Syflex in "Troy"

Carl: Indeed, Syflex was used to create all the sails and rigging for our CG boats on Troy.

Carl: We needed to provide sails in every possible state; billowing, hanging, furled, furling, damaged, and in sufficient quantity and variety to be seeded across hundreds of boats, and to be capable of withstanding prolonged scrutiny throughout long sequences.

We created 6 different sail and rigging setups, 3 of which had to accurately match the full-size replicas used on location. The sails needed to display a wide range of animation; the main shots of the armada at sea required the boats to be under full-sail, whilst the beach and harbor sequences needed boats at rest with their sails furled in various states, in addition to showing sails in the process of being furled and dressed, and reacting to impacts upon beaching.

In all cases, the animation needed to have sufficient variety to be distributed across anything up to 1000 boats, throughout sequences as long as 800 frames without showing obvious signs of repetition. In order to achieve this, we generated a large number of animation sequences, many of 2000 frames duration.

Carl: Syflex was used to create not only the sails, but also all the animated rigging on each boat. The sail and rope geometry was converted to Syflex cloth, and constrained to an underlying rigid-body dynamics rig. Forces were then added to generate wind and other effects, and extensive use was made of animated springs.

Combined with Maya's rigid-body dynamics, it allowed us to build a complex simulation rig that would respond both to the underlying animation of the boats and to external forces and manual animation controls, enabling us to create a wide range of effects.

The computation speed of the simulator, and the ease of caching, enabled us to simulate the large number of sequences required in the time available.

Carl: Our main boat setup comprised a Maya rigid-body dynamics rig, driving a sail of some 17600 vertices, together with around 33 separate pieces of rigging (totaling approx 3300 vertices). This would typically simulate at approximately 1 frame every 8 seconds.

An even higher-res version, rigged as above but employing a sail of some 33500 vertices, would simulate at a rate of about 1 frame every 50 seconds.

Approximately 100 master sequences (ranging from 1000 to 2000 frames duration) were created to provide the variety of animation required throughout the sequence. Our biggest shots (both in terms of duration and scale) were drawing upon over 150000 frames of simulated animation.

Carl: The speed and stability of the Syflex cloth simulator was fundamental in enabling us to achieve the huge amount of simulation necessary. Syflex is easy to pick-up, and the range of constraints and forces available lend themselves to a wide variety of applications, making it an admirably flexible package.