An open-source implementation of GPU-accelerated Finite-Difference Time Domain (FDTD) simulations in the Unity game engine to visualize elastic wave propagation and scattering for pedagogical or training scenarios

Abstract

Simulations of elastic wave propagation through solid materials can be realized through industry-standard software or custom implementations in a variety of programming languages. These codes are generally optimized for numerical accuracy and can be difficulty to interact with, slow to run, and often require external processing of results to create 3D visualizations. This is especially true for parallelized or Graphical Processing Unit (GPU)-based simulations which require additional libraries. These factors tend to limit the use of numerical simulations of wave propagation in pedagogical applications to simple 2D implementations of acoustic propagation through fluids. Here we present a fully-3D open-source Finite-Difference Time Domain (FDTD) simulation of elastic wave propagation that is implemented in the Unity game development engine. Due to the nature of the engine the simulation code runs entirely on the GPU without additional coding. Additionally the solutions are rendered as the simulation runs which removes the need for saving and post-processing large data files, as well as allowing the user to rotate the viewpoint in real-time to better visualize the wave propagation and scattering in complex geometries.