Oppenheimer's Matt Damon explains preparation to play real-life person

Matt Damon has explained how he prepared to play a real-life person in Christopher Nolan's Oppenheimer.

Damon appears in the all-star biopic as General Leslie Groves, the US Army engineer who directed the Manhattan Project, also known as the top secret research project that developed the world's first atomic bomb during World War II.

Discussing the film with Digital Spy, Damon revealed he mostly prepared for the role by reading, though he did add: "I wouldn't have had to do any research if I didn't want to because the script was so good."

The actor continued: "When reading American Prometheus [the book Oppenheimer is based on], I read the script and I was like, 'This is amazing', and then I read the book and went, 'Wow, I have a whole other level of appreciation for this adaptation'."

Damon, who previously worked with Nolan on Interstellar, went on to the praise the filmmaker for managing to boil the book down to "the most important parts with all of this nuance and subtlety and precision."

"Every little scene and every little interaction is loaded with and backed by history," he added.

"It was really an incredible script and for me, it was about trying to look at what place do I fit in this larger tapestry," Damon concluded. "If he's the master artist, I'm one of his colours and where does he need me to go?"

Earlier this week, Damon revealed that he had planned to take an acting break before being cast in Oppenheimer.

"I actually negotiated in couples therapy ­– this is a true story – the one caveat to my taking time off was if Chris Nolan called," he said.

"This is without knowing whether or not he was working on anything, because he never tells you. He just calls you out of the blue. And so, it was a moment in my household."

Oppenheimer is released in cinemas on 21 July.