Managing Low-Volume Objects

When many objects are playing simultaneously, you need to maintain an optimal level of performance. A good way to achieve this is to flag objects that fall below a certain volume level so that they don't take up valuable processing power and memory. Although you can continue to play these inaudible objects, you may want to either stop them outright or queue them in the virtual voice list.

The virtual voice list is a virtual environment where certain parameters of an object are monitored by the sound engine, but where no processing occurs. The benefit of adding them to the virtual voice list is that these objects can move back and forth between the physical and the virtual voice based on their volume levels. As the volume falls below the volume threshold level, the objects are added to the virtual voice list and processing stops. As volume levels increase, as is the case when objects move within the attenuation maximum distance radius, the objects will move from the virtual voice to the physical voice where the audio or motion will be processed again by the sound engine. Despite the benefits of using virtual voices for low-volume objects, it is not the right solution for all objects due to certain limitations, including small delays and the lack of sample accuracy when returning to the physical voice.

To give you additional power and control, you can also define the playback behavior of objects as they move from the virtual voice back to the physical voice.

[Note] Note

You can set the volume threshold for your project in the Project Settings dialog box. For more information on setting the volume threshold levels, refer to Specifying Volume Thresholds for a Project.

Managing Low-Volume Sounds - Example

Let's say you are creating a first-person shooter game where your main character is navigating through a series of hallways. They have picked up one of the enemy's two-way radios and are able to listen in on the enemy's communication. In this situation, you can have many sounds playing at the same time, including your character's footsteps, the torches burning in the dimly lit hallways, and the sounds coming from the two-way radio. Each of these sounds has different characteristics and requirements. Therefore, they require different treatments as their volumes change.

Sound

Treatment

Wwise Option

Footsteps

Footstep sounds are generally short, one-shot sounds, so when their volume falls below the volume threshold, you may want to kill these sounds to save valuable audio processing power.

Kill voice

Radio

Since the character within your game can turn the volume of the radio sounds up or down, you will need continuity, sample accurate precision, and immediate feedback for the radio communication. When the volume of these sounds falls below the Volume Threshold, you can continue playing these sounds. This enables you to generate an immediate and sample accurate response to when the game player turns the volume back up to continue listening to the enemy's communication.

Continue to play

Torch

Torch sounds are relatively short sounds that are looped continuously. Although these sounds require some continuity, they do not require the same amount of precision as the radio sounds. When the volume for these sounds falls below the volume threshold, you can send these sounds to the virtual voice list. The sound engine will monitor their volume levels but will not perform any audio processing until their volume levels return above the Volume Threshold.

Send to virtual voice

To manage low-volume objects:

  1. Load an object into the Property Editor.

    [Note] Note

    If the object is not a top-level object, you must select the Override parent option before you can set the Volume Threshold options.

  2. Switch to the Advanced Settings tab.

  3. To specify the behavior of an object when it falls below the Volume Threshold, select one of the following options from the Virtual voice behavior list of the Virtual Voice group:

    • Continue to play to continue playing the object even though it will no longer be heard or felt. This is the only option that ensures sample accuracy.

    • Kill voice to stop playing the object.

    • Send to virtual voice to send the object to the virtual voice list, where certain parameters are monitored by the sound engine, but where no processing occurs.

  4. If you selected the Send to virtual voice option, you must specify the behavior of the object when it moves from the virtual voice back to the physical voice. To do so, select one of the following options from the On return to physical voice list:

    • Play from beginning to play the object from its beginning. This option resets the object's loop count.

    • Play from elapsed time to continue playing the object as if it had never stopped playing.

    • Resume to pause the object when it moves from the physical voice to the virtual voice list and then resume playback when it moves back to the physical voice.

    [Note] Note

    Music objects returning to the physical voice will always use the Play from elapsed time option.