WHILE set in a specific time and place, the wartime drama Lore is a truly international film – with Glasgow at its core.

The story of a teenage German girl left to flee with her younger siblings as the Second World War ends, Lore is based on the novel The Dark Room, by Glasgow MLitt graduate Rachel Seiffert, 42, and is produced by Paul Welsh, a Glaswegian.

Further adding to its international credentials, the director, Cate Shortland, is Australian and the production was a joint effort between the UK, Germany and Australia.

It was an ambitious endeavour that took time to pull together, but the result is a drama that has played to acclaim around the world. It is "absolutely critical" for Scottish film to look outwards, believes Welsh, whose previous work includes the 2010 comedy, Skeletons.

"There are people doing things of international standard and doing things internationally, but it is the exception to the rule when, in fact, given we are such a small country, we really need to strive to do it more, accept the risks that come with that, but knowing that if the effort and attention is put into it, it will come good."

Welsh first read the book in 1999 when Seiffert, with whom he had worked on short films, showed him the manuscript. "I was intrigued by the dilemma that the children face. Immediately my reaction to it was that it would make a great film." Fast forward to 2001 and The Dark Room had been shortlisted for the Booker and was about to become an international success.

Welsh and Seiffert kept in touch and finally, in 2004, the book was optioned. After that he approached Shortland, then showing Somersault at the Edinburgh International Film Festival. With a director and writer in place, he carried on raising the money while Shortland began casting. Scottish Screen, followed by Creative Scotland, supported the film, with the rest of the money coming from Australia and Germany.

"The only way to finance this film independently and not through a studio was to look to different territories to provide some of that finance," says Welsh, 44.

Most of the dramatic weight on screen rests on the young shoulders of Saskia Rosendahl, who plays Lore. "Saskia came in and just delivered a completely uninhibited, 100% performance of one of the key scenes in the film. I was sitting at my laptop and my head came up, everyone's head came up, it was one of those moments. She was cast on the spot."

With her parents gone, Lore's charges include a baby. "Baby Nick," smiles Welsh. In keeping with the story, the baby spends much of the time crying. He's either an actor of De Niro quality, or those tears were real.

When the camera wasn't running he was happy and laughing, says Welsh. But when it came time to film a scene and the set went quiet the baby didn't like it. "He didn't know what was going on and he got spooked." Scene over, he was all smiles again.

The Dark Room was based in part on the experiences of Seiffert's mother, who was 11 at the war's end, her great aunt, who was a nurse with the Red Cross, and research. Both had to trek across Germany, in her great aunt's case from what is now the Czech Republic to Hamburg.

Having made films and written the novel, Seiffert, pictured below, would have seemed a natural fit to write the screenplay, but she left that to someone else.

"It has to be reimagined, and it's better if it's somebody who is not so close to the story does the reimagining."

The Lore on screen is older than Seiffert's mother was at the time, but the resemblance between the two turned out to be uncanny.

"When they did the casting and they sent me an email with a photo attachment I really got a shock. She's so like my mother at 16. They weren't working from photos, it was pure coincidence."

Most of The Dark Room was written while Seiffert studied part-time for an MLitt in creative writing at Glasgow University. The course gave her structure and deadlines to meet.

"It takes a certain amount of steel to say I'm going to sit down and write a book, especially if you are working as well. Doing something like a course just affords you that space and a legitimacy to say 'I am now doing this for one year, two years'."

Though now living in London, her connections to Glasgow remain strong. When we speak, she is in the city with her husband and two children to attend the film festival gala of Lore, and she has just completed a Glasgow-set novel, Hands Across the Water. The tale of a boy whose father is from Scotland and whose mother is from Northern Ireland, it will be published next year.

Glasgow continues to exert its influence, then, wherever its residents, current or past, travel. Welsh is heading to Australia to work with new filmmaking talent and will be there until June, with a break to shoot a pilot in the UK.

Since Lore finished, he says, it has been appreciably easier to get attention for projects that are Scottish-driven. "It has an impact, we have to try to do it more often."

Glasgow Film Theatre, February 25-March 7; Cameo, Edinburgh, from February 22; Dundee Contemporary Arts, March 1.