Buses

The schema for bus definitions is defined in schemas/buses.fbs. A bus data file must be supplied by the user which contains a list of Bus defintions and how they are related. The audio engine will load the bus file specified in the configuration file.

The main purpose of a bus is to adjust the gain (or volume) of a group of sounds in tandem. Any number of buses may be defined.

All SoundCollectionDefs define which bus they are to be played on. Example buses might be music, ambient_sound, sound_effects or voice_overs. A bus may list other buses as child_buses, which means that all changes to that bus's gain level affect all children of that bus as well. There is always a single master bus. This is the root bus from which all other buses descend.

A bus may also define duck_buses, which are buses that will lower in volume when a sound is played on that bus. For example, a designer might want to have background sound effects and music lower in volume when an important dialog is playing. To do this the sound effect and music buses would be added to the duck_buses list of the dialog bus.