39Udta Punjab39 director Abhishek Chaubey says he is happy about stars in his film shedding their star persona to become various characters in his film.At the launch of the film39s song 39Ikk Kudi39, Chaubey was asked how despite the presence of four stars -- Shahid Kapoor, Kareena Kapoor Khan, Alia Bhatt and Diljith Dosanjh -- the film didn39t look like it belonged to one particular star.He said: "When I39m writing the script I don39t know who39s going to play it. You first create the character and then find the right actor to play it. I39m happy about the fact that these four are different kind of actors, and good actors. But they have come to shed their star persona to become a character."The first look at all the four characters -- Shahid as rockstar, Kareena as doctor, Diljith as cop and Alia as labourer -- were revealed together and the trailer of the film also gave equal importance to all the four.Chaubey39s first two films, 39Ishqiya39 and 39Dedh Ishqiya39, had romance, comedy and crime, but 39Udta Punjab39 seems to be an out-and-out serious film based on the issue of drugs. About the film, he said: "The most difficult film that I made and I39m still making it. What the film will be for me, I39ll only be able to tell in about 5-10 years time. But right now, it39s been a wonderful journey a wonderful experience and I39m still in the middle of it."Alia39s look as a Bihari labourer has got some criticism for its 39stereotyping39 of people belonging to Bihar. When asked if Bihar will be shown in a positive light or negative light, he said, "This film is about Punjab, there is no take of mine on the land of Bihar in this film. She is just one character in the film."39Udta Punjab39 releases on 17 June.