It's an actor's job to put flesh and bones on a character and bring it to life. But what if that character is a two-dimensional comic book creation? According to Kevin Bacon, who portrayed the power-hungry Sebastian Shaw in X-Men: First Class, and now plays a bad cop in R.I.P.D., a supernatural action comedy based on a graphic novel, the process is no different.
Research, back story, and finding human elements to latch on to still come into play. "I try to humanise comic book characters, to make them real," the actor says.
"I tend to approach them in the same way that I approach any other character. I try to think about where they are from and what their life was like before we meet them; I look inside them and find out what makes them tick."
Bacon has a somewhat illustrious career behind him, mainly as a supporting actor. The 55-year-old pops up all over the place: as a villain in the thriller The River Wild (1994); a Nixon honcho in Frost/Nixon (2008); a gay prostitute in JFK (1991); and as a paedophile in The Woodsman (2004).
The 1982 ensemble film Diner, directed by Barry Levinson, got him noticed, and the 1984 musical movie Footloose made him famous. He has worked with so many people that he has given his name to the Six Degrees of Kevin Bacon parlour game, in which players try to connect an actor to another actor in a chain involving Bacon.
Bacon's latest outing, R.I.P.D. - which stands for "Rest in Peace Department", and is based on the Dark Horse Comics graphic novel of the same name by Peter M. Lenkov - is about a couple of dead cops sent back to earth to rid it of monsters and zombies, known as "deados", who have managed to scheme their way back from hell.
Jeff Bridges and Ryan Reynolds play the dead cops, while Bacon essays a saturnine villain with some extremely nasty personality traits.
Bridges hams it up as an eccentric 19th-century lawman in modern-day Boston. He's gruff, gregarious, and never short of a wisecrack. Bacon, as befits his role, is a counterpoint: he's cool and mean, and plays it for real, as if he's in a police drama rather than a comedy.
Bacon says he reads as much as he can about the characters he plays. To get himself ready for X-Men: First Class, he studied as many of the comics as he could. He learnt everything he could about Sebastian Shaw, he says. But his approach to Hayes in R.I.P.D. was necessarily different.
"The X-Men series has been going for a long while, but for R.I.P.D. there is only one graphic novel so there was a lot less material for my research. But part of being an actor is inventing things: that's one of the creative parts. If it's not all given to you, you invent it. You say, 'Let's work through this, let's figure out who this person is and how they got that way'."
Actors - especially those trained in the Method techniques created by acting teacher Lee Strasberg - often look for a physical trait to latch on to as a psychological marker for their characters. For Robert De Niro in Raging Bull, for instance, it was Jake LaMotta's bulk that told the actor who the former boxer was - and who he used to be. Once De Niro had put on the weight - he gained 27kg in real life - he felt ready to play the character.
Bacon's Hayes may be lighter - metaphorically as well as physically - than LaMotta, but he used a similar technique. While reading the comic book, the actor noticed that Hayes, who also was middle-aged, had been drawn with spiky blond hair more suited to a young punk than an ageing cop. "When I saw the drawings I thought, 'Well, that is kind of interesting'. So I had my hair highlighted - not subtly, but so that you could see it had highlights. I started to think to myself, maybe this guy Hayes is in the midst of a mid-life crisis."
Hayes' flashy car adds to that perception, Bacon says. "He drives a great big orange Dodge Challenger, a big-ass muscle car that should really be driven by someone in their 20s. Coupled with the frosting of his hair, his tight jeans and his gold chain, I started to treat him as a character who was worried about getting old. And that gave me a hook to hang him on."
It doesn't always work like that, Bacon says. When he saw pictures of Shaw in X-Men: First Class, he wondered why director Matthew Vaughn had picked him for the role. "If you look at the way he is drawn, he looks nothing like me," says Bacon. "He looks like an 18th-century character, and he even has a pony tail. When I saw it, I said 'How am I going to be this guy?' But it didn't bother people, even fans of the comic book, that we didn't adopt that look. The film is different, and people accept that."
Bridges, who is gnarled and rambunctious in this film, was one reason Bacon took the role in R.I.P.D. Bridges looks like he is a lot of fun to work with, and that is true, Bacon says. "When I looked at the film's pedigree, I knew it was going to be fun. I had never worked with Jeff and I am a big admirer of him.
"I was hesitant about joining the production at first, as X-Men had just come out when they approached me. I thought twice about going straight back into the comic book villain thing. But it was different enough so I went for it."
R.I.P.D. opens on Thursday