The Cat and the Whos are on their way to a theater near you. All images © Universal.

For Rhythm & Hues visual effects supervisor Doug Smith, Universal Pictures’ and Imagine Entertainment’s The Cat in the Hat was unusual. Smith was involved with the film for 16 months, including pre-production and every day during production -- from call to wrap. Usually it’s not necessary for a vfx super to be on set daily, but because the project had to fit into a certain price range, questions came up almost hourly that involved decisions with implications for post production.

Most of the sequences had very precise animatics on the production side, but in the editing process, the structure of everything changed. Shots intended for one sequence ended up in another. Elements from different sequences were composited into “new” shots. It was possible to rotoscope out the actors, put them in a new background or switch out people. According to Smith, this manipulation of images is happening more and more lately because the tools are available.

Smith likes working on films that are a bit goofy and not all blood and guts. The most challenging shots were of the “Talking Fish” in its environment – the bowl and the water.

It’s the shakiest fish in the fish bowl, modeled after Don Knotts.

The hilarious, “Talking Fish” character is based upon Don Knott’s character, Barney Fife, from The Andy Griffith Show. He’s passive aggressive. He lectures people, but is easily cowed when confronted. Craig Talme, the animation director, put Fife material online for the animators so that the facial expressions and behaviors of Barney drove the look and actions of the fish.

Technically sophisticated, the fish took four to five months of work. It is completely ray-traced, reflecting its environment in different layers: a shiny wet surface with different degrees of wetness depending on time out of the water; a slimy, overall, jelly layer; and 3D scales. It also has iridescence. Challenges included having plates move against each other on the fish without intersecting and allowing freedom of movement.

Because of their extensive work on animals, the fish eyes that R & H developed are very sophisticated. They have a large refractive layer in them, so as the eyes move the irises refract differently and pick up light very subtly.

Smith believes his team broke new ground with the self-contained world of water in the bowl. It had to fit into the bowl perfectly. There was splash out from the bowl. Of course there was the reflective and clear nature of water. Six to eight months of research and development went into perfecting the techniques for water reacting to the bowl; reacting to the fish and reacting to its environment.

Rhythm & Hues’ Doug Smith.

Another breakthrough, a new process called high dynamic range imagery, or HDRI, was used on the set to gather information. Two cameras with fish-eye lenses were placed back-to-back to shoot an exposure wedge from the position of the CG object. The entire lighting set-up and intensity was mapped out in a series of stills. During post the camera crew and unwanted objects were painted out, allowing the HDRI to be used as a lighting source.

Smith explains the results of using this technology: “On some of the fish you could actually see the camera and assistant reflected on the nose of the fish! These are the same problems you’d have in production if you actually had a shiny fish there. That’s the level of detail possible. Getting integrated, reflective layers on the fish, or any object for that matter, is an important step.”

New technology has drawbacks. Because it’s all a ray-traced environment, the HDRI process consumes a massive amount of rendering time. To approach a project this way requires a lot of very expensive computer time. Also, developing a new working process can be cumbersome. Nobody knows the exact way to do it.