Let's have a look at Sourcetrail, a great tool for code (C++/Java) visualtiozation:

Better code understanding with Sourcetrail

by Bartlomiej Filipek

From the article:

I’m exploring the tool, and overall I am impressed! It works very well; the setup is easy to do, there’s a lot of help, beautiful and dynamic diagrams (even with smooth animations), under active development… what else would I want?