I’ve seen humanizing done 2 ways
Random:
VSL’s Vienna Instruments Pro can play a random performance every time
Cubase’s logical editor can very roughly do the same thing
Fixed:
Cubase’s logical editor has a preset to randomize velocity of selected notes
Studio One has the same thing as a UI embedded feature, but also randomizes start times of each note
S1’s is the most effective to me as it randomizes both points, it does within a limited range as players don’t trend to randomly blurt out excessively loud notes, and it goes the farthest at making a duplicated set of bars just unique enough not to sound mechanical, like a measure by measure machine gun effect.
I assume by using a term like humanize, that developers will be familiar with how existing tools have been approaching this. But some comments lead me to think I will be misunderstood instead. Hopefully this helps to clarify.
-Sean