In Visual Studio 2005 and prior you could export your code to Visio and view the relationships between the objects and what methods, properties and fields it had. This was great
You may have tried PowerDesigner, it runs under Eclipse through a plugin and it also supports Visual Studio. The only downside is that it only works on Windows.
Another application for modeling is System Architect from IBM (Popkin). It has been used by some major corporations and is still maintained.