To create this simulation of a Porsche 911 car engine, two main operations were performed. First, a pitch curve was created for each Sound SFX to link pitch to RPM. Next, these Sound SFXs were placed in a Blend Container to define which would play within defined RPM ranges.
To listen to the car engine example:
Load the “Porsche 911” Blend Container or the “Play_Porsche_911” Event in the Transport Control.
Click RTPCs to modify the Engine_Load and RPM game parameters.
Begin with the Engine_Load at “1” and the RPM at “1000”, then move the RPM value slowly.
Each of the engine Sound SFXs (except idle) has a pitch curve attached to an RPM game parameter. To speed up the process, Wwise allows you to automatically draw a pitch curve based on the actual RPM at which a file was recorded. To use it, right-click any graph segment and select Build Smart Pitch Curve. For more information on this or any other feature, refer to the Wwise Help.
You might have noticed that while certain engine Sound SFXs will not play at certain RPM values, each Sound SFX's pitch curve still extends for the full range of possible RPM values. In this case, because the curves extend past values that will be used, points have been removed to save runtime memory.
The car engine simulation consists of six looping Sound SFXs revolving at different RPM on-load values (on-load meaning that the gas pedal is pressed) and six other Sound SFXs matching the same RPM off-load (off-load meaning the gas pedal is released). These Sound SFXs were inserted into the Blend Container on two blend tracks named On-Load and Off-Load. A crossfade region was defined between each of these Sound SFXs to ensure a smooth transition between them for when the RPM game parameter changes in real time.
A volume curve attached to the game parameter “Engine_Load” was created for each blend track. This curve, which is displayed in red, defines which blend track is heard based on the current Engine_Load value:
From -1 to ~0: the Off-Load track is heard.
From ~0 to 1: the On-Load track is heard.
Therefore, as the game updates the current Engine_Load game parameter, the corresponding curve is heard.
