Car engine

Can anyone please tell me how program a car engine sound that changes according to your speed (like on f-zero or something) where if your car is still, theres just a smooth steady engine sound, but as your start to accelerate, it changes according to your speed.

Thanks for any help

The first thing I'd try is making a base engine sound loop and then alter it's pitch (SoundPitch/ChannelPitch commands) according to engine revs.

Hmmm, thanks Big, i'll give it a try :)

Cheers

I use something like this ( need refinement ) but does it's job.

Gear = Floor( LIMIT( CMspeedZ ,  0 , 10.0 ) / v\GearRatio ) 
				
Diff# = Abs( CMspeedZ - Gear * v\GearRatio ) 
				
ChannelPitch v\CHANNELengine , ( 20.0 + Gear * 5.0 + Diff * 10.0 ) * v\Enginepitch

ChannelVolume v\CHANNELengine , ( 1.5 + v\SOUNDvol * Abs(Throttle) * .5 ) * .5

Where

CMspeedZ is the cars forward speed
Throttle is 1 if accelerator pressed, -1 if breaking.
GearRatio is just a number to determine how many gears you can go through based on the top speed. (e.g. TopSpeed 10, GearRatio = 3, => 4 gears.

Other vars should be self explanitory. Just a case of playing with them.

Stevie

Cheers Stevie, it may take me a while to figure all that out properly :p but i will certainly give it a try.

Cheers man

Oh yeah, ChannelVolume as well - forgot about that one. :)

Make sure the multipier for Diff is greater than Gear for best effect ...

Oh and the LIMIT function is just ...

Function LIMIT#( q# , low# , hi# )

	If q < low q = low
	If q > hi q = hi
	Return q
	
End Function

The 'big boys' way of doing it is pretty much like the above except there are several samples of the same car engine:

1) Idle.
2) Low revs.
3) medium revs.
4) high revs.
5) maximum revs.

When you want to output the engine sound which is in-between any of the samples, you layer the 2 adjacent samples over each other.

Sounds good, it's just getting the original samples which can be a challenge.