Crowd details were given a lot of attention in Shrek 2. Check out these progression images of the arrival of Shrek, Fiona and Donkey at her parents’ castle: (1) Story artist’s rendition; (2) using “wedge” points to determine direction of heads and bodies of crowd; (3) layout artists block camera moves and final character poses; (4) final fx motion render; (5) final lighting is placed on the scene. All images courtesy of DreamWorks Pictures.

If you happened to be cruising the parking lot at PDI/Dreamworks’ Northern California studio during production of Shrek 2, you might have seen something that looked like a stunt for the David Letterman show — containers of water being dropped from ladders, with several people scrutinizing the splashes when the containers hit the ground.

“We always shoot live-action references for ourselves,” says Shrek 2 visual effects supervisor Ken Bielenberg about PDI’s approach. “On Halloween, we had cauldrons in the cafeteria with dry ice that gave off a smoky effect, and our effects guys came by and said ‘Oh that’s perfect!’ They shot footage and used that as reference, too.” So audiences at Shrek 2 can expect to see more realistic-looking effects than they’ve seen before in the computer-animated ogre’s stylized world.

It’s a high standard to exceed, since the original Shrek won the animated feature film Oscar for 2001, the first winner in that category. Bielenberg, who earned a BAFTA nomination for the visual effects in Shrek, garnered wide attention for breakthrough work in several areas, including an innovative approach for animating fire. For this sequel, Bielenberg says, “We’ve raised the bar again. The overall level of complexity is two or three times the complexity of the first Shrek. For instance, in the forest scene where Donkey and Shrek first met there was a certain simplicity to the environment. There was moss-like grass and not much ground cover. This time, in a similar forest scene, the amount of detail that we have in the environment is much richer. There are vines and flowers and grass, and the leaves on the trees flutter in the wind. It’s not photoreal, but the richness has increased.”

For this new film, Shrek co-director Andrew Adamson paired with co-directors Kelly Asbury and Conrad Vernon, and the voice actors from the original are back in force. Newlyweds Shrek and Fiona (Mike Myers and Cameron Diaz) are once again accompanied by sidekick Donkey (Eddie Murphy). They’re also joined by some major new characters — the tabby cat Puss-in-Boots (voiced by Antonio Banderas) and a quartet of humans, including King Harold (John Cleese) and Queen Lillian (Julie Andrews) as Fiona’s royal parents.

Visual effects supervisor Ken Bielenberg does his second Shrek tour of duty.

Up Close and Personal
When it came to the look of the characters, reports Bielenberg, “There were a lot of refinements done ‘under the hood.’ We’ve added more muscles, especially in the necks of the characters — for example, the male characters have Adam’s apples now.” Using the sci-tech Academy Award-winning facial animation system developed by longtime PDI animator Dick Walsh, the studio was also able to achieve what Bielenberg calls “amazing close-ups where the acting shows through. You’re no longer looking at an animated character — you’re really looking at an actor.”

Overall, asserts Bielenberg, “We did very little to change Shrek’s and Fiona’s appearance, so they’re very consistent with the first film. We’ve done a little bit of upgrading, adding a little bit more subsurface scattering on their skin, but not a lot, actually. We did use subsurface scattering to soften the area around Shrek’s nose, and also with his ears so that when they’re backlit the light shows through. And we’ve redone Fiona’s hair a little bit, but I don’t think it will be an apparent change.”

“The bulk of visual development time was spent working on the new human characters and developing new technology for modeling and moving hair,” says Bielenberg. “Modeling hair is a real challenge because you’re not dealing with something that’s hard and easily definable. You have tens of thousands of hairs that you’re trying to move around. We came up with new programs and techniques for modeling hair.” Compared to PDI’s previous method of modeling a “clump volumes” of hair, the new approach enables PDI to interpolate the movement of neighboring hairs on a much finer level. As a result, the characters’ hair parted in more convincing ways and the haircuts showed off some better-looking bangs.