Whether it's Lego or flat-pack furniture, one thing you never want to experience is having pieces left over at the end. Doing so inevitably incites a panicked scramble back through the instructions to see where you went wrong.

Fortunately, the world of manuals is going digital - and 3D. California-based Autodesk has released a new version of its Inventor Publisher software, which allows manual writers to create three-dimensional and animated instructions that can viewed on an iPad. The end user can then pan around and zoom in on whatever they're building to get a better look and so avoid missing important steps.

Autodesk has created a sample 3D manual for Lego's Harry Potter Hogwarts Castle to show off its new software (see video). Inventor Publisher doesn't just make things easier for children (or adults) playing with their latest toy - it is also intended to make it easier to write manuals for any new device.

Typically, the creation of product documentation must wait till the end of the design process because of the many changes that can happen along the way. Inventor Publisher, however, ties the steps together - a manual can be created at the start of the process and instantly be updated whenever design changes happen.

The Lego example wasn't officially sanctioned by the Danish toy maker, but others - including Ohio-based farm equipment manufacturer Unverferth and Stanford University's Bloom laptop project - have officially used Inventor Publisher for their products.

http://www.newscientist.com/blogs/onepercent/games/