Min Pitch not working as documented?


I’m using FMod v2.00.06 (still because of compatibility reasons).
When creating a car-engine like event in FMod Studio and add AutoPitch modulator on the wave files, I don’t get what MinPitch does. The documentation states that ‘MinPitch’ is the pitch when the parameter is 0.
However, it seems like what actually happens is that ‘MinPitch’ controls the pitch at the minimum value parameter (from the parameter sheet). So if you have a parameter sheet with parameter ‘rpm’ with a range of 700-8000, MinPitch cannot be left at 0.

My suspicion grows because of this: I have a working audioset with an rpm parameter range of 700-8000, which uses MinPitch values that are NOT zero. I modify the parameter range (‘Edit Parameter’) and set it to 0-8000 and choose ‘don’t stretch’. At that point my audio sounds differently and I have to reset to MinPitch AutoPitch dials to 0 to make it work.

The solution I have right now is to design for an rpm range of 0…8000 (so starting at zero) and all the MinPitch dials can then be left at zero. But it seems to conflict with the documentation stating that MinPitch is the pitch when parameter ‘rpm’ is zero.

Thanks for pointing this issue out. It looks like our documentation is wrong; as you say, the property represents the multiplier to pitch at the parameter’s minimum value, and our documentation should reflect that.

The autopitch modulator’s “Min Pitch” property is designed to be the equivalent of FMOD Designer’s “Autopitch at Min” sound def property, which the FMOD Designer manual correctly defines that as the multiplier to pitch at the parameter’s minimum value.

I’ve added this issue to our bug tracker, so our documentation will be updated to contain the correct information in an upcoming version of FMOD Studio.

1 Like

Thanks for checking that out! Note that it does seem far more logical to me to define MinPitch with respect to zero instead of the minimum parameter value though. But that of course would make things incompatible in the future.

The adjustment from autopitch is applied to the underlying “linear pitch,” rather than to the displayed pitch as measured in semitones. On this scale, a 1 represents the unaltered pitch of the file played with no pitch adjustment, a value of 2 represents a shift of up an octave, and a value of 0.5 represents a shift down an octave.

Yes, that’s what I would have expected. I must have missed something yesterday, I seemed to notice something else. Anyway, my mistake, those posts can be deleted from the thread.