EWAN McGregor has described reuniting with his fellow Trainspotting stars 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".

He was joined by Maryhill-born actor Robert Carlyle, Jonny Lee Miller, Ewan Bremner, Kelly MacDonald and writer Irvine Welsh on the red carpet for tonight's premiere in Edinburgh.

Read more: How Scotland grew up with Trainspotting

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 - Begbie, Sickboy, Spud and Diane.

"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, but then Renton hasn't been in Scotland for 20 years either because he's been in Amsterdam, so our stories are not dissimilar I guess."

Read more: Herald writers on how Trainspotting changed Scotland

McGregor, who made his international breakthrough with the first film, also spoke fondly of reuniting with Boyle and his castmates, despite not having seen some of them in the intervening years.

He added: "It was very lovely to work with Danny again. I didn't feel like that had changed. The dynamic there was wonderful, and I found him to be a director who pushes you.

"He is somebody I have done my best work for, I think he pulls great work out of actors. He knows how to do that somehow.

"Just being back with these characters again. Looking back into the eyes of Sickboy again, looking into the eyes of Spud, Begbie and Diane.

"It was amazing. That was the best bit, they are like people we know."

Read more: The Herald review of T2 Trainspotting

Meanwhile, Robert Carlyle has said he is keen to bring Trainspotting's Begbie back to cinema screens for a third time, hinting at a possible third film.

The actor plays Francis "Franco" Begbie, who is the focus of Irvine Welsh's 2016 book, The Blade Artist.

Carlyle said the sequel to the 1996 original Trainspotting film might not be the last that fans see of his character.

He said; "It's been 20 years coming, it's been a long time coming.

"We always felt that we would do it, but as the years went by, you thought is this ever really going to happen.

"Danny was always determined we were going to be 20 years older before he was going to shoot it.

"That is the first time you see maybe there is another side to this guy.

"There is something quite emotional about that. He's capable of feeling something more just rage, so I am pleased that that element of Begbie has been shown.

"And maybe that sets up another film in fact because Irvine Welsh has written The Blade Artist.

"We've been talking about that, I am up for doing it.

"So maybe we ain't seen the end of Begbie just yet."

Read more: Jonny Lee Miller on the new Trainspotting film, Elementary and why he's nothing like Sick Boy

Direct Danny Boyle said he felt it was a, "pleasurable obligation" to make a second film.

He said:  "They (the cast) are amazingly experienced now.

"They stepped back into the roles...they factored in their own 20 years of experience into their characters and they were off and on their way.

"The past is alive in all of us really. It's in a telescope, and depending on which end of the telescope you look at, it's either there or it's gone, it's distant, and it preoccupies you more and more in life.

"So it was to get them (the characters) to reflect on that but hopefully in an entertaining and surprising way, and in an emotional way as well I hope."

As an Englishman, Jonny Lee Miller had the added challenge of reprising his Scottish accent for the role of Sickboy.

"It wasn't that hard (to get back into character) but I worked on the accent a bit," he said.

"I tend to pick it up by spending some time here, and I worked with a voice coach this time which I didn't do before.

"But it's (the character) sort of ingrained really."

Read more: The Herald review of T2 Trainspotting

Kelly Macdonald, whose original character Diane makes a cameo appearance in T2, arrived at the premiere with McGregor.

"Ewan McGregor was my first screen love and I hold him the same sort of affection as I do my first love," she said.

"I just adore him, and it's lovely to get to revisit that again really."

Other celebrities attending the screening at Cineworld, Fountain Park  included Outlander stars Sam Heughan and Catriona Balfe and actress Sadie Frost.

Although it was shot mostly in Edinburgh the stars of T2 were spotted filming at various locations in Glasgow and the surrounding areas last year including Glasgow University, Pollokshields and Stobcross Road in Finnieston.

Scenes were also filmed at working man’s club The Orb in Bellshill and The Douglas Hotel in Clydebank.

T2 Trainspotting will be released in UK cinemas on Friday.