## 2 Materials and Methods
### System Core Components  
The V-Cockpit system architecture is divided into six core components, described below:  
1. Third-Party CAD/3D Editing Software Plugins: To streamline the seamless progression from the design phase to the virtual environment, a series of specialized instruments serve as connectors, bridging third-party CAD/3D editing systems and the IVI development software. Such instruments are implemented as plugins developed for popular CAD/3D editing software such as Dassault Systemes SolidWorks(r) 2021 SP2.0 and Blender 3.5.0 to facilitate the direct migration of 3D models. An ad hoc file exchange format is used to store the relevant information and to optimize 3D data for real-time performance within a VR context. This integration significantly improves  
Figure 1: V-Cockpit system architecture. Numbers indicate the core components that implement specific functionalities, while unnumbered boxes represent functionalities provided by common external tools (such as databases and Android emulators). the overall workflow, fostering a more efficient and cohesive transition throughout the development process. Moreover, the seamless integration facilitates a dynamic exchange of data and insights between the design and testing phases. Engineers and designers can interact with virtual prototypes in a more immersive and intuitive manner, gaining valuable perspectives that may not be evident in traditional design workflows. This iterative feedback loop, empowered by the interconnected software tools, promotes a collaborative and innovative approach to refining designs with V-Cockpit-related instruments natively integrated into the working environment that users are already familiar with. 2. VR Client: The heart of the system lies in the VR simulation engine, responsible for rendering realistic 3D environments and tracking the user experience and performance [21]. This is possible thanks to Unity, a cross-platform game engine used to create 3D real-time applications, that also provides support for VR development [22]. Leveraging its advanced graphics and physics engines, this component immerses users in a dynamic and lifelike representation of the car cockpit. It enables real-time interaction, customization, and testing of various design elements, including the ones authored in CAD/3D editing software and imported through our ad hoc exchange format. Key to reducing time-to-market is a digital twins module, which creates virtual replicas of multiple console components within the car cockpit. This includes intricate details of infotainment surfaces, knobs, levers, controllers, and other relevant elements. These digital twins serve as the foundation for rapid prototyping and iterative design processes. The VR client also implements a basic car simulation and scripting system for the creation and replication of different scenarios. All of this is made possible thanks to the Unity XR Interaction Toolkit, which is employed to manage user interactions, including gaze, gesture, and controller inputs. Scripts are developed to handle lifecycle events, input/output events, and interaction behaviors, ensuring a smooth and responsive user experience. 3. Hardware Integration: To ensure a user experience as close as possible to the real world, it is essential that the IVI system is run directly on the hardware foreseen for the real cockpit. For this purpose, a dedicated component, which allows the IVI software to run seamlessly on its native platform, is integrated into V-Cockpit. Custom drivers and middleware are provided to facilitate communication between the VR client and embedded hardware. This integration is tested extensively to ensure reliability and accuracy. 4. Cloud Backend/Middleware: The cloud backend manages data storage, processing, and analytics. It utilizes REST APIs for communication with various system components, ensuring data integrity and availability. The middleware handles tasks such as model conversion, data synchronization, and real-time updates.