Source Occlusion

The atmokySpatializer plug-in has an occlusion parameter, which can be used to simulate the occlusion of a sound source by an obstacle. The occlusion parameter is a value between 0 and 1, where 0 means no occlusion and 1 means full occlusion.

To set the occlusion value of a source automatically you can use the Atmoky Occlusion Probe Group component, which controls the Occlusion of either the GameObject it is attached to, or the AtmokySource specified in its Override Source property.

Tag occluders

Add the Atmoky Occluder script to every game object that should occlude audio sources and set their Occlusion value, which defines how strongly this object occludes audio sources.
(Optional) Choose an occlusion layer for the occluder. Working with occlusion layers can massively reduce the number of objects that need to be considered during raycasting, which improves performance.

Add occlusion probe group

Add the Atmoky Occlusion Probe Group script to the audio source.
Add or delete occlusion probes in the inspector
Adjust the position of the occlusion probe in the Scene View by selecting the occlusion probe tool and dragging the handles.
(Optional) Turn on non-allocating raycasting for better performance. If turned on, be sure to adjust the maximum number of hits that the raycasting command should consider to your usecase. Less means better performance, but can potentially lead to some occluders not being considered if configured too low.
(Optional) Adjust the occlusion layers considered for raycasting. Per default, all occlusion layers are considered. You can configure the raycasting to exclude certain layers, which can drastically improve performance when there are many objects in the scene.
(Optional) Set the Reference Object to a different object than the Audio Listener. The Reference Object is the object that defines the position of the target of the raycasts, which defaults to the currently active Audio Listener. You might want to change that to the Main Camera or any other object that should be used as the target of the raycasts.

For every Occlusion Probe, a ray is cast from the probe to the Reference Object, which defaults to the active Audio Listener. All occluders that are hit by this ray add to the occlusion value of the probe (which is also displayed for every probe in the inspector). Per default, the final occlusion value of the source is then calculated by averaging the occlusion values of all probes. You can change this behaviour by changing the Occlusion Sensitivity parameter: setting it to min will take the minimum occlusion value of all probes, setting in to mean will take the mean occlusion value of all probes, and setting it to max will take the maximum occlusion value of all probes. All other values will interpolate between the min, mean, and max. This way you can adjust how rapidly the occlusion value changes when one or more probes are occluded and thus implement different occlusion behaviours.

When the game object with the ProbeGroup component is selected, all rays are visualized in the Scene View when in play mode. The color of the rays represents the occlusion value of the probe: green means no occlusion, red means full occlusion.

In Edit-Mode, all computations use the SceneView camera instead of the Reference Object per default. This way you can adjust the occlusion probes without having to enter play mode. You can turn off this behaviour by unchecking Use Editor Camera in Editor in the Atmoky Occlusion Probe Group component. The Scene View camera position in Unity is updated quite sparsely, so occlusion values might not be updated as frequently as expected.