The Mixers Panel shows a complete list of all AudioMixers within the project. AudioMixers can be quickly switched between by selecting them within this panel. Routing one AudioMixer into the AudioGroup of another AudioMixer is also performed within this panel.
You can also create new AudioMixers in the project my clicking the ‘+’ icon in the top right of the panel.
Unity supports having multiple AudioMixers used within a scene at once. By default, each AudioMixer outputs the audio signal directly to the AudioListener.
Developers can also choose to route the audio output of an AudioMixer into an AudioGroup of another AudioMixer. This allows for flexible and dynamic routing hierarchies at game runtime.
Routing an AudioMixer into another AudioGroup can be achieved two ways, firstly in the editor within the Mixers Panel, and the other dynamically at runtime using the AudioMixer API.
The hierarchy view is where you define the sound categories of an AudioMixer and the mixing structure. As described above, it allows you to define your own custom categories that AudioSources can connect to and play through.
Adding and modifying the topology of an AudioMixer is done within the AudioGroup Hierarchy Panel.
The AudioGroup View shows a flat arrangement of the AudioGroups in the AudioMixer. This arrangement is organised horizontally within the view. The groups shown within the AudioGroup View are dictated by the current View selection (covered later).
Each AudioGroup within the view is represented as a vertical “strip”. The layout and look and feel of the strip is common to Digital Audio Workstations and other audio editing packages. This layout is chosen to facilitate the transition of Audio Engineers from a music and video background, as well as serve as a parallel for audio hardware integration.
The strip is made up of title bar, followed by a vertical VU meter which represents the current audio levels through that AudioGroup. Beside the VU meter is a volume selector which allows you to input the AudioGroups attenuation along the same scale as the VU meter, which is represented in dB levels.
Below the VU meter are 3 buttons with the following functionality:
The AudioGroup also contains a list of DSP Effect Units and the Attenuation Units within the AudioGroup. The attenuation can be applied anywhere within the Effect Unit chain within an AudioGroup and allows you to decide exactly where you would like the volume adjustment to be applied. This is useful for non-linear effects and Send and Receive Units (covered later).
Each Effect Unit slot has the following functionality:
You can also add new Effect Units by right clicking on an existing effect to add before or after it, or by clicking the “Add..” button at the bottom of the strip.
The Snapshot Panel allows you to create, switch between and tweak different Snapshots within the AudioMixer. There is always at least one snapshot active, and selection of a snapshot within the Snapshot Panel indicates that further edits of the AudioMixer are edits to that snapshot.
Snapshots defined in the Snapshot Panel also show up as sub-assets of the AudioMixer. This allows you to access the snapshots elsewhere in the editor and within scripts.
You also define a ‘Start Snapshot’ (indicated by the star icon on the right hand side of the snapshot list). The Start Snapshot is the snapshot that the AudioMixer will be initialised to when loaded (for example, when the scene starts)
Views allow you to create groups of visible AudioGroups in the AudioMixer. With views, you can create perspectives of interest into the AudioMixer, instead of always being presented with the full hierarchy at all times. Views are purely for workflow optimisation purposes are do not affect runtime setup or performance.
Like the Snapshot Panel, there is always one view selected and currently shown in the AudioGroup View. By default, all AudioGroups are visible in the default view. What is contained within a view is controlled by the Eye Icons in the Hierarchy Panel (see above).
Each AudioGroup within the hierarchy panel has a small eye icon to the left of the group. This icon serves 2 purposes;