Sunday morning and in this North Shore cinema Andrew Adamson looks like any other Auckland dad gently herding a row of kids to the flicks.

But this isn't just any other flick - it's a private preview screening of Shrek Forever After. After his directing and writing stints for the first two films in the hit animated series, Adamson stayed on as executive producer to the third and now final fourth instalments.

He's seen the new film before a few times before in his "EP" role - "I'm there to make sure it tries to stay true to what I created and just to enforce my opinion occasionally and step on toes if I need to" - but as the end credits roll today he's got bit of a lump in his throat.

As well as the long list of folks who worked on the movie, that final reel also shows clips from the previous films. That for Adamson represents a big chunk of his life - ever since he took on the task of adapting William Steig's original 1990 fairy tale picture book after a near-decade as a visual effects guy took him from Auckland to Hollywood.

"I started working on it 13 years ago ... I got very emotional again yesterday," he reflects over a coffee the next morning. "I've watched it a number of times, particularly at the end when they [do] all the credits and they [have those] little clips of all the old films. It's a long time and lots of things have changed over [that] time."

Sure have. Of course, he subsequently directed the first two Narnia films and is involved in producing the third, while also working on his adaptation of Lloyd Jones' acclaimed novel Mr Pip, among other projects.

Oh, and he'll be in a producer role on the Shrek spin-off Puss in Boots movie.

But the end of Shrek doesn't just mark the end of a major chapter in Adamson's career. Two of those kids in that cinema row yesterday were his - Isabelle (who once confessed to her dad she hated Shrek. She's since come around) and Sylvie, who had brought along some mates for a birthday treat.

Adamson says the Shrek stories have reflected what's happened in his own life.

"The first Shrek I made just after meeting Nikki here," he says of the very Ponsonby cafe, which was suggested by TimeOut as the interview venue and was also once also part-run by his brother.

"The second Shrek was [made] after we got married and the third Shrek was after we had children - we had Isabelle and Sylvie was on the way. The fourth one was at about mid-life crisis point [when] I had moved out of Hollywood, come back to New Zealand and taken two years off my career.

"Subconsciously it's been a fairly close chronicling of what's been going on."

Given those personal connections you almost hate to mention that Shrek The Third - the first one he didn't direct - wasn't much cop. Though Shrek Forever, in all its 3D wonder, sure is an improvement.

"I don't know if I agree that [the third] wasn't much cop. But I do agree this one is better. I have to be sensitive about how I say that because I do feel very attached to it and the people who worked on it. With Shrek 3, the main idea I wanted to get into it was [that] you have to get comfortable with yourself before you have children. You are passing on your genes, you are being a mentor. You have to be okay with yourself to do that - 'I'm worthy enough to do that, I am not going to ruin this thing'. So I am very attached to the idea. But that said, it didn't reach the same levels of the other three films."

Shrek Forever After opened smaller than its sequel predecessors on its US release but it's still heading towards the US$300 million ($433 million) mark after a supposedly slow start. The opening week studio psychosis is something Adamson doesn't miss about Hollywood after setting up house in Westmere, where he can write and keep an eye on the Waitemata tides and do a bit of fishing.

"The whole phenomenon [that] if you don't do $100 million on the opening weekend you are a failure these days, has gotten crazy. It means that movies aren't given time to get up on their legs. It means the success of the movie is about the marketing campaign, it's not about the movie itself."

But whatever amount the fourth and final instalment reaches, Shrek will still go down as one of the most successful big screen franchises - computer animated or otherwise - of all time.

Here, the Dreamworks title is opening a week before the Pixar competition of Toy Story 3, a clash of the cartoon titans in time for the local school holidays. It's a good time to be an animation fan ...

"It's a good time to be an adult with kids because you can see them back to back," laughs Adamson. "A good thing I realised was that a lot of people who went on dates to Shrek 1 are taking their children to Shrek 4 ...".