Visit Ankh-Morpork On Your iPad!

Terry Pratchett's official Ankh-Morpork interactive map launched this week on the app store - it's packed with detail so we interviewed the developer about how it was brought to life

The first ever Discworld app, a detailed, animated guide to Terry Pratchett's fantasy city , arrived on the iPad store on Tuesday and immediately became the number one paid-for app. Quite an achievement for a £9.99 interactive map, but a sure sign of the love out there for Pratchett's world. The app itself is certainly crammed with as much information as you'd find in a posh coffee table book - plus new art and audio-visual effects. You might be surprised how much work went into making it so detailed, so we've interviewed the folk behind it. First, though, here's the trailer video with Sir Terry himself:

If you're a Discworld fan, it's an immense thrill to zoom in and tap on locations like Pseudopolis Yard and the various guild buildings. Based on The Compleat Ankh-Morpork but with new illustrations and bonus video, sound, animation and other content, it allegedly boasts over 2,000 locations and landmarks highlighted on two detailed illustrated maps. You'll apparently see over 1,500 residents wandering the streets including famous Discworld characters going about their business. There are recommended walking tours plus one guided tour with historian Hortensia D'Antiqua (voiced by Helen Atkinson Wood).

The driving forces behind this app were Sophie Holmes, Digital Publishing Manager at Transworld , and Dave Addey , Managing Director at developers Agant . SFX had questions about how it came to be so we grabbed the chance to hear from Addey about how it was made:

SFX : Much of the detailed research was from The Compleat Ankh-Morpork . What was the biggest challenge in wrangling it all into an app?

The biggest challenge was adapting the map itself. I remember the first time I saw that beautiful perspective map, put together by the incredibly talented team at The Discworld Emporium - my immediate response was "we have to bring that to life."

Doing so was no mean feat, mind. Firstly, we had to remove the static illustrated characters from the streets of the hand-drawn map, along with the illustrated smoke. We then plotted the location of every chimney in the city, and added the smoke back onto the map as individual animations. In parallel, we re-plotted the entire road network - using a mapping tool normally intended for the Roundworld - and converted this map into a grid of paths that our AI residents could follow. Each of these residents was then created as a digitally-drawn animation, with bonus animations for the named Discworld characters hidden in the city.

The biggest job of all, however, was masking out the buildings so that characters could walk behind them. Because the map is hand-painted, there's no quick way to extract all of the buildings from the picture. So, we traced every single one of them (using a Cintiq monitor tablet and stylus), and extracted them as overlaid image masks. It was worth the effort; the way characters walk behind buildings really makes the illustration come to life.

Were you all fans of Terry Pratchett before this project came along? How involved was he in developing the app?

Both myself and Graham Lee, the app's lead developer at Agant, grew up reading the Discworld novels, and are huge fans of the books. We'd both owned previous Discworld maps, and so working on this project was particularly fun as fans of the world ourselves.

One of the great things about working directly with Transworld (Terry's publishers since the first Discworld novel in 1985) was that we got to work closely with both Terry and The Discworld Emporium, who'd created the book on which the app is based. Much of the book's content already existed when we began development, but the new material created for the app - such as the audio soundscape and character audio - was created with Terry's involvement, and approved by him during development. Indeed, if you listen closely, you might just recognise the voice behind a few of the characters...

How did you go about planning all the new audio and video - did you have a wishlist of what you wanted to include?

The whole thing has very much been a collaboration with Transworld and Terry. To give an example: we worked together to define the list of characters we'd want to appear in the city, and also to work out how often they should appear. (Nanny and Granny aren't always in town, for example - they only visit the city occasionally.) We also worked very closely with Transworld to adapt the book's text and imagery for app use, creating custom content editing tools so that they could edit and preview the app's content themselves.

For the audio - all of which was created specifically for the app - we worked with a brilliant radio producer called Chris Vallance, who recorded and mixed new soundscapes to complement the city. For example, the sound of the docks is based on a recording of a particularly gloopy river, slowed down to a fraction of its normal speed. Overlaid on top of that is the sound of a polystyrene cup being gently squeezed - again, slowed down way below its normal speed - which sounds uncannily like the creaking ropes of a boat at harbour.

We had a lot of fun recording the audio - I spent a particularly constructive day running after a horse with a microphone - and I'm really pleased with how the soundscape brings the city to life. One particularly lovely thing about working on the project was attending last summer's Discworld Convention, for which I wisely took along a microphone and recording equipment. The applause you hear when unlocking an achievement is the sound of a couple of hundred Discworld fans congratulating you on your success!

The app has already reached number one in its category. Why is Terry Pratchett's universe so popular with people?

I think one of the reasons that the universe is so popular with fans is the level of depth and richness that it now contains. There are nearly 40 Discworld novels, which means locations such as Ankh-Morpork are very well defined in people's imaginations.

Actually, if anything, this was part of the challenge with making the Discworld app. We wanted to make something that complements the vision of the city you have in your own mind, without defining it too absolutely. It's one of the reasons we've spent a lot of time on the audio soundscape - we've found this really helps to paint pictures in your brain, and to stimulate your imagination's own vision of the city.

£10 seems a lot compared to some of the content out there, but obviously people are prepared to pay for things that they love. As a developer, what's your personal take on the state of the iPad app market right now?

App pricing is in an odd place at the moment. Taken in the context of other apps on the store, £10 is indeed seen as expensive - but when you consider that you're getting a living, breathing version of a £23 book, it's actually something of a bargain.

A big part of the problem is that there's no way to try out an app before you buy it. You can take a book off its shelf in a bookstore and leaf through it before making a purchase, but there's no way to do the same with an app. This limits the maximum price - and I guess really the risk - that people are willing to accept when deciding whether to buy. (It's one of the reasons that developers often make really nice demo videos for their apps, as Transworld did for this app; it's the best way to show people what they're going to get for their money.)

The best approach, we find, is just to make a really good app, and let it sell itself. Reviews on the store from other Discworld fans - the app currently has a five-star average - definitely help to convince people that the app is worth it.

SFX : Thanks!

The app is available for download now for iPad only from the Apple app store . Find out more at www.discworldapp.com . (While you're in an iPad kind of mood, maybe subscribe to SFX 's digital edition ? Ta.)