Amaan Khan's 3D animated film "Mahabharat" is coming out on Christmas Day and the director says it's a result of seven years of hard work.

Khan has pulled up a casting coup for the film as big names like Amitabh Bachchan, Ajay Devgn, Sunny Deol, Vidya Balan, Anil Kapoor, Jackie Shroff, Anupam Kher and Manoj Bajpayee have lent their voice for various characters in the film, which is based on the epic "Mahabharat".

"It's a time consuming process and we started working on the film in 2007. We started with scripting and then dialogue writing," he said and added that they had to finish the dubbing first as it was an animated film.

"So we had to get the stars on board for the voiceover. Once the dubbing was done, we started working on the visuals. So technically, it took seven years to complete 'Mahabharat'," Khan said.

According to a report by FICCI-KPMG, the estimated size of the Indian animation industry is around $200 million (about Rs.1,100 crore), but Khan says that the genre has not been explored the way it is being done in Hollywood.

He said: "As a filmmaker I want to break all the barriers. We hope more filmmakers make animated film and we will have more audiences to watch it. From the producers' point of view, it's a huge risk though. "I want to attempt something that has not been done before. Animation in India has not been explored as much as in Hollywood."