The Music Work Unit in the Interactive Music Hierarchy includes two examples of game music to demonstrate both a basic and an advanced integration of interactive music. These interactive music examples show how you can create music that evolves through three distinct States representing the level of intensity of the gameplay:
Stealth: No threat in sight. The player moves quietly through the environment.
Stress: The player is in danger and should hide or escape to avoid trouble.
Fight: Action sequence where the player is attacked by bad guys and fights for his life.
Wwise allows you to examine game music at different levels of detail. The following procedure shows you how to take advantage of Wwise’s interface when looking at one particular project element.
To examine the Stealth music:
Double-click on the music segment named “Stealth_Seg_01” to reveal its properties and to see the four tracks in the Music Segment Editor.
In the Music Segment editor, hold “Z” while clicking in the Music Segment Editor track view to zoom out and see the four tracks.
The volume of the tracks “Stealth_Ambient” and “Stealth_Drums_Ambient” has an RTPC curve attached to it. Double-click on one of these tracks to reveal its properties in the Property Editor, and switch to the RTPC tab to see the curve that was created.
The volume of this track is influenced by the game-driven parameter “Stealth_Factor”.
The “01_In-Game Music” music Switch Container holds three music playlist containers, one for each state of the game.
Stealth Music: The Stealth music is made up of multiple tracks, the contents of which are played according to the game’s state and RTPC values. Effects can also be applied to these tracks.
Stress Music: The Stress music is also comprised of multiple tracks which can be affected by states, RTPCs, or effects. Like the Stealth music, the stress music has also been inserted into a music playlist container to sequence the three segments.
Fight Music: The Fight music takes another approach in terms of music composition. Instead of using multi-track segments, the fight music has simple two-bar long segment playing stereo files. This approach allows for elaborate combinations inside the music playlist container.
Transitions: The transitions between Stealth and Stress use different fade-in and fade-out curves. However, they both use the “Same Time as Playing Segment” option as the destination sync point. This means that the destination segment starts playing at the exact moment at which the source music leaves.
Outro_to_Stealth_or_Stress: For the transitions from Fight to Stress and Fight to Stealth, a transition segment is used to bridge the source and the destination segments smoothly. This transition segment was needed to cover the tempo difference between the source music (120 BPM) and the destination music (90 BPM).
To listen to Game Music Part 1:
Load the Music Switch Container “01_In-Game Music” into the Transport Control.
In the Transport Control, click States.
Set the State to “a_Stealth”.
Start the playback.
Change the State in the list to go from Stealth to Stress to Fight.
While in the Stealth state, you can click RTPCs to change the “Stealth_Factor” level and therefore modify the volume of certain tracks.
The example “02_In-Game Music” reuses the music from “01_In-Game Music” and adds more transitions segments, stingers, and an additional set of variables to transition music over different contexts. The following are advanced features included in this example:
An additional State Group for Music Transition: A new state group is used to manage interactive music transitions between the In-Game music and the Menu music. It provides an example of how transitions can be set between different game contexts.
Stingers: Stingers are brief musical phrases that are superimposed and mixed over the currently playing music.
Bonus Stinger: The “Bonus” stinger uses the segment “Stinger Bonus” for all objects except for the Fight music container, which uses the segment “Stinger Bonus - Fight”. “Stinger Bonus - Fight” has three subtracks set to play in sequence. This ensures that you hear a different music punch each time the Bonus stinger is triggered in the Fight state.
Backup Team Arrives: The “Backup Team Arrives” theme has been composed to play over the Fight music only. It uses the music segment “Stinger Backup Team”, which has been routed to a control bus that auto-ducks the “00_Fight” bus by -10 dB.
Additional Transition Segments: The transitions found in the “02_In-Game Music” music Switch Container manage the transitions between the in-game music and the menu music. There is also a custom transition between Fight and Menu music that uses the dedicated transition segment "Fight to Menu Transition".
Transition from Fight to “Nothing”: This transition uses a transition segment named “Death”. In this case, the “Nothing” state occurs at the main character’s death.
Stealth to Stress Transition: The transitions between Stealth and Stress have been enhanced by adding rules to the Transition Matrix to get more interesting results. For example, if segment “Stealth_Seg_02” is playing when a transition to the Stress state occurs, the specific destination segment will be “Stress_Seg_02” instead of the first segment of the Playlist as the default behavior proposes. Six rules have been defined to cover all possible transitions between the three Stealth segments and the three Stress segments.
To listen to Game Music Part 2:
In the Sessions tab of the Project Explorer, double-click the Soundcaster session named “Music”.
In the Soundcaster, set the states to “InGame” and “a_Stealth”.
Start the music playback by playing the “Play_Music” Event.
Change the different States; launch the other Events such as Mute_Drums or Set_LPF (low pass filter).
With the State set to Fight, click each trigger button (>) to hear the “Backup_Team_Arrives” and “Bonus” stingers.