Harry Potter and the Chamber of Secrets

In the movie's climactic scene, Harry Potter faces mortal combat with a Basilisk in the Chamber of Secrets. The giant creature resembles an 80ft cross between a snake and a sea monster as it chases Harry around the Chamber – a watery, subterranean cavern – before the final battle scene, in which he perches atop a gigantic stone face.  Featuring in 45 shots, the reptilian creature inspired by the teams character reference, an 8ft Burmese Python named Doris.

The actual logistical problems presented to the Framestore team were complicated by the creature's interaction with water – no matter how convincing the creature itself, it had to look good in the water for the sequence to work. The blend of CG water and real water elements that place it convincingly into the Chamber environment are a brilliant example of both 3D know-how and the compositors' artistry. The CG team worked in Maya, Houdini and Renderman.

Fawkes is a Phoenix, the mythological bird that immolates itself and is then reborn. He becomes an ally of Harry’s and comes to his aid in his hour of direst need, when he battles the Basilisk in the Chamber of Secrets. Fawkes onscreen is a largely digital creation, with some animatronic close-ups.

Feathers, like hair a couple of years ago, have become a hot topic in CG animation. In fact, feathers are an even trickier proposition. The surface geometry of feathers is more complex and their interaction with each other subtler than that of hair. The 3D team initially attacked the feather problem as if it were a variant on the hair problem, but soon realised that this was unsatisfactory. Fawkes’s distinctive bright red and gold plumage meant that the interaction of individual feathers could not be fudged, as it might be with hair.

Returning to first principles, the team had several live birds brought in for examination, including a Blue Macaw and a Turkey Vulture. The birds were videotaped and the footage pored over before work began.

The pixie sequence is an early comic highlight in the film, coming soon after Harry returns for the new term. Professor Gilderoy Lockheart, the self-regarding and inept new teacher (played by Kenneth Branagh), tries to impress an inattentive ‘Defence Against the Dark Arts’ class with a cage full of 'freshly-caught Cornish pixies'. He rashly releases the creatures, which fly eagerly out into the classroom causing mayhem and panic with their malicious pranks, until Hermione brings the action to a standstill with a well-placed spell.

Framestore artists painted out wires and other rigs used to propel the practical elements in the shots. The production-designed maquette was scanned in-house and the results used to create a polygonal model. Sub-surface scattering helped give the pixies skin an appropriate texture. Great care had to be taken to avoid the problems inherent with blue colouring and its instability on film stock.

The CG models were rigged for animation, which would include both running and flying cycles, and they were placed on screen at three levels – background, medium and foreground – to create a sense of depth. Some shots feature over twenty of the little blue pests flitting around the screen at once.