Let's said for example I'm doing a drum plug-in, is there any way to match the velocity of the sound to respond to the velocity of the drummer?
I don't know if you understand what I'm trying to do, something like Superior Drummer or so
I am not sure what you mean, I've never used superior drummer. Could you elaborate?
In the case of Superior Drummer, You will have to sample a drum at different velocity levels, and then assign them to appropriate zones in the Sampler.
If the drummer plays softer, it will trigger a softer sample.
Unless you're talking about playing back a single sample at different volumes based on the velocity of your keyboard/drum pad.... but that's not how SD does it.
You need to make something like this. Each drum element should be routed upon the related velocity value. You need to record samples separately: for soft hits with lower velocity, for hard hits with higher velocity.
NOTE: By the way, Superior Drums have so much samples for each note :) So, more samples means more realistic dynamics on drums ;)