AUDIO FOR AI AIRCRAFT

If your aircraft is going to be used as part of the fleet of AI aircraft within the simulation then you will also need to setup sound effects for them independently of the main user aircraft. These sound effects will work exactly as the main sounds, ie: you create the sounds and events in Wwise, then you export them in a PC.PCK file, and finally you create an XML file to reference them. The only real differences between AI sounds and regular sounds is that the PC.PCK and XML files should be clearly labelled as AI, and the number of effects that you need is greatly reduced.

Example Showing The AI Sounds File Structure

 

 

 

AI Traffic Sounds In Wwise

The good thing about AI traffic is that you can copy/paste most (if not all) of the sounds from the main aircraft and re-use them in the AI aircraft. The sounds you'll need will only be the ground sounds and the engine sounds, so in the sample project you would do the following:

  • Go to the AIRCRAFT_AI folder and create a new work unit named after your aircraft
  • Create an "engine" folder
  • Create an "engine" Actor Mixer
  • Create Blend Containers for each of the engine elements, eg: combustion, combustion start, propeller, etc...

 

Once you have set that up, it's simply a case of copying the sounds from the outside engine into the new blend containers. When finished you should have something that looks a bit like this:

The Copied Outside Audio For AI Aircraft

 

You would then want to do the exact same process, but this time for ground effects, so that it looks like this:

The Copied Ground Audio For AI Aircraft

 

When looking at the images above, you'll notice that we've not created any switch container for the audio like we did for the regular aircraft. This is because there is no need to use the VIEWPOINT state family (which includes the INSIDE/OUTSIDE states) since there is no inside state for AI aircraft.

The next thing you'll have to do to the audio is change the output bus so it uses the already created AI buses. This is done from the General Settings section of the Property Editor for each of the different blend containers, and for each one you should check "Override parent" then navigate to the appropriate output bus so that they looks like this:


The Different AI Audio Buses

 

 

The final step is to go to the 3D Actor Mixer and then in the Property Editor go to the Advanced Settings tab. You want to edit this so that it limits the number of voices being played in live multiplayer sessions, which is done with the following settings:

  • Check Limit sound instances to and set it to 28
  • For When limit is reached set it to "Use Virtual voice settings"
  • Set Virtual voice behaviour to "Send to virtual voice"
  • Set Priority to 75
  • Check Offset priority by to -75

Advanced Settings For The 3D Actor Mixer

 

Attenuation

Before continuing it is also worth noting how important it is that you mix your AI aircraft audio carefully and pay great attention to the 3D sound attenuation distances, since this will have a great impact on the sound experience of the other users. You can find all the Attenuations sharesets in the Sharesets tab of the Project Explorer, and then edit them as required to get properly balanced audio:

The Attenuation Editor In Wwise

NOTE: The maximum distance for sounds from AI aircraft to be audible to other users in the simulation is 5km, therefor your max distance attenuations curves should not exceed 5,000m.

 

To use an attenuation shareset and apply it to a container, simply go to the Positioning tab after selecting your container, then check the Attenuation box and select a Shareset using the >> button:

Applying An Attenuation ShareSet To A Container

 

Be aware that attenuation on AI sources from a user cockpit perspective is handled with the <AcousticParameters> insulation attributes from the aircraft sound.xml. If you want to know more about the Attenuation Editor and the different available parameters, you can check the Audiokinetic Wwise documentation:

 

 

soundai.XML

When it comes to creating the soundai.xml file, the format is exactly the same as that used for the sound.xml. You can use all the same elements and most of the same attributes, however you are limited to the SimVars that you can access. Ai aircraft will only have access and use the following SimVars, depending on the distance the aircraft is from the listener:

 

  • Far distance (up to a maximum of 10,000m, although sounds will not be audible after 5,000m):
    1. SIM ON GROUND
    2. GENERAL ENG PCT MAX_RPM
    3. GENERAL ENG RPM
    4. VELOCITY WORLD X
    5. VELOCITY WORLD Y
    6. VELOCITY WORLD Z
    7. GROUND VELOCITY
    8. TURB ENG REVERSE NOZZLE PERCENT
    9. TURB ENG N1
    10. TURB ENG N2
    11. PROP BETA
    12. PROP RPM
    13. GENERAL ENG COMBUSTION
    14. GENERAL ENG COMBUSTION SOUND PERCENT
    15. ENG ROTOR RPM
    16. TURN INDICATOR RATE
    17. ROTOR COLLECTIVE BLADE PITCH PCT
    18. ROTOR CYCLIC BLADE PITCH PCT
    19. ROTOR CYCLIC BLADE MAX PITCH POSITION
    20. DISK PITCH ANGLE
    21. DISK BANK ANGLE
    22. DISK PITCH PCT
    23. DISK BANK PCT
    24. DISK CONING PCT
    25. ROTOR ROTATION ANGLE
    26. ROTOR LATERAL TRIM PCT
    27. ROTOR LONGITUDINAL TRIM PCT

 

  • Close distance (up to 500m):
    1. GEAR POSITION
    2. TRAILING EDGE FLAPS LEFT PERCENT
    3. TRAILING EDGE FLAPS RIGHT PERCENT
    4. LEADING EDGE FLAPS LEFT PERCENT
    5. LEADING EDGE FLAPS RIGHT PERCENT
    6. SPOILERS LEFT POSITION
    7. SPOILERS RIGHT POSITION
    8. GEAR ANIMATION POSITION
    9. CENTER WHEEL ROTATION ANGLE
    10. GEAR CENTER STEER ANGLE
    11. GEAR LEFT STEER ANGLE
    12. GEAR RIGHT STEER ANGLE
    13. GEAR STEER ANGLE
    14. RUDDER DEFLECTION PCT
    15. RUDDER TRIM PCT
    16. ELEVATOR DEFLECTION PCT
    17. AILERON LEFT DEFLECTION PCT
    18. AILERON RIGHT DEFLECTION PCT
    19. FLAPS HANDLE PERCENT
    20. PROP MAX RPM PERCENT
    21. PROP THRUST
    22. ENG RPM ANIMATION PERCENT
    23. PROP ROTATION ANGLE
    24. GENERAL ENG STARTER ACTIVE
    25. TURB ENG AFTERBURNER
    26. TURB ENG AFTERBURNER PCT ACTIVE
    27. TURB ENG AFTERBURNER STAGE ACTIVE

 

To give an idea of what a typical soundai.xml file looks like, here's the full contents of the file for the C152:

<?xml version="1.0" encoding="utf-8" ?>
<!-- Copyright (c) Asobo Studio, All rights reserved. www.asobostudio.com -->
<SoundInfo Version="0.1">
    <WwisePackages>
        <MainPackage Name="Asobo_C152_AI"/>
    </WwisePackages>
    <EngineSoundPresets>
        <Sound WwiseEvent="Combustion" ConeHeading="180" FadeOutType="2" FadeOutTime="0.2" RPMMin="200" WwiseData="true" EngineIndex="1" >
            <WwiseRTPC SimVar="GENERAL ENG COMBUSTION SOUND PERCENT" Units="PERCENT OVER 100" RTPCReleaseTime="0.5" Index="1" RTPCName="SIMVAR_GENERAL_ENG_COMBUSTION_SOUND_PERCENT" />
        </Sound>
        <Sound WwiseEvent="Starter" FadeOutType="2" FadeOutTime="0.1" WwiseData="true" EngineIndex="1" >
            <WwiseRTPC SimVar="GENERAL ENG COMBUSTION SOUND PERCENT" Units="PERCENT OVER 100" RTPCReleaseTime="0.5" Index="1" RTPCName="SIMVAR_GENERAL_ENG_COMBUSTION_SOUND_PERCENT" />
        </Sound>
        <Sound WwiseEvent="CombustionStart" ConeHeading="180" WwiseData="true" EngineIndex="1" > 
            <WwiseRTPC SimVar="GENERAL ENG COMBUSTION SOUND PERCENT" Units="PERCENT OVER 100" RTPCReleaseTime="0.5" Index="1" RTPCName="SIMVAR_GENERAL_ENG_COMBUSTION_SOUND_PERCENT" />
        </Sound>
        <Sound WwiseEvent="CombustionStart" CustomSuffix="Propeller" ConeHeading="0" WwiseData="true" EngineIndex="1" >
            <WwiseRTPC SimVar="GENERAL ENG COMBUSTION SOUND PERCENT" Units="PERCENT OVER 100" RTPCReleaseTime="0.5" Index="1" RTPCName="SIMVAR_GENERAL_ENG_COMBUSTION_SOUND_PERCENT" />
        </Sound>
        <Sound WwiseEvent="Shutdown" ConeHeading="180" RPMMin="200" WwiseData="true" EngineIndex="1" >
            <WwiseRTPC SimVar="GENERAL ENG COMBUSTION SOUND PERCENT" Units="PERCENT OVER 100" RTPCReleaseTime="0.5" Index="1" RTPCName="SIMVAR_GENERAL_ENG_COMBUSTION_SOUND_PERCENT" />
        </Sound>
        <Sound WwiseEvent="Shutdown" CustomSuffix="Propeller" ConeHeading="0" RPMMin="200" WwiseData="true" EngineIndex="1" >
            <WwiseRTPC SimVar="GENERAL ENG COMBUSTION SOUND PERCENT" Units="PERCENT OVER 100" RTPCReleaseTime="0.5" Index="1" RTPCName="SIMVAR_GENERAL_ENG_COMBUSTION_SOUND_PERCENT" />
        </Sound>
        <Sound WwiseEvent="Propeller" ConeHeading="0" FadeOutType="2" FadeOutTime="0.2" RPMMin="200" WwiseData="true" EngineIndex="1" >
            <WwiseRTPC SimVar="GENERAL ENG COMBUSTION SOUND PERCENT" Units="PERCENT OVER 100" RTPCReleaseTime="0.5" Index="1" RTPCName="SIMVAR_GENERAL_ENG_COMBUSTION_SOUND_PERCENT" />
        </Sound>
    </EngineSoundPresets>
    <GroundSounds>
        <Sound WwiseEvent="CENTER_TOUCHDOWN" FadeOutType="2" FadeOutTime="0.5" WwiseData="true" />
        <Sound WwiseEvent="LEFT_TOUCHDOWN" FadeOutType="2" FadeOutTime="0.5" WwiseData="true" />  
        <Sound WwiseEvent="RIGHT_TOUCHDOWN" FadeOutType="2" FadeOutTime="0.5" WwiseData="true" />
    </GroundSounds>
</SoundInfo>

As you can see, it's much smaller than a normal sound.xml file and only covers the essential exterior engine sounds and ground sounds.

 

Related Topics

  1. Using Wwise
  2. Setting Up Wwise
  3. Creating Aircraft Audio
  4. Creating The Sound.xml
  5. RTPC And Simulation Variables
  6. Sound XML Properties