'Gaayaka' (part of Rasika package) will play exactly the notation that is entered. To get realistic music the notation has to include details of nuances ('Gamakam'). Notation used in Carnatic Music is generally skeletal and the nuances are filled in by the performer. Along with the Gaayaka program included in RasikaV1 package, sample files are given where these nuances are notated. It is difficult to write detailed notation for nuances and so an attempt has been made to programmatically generate the detailed notation including the nuances based on the Raga characteristics.
Click http://rasika.1apps.com/autogmk/AutoGamakam.pdf for a an article on automatic computer generation of gamakam published in 'Sangit Natak', New Delhi.
A slide set of a Lecture Demonstration (Music Acedamy, Chennai 17th Dec., 2012) on the subject is available at http://rasika.1apps.com/autogmk/title.htm.
For a link containing instructions to download the program to add anuswarams to bare notation to generate Gamakam , supporting files etc. click http://rasika.1apps.com/addgmkdl.htm. To effectively use this program you should already have downloaded RasikaV21 package mentioned above and extracted the files following instructions in the link.