For Shrek the Third, PDI/DreamWorks handled more scale issues and detail than before. An orbiting camera motif was achieved during the royal dressing sequence. All images ™ & © 2007 DreamWorks Animation Llc. All rights reserved.

When it came time to make Shrek the Third (opening May 18, 2007), the 350 artists at PDI/DreamWorks that worked on 1,300 animated shots no longer had to worry about limitations: the character rigs were revamped, with improved facial animation for more interactive and believable performances; they had more tactile clothing and fabrics with multiple areas for simulating movement; long and bouncy hair for more than Prince Charming that didn't take months to render; more effective fire and water engines; more controllable crowds; and greater and more beautiful environments.

"Overcast lighting was hard on Shrek 2, proclaims production designer Guillaume Aretos. "Global illumination [throughout the pipeline] was key in making it easier. Aretos collaborated with art director Peter Zaslav in adding 65 new locations for Shrek the Third, in which the iconic green ogre prepares for fatherhood and encounters a gawky teenager named Artie, who eventually becomes the legendary King Arthur. The sets are moodier and, for the first time, the artists could animate overcast skies with no direct light for the funeral of King Harold.

Shrek the Third boasts more effective fire engines. Here is the effects progression for the scene of Donkey with shrimp skewers on the fire.

"CG is still in its infancy," adds Zaslav, but technology is fairly pushed at DreamWorks. Lighting is very controlled and global illumination is used with a bounce card as a tool, not an end in itself. It's close to live-action cinematography."

Meanwhile, Nick Walker, head of layout, says they were able to handle more scale issues and greater level of detail. For instance, an orbiting camera motif was achieved with a new camera rig during the early uncomfortable royal dressing sequence between Shrek and Fiona and later during the sea voyage in which the ship rocks back and forth. "We had to figure out real world qualities so that the camera rigs and motion feel natural," he explains. He adds that they also swapped in default facial poses for layout shots to interject more emotional representation.

Speaking of which, character td, Lucia Modesto admits that they had to scrap every legacy character and redo from scratch. They built generic characters with casting tools for clothes, shoes and hairstyles. There were a dozen hairstyles and such facial enhancements as increased muscle control, folds over the eyes and sliding skin around the jaws for more believability. There were five body types for men and one for women. There were 16 head variations, 25 facial variations, 14 outfits for women and eight for men. There's even a new Shrek motor ("We did tight pants!").

Thanks to a new in-house hair simulator called Rigid Rod, the four princesses (Rapunzel, Sleeping Beauty, Cinderella and Snow White) all have hair to die for.

Thanks to a new in-house hair simulator called Rigid Rod, the four princesses (Rapunzel, Sleeping Beauty, Cinderella and Snow White) all have hair to die for. Then there's Merlin, with his long, flowing beard. There were a lot less constraints on dynamic flowing and many silhouettes. "Hair is a blend between keyframe and dynamic simulation and we created magnets but it moves as a mass," suggests Andrew Pearce, director of R&D at DreamWorks Animation in Redwood City, California.

For Sleeping Beauty, they created hundreds of strands for a proof of concept. The interpolated hair overcame collision problems, but they made it cling to fabric by adding static friction and made it look a little dirtier. They didn't want the hair to be too perfect.

Merlin's beard posed its own set of challenges; namely, achieving individual separation and movement while maintaining its shape and not splitting apart.

The next challenge, however, was to gain more artistic control over simulation. They were aided by greater computational power by incorporating more than 150 HP xw9300 workstations powered by AMD Dual Core Opteron 275 processors and NVIDIA Quadro FX 3450 graphics cards.