Cinefex Vault #15 – Harry Potter 3

by Joe Fordham

Cinefex Vault - "Harry Potter and the Prisoner of Azkaban"

Here’s an episode that we could not quite fit into our Cinefex 99 story on Harry Potter and the Prisoner of Azkaban, the third film in J.K. Rowling’s boy wizard saga, directed with great panache by Alfonso Cuarón. This amusing sequence – where Industrial Light & Magic visual effects supervisors Roger Guyett and Bill George shared duties with Potter series visual effects supervisor Tim Burke, and Nick Dudman’s creature effects team – deals with a mythological creature that allows students to confront their darkest fears. Now unleashed again, for your online reading pleasure, from the Cinefex Vault.


Building a Better Boggart – article by Joe Fordham

Director Alfonso Cuarón on the set of ‘Harry Potter and the Prisoner of Azkaban,’ with actors Rupert Grint and Daniel Radcliffe.

Chocolate frogs, flying broomsticks, haunted castles and a bestiary of strange creatures fill the pages of J.K. Rowling’s novels chronicling the education of fledgling wizard Harry Potter. Director Alfonso Cuarón stirred the cauldron of ingredients for Harry Potter and the Prisoner of Azkaban, the third installment in the movie franchise, bringing new flair to magical goings-on in Hogwarts School of Witchcraft and Wizardry, producing a darker tale where teenage Harry Potter meets mysterious characters and spectral apparitions seemingly intent on his demise.

During one such sequence, Hogwarts’ Professor of the Dark Arts Remus Lupin (David Thewlis) invites Harry Potter (Daniel Radcliffe) and other students to confront their fears embodied inside an ornate wooden wardrobe containing a ‘Boggart.’ Like many of Rowling’s creations, the Boggart was drawn from mythological reference – in this case, an obscure and mischievous spirit from Northern English folklore – and required thoughtful interpretation to define its appearance on-screen.

ILM visual effects supervisor Bill George, production visual effects supervisor Roger Guyett, and ILM animation supervisor David Andrews.

“The Boggart was a constantly changing chameleon,” commented visual effects supervisor Roger Guyett, who divided duties on the production with visual effects supervisor Tim Burke. “The idea was that it did not exist in any other form other than the creature it turned into, and it took the form of whatever its victim feared most. We decided it should be like scanning channels on a radio. If you scan radio channels in England, between BBC Radio Four and Radio One you might pass through other channels, passing Radio One then coming back and missing it a couple of times. The Boggart was like that – constantly trying to figure out what it was supposed to be.”

In the classroom scene, Lupin encourages pupils to take turns opening the haunted wardrobe, revealing and then suppressing their personal Boggart demons. Industrial Light & Magic – one of five main visual effects vendors on the film — generated the Boggart as a swirling, airborne apparition. “Alfonso didn’t want to simply see one creature morphing into another,” stated ILM supervisor Bill George. “He wanted a shapeless creature, like a vortex. Tim and Roger found reference of a very high-tech CG simulation of a nasty, industrial, geometric shape that was buzzing, vibrating and spinning. They sent that to us and said, ‘It should be something like this, but organic.'”

The Boggart takes the form of a giant serpent.

To create the nexus of the effect, ILM lead CG modeler Michael Koperwas designed a series of glasslike digital shapes – spheres, ovoids, rods and interlocking orange-segments – which lead animator Paul Kavanagh articulated to describe motion like shifting tumblers in a combination lock. “It was an abstract art style of animation,” said ILM animation supervisor David Andrews. “We made the pieces pop and flip and spin, and applied them to this completely bizzare creature. Alfonso wanted it to behave like a visual representation of a radio tuner sound, picking up these different nightmares. We tried to give it a very frenetic quality to match that weird sound, and used the animation principle of a bouncing ball – it anticipated the action by a couple of frames and then popped and changed shape, like a frog squishing down and then hopping.”

The Boggart serpent is transformed into a huge jack-in-the-box.

The giant jack-in-the-box was built as a full-size animatronic by Nick Dudman’s team.

The Boggart shifts from one child’s nightmare to another.

The spinning, shifting pieces drove transformations between Boggart forms, culled from a library of live-action images representing elements on the Boggart nightmare scale. “Alfonso asked us to come up with 100 different scary things that we thought would make interesting images,” related Guyett. “He was very good at tapping into the kinds of things kids are afraid of – things within their own set of experiences, like the classic fear of going to the dentist. But we also tried to put an angle on it because these were Hogwarts kids, not in the normal world.” The production allocated a Boggart shooting unit to film a wild variety of childhood fears – including a dentist, a crocodile, a shark’s mouth, lunging knives and a flamethrower. Censorship concerns of placing children in peril whittled imagery to a handful of horror archetypes – a gecko, raven, witch and snake – which ILM mapped and revealed subliminally in the shifting CG object.

The first Boggart apparition involved the appearance of Hogwarts Professor Severus Snape (Alan Rickman), who terrifies Neville Longbottom (Matthew Lewis) before acquiring women’s apparel. “We used a small motion control rig where we hand-operated and recorded the move,” related Guyett. “We filmed Alan Rickman stepping out of the wardrobe in his professor robes and recorded the move. We then dressed Alan as a woman and played back the selected take. Alan is such an incredibly skilled actor, he matched his movements exactly; then, ILM did a fantastic job of matching Snape in his robes to Snape in the dress, through what looked like a handheld camera move.”

The Boggart as Professor Snape (Alan Rickman).

Snape’s garments undergo a drastic transformation.

ILM next modeled and animated a giant spider, reminiscent of the monstrous Aragog from Harry Potter and the Chamber of Secrets, to terrify Ron Weasley (Rupert Grint) before the young wizard succeeds in conjuring rollerskates onto the spider’s feet, causing the giant arachnid to skitter and skate. The third candidate (Sitara Shah) transforms a giant lunging snake — another ILM animated character — into a giant jack-in-the-box, constructed as a full-scale animatronic by creature effects designer Nick Dudman.

The sequence then concludes with Harry Potter facing his own demon — a towering spectral form representing one of the robed prison guards from Azkaban wizard prison. One of the most nightmarish creatures in the film, the form was generated digitally by ILM. “The Boggart started out as a longer sequence than it appears in the movie,” stated Guyett. “But it was a cute idea, and short and sharp is probably the way it should be.”

Harry Potter repels a faux dementor.

For more on the effects from Harry Potter and the Prisoner of Azkaban, visit Cinefex 99.

Photos copyright © 2004 Warner Bros.

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