By default, sounds in Wwise emanate from an omni-directional source. In reality, however, sounds usually have some direction to them. To simulate the direction of a sound in Wwise, you can use a sound cone. The sound cone simulates the propagation of the sound in a particular direction using angles of varying degrees. As the listener moves outside these angles, the Output Bus volume (acting as the dry component) is attenuated. Because 3D game-defined positioning uses live game data, the direction of the sound cone is ultimately controlled by the orientation of the game object.
The following angles define the regions within the sound cone:
Inner angle: Defines the region where no Output Bus volume attenuation or Low-Pass Filter effects occur.
Outer angle: Defines the region where Output Bus volume attenuation and Low-Pass Filter effects remain at their maximum levels.
Output Bus Volume roll-off occurs in the transition area or the region between the borders of the inner and outer angles. The volume is attenuated using linear interpolation between the inner angle border where no attenuation occurs and the outer angle border where the max attenuation value is reached. In the region defined by the outer angle, volume attenuation is always equal to the max attenuation value.
The Output Bus volume attenuation and Low-Pass Filter values within the cone attenuation are added to those defined by the Output Bus volume and Low-Pass Filter Attenuation curves. The auxiliary send volumes and values remain unchanged.
The Cone Preview display located beside the Cone Attenuation properties gives you a visual representation of the different regions within your sound cone. It automatically updates as you change the inner and outer angle values.
Although motion emanates from an omni-directional source, there may be situations in game where you want to simulate the propagation of the motion in a particular direction. In these situations, you can use the Cone Attenuation properties. The sound cones work in the same way for motion as they do for sounds, except that the Low-Pass Filter setting has no effect on motion objects. The sound cones use angles of varying degrees to attenuate the motion based on the listener's position in relation to the orientation of the source.
To simulate directivity using sound cones:
Load an object into the Property Editor and switch to the Positioning tab.
In the Attenuation group box, select or create an Attenuation ShareSet.
You must enable Listener Relative Routing to activate the Attenuation group box.
The Attenuation Editor opens with the property settings of the selected attenuation instance.
Select the Cone Attenuation option.
The sound cone controls become available.
In the Inner angle text box, specify an angle that defines the region where you want no Output Bus volume attenuation to occur.
In the Outer angle text box, specify an angle that defines the region where Output Bus volume attenuation and Low-Pass Filter Effects remain at their maximum levels.
The area between the inner and outer angles is called the transition area. In this area, the Output Bus volume is attenuated using a linear interpolation between the inner angle border where no attenuation occurs and the outer angle border where the max attenuation value is reached.
In the Max attenuation text box, define the amount by which the Output Bus volume will be attenuated when an object falls within the outer angle.
To apply a Low-Pass Filter to sounds that fall between the inner and outer angles, type a value in the Low-Pass Filter text box. The Low-Pass Filter is a recursive filter that attenuates high frequencies based on the value specified.
The units for the Low-Pass Filter represent the percentage of Low-Pass Filtering that has been applied, where 0 means no Low-Pass Filtering (signal unaffected) and 100 means maximal attenuation.