The Cost of the 3rd Dimension : Comparing Unity-Based 3D And 2D ABMs

Sammanfattning

When developing an agent-based model (ABM), an important decision that has to be made is whether it should be two- or three-dimensional. 3D is often more realistic, while 2D typically has better computational performance. Since requirements on simulators vary, there is no single correct answer as to whether one should use 2D or 3D. The Unity game engine is popular both among video game developers and simulation developers, and has support for both 2D and 3D. However, there is little research regarding the performance differences between the two. To this end, this sets out to determine the difference in performance between 2D and 3D simulations in Unity. We develop two functionally identical simulators in Unity, one in 2D and one in 3D, and compare their computational performances. The results of this study show that with a low number of agents (500 and less) there is no meaningful difference in performance except a slightly higher memory usage in the 3D simulator. However, larger agent counts (1000 and higher) cause the 2D simulator to use more CPU time than its 3D counterpart. We conclude that the use of 3D simulators is preferable to 2D as it is more realistic and has better CPU performance. However, 2D simulators can still be useful for low agent counts when memory is a concern.