Cinefex Weekly Update | Issue 27

The 55-second opening shot begins with a view of a mountain range -- though, the camera is so close, the viewer cannot distinguish it. In one continuous move, the camera pulls back, sweeping through a canyon and up a mountainside, then flies past the first peak to reveal a fairytale-like castle on the next pinnacle. As the camera circles the edifice, the lighting slowly changes, and huge snowflakes begin to fall. The camera then pulls back to reveal that the magical setting is, in fact, a miniature inside a snow globe, held up by Sam's father. Continuing its pullback, the camera performs a sudden 180-degree flip, zeroing in on the real setting for the film -- the San Fernando Valley, viewed from atop Mulholland Drive. "The gag," explained Digital Dimension visual effects supervisor Ben Girard, "is that the film starts out looking like a traditional fairytale, all pretty music and castles; and suddenly, there's the sound of a needle scratching across a record, and you come into the reality of L.A. The joke is that this Cinderella is really a valley girl."

To ensure maximum flexibility, Girard decided on an all-CG approach for the shot, which would transition to live-action once the camera had passed through the glass of the CG snow globe. Girard and his crew began by browsing the web for reference to help achieve a photorealistic mountain range and castle, both of which had to withstand close scrutiny during the flyover. "At the same time," noted Girard, "we were also exploring how the camera was going to fly through the scene. We went through a previz phase, shooting animatics so that we could try out different camera moves, coming up with ideas of how to go around the castle, deciding when the opening credits should roll, what the tempo should be, and how to make it grandiose enough."

For the beginning of the shot, the filmmakers strove to create the impression that the camera was climbing a real mountain. "Once we were past the mountain," said Girard, "the vibe was: 'Make sure the castle is fairytale-ish. Make it look a little too good, a little too saturated.' Then, when we transitioned to the real setting, it had to look like a real snow globe with a plastic castle inside. It was tricky to blend all of those things together smoothly, without any cuts or dissolves."

Rendering in mental ray, Digital Dimension built in layers of detail, including fog and mist, for the mountain flyover, and used procedural applications and in-house shaders to apply snow, moss and trees to the mountains. "We wrote a shader that allowed us to make each tree look a bit different," remarked Girard, "so there would be the illusion of a more natural forest." The castle, too, was a highly detailed model. "We're very far away from the castle at first, but then we get really close to it -- close enough to see individual bricks and windows with cloth banners hanging from them."

The biggest challenge was the transition from the all-CG environment to the live-action plate, as the camera moved out of the glass globe and into the real world. "Technically, storytelling-wise and lighting-wise, it was very tricky," said Girard. "When we were on set, we took high dynamic range photography and sampled the lighting from the scene, which had been shot outdoors around 2:00 in the afternoon, with the sun very high in the sky. But when we started building our environment and tried matching the position of the sun, it didn't work. It was very flat lighting. So we moved our virtual sun around until the castle looked good. Then we adjusted our whole lighting system over the course of the transition so it matched the live-action."