Treffer: 3D-Visualization of Utility Lines in the Browser Using Augmented Reality on Tablets

Locating underground utility lines such as water tubes or gas pipes is a complex task due to the fact that they are mostly hidden. The aim of this project is to create a solution which represents an innovative, cost-effective alternative to current solutions. Current solutions are dependent on expensive hardware and native applications. This thesis introduces a web-based augmented reality (AR) application for visualizing under- ground utility lines on Android tablets. Thereby, addressing the challenge of locating such lines. It utilizes WebXR and WebGL to integrate Building Information Modeling (BIM) data, specifically Industry Foundation Classes (IFC), into a 3D web environment. This process involves converting IFC data for compatibility with WebGL, using Blender with the BlenderBIM add-on. The appli- cation’s frontend was developed using Vue.js with Typescript, and the backend with Python Flask. Besides the already mentioned technologies, the application utilizes PostgreSQL, Post- GIS, Three.js, Turf.js and Vuetify. A key aspect of this project was the application’s ability to approximate the positioning of utility lines. Using the device’s geolocation and the lines’ coordinates, the relative distance is calcu- lated and applied in the virtual space. Additionally, the virtual space has to be aligned with the real world, which is achieved by rotating the virtual coordinate system based on the device’s compass. This thesis identifies a challenge in aligning the virtual and real-world coordinate sys- tems, due to the compass inaccuracy on mobile devices. These compass inaccuracies lead to a wrongly rotated virtual coordinate system and therefore imprecise placement of the utility lines.