Multithread implementation for calculating room impulse responses.

Abstract

Modern simulation programs are committed to calculate full impulse responses instead of doing simple mapping presentations. The main problem here is how to obtain such IRs quickly but accurately. The usual algorithm simulates sound propagation by tracing a statistical ensemble of acoustic rays. In this contribution, we deal with a new ray‐triangle intersection algorithm, based on a three‐dimensional grid scheme, that provides significant performance improvement for ray tracing. We report about the introduction of a uniform grid ray‐tracing algorithm, which is optimized for acoustic models and can be up to five times faster (standard Pentium 4) than hierarchical space decomposition. Furthermore, the algorithm has been parallelized, taking advantage of the inherently independent propagation of distinct rays. On multicore processors, the computation employs a variable number of thread tracing groups of rays in parallel. The speed increase is almost linear with the number of cores. An overview is given to explain this approach. To support this fast calculation, an additional algorithm derives a suggested particle number and length from the mean free path properties of the room and the desired detection rate at the receiver. So time‐consuming guesses about the selecting particle numbers will be avoided.