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Creating room geometry

To add geometry to RAC, create an empty GameObject and add the RACMesh or RACMeshLoader script.

RACMesh

Assign any 3D objects (e.g. quads, cubes) as children of the GameObject with the RACMesh component. Quads are recommended over planes due to the reduced number of triangles in the default Unity mesh.

Modify acoustic properties

A number of properties can be modified in the RACMesh component to control the acoustic behaviour of the room.

  • Room Dimensions: The primary dimensions of the room in meters (for a shoebox room this would be the width, height, depth). This controls how quickly the late reverberation echoes build up. Larger dimensions result in longer delay lines with the FDN and a sparser build up of late reverberation.
  • Volume: The volume of the room in cubic meters. This is used to calculate the late reverberation time (T60) if a Sabine or Eyring's formula is selected in the RACManager. A larger volume results in a longer reverberation time.
  • Absorption Skew: This scales the absorption coefficients of the mesh surfaces. This affects both early reflections and late reverberation (if using Sabine or Eyring's formula).

RACMeshLoader

This is designed for preprocessed static environments and can take advantage of the more advanced MoD-ART late reverberation model.

If you want to use a custom environment, the first thing you'll need to do is analyze it with MoD-ART. Follow the instructions on the MoD-ART repo's main page to create the following files describing your acoustic environment: 

YourEnvironmentName/
├── materials.csv       <-- User-provided
├── mesh.mtl            <-- User-provided
├── mesh.obj            <-- User-provided
├── MoD-ART.csv         <-- Generated by MoD-ART
└── path_indexing.csv   <-- Generated by MoD-ART
Once the analysis is complete, place these five files in Unity project/Assets/Resources/PythonExports/YourEnvironmentName/.

The MoD-ART pre-processing will also generate several other files as part of the analysis. Only the five listed here are necessary for use in Unity; don't place the extra files inside the Assets/Resources folder to avoid bloating the Unity project's size.

Disable Mesh Renderers

It can be useful to use a simplified mesh with a low number of triangles for acoustic rendering. This reduces the computational load for the image edge model and ensures any latency due to updating the acoustic model is minimized. A second mesh with a higher triangle count can be used for visual representation without affecting the acoustic calculations. To simplify this process RACMesh and RACMeshLoader provide an option to disable the mesh renderers of all child objects at runtime.

  • Disable Mesh Renderers: If enabled, this will disable the mesh renderers of all child objects at runtime.