"'Fitoor' is a script I fell in love with the moment I heard it. I was very excited and passionate about it. When I started working on the film, we initially went slow, then I started understanding things," Katrina told PTI.
"I have learnt so much from the film. It has re-inspired me... ignited the passion in me as an actor. It is like a new journey for me as an actor. If I could go back and live everyday on the set, I would," she said.
Earlier, the Abhishek Kapoor-directed film had veteran actress Rekha, but instead of her Tabu is now doing the movie.
Katrina said she had a memorable experience working with Rekha.
"I got few days to work with her. I always had a great connection with her. She had been amazingly friendly, warm person. We are saddened that it did not work out. Every film has its destiny and we respect that.
"I have seen Rekha quite a few times. So when she came on sets we had a warm connection. As a performer... as work everyone is a fan of her. I was very respectful towards her.
Since we knew each other so it was a close connection," she said.
The 'Namastey London' actress will be seen with Siddharth Malhotra in Nitya Mehra's 'Baar Baar Dekho'.
"Nitya's film is an amazing love story. It is an idea that shocked me when I first heard it. I have not seen or heard a film like this in long time. Most of the love stories are of similar types, but this seemed new and exciting. There is lot of performance in it," she said.
Both Katrina and Siddharth will go for prosthetics for getting a certain look for the film.
"It (prosthetics) is there for a small portion in a film. Like in 'Barfi', when they (Ranbir and Priyanka) are growing old and dying so you won't say it is a film using prosthetics. It is used in a small portion in the film. There is a very small portion (growing old) that comes towards the end of the film," Katrina said.
