a CAD model has to be possible, the VR-created surface models must be automatically converted into solid bodies, collision detection has to be integrated to prevent overlapping of the objects and an automatic alignment of edges and axes must be enabled. In addition, they highlight that the software has to be intuitive and easy to use to enable wider adoption. As one of the main issues that hinder the use of this technology in engineering design, the authors name the reduced quality of imported models and the inability to edit them. The use of VR for creating design concepts was explored in several studies. [PERSON] et al.