Wwise Help

SoundSeed Wind emulates the flow of wind through a scene; the direction specifies the point of entry of wind flow on to a scene. Thus you should expect pressure waves to hit the deflectors closest to the entry point first. The flow will then propagate through the scene as it is pushed by incoming wind. As it propagates, you will hear deflector objects that are placed farther from the entry point as they encounter the oncoming pressure wave. Note that higher wind speeds at the entry point push the flow at a quicker rate than slower speeds.

The following illustration demonstrates a typical scene where wind and a series of deflectors are defined using a set of properties. Deflectors will appear smaller or larger in size and lighter or darker in color depending on the frequency and gain property values assigned to them.

A variety of other tools exist to help you further refine the wind sound. For example, both wind and deflector properties can be controlled over time using automation curves. You can create sophisticated curves by adding any number of points and using a variety of curve shapes. The following illustration shows an example of a sophisticated wind speed automation curve.

When wind sounds are looped, the automation curves are repeated in a cyclical manner. When using very short durations, you may experience the phenomenon where, at increasing playback rates, the sound appears to speed up and slow down in a random way. This occurs because the space between each sample becomes larger than the actual automation curve. When this occurs, the next control sample will be taken from a different point at the beginning of the next cycle of the automation curve.

You can also apply distance-based attenuation to the wind sound. Basically, a -6 dB attenuation is applied each time the deflectors' distance is doubled after the Minimum distance. You can fine-tune the attenuation of the deflectors in your scene by specifying values for the following properties:

The following illustration demonstrates the attenuation model used by the SoundSeed Air plug-ins. Three different roll-off factors are used with the same min and max distances to show how the attenuation gain is applied in each case.

In Wwise, most properties can be modified in real time using the property sliders. Many of the properties can also be mapped to parameters in your game using RTPCs. A special indicator is placed beside the property value showing whether it uses an RTPC or not.

The following table describes the two types of RTPC indicators:

Indicator	Name	Description
	RTPC - On	A property value that is tied to an in-game parameter value using RTPCs.
	RTPC - Off	A property value is not tied to an in-game parameter value.