Ewan McGregor has described reuniting with his fellow 'Trainspotting' stars for the sequel as an "amazing" experience.
The actor also said he has done the best work of his career for director Danny Boyle, with whom he still has a "wonderful dynamic".
McGregor was joined by Boyle and his co-stars Jonny Lee Miller, Robert Carlyle and Ewen Bremner, in Edinburgh for the world premiere of 'T2 Trainspotting' last night.
The sequel comes 21 years after the first film, which followed a group of heroin addicts and explored urban poverty in Scotland's capital.
It is based on the novel of the same name by Irvine Welsh, with T2 based on his book 'Porno'.
Set in the present day, the main characters - Renton (McGregor), Sick Boy (Jonny Lee Miller), Spud (Ewen Bremner) and Begbie (Robert Carlyle) - are now middle-aged.
"It is quite daunting to come back to a character who is so well known and loved," said McGregor.
"Like all of the characters in 'Trainspotting', they are people who we feel like we know. They are like people who we have really met in life. It was sort of daunting, but I am Renton, and Renton is me.
"I haven't lived in Scotland since I was 17 years old and there was a sort of trepidation about coming back, thinking maybe I don't have it any more."