Smarty projects transformation and CodeIgniter

I like to know how to start transformation of PHP coded applications into Codegniter framework.

Is there some good article?

CodeIgniter use the MVC pattern (Model-View-Controller). So, if you have spaghetti code, you'll need to rewrite almost everything.

If you never used CI, you can start by reading the Tutorial and the rest of the very well written user guide :
http://www.codeigniter.com/user_guide/tu...index.html