Jack and the Beanstalk - Jim Henson's Creature Shop

Picking features in a heap of leaf-mould or a frame filled with meadow is like looking for a needle in a haystack - unless you have boujou.

As The Creature Shop's Technical Director Alex Wuttke explained, shots in the forest and hilltop locations used for Jim Henson's Jack and the Beanstalk : The Real Story were often filled with complex organic textures such as moss, leaves and grass, which are all very difficult to track with conventional methods.

In one shot, the camera draws back from the sleeping Jack to reveal the computer-generated beanstalk erupting through the leafy forest floor. 'As the beanstalk emerges,' Wuttke continued 'it throws a lot of soil and leaves into the air. We created this flying debris in the original shot and we were pretty sure that all the movement in the foreground would stop boujou giving an accurate track. In fact boujou locked on to the static leaves filling the rest of the frame and had no problem at all with the movement in the foreground.'

In the sequence where Jack arrives at the top of the beanstalk for his first steps in the land of the giants, he's seen in close up rising to his feet on a grassy bank before the camera pulls away to reveal a mountain valley below. At the beginning of the shot the frame is filled with an almost flat plane of grass with no other detail to track, and no markers in shot or other survey data to work with.

In the same sequence the forest floor fills the frame, this time forming a strongly defocused background. Because of the combination of soft focus and the lack of reference to features at different distances from the camera lens, Wuttke anticipated problems in tracking the shot, but boujou easily produced an accurate solve entirely automatically. 'I've been very impressed with the way boujou copes with really challenging shots like these,' Wuttke concluded, 'and of course with the time it saves us by doing the whole thing automatically. When we know shots are going to be very difficult we've been used to allowing extra time for the tracking. But with boujou the process was amazingly quick - we would set it off at 11 in the morning and have the solved shot by lunch time, with no need for any tweaking at all.'