Abstract
An open-source C++ library named RoomAcoustiC++: Real-time Acoustics Library for real-time room acoustic modelling is introduced that implements a hybrid geometric acoustic and feedback delay network model. The geometric acoustic component uses the image edge model to locate geometry-dependent early specular reflections and edge diffraction. The feedback delay network models late reverberation for a target reverberation time. The model is capable of a dynamic simulation including moving geometry, sources and listener and changing wall absorption, with binaural spatialisation over headphones and customisable head-related transfer functions using the 3D Tune-In toolbox. A comparison with existing closed-source and open-source projects is presented. This found that many state-of-the-art room acoustic models for real-time applications are closed-source, limiting reproducibility. RoomAcoustiC++ offers an improved room acoustic model compared to existing open-source projects. The library was validated against physical measurements from the Benchmark for Room Acoustic Simulations (BRAS) database. An analysis of the real-time performance shows that the software is capable of binaural rendering for scenes with occluding geometries and multiple sources.