# Designing an Educational Metaverse: A Case Study of NTUniverse
## 2 Overall System Design
### Design Tools  
To support collaboration, simulation, and real-time 3D graphics design, the NVIDIA Omniverse platform provides a collection of workflow-focused foundation applications, e.g., Omniverse Create/USD Composer for scene composition, and Isaac Sim for robotics, etc. [15]. Omniverse enables collaboration across various development tools by different users. Universal Scene Description, a file format first introduced by Pixar and now adopted natively by Omniverse, is an extensible 3D interchange standard utilized for the sharing of 3D data between various applications and tools. USD allows 3D models from other software, such as Unreal Engine (version 5) or Unity 3D (version 2022.3.0), to be integrated into Omniverse. Nucleus is the database and collaboration engine in the Omniverse platform. It offers storage and database capabilities, and as a collaboration engine, it helps users connect with multiple apps and allows them to establish bidirectional file connections between Omniverse and their custom application via Connectors [13].  
A user interface for accessing the virtual environment rendered on the Omniverse platform and viewing project-related data is provided via the NTUniverse webpage, which is created using React. This online interface improves accessibility and offers users a central location to communicate with the platform and receive pertinent information. By fostering interoperability, scalability, and seamless collaboration, this system design approach enables users to take advantage of their favorite tools and collaborate effectively when building and exploring virtual environments within Omniverse. The SDA for NTUniverse is enabled in the Omniverse architecture for visualization and analytical applications. Real-time physics simulations and visualizations are available for the creation and modification of intricate models based on USD across different platforms.  
SolidWorks (version 2023) is a popular tool widely used in design, and it forms the basis of our campus's CAD model. Currently, there is no connector between SolidWorks and Omniverse; thus, we designed our campus model in SolidWorks and converted the data into a 3D data format (OBJ file type) before importing it into Omniverse as a unified USD file.  
The first module to build is the NTU Campus Digitalization. This involves constructing a photorealistic digital twin of the physical NTU campus, with a focus on improvements in campus navigational accuracy and efficiency. In this construction, 3D directional signs and navigational aids are strategically created and placed to outline locations of significant structures and key installations. This increases the overall accessibility of NTUniverse.  
The second module to construct is the design and modeling of the future campus-train system that is currently under construction. The 3D models of trains, train stations, and tracks are incorporated into NVIDIA Omniverse for dynamic simulations. Both first-person and third-person views are available for the train system in NTUniverse. Possible applications include the analysis and behavior testing of the campus train models. From a system design standpoint, Omniverse USD Composer provides useful scene composition tools for VR and 3D applications, including simulation of physics-based effects. Furthermore, action  
Figure 2: High-level flow of the system design architecture.  
graphs and PhysX are features that enable users to simulate and view realistic physical activities in the virtual world using push subgraphs to produce physics simulations [16].  
The third module is for Virtual Heritage, Design, and STEM education. Action Graphs can be applied to streamline the experiment process, providing an immersive and educational experience. Figure 3 summarizes the design and development of NTUniverse.