Henry Naylor and Saurabh Kakkar on the difficulties of making an animated sketch show in 3D.

Working on Headcases, ITV1's new animated comedy satire series has been stressful. Every morning we turn on the news with dread: has Becks suddenly grown a mullet? Has Alistair Darling been fired? And, more importantly, does he still have those huge eyebrows?

Making animated satire is extremely difficult. The first problem is that CG animation takes a ridiculously long time even when it is made on state-of-the-art Maya 3D animation and motion capture software. After Paul Jackson and Simon Shaps at ITV commissioned the series, we sat down with Red Vision, the company responsible for the animation, to work through a variety of ways of speeding it up. We were helped by a convention of the genre - all topical shows, from Spitting Image onwards, rely on a certain amount of material that's written in advance. There is a finite number of jokes one can make about the week's news anyway (even if Heather Mills is in it) and certainly not enough to fill 24 minutes. The skill is in predicting which issues are going to be hot during the show's transmission period, partly through extensive research, partly through prayer.

Our writing team, marshalled by Rhodri Crooks, would then meet regularly to plough through dozens of ideas and angles for each subject, some inspired (Dames Helen Mirren and Judi Dench as bullying chavs) and some less so (giving Paris Hilton's genitals their own sketch was hilarious for about five seconds).

Once an angle on a particular celebrity had been agreed, the cartoon character would have to be designed. Mark Reeve, former political cartoonist of the year, would draw up detailed caricatures. These were passed on to Red Vision's modellers for 3D versions to be built and rigged, using a combination of technical genius and witchcraft.

At this stage we would regularly find ourselves in heated conversations about exactly what we meant when we said Kate Middleton's breasts should be “perky” or whether Vladimir Putin was funnier with his shirt on or off (off, since you ask).

Then we'd cast the voices behind the characters. Some were easy - Lewis Macleod's lumbering Gordon Brown made us laugh before we'd written a word, Kayvan Novak's Peter Andre perfectly captures his strange, child-like naivety, and Katy Brand's Victoria Beckham is the aural equivalent of a paper cut, but in a good way. Some were unexpected - listen out for Robert Mugabe and Madonna. And some were tough to get right - finding the precise, supercilious tone for David Cameron or the correct level of pomposity for Jeremy Clarkson. The sketches were recorded by Nick Harris at Tamborine.

After voice recording and editing, the sketches were passed into the hands of Stephen Coren, our animation director. Some of our more impossible ideas would be politely nixed (“Why can't Clarkson be blasted into space in a caravan?”) and some of our throwaway pipe dreams were realised in a manner that we simply couldn't have imagined - check out Angelina Jolie's vast underground sweatshop.

The huge team of animators in Manchester and London would then take the initial animation and fill it with movements and gestures some so unexpectedly brilliant that we'd find ourselves laughing where we hadn't imagined there was space for a joke. After a few editing stages, the animation would be lit and rendered.

To solve the issue of topicality, we worked with Red Vision and motion capture company Centroid using actors to animate the movement of several characters in real time, while banking a library of movements for future use. This was a huge success, so much so that we're rather insanely planning to produce several minutes of topical animation in the week of transmission itself, something that has, as far as we know, never been attempted before.

A few mentions in dispatches - Fiona, Pete and Dave at Red Vision and Julie and Rob at Granada, who have had the unenviable task of making two feature films in a 10th of the time on a 50th of the money; Matt Holt and Tom Hopgood for keeping our rather unstable juggernaut on the road; and to Gordon Brown - for not firing Alistair Darling, or his magnificent eyebrows.
Headcases is a ITVP production for ITV1. It airs at 10pm from 6 April

Henry Naylor/Saurabh Kakkar: tricks of the trade

It's not what you know or who you know. It's what you know about who you know. This justifies claiming gossipy lunches on expenses.

When dealing with technical matters, learning five important-sounding phrases and dropping them in randomly will make you sound like an idiot.

When writers come up with ridiculous ideas, don't dismiss them; they may end up closer to the truth than you imagine. See Heather Mills.

There is much less caffeine in a cup of tea than in a cup of coffee. Fourteen cups a day is therefore unlikely to be the cause of your rapid heartbeat. See a doctor.

Don't make an expensive model of Lewis Hamilton expecting that he'll do anything interesting you can take the piss out of. He won't.

Saurabh Kakkar is executive producer of Headcases, which was created and directed by Henry Naylor