View source for Documentation/Engine/Sound/TruckEngine

=== Sounds - Truck Engine ===
The sound of the truck engine is very specific kind of the sounds.<br>
Engine sound is very sensitive to be balanced between sound sources.<br>
<br>
So there are a few rules for the engine sound:
* The each sound of the truck engine should be in the separate sound bank.
* There are only the four events and all should be implemented in the same bank.
* It is not recommended to combine events of different banks for the engine sound.
== Engine Sound Events ==
* All events should be at the folder "engine" in the events browser.
* This events should exist in the bank:<br>'''engine/engine'''<br>'''engine/exhaust'''<br>'''engine/turbo''' ''(from 1.39)''<br>'''engine/start_bad'''

=== Event "engine" ===

Event "engine" plays sound of the engine.<br>
It has to be 3D event. The event should be routed to the "truck_engine" audio bus.<br>
The event must be looped and its living cycle is controlled by "play" parameter (see bellow).<br>
<br>
These event parameters must exist:
* engine/play<br>The parameter "play" control living cycle of the event:<br>value play = 1 means - sound is playing<br>value play = 0 means - sound should be stopped
* engine/brake<br>the value is in the range <0 - 1> and represents the action of the motor brake
* engine/load<br>the value is in the range <0 - 1><br>value represents the motor load<br>value < 0.05 means idle engine sound
* engine/rpm<br>the value is in the range <0 - 3000><br>the value represents the number of engine revs per second

=== Event "exhaust" ===

Event "exhaust" plays sound of the exhaust.<br>
It has to be 3D event. The event should be routed to the "truck_exhaust" audio bus.<br>
The event must be looped and its living cycle is controlled by "play" parameter.<br>
<br>
These event parameters must exist:
* exhaust/load
* exhaust/play
* exhaust/rpm
The purpose of the parameters is the same as for the "engine" event (see Event "engine").

=== Event "turbo" ===

Event "turbo" plays sound of the turbo.<br>
It has to be 3D event. The event should be routed to the "truck_turbo" audio bus.<br>
The event must be looped and its living cycle is controlled by "play" parameter.<br>
<br>
These event parameters must exist:
* engine/turbo<br>the value is in the range <0 - 1> and represents the action of the turbo system

=== Event "start_bad" ===
Event "start_bad" plays sound of unsuccessful starting of the engine.<br>
It has to be 3D event. The event should be routed to the "truck_engine" audio bus.<br>
The event is one-shot sound (without loop).<br>
There are no other parameters for the event.<br>
It is possible to use randomization of the assets supported by FMOD Studio.<br>

== Engine Sound Configuration ==

The sound configuration of the engine sounds is stored in the "accessory_engine_data" data.<br>
There is array "sounds" which contents specification for the mandatory events of the engine.<br>
That means that each type of the engine can have assigned its own sound bank.<br>
<br>
Example:<br>
There are configuration files of engines for the "Peterbilt 579" at the folder "\def\vehicle\truck\peterbilt.579\engine".<br>
Each engine include ''@include "sound.sui" '' file which contents indirect definition of the events:
<pre>
	sounds: 4
	sounds[]: "engine|/def/vehicle/truck/peterbilt.579/engine/sound_engine.soundref"
	sounds[]: "exhaust|/def/vehicle/truck/peterbilt.579/engine/sound_exhaust.soundref"
	sounds[]: "start_bad|/def/vehicle/truck/peterbilt.579/engine/sound_start_bad.soundref"
	sounds[]: "turbo|/def/vehicle/truck/peterbilt.579/engine/sound_turbo.soundref"
</pre>
There are .soundref file (for each event) to specify bank end FMOD event of the sound.

Content of the sound_engine.soundref is:
<pre>
source="/sound/truck/peterbilt_579.bank#engine/engine"
</pre>

The record<br>sound: ''"/sound/truck/peterbilt_579.bank"''<br>at the any engine configuration file assigns the sound bank to the engine.

== Engine Sound Position ==

The 3D position of the engine sound is (by default) 1 m above the first axle of the truck.<br>
This position could be modified by the .soundref file. (see [[Documentation/Engine/Sound#Sound_reference_file|Sound reference file]])

== Engine Sound Example ==

Visit the [[Documentation/Engine/Sound/Downloads|Downloads]] section to get template project or sound examples.