Fur Real
By: Karen Moltenbrey
December 18, 2009

Fur Real

Tippett devises a new hair tool that lets the crew create realistic wolves for the film New Moon
Tippett devises a new hair tool that lets the crew create realistic wolves for the film New Moon.

When Tippett Studio was tasked to create realistic CG wolves for the film Twilight New Moon, the timing couldn’t have been better. The studio had recently finished a new hair/fur tool, called Furator, which would be a perfect solution for the complex fur coats on the wolves. (For the complete story of how the wolves were created, see the December issue of CGW.)

Mike Farnsworth and Andrew Gardner from the studio’s R&D department had been working on the new technology for approximately six months before the artists began using the tool for work on the upcoming Cats & Dogs 2 movie. “Even though we kind of cut our teeth on Cats & Dogs, this show [New Moon] pushed the requirements of the tool further,” says art director Nate Fredenburg. “We wrote some custom nodes to get the look we wanted for the wolves.”

To facilitate the necessary changes in the tool, R&D was temporarily located to the art department during the production of New Moon. “It turned out to be a great collaborative effort,” says Fredenburg. “It was wonderful to watch them problem-solve together from a technical and artistic standpoint. It was definitely a collaborative effort; it was not one side driving the other or pulling the other. It was not R&D saying, ‘Here, we built this tool, have fun.’ And it wasn’t art designing their ideal tool. It was a meeting of the minds.”

For Farnsworth, the relocation was an eye-opener. “When we moved to the art department, the tool was already quite functional. But when the rubber hits the road and you see people use it in production, it sure changes your idea of how complete a software package is. When you are designing and developing something, you as a programmer are thinking, ‘This is what they need.’ Then you spend five minutes with them and realize all the other things they need as well.”

Adds Gardner: “Quickly the demands of a show get bigger than we can ever dream up. Yes, we did iterate quite a bit after the move.”

While moving R&D into the art department is highly atypical at Tippett, it was warranted in this instance because the technology was so new. “We had many painters who were working with this tool for the first time. Our R&D guys were there to teach them how it was meant to be used and to watch how they used it, and modified it to meet the artists’ needs,” says Fredenburg.

Creating the various types of fur in Furator.

Furator is now about a year and half old, replacing another in-house fur-grooming tool, Furocious, and giving the artists more flexibility and more functionality. Written from the ground up, Furator is a node-based system that lets the software developers make changes or add nodes quickly, and lets artists compose arbitrarily complex fur projects to get the look they desire. “We have been surprised at how complex projects have gotten,” says Farnsworth.

With Furator’s new setup, the developers could easily write and add code that enabled an artist to tweak the fur his or her own way, while accommodating similar requests for other artists in the group. “Living with the artists for a while, we were able to work with them on things like that,” says Gardner. “We would add one type of operation, say a clump or scraggle, and an artist would say, ‘I want it to behave more like this.’ We could go in and change the code a little to accommodate their request. Everyone has a different style, their own flavor, and with the extensibility of the tool, we can accommodate these requests.”

While both Farnsworth and Gardner are pleased with the capabilities of the software, the computer hardware continues to be a sticking point. “While computers are so much better than they were 20 years ago, artists want a millimeter-accurate representation of what their art is going to mimic, and we can get very, very close, but there is always more we want to be able to do,” says Farnsworth. For instance, the crew would love to be able to put more fur through the same system in the same amount of time and improve the speed of the fur generation.

The trick to achieving that, as well as overcoming the current hardware and resource restrictions the group faced, was in finding interesting ways to solve the problem without losing functionality. “That is the art of programming right there,” says Farnsworth.

Toward the end of New Moon, the developers came up with some improvements that made a big difference in performance. For example, they added technology derived from work at PDI, called shells, to the fur technology that allowed artists to, in effect, place a mesh outside the character, and then during animation, deform the mesh; in turn, it would push the fur around underneath, making it easier to animate and more natural looking. Another technique focused on level of detail. Inspired by a Pixar paper, the programmers incorporated a function whereby the tool automatically begins dropping the amount of fur that is rendered as the character gets further away from the camera, and increases the width of the remaining hair to compensate for the hair loss.

“It is very difficult to determine this is happening when you look at it on screen,” says Farnsworth. “When we added this improvement and was showing it to the team, Phil Tippett kept saying, ‘I want you to push this further.’ And we pushed it very far before he finally said he could see the effect, and we were down to a quarter of the fur or something insane like that. It was great to see these guys get excited over an improvement like that. And we still have more up our sleeves for future projects we will be working on.”