Bollywood director Anurag Kashyap revealed that his upcoming movie "That Girl in Yellow Boots", was an emotionally difficult film to make and he did it only for writer-actor Kalki Koechlin.

"To make 'That Girl in Yellow Boots' I had to push my moral boundaries a lot. It was emotionally a very difficult film to make. I only did it because Kalki was both the writer and actor of the film. She trusted me and I trusted her. We both had to push our moral boundaries a lot, " Anurag told in an interview.

Anurag ventured into production with Vikramaditya Motwane's directorial debut "Udaan" because he wanted the director to have complete freedom to make the film.

"The idea of being a producer was to give cent percent liberty to the director. 'Udaan' is 100 percent his film. He is solely responsible for all the mistakes and credits of the film, " Anurag said.

The director who has given films like "Dev D" (2009), "Gulaal" (2009), "No Smoking" (2007) and "Black Friday" (2004) said he would continue co-producing his films to enjoy independence while making films.

"I want freedom to make my own films and hence I will co-produce all my movies -- be it with UTV or MTV, " Anurag said.

He also does not write the script of his films.

"All the initial drafts are written by some other writers. I only do the shooting draft. This is because the vision becomes very narrow if I write it from scratch. If directors write all their films, all by themselves, it becomes repetitive, " he said.