The critically-acclaimed film "Room" tells the story of a mother and son who are forced to live for years locked in a single room, completely isolated from the outside world. While shooting the movie by no means included such torturous conditions, the crew did have to squeeze themselves into quite the tiny space to make cinema magic happen.

Director Lenny Abrahamson talked with HuffPost Live on Thursday about how he brought the titular room from the pages of Emma Donoghue's novel to the big screen, which included figuring out how to depict the space as the film's 5-year-old protagonist Jack would see it.

"The key is [that] to Jack, to the little boy, it's not a prison and it's not limited. It's all he's ever known, and his mother told him that this is the whole world," Abrahamson said. "By being inside his head, the challenge was how do we make this tiny room feel like a universe?"

Those scenes were shot on a tiny 11'-by-11' set, and Abrahamson said the crew worked completely within the confines of the space, never removing walls or using other tricks to make filming easier. That meant shooting around the kitchen space, bathtub and other aspects of the room required lots of creativity.

"It was a big challenge," Abrahamson said. "I spent a lot of time in the bathtub because that was the one place I could lie and not be visible within what we were shooting, and then I'd pop up and interact with the cast and then lay back down again."

The second half of the film takes place in the outside world, and the director said he was excited to finish the scenes within that small room and take the production to other settings. But he surprised himself with how he felt after the transition:

Coming toward the end of basically a month shooting in that space, we were all going stir crazy and saying, "Come on, three more days and we're out. We'll be out again. Streets! The world!" Like the characters, we were looking forward to that escape. We got out into a Toronto freezing cold winter, traffic, all the hassle of shooting on streets, passersby, and we found ourselves weirdly -- like the characters -- kind of longing for the simple, regular world of shooting on a soundstage in that tiny little set. So we weirdly missed it, and that I was not expecting.

Watch the full HuffPost Live conversation with Lenny Abrahamson here.

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