CodeCity: On-Screen or in Virtual Reality?

Over the past decades, researchers proposed numerous approaches to visualize source code. A prominent one is CodeCity, an interactive 3D software visualization that leverages the "city metaphor" to represent software system as cities: buildings represent classes (or files) and districts represent packages (or folders). Building dimensions represent values of software metrics, such as the number of methods or the lines of code. There are many implementations of CodeCity, the vast majority of them running on-screen. Recently, some implementations visualizing CodeCity in virtual reality (VR) have appeared. While exciting as a technology, VR’s usefulness remains to be proven.The question we pose is: Is VR well suited to visualize CodeCity, compared to the traditional on-screen implementation?We performed an experiment in our interactive web-based application to visualize CodeCity. Users can fetch data from any git repository and visualize its source code. Our application enables users to navigate CodeCity both on-screen and in an immersive VR environment, using consumer-grade VR headsets like Oculus Quest. Our controlled experiment involved 24 participants from academia and industry. Results show that people using the VR version performed the assigned tasks in much less time, while still maintaining a comparable level of correctness.Therefore, our results show that VR is at least equally well-suited as on-screen for visualizing CodeCity, and likely better.