Interactive Visualization of Underground Infrastructures via Mixed Reality

Abstract: Visualization of underground infrastructures, such as pipes and cables, can be useful for infrastructure providers and can be utilized for both planning and maintenance. The purpose of this project is therefore to develop a system that provides interactive visualization of underground infrastructures using mixed reality. This requires positioning the user and virtual objects outdoors, as well as optimizing the system for outdoor use. To accomplish these, GPS coordinates must be known so the system is  capable of accurately drawing virtual underground infrastructures in real time in relation to the real world. To get GPS data into the system, a lightweight web server written in Python was developed to run on GPS-enabled Android devices, which responds to a given HTTP request with the current GPS coordinates of the device. A mixed reality application was developed in Unity and written in C# for the Microsoft HoloLens. This requests the coordinates via HTTP in order to draw virtual objects, commonly called holograms, representing the underground infrastructure. The application uses the Haversine formula to calculate distances using GPS coordinates. Data, including GPS coordinates, pertaining real underground infrastructures have been provided by Halmstad Energi och Miljö. The result is therefore a HoloLens application which, in combination with a Python script, draws virtual objects based on real data (type of structures, size, and their corresponding coordinates) to enable the user to view the underground infrastructure. The user can customize the experience by choosing to display certain types of pipes, or changing the chosen navigational tool. Users can also view the information of valves, such as their ID, type, and coordinates. Although the developed application is fully functional, the visualization of holograms with HoloLens outdoors is problematic because of the brightness of natural light affecting the application’s visibility, and lack of points for tracking of its surroundings causing the visualization to be wrongly displayed. Visualization of underground infrastructures, such as pipes and cables, can be useful for infrastructure providers and can be utilized for both planning and maintenance. The purpose of this project is therefore to develop a system that provides interactive visualization of underground infrastructures using mixed reality. This requires positioning the user and virtual objects outdoors, as well as optimizing the system for outdoor use. To accomplish these, GPS coordinates must be known so the system is capable of accurately drawing virtual underground infrastructures in real time in relation to the real world. To get GPS data into the system, a lightweight web server written in Python was developed to run on GPS-enabled Android devices, which responds to a given HTTP request with the current GPS coordinates of the device. A mixed reality application was developed in Unity and written in C# for the Microsoft HoloLens. This requests the coordinates via HTTP in order to draw virtual objects, commonly called holograms, representing the underground infrastructure. The application uses the Haversine formula to calculate distances using GPS coordinates. Data, including GPS coordinates, pertaining real underground infrastructures have been provided by Halmstad Energi och Miljö. The result is therefore a HoloLens application which, in combination with a Python script, draws virtual objects based on real data (type of structures, size, and their corresponding coordinates) to enable the user to view the underground infrastructure. The user can customize the experience by choosing to display certain types of pipes, or changing the chosen navigational tool. Users can also view the information of valves, such as their ID, type, and coordinates. Although the developed application is fully functional, the visualization of holograms with HoloLens outdoors is problematic because of the brightness of natural light affecting the application’s visibility, and lack of points for tracking of its surroundings causing the visualization to be wrongly displayed.