Measuring QoS in Web-Based Virtual Worlds : an evaluation of Unity 3D web builds

Abstract

Web Based Virtual Worlds (WBVW) provide users with an immersive 3D experience through their regular browser. They can be seen as prototypes for the 3D Web. This paper uses key Quality of Service metrics to compare and present measurements of two major formats for WBVW – Unity Web Player and WebGL. Significantly, in terms of realizing the 3D Web, the former requires a plug-in whereas the latter is now directly supported by major browsers. Metrics include Frames per Second, Frame Time, CPU usage, GPU usage, memory usage and Initial Download Time. The WBVW used in these experiments is Timespan Longhouse, a virtual world hosted originally in OpenSim and then transformed into Unity 3D and WebGL. The ability to transform virtual worlds built in OpenSim/Second Life to Unity 3D and then to the web has great potential to bring 3D immersive interaction capabilities to all web users but our results show that there is a significant performance difference between Web Player (plug-in needed) and WebGL (no plug-in required), in terms of all the metrics listed above. This paper explores the performance characteristics of the respective formats and proposes possible optimizations to improve their performance.