Documentation/Engine/Sound/TruckTransmission

Sounds - The truck transmission and the retarder

The next group of the sounds of the truck are sounds of the transmission and the retarder.

Retarder

Event "retarder" plays sound of the retarder.
It have to be 3D event. The event should be routed to the "truck_effects" audio bus.
The event must be looped.

These event parameters must exist:

• retadred
  the value is in the range <0 - 1>
  value represents the retarder activity
• trans_rpm
  the value is in the range <0 - 3000>
  value represents the rpm of the transmission

Gear grind

Sound of grinding of the transmission gears. It have to be 3D event. The event should be routed to the "truck_effects" audio bus.
The event must be looped. There are no parameters.

Gear wrong

Sound effect of incorrect gearbox engagement. It have to be 3D event. The event should be routed to the "truck_effects" audio bus.
This is a simple ("one shot") event.

Sound Configuration

The group of sounds configuration is stored in the "accessory_transmission_data" data.
There are not mandatory events but there are not default events too. Only the defined sounds will be played.
There is array "sounds" which contents specification for the events:

• retarder
• gear_grind
• gear_wrong

Example:
There are configuration files of transmissions for the "Peterbilt 579" at the folder "\def\vehicle\truck\peterbilt.579\transmission".
Each accessory include @include "sound.sui" file which contents indirect definition of the events:

	sounds: 3
	sounds[]: "retarder|/sound/truck/default/retarder.soundref"
	sounds[]: "gear_grind|/sound/truck/default/effects_gear_grind.soundref"
	sounds[]: "gear_wrong|/sound/truck/default/effects_gear_wrong.soundref"

Sound Position

The 3D position of this sounds is (by default) the same position as the engine.
This position could be modified by the .soundref file. (see Sound reference file)