A Performance Comparison for 3D Crowd Rendering using an Object-Oriented system and Unity DOTS with GPU Instancing on Mobile Devices.

Abstract: This paper aims to address what is a suitable programming paradigm for real-time crowd rendering from a performance standpoint, with smartphones as the target platform. Among the most prominent and intuitive programming paradigms is the object-oriented (OO) one, with data-oriented designs be- coming more common in recent years. In this paper, Unity’s GameObject approach built on an object-oriented foundation is compared with their DOTS system using GPU instancing, arranging different test scenarios later built using Xcode on an iPhone 6S and an iPhone XR. The results from the different scenarios and builds are represented through multiple graphs focusing on the obtained frame rate, CPU usage and GPU usage. The DOTS system proved to outperform the object- oriented system in six out of eight scenarios with the iPhone XR yielding better performance. With DOTS currently being under development, several acceleration and enhancement techniques are yet to be integrated such as culling or LoD, which currently can be used by its counterpart. The OO sys- tem is more robust with variation whereas the DOTS system is better suited when the number of characters increases.