NOw first of all let me say that this is not a bug or something like .
But it seems that there are slight differences in automating vst parameters with the automation device and the midi device .
I noticed this last night when I was automating the pitch of microtonic , which oscilators goes to 20khz , first I automated it with an automation device , thus directly affecting the parameter and probably the interpolation method used by the developer , then I copied the automation curve into a midi cc device , and automated the same parameter , it seemed that there where slight differences in pitch , is this because of the limited range of midi cc ( 127) ?
ONe more question , when automating with the cc device we only have 127 values available , given that certain parameters of vsti’s goes well beyond this range , is it the vst that handles the interpolation method or renoise ( not talking about the envelopes curves here ) ?
Yes.
In VST/AU plug-ins, each parameter is represented in a ‘standard’ way as a floating point value from [0.0 to 1.0]
When you use the Automation Device, Renoise is sending a value from [0.0 to 1.0] to the plug-in. The plug-in then scales that value to some useful range, ie. [20Hz to 20,000Hz] in the case of MicroTonic’s oscillator frequency. Using this method, you get very smooth parameter changes because you have the full floating point range to work with, which allows for millions of possible values.
When you use the MIDI Control Device, Renoise is sending a value from [0 to 127] to the plug-in. The plug-in will usually scale that value from [0 to 127] back down to [0.0 to 1.0] first simply by dividing it by 127, and will then scale it back up to the useful range as before. Using this method, you often get very noticeable steps in the parameter changes, because there are only 128 possible values you can use.
Renoise can only send the standard expected values to the plug-in, ie. [0.0 to 1.0] for automation or [0 to 127] for MIDI. It has no control over how those values will actually be scaled or transformed by the plug-in itself.
thanks for the explanation dblue .