We talk to Ben Stiller, Chris Rock and the rest of the Madagascar 3 cast

The voiceover cast from Madagascar 3 talk to The National about what it was like to work together and what the third film in the successful franchise has in store for us.

Madagascar 3: Europe's Most Wanted, sees the animals travel through Europe as part of a circus.

The actor and comedian Chris Rock had a memorable routine about doing voice-overs for animation films when he presented the Oscars in 2005. "It's the easiest job in the world," he told the star-studded audience. "I go in a booth and I say: 'What's the line?' A guy goes: 'It's time to go to the store.' And I go: 'It's time to go to the store!' … And then they give me a million dollars."

But is it that easy? At last month's Cannes film festival, Rock and the voice cast of the third movie in the hugely successful Madagascar series, Madagascar 3: Europe's Most Wanted, gathered to talk about their work.

All the leads were present and correct: Ben Stiller, who voices Alex the lion; Rock, who is Marty the zebra; Gloria the hippopotamus (Jada Pinkett Smith) and David Schwimmer (Melman the neurotic giraffe). They were joined by two actors who play new characters in this third film: Jessica Chastain (Gia, a jaguar) and Martin Short (Stefano, a comic sea lion).

In Madagascar 3, the four leading animals from a New York zoo, having previously been shipwrecked on the island of Madagascar, then escaped only to crash-land in mainland Africa, are still trying to return to New York, but travel through Europe under cover of a touring circus.

They arrived in the luxury suite of a Cannes seafront hotel in pairs to do interviews. Rock teamed with Stiller. Schwimmer arrived with Pinkett Smith, while Chastain was with Short.

In the course of the interview they disclosed the secrets of voice work; why it's harder than it may seem; and what keeps them coming back for more.

So is it really that easy?

Rock: It's easy compared with work. I mean, we're working right now, but we're not working like the person who's got to clean up this room later. That's real work.

Chastain: This was my first experience. I found it difficult. I used everyone (at the recording studio) there to help me.

Short: Being a Chilean coal miner, I think, would be harder.

Can you really feel as invested in an animation movie?

Schwimmer: Yes. The fun and challenge of this genre is exercising the muscle of imagination. Unlike live action, when you're in scenes with other actors, you're completely alone when you're doing this. So you really have to use your imagination: OK, I'm in a jungle, I'm clinging to a vine or swinging on a trapeze or on a tightrope about to fall off. Nothing's helping you except your imagination.

Pinkett Smith: I think you almost have to be a child to act animation like this. You do have to use your imagination in a different way, imagine what the scenery, the place, looks like. In this movie, for instance, you're at the circus. You have to let go of all that seriousness of being an adult.

How does voicing an animation movie work?

Schwimmer: I was in New York in a small recording booth. When they record, they also videotape us, so the animators watch us on the playback and see what expressions we're using. They'll animate the characters based on our expressions, reactions and our timing. Then we'll see a rough cut of different scenes and say: "I think I could do a better job there. Could I try something else?"

We try to do each line 10 different ways. Because the four of us are never in the room at the same time, we want to give them as many choices as possible in editing. So we don't know what it will all look like until we see the final film. We do maybe 12 sessions over three years. Each session runs from three to eight hours. Sometimes to change one line, you come back for 20 minutes.

Short: You're on your own, but you know the people involved. It's a very safe little zone you're in. And no one's in a hurry. Nobody's saying - you've got to get this done by lunch. They'll say - do you want to do anything else?

So you never meet each other while the film's made?

Chastain: No. I just met Marty [Short] an hour ago for the first time. I was so thrilled! The Three Amigos was one of my favourite films.

At the Oscars, Chris made it sound like you make a lot of money.

Chastain: [laughing]: Oh yeah, you go in, say a couple of lines and they give you, what? $20 million. I have to say, I didn't experience that.

Schwimmer: I don't think we do it just for the money. We're all fortunate enough to have had a career. For me, I'm such a fan of animated movies and wanted to be a part of a great one. Ever since I was a boy, I loved animals and in The Jungle Book it was wonderful to see them brought to life. I'd never tried it, never voiced a character. So I said: "Who's the character?" They said: "A giraffe." And I said: "Of course. I have a long face, I'm taller than the other guys. It was a chance to try something new."

Pinkett Smith: I once auditioned for Simba's mother in The Lion King. And I was absolutely horrible. I had no idea what I was doing. I made myself sound like a lion, because I had no idea I could use my own voice. I felt I need to do this to make up for that faux pas in my career.

Any theories about why the Madagascar films are so popular?

Stiller: I think people like the friendships and relationships our characters have - and they're always there for each other. There's an innocence about them. They go through life without quite knowing how to deal with the real world. They're in the process of learning, and they're doing it together. That's a big part of it.

Money talks: the key to Madagascar's success

Is there any reason why the world needs a third movie about the loveable animals from the Madagascar franchise?

To seek the answer, follow the money. The first film, released in 2005, grossed US$532.5 million (Dh1.96bn) worldwide. Its sequel, from 2008, did even better, amassing a global total of $603.6m. So it's already a billion-dollar series. Audiences love it.

Madagascar 3: Europe's Most Wanted has already made a sensational start in America, grossing $60m on its opening last weekend. It was the top film in the US, beating the long-anticipated sci-fi epic Prometheus by an impressive $10m.

As the director Eric Darnell points out, the massive success of the first two films has allowed its studio, DreamWorks, to spend more lavishly on the third. (Its budget has been estimated at $145m). "We're making this a 3D movie for the first time," he says, "and we also had the chance in the scenes at the circus, to go really graphic and stylised. We also had fun with a car chase, which is a big set-piece in the movie.

"Animation gives you the ability to push even more into fantasy. You're already in a fantasy world. It doesn't take you out of the story and characters the way it might in a live-action film."