One of the film's centerpieces, a stampede of the cattle on the edge of a cliff overlooking a gorge, was created with Massive. Courtesy of Framestore.

That was quite useful on Australia, which pushed the limits of its schedule. Szuminska cites as an example a shot in which Kidman's character looks across the river at the just-crossed herd. "They said: 'We actually don't want the cows on the other side of the bank anymore. Can we bring them on to this side?'" she says. Moving the cattle was less difficult than finding a way to make work their fur, which had been designed only for mid- and background shots.

But solving that problem, the scene ended up evoking compliments from Luhrmann. "He said, 'I don't even remember having cows over there,' which is about the highest compliment he can give," Szuminska admits.

Rising Sun's digital cattle mixed frequently with real cattle, filling in scenes or extending them to the horizon, Kolve suggests. It also was a challenge to match the speed and placement of digital cattle with real cattle.

"It was a massive job from the 2D side just to rotoscope out the shape of the real cattle so that we could put the CG cattle behind it," says Kolve. "And then it would be a big task for the crowd team to integrate them speed wise and general animation wise."

Beyond the cattle, Rising Sun worked on nighttime camp sequences, expanding the sets to establish a sense of geography while also being flexible enough to accommodate changes Luhrmann would ask for on aesthetic grounds.

Dust was added to the stampede sequence using both 2D and 3D elements, the latter generated in Houdini using a proprietary particle rendering system called Wisper. Courtesy of Framestore.

One of the centerpieces of the film involved a stampede of the cattle on the edge of a cliff overlooking a gorge. The sequence was created by London-based Framestore, which was the only non-Australian facility to work on the film. Mike Mulholland, CG supervisor at Framestore, says they got the sequence late in production -- only four months ago. The client had provided a rough previs of the sequence and Framestore's first task was to nail down the details of the sequence.

"The director, Baz, is keen to always be tweaking and changing things, so it was ever-evolving," says Mulholland.

The cattle sequence was created with Massive and was the most extensive Massive sequence Framestore has done to date, requiring changes to their pipeline to accommodate the work. Tools were written to preview Massive data in Maya and to preview and edit the crowd simulation.

Mulholland says Framestore inherited a cattle model and extensively reworked it and cleaned it up to meet the requirements of the stampede sequence. "We also spent a lot of time doing iterations on the cow," he continues. "The cow they gave us was a hefty, fat cow and in our sequence the cows are a lot thinner because they've been driven across the desert."

Dust was added to the sequence using both 2D and 3D elements, the latter generated in Houdini using a proprietary particle rendering system called Wisper. The Massive simulations were exported to Houdini so the dust could be generated from the cattle's footfalls, Mulholland explains.

Framestore also did extensive environment work, ensuring that footage shot on location at different times of day or in the studio against greenscreen matched up in the final sequence, Mulholland says. The scenery of the cliff and gorge was created with matte paintings and projections.

This also was the first project on which Framestore used all 64-bit rendering, a technique they had used on some sequences of The Chronicles of Narnia: Prince Caspian. "It gave us more memory for our renders," he says. "This allowed us to raytrace the cows, which was important to get shadow detail."

In all, Framestore had a crew that peaked at 50 people working on the project, including a group in Iceland, and produced 117 shots for the film.