Bremner, Ewan McGregor, Jonny Lee Miller and Robert Carlyle reunited with Oscar-winning director Danny Boyle for the follow-up to the ground-breaking 1996 hit movie.
The 45-year-old, who plays Spud, told NME magazine that Boyle is an “incredible visionary”.
“It’s like he can see into the future, or see into the culture.”
He added: “He actually shot a huge volume of material that’s not in the finished film - my estimate would be that 40 per cent of the scenes we shot never made it.”
The actor added that the original film was like setting off “an exotic bomb” outside of Scotland.
“It was a strange, foreign world that hadn’t been discovered yet, a world that was invisible in mainstream media.
“The idea of a film actually allowing you to enjoy the company of drug addicts - that was revolutionary.”
Meanwhile, novelist and actor Irvine Welsh, whose books inspired both films, compared them to The Godfather trilogy.
“In the UK, we don’t really make big films - our shtick is interesting, quirky wee films.”
He said: “But this film is massive, and when you put the two together it’s almost like The Godfather trilogy - a huge emotional landscape that gives you a sense of what’s happened during our times.”
Welsh added that the film had him “fired up about the possibilities of writing more about these characters again”.