Peter Jackson's new First World War film, comprised of restored archive footage that has been colourised, will get its world premiere during the BFI London Film Festival.
The project has been newly-titled They Shall Not Grow Old and will air at the event in October - and simultaneously in cinemas across the UK - to mark the First World War's centenary.
The Lord Of The Rings and The Hobbit film-maker, who has won three Oscars, has created the film in 3D, remastering 100-year-old footage from the Imperial War Museum's vast archives using modern production techniques to present never-before-seen detail.
Jackson said: "I wanted to reach through the fog of time and pull these men into the modern world, so they can regain their humanity once more - rather than be seen only as Charlie Chaplin-type figures in the vintage archive film.
He said he used "computer power to erase the technical limitations" of such old footage, adding that we can now "see and hear the Great War as they experienced it".
The footage is accompanied by the voices of war veterans.
Tricia Tuttle, BFI London Film Festival artistic director, said: "A hundred years after the First World War, we know much about the horrific impact of this conflict on its soldiers, especially the brutal scale of the casualties which decimated a generation, but Peter's film offers new understanding of the human experience of life at the front.
"Using original audio and moving image archive, he allows the soldiers to tell their own stories. The work his team have done on the materials, adding colour and converting to 3D, is painstaking and beautiful. It makes these people from 100 years ago seem so alive and gives an uncanny sense the footage was shot recently."
The film was originally announced in January as part of a series of events announced by arts organisation 14-18 NOW.
The premiere will be shown as the BFI London Film Festival's Documentary Special Presentation on October 16.
It will be screened in both 2D and 3D in cinemas and venues across the country at the same time.
Jackson will attend the premiere, which will be broadcast live, and will later attend a post-screening Q&A with film critic Mark Kermode.
The film festival, held in association with American Express, kicks off on October 10 with Widows, directed by Steve McQueen and starring Viola Davis.
It ends on October 21, with Laurel and Hardy film Stan And Ollie, starring Steve Coogan and John C Reilly and directed by Filth director Jon S Baird.