Add a new character to library

Hi everyone, I was wondering if anyone he knows how to add a new character to a library.
And if you can create custom libraries with different models and different tools?

I’m not sure I understand your question, but you can follow this link to a tutorial explaining how to create an object:
youtu.be/Sb7QG_tZ9-s

and this one showing how to create an object from a selection of polygons from an Artlantis scene detaching an object: youtube.com/watch?v=WN-9oswDx1M&t=40s

Hope this helps.