Smooth sailing.(SyFlex Cloth (simulation software))

In mythology, Helen of Troy had a face that launched a thousand ships and sparked a war between the Trojans and the Greeks, But for the computer-generated armada in the feature film Troy, digital artists at Framestore CFC used SyFlex's cloth-simulation software to create the realistic sails and rigging that propelled those ships on their journey.

According to Carl Bianco, lead technical director, the artists needed to provide the sails in a range of states--billowing, hanging, furled, furling, and damaged. Moreover, they had to produce them in a sufficient quantity and variety so they could be seeded across hundreds of 3D boats that appear in the various shots.

Most important, the sails had to withstand prolonged scrutiny through the long sequences without showing obvious signs of repetition. This alone required Framestore to generate nearly 100 animation sequences ranging from 1000 to 2000 frames in duration.

"We created six different sail and rigging setups, three of which had to accurately match the full-size replicas on the real boats used on location," says Bianco. "The main shots of the armada at sea ...