“When I arrived in London, Doug took me to a sound stage where Tom was trying on one of the exo-suits that the special effects guys built. When he saw me walking across the stage he yelled to me, ‘Hey, Paxton. It’s about time you got here! Are you ready to work out? These things are going to be punishing.’ I was kind of like, ‘Oh, f—,'” Paxton told me, laughing, in a recent interview. “I had already been working out, but these suits were about 70 pounds.”

Paxton said the special effects artists “made the suits as light as they could, but because of what they had to do, there were a lot of metal parts.”

“That was the most challenging part of the role – the physicality of it,” Paxton said. “But Tom loves a challenge and he’s a very physical cat, so he’d just egg all of us on to do what he was doing. You can’t complain when No. 1 isn’t bitching about the suits.”

Opening in 2D and 3D theaters nationwide Friday, “Edge of the Tomorrow” stars Cruise as Maj. William Cage, a  military officer who recruits soldiers for an international coalition to fight off brutal alien invaders, even though he has never seen a day of combat himself. Cage’s luck runs out, though, when he is suddenly thrust into a suicide mission against his brutal enemies and is killed within minutes — only to instantly wake up at an earlier point in time in his life to discover that he’s been thrown into a mysterious time loop.

Through the help of Special Forces Warrior Rita Vrataski (Emily Blunt), Cage learns how he can effectively “re-set” his day by dying. His multiple deaths ultimately give Cage the opportunities to relive the same battle over and over again, but each time learning his enemies’ moves as he develops his own skills and precision — leading him one step closer each time to the key to winning the war.

Paxton stars as Master Sgt. Farrell, a tough-as-nails combat leader who initially holds sway over Cage, only to eventually outsmarted by the soldier since his time-loop secret has only been shared with select people.

“Edge of Tomorrow” is packed with lots of action and stunning visual effects, naturally, but woven within the film is a smart, mind-bending plot laced with lots of wicked humor. It’s the sort of thing Paxton said he craves as an actor.

“The role played to all of my strengths. I love playing these real ramrod characters. I also love that was this real perversity built into it — it had this nice vein of dark humor that runs through all of it from the script. Plus, Doug Liman has great sensibilities as a director as well as an entertainer.”

Working virtually nonstop in both film and TV for the past 30-plus years, Paxton has done it all, from action, comedy and drama, to crime thrillers, horror and science fiction. The 59-year-old actor told me that he’s not necessarily drawn to one particular genre, although he’s glad that directors like James Cameron and Liman have called on for science fiction fare like “Aliens” and “Edge of Tomorrow.”

“It’s a luck of the draw, really. I like science fiction and using my imagination, and love the scale of sci-fi,” Paxton said. “I also love the production design of sci-fi films. You have to remember I started out in the art department on films. That’s how I met Jim Cameron, as a set dresser years ago on the movie ‘Galaxy of Terror.’ The big visions the films have are challenging, physically, but I love to see spectacle. You pay the price, though, because they are painstaking to make. You can spend many endless days just to shoot a three-minute sequence, like on the battlefield of ‘Edge of Tomorrow,’ for example.”

Paxton said he feels blessed to continue getting opportunities to work with directors the ilk of the Cameron and Liman because as effects-heavy as their movies are, the visual tools they use never outweigh the importance of the narrative.

“Jim and Doug are top directors, and as a film actor, you look to see who’s directing the picture before you sign on,” Paxton said. “I’ve been lucky lately to work with some really good directors. Sometimes you take a chance on a new director, but you go in to talk with them and you feel their passion, but it’s a no-brainer when Jim Cameron or Doug Liman calls you up because you know you’re going to be in good hands because they’re really good storytellers — I get just as excited about the director on a film than I do any other aspect of it because it all starts and ends with them.”

That’s not to say Paxton doesn’t appreciate his fellow actors — especially one as enthusiastic as Cruise.

“Tom was super-personable on the film and really encouraged me,” Paxton said. “Early on he said to me, ‘Paxton, you’re killing this part,’ and I said, ‘Tom, we haven’t even shot anything yet!’ Then he, ‘Yeah, but you’re killing it!’ You want to be with good actors like that because they’re going to bring your game up. It’s like a tennis match. The better players you play with, the better your game gets. Tom has a great sense of professionalism and brings a real passion and conviction to whatever’s he’s doing.”