There were many challenges with animating Puss-in-Boots: his fur, plume, belt and cape.

Faux Fur
Among the biggest challenges of Shrek 2 was creating the furry feline Puss-in-Boots. While the original inspiration for the character was co-director Andrew Adamson’s gray cat, Bielenberg admits, “Along the way I objected to that because having a gray cat next to the gray donkey wasn’t working. So I brought in pictures of my orange tabby cat — I was able to push that new look on the director!”

“We had to develop various things for this character,” recalls Bielenberg. “He has your standard orange tabby tail, and we spent a lot of time retooling our fur shader and tweaking his fur.” Adding to the degree of difficulty presented by Puss-in-Boots was the fact that the cat wears a hat with a big feather plume, which he sweeps with a flourish. “I tried to talk them into a stiff feather, but it just didn’t have the same effect, so we went with a full plume. There were two levels of simulation — the first level simulating the spine of the feather and what the overall feather would do. Then each barb on the feather had simulation so there was a nice fluttering.”

Dressed for Success
The appearance of Puss-in-Boots was further complicated by the fact that the character wears a belt, and also a cape that ties around the front. “So we had fur interaction challenges,” explains Bielenberg. “The biggest was the belt — which was hand-animated —that rides around on his body. We developed a simulation system for automatically getting the cat’s fur out of the way.”

Bielenberg identifies clothing as an area of major R&D focus for PDI, noting that in the past, “We made a lot of creative choices that were based on what would be efficient — something that’s tight-fitting versus something that’s loose. On Shrek we always had belt lines. That’s something that we worked on for Shrek 2. We have a number of characters where we’ve figured out the blending from a procedurally-driven, tight-fitting top to a simulated skirt.”

To achieve this, PDI used both its proprietary software and Alias’ Maya. As Bielenberg notes, “The queen has a one-piece dress in which the top is procedurally-generated. That blends seamlessly into a Maya-simulated dress on the bottom, without a belt line. We’ve worked on several things like that for the clothing in Shrek 2.’When you’re dealing with the Middle Ages there are some pretty fantastic outfits that you can use for inspiration. We developed a new fabric shader for this film that deals with threads running in different directions, which gives surfaces different properties. By tweaking the parameters, we could go from cotton to satin to silk.”

Shrek and Fiona get ready to interact with fluids in this homage to From Here to Eternity.

The Cast of Thousands
While great care was lavished on the leading characters, PDI also focused on upgrading the secondary characters and the crowds that frequently populate Shrek’s world. “There are shots where you see a half dozen people and shots where you see thousands,” notes Bielenberg.

“We thought we could improve the level of detail of the secondary characters, so we went back to the drawing board and remodeled the generic characters from the first Shrek. Secondary characters now have more high-resolution assets and more anatomically correct physiques. We had full skin shaders with subsurface scattering and wrinkles. The textures of their clothing also got a lot richer and the hairstyles were all redone.” The background characters in Shrek 2 are convincing enough, believes Bielenberg, “to get their SAG cards.”

Dynamic Fluids
The irreverent humor that made Shrek so appealing often came from the film’s clever parodies of classic movies, and that tradition continues with Shrek 2. In a takeoff on the “famous lovers on the beach scene” in From Here to Eternity, Shrek and Fiona embrace as waves crash over them — not a trivial task in CGI. Bielenberg admits, “It’s certainly difficult when we’re ‘art directing’ fluids, especially when the fluids are interacting with characters.”