Once we know the desired sounds and the method of playing that sound it can be achieved by various mechanisms. In case of a violin we can press a key to hit the tabs to make sounds, so we it’s possible to build a keyboard that plays various violin sounds. Thanks.
I am not sure if this is a question or comment. Do you want to know about “virtual Violin” instruments, or are you pointing out they exist?
I am a hobbyist music producer and have a little experience with virtual strings, if you are asking a question I may be able to help you find the desired resources for answers.