|We had trouble finding Jean Bolte in Industrial Light & Magic’s new state of the art building in San Francisco. The group working on ‘Eragon’ had disbanded the day before, and everyone had moved onto new projects. Bolte, who had covered the surface of the dragon in ‘Eragon’ with painted textures, would soon be painting textures for ‘The Spiderwick Chronicles,’ which was ramping up for a February, 2008 release. |
People were just settling into their new digs. “No,” the ‘Transformer’ group said, “They’re not near here. Try the third floor.”
“Not here,” said the ‘Pirates’ crew. “Try the fourth floor.”
“We’re growing so fast,” said my guide as we walked down another long hallway to the elevator. So fast, it turns out, that ILM is pushing LucasArts out of the connecting four-story building and into another on the Letterman Digital Arts campus.
Finally, we called her on a cell phone and got directions. In her new workspace - two walls and half a cubicle, she had already filled the bookcase opposite her desk with reference books. Two paintings hung on the wall above the bookcase; her personal work. In each, she had painted two brightly colored devilish-looking clowns against a background of tiny red sperm-like creatures. “When I started painting the devil clowns, I felt compelled to do them in pairs,” she says. “I had never done anything like them. I was painting fear and craziness. I realized at some point that I was painting Bush and Cheney. Now that I know, I have to stop.”
|On the floor, leaning up against the bookcases, Bolte had propped several pieces of black cardboard. “The first thing I do when I move onto a show is go through all my books,” she says. “I love having paper on cardboard to show people.” She had saved this reference work from her early days on ‘Eragon'.|
On one piece of black cardboard, she had pasted photos of fish with iridescent scales. On a second, pictures of butterflies. A third collected a group of animal eyes. She pulled yet another from the corner of her space. This one had claws.
From these she had fabricated texture maps for the entire surface of Saphira, the 15-foot dragon star of ‘Eragon’, from head to wingtip to talon. The process took nearly a year.
Bolte works in Photoshop, from digital scans of such images as those on the black cardboard and from digital photos she snaps of other reference materials. ILM calls the process viewpainting. “From the beginning, we wanted to make something that hasn’t been seen before,” she says.
Even so, she turned to natural substances to ground the creature in reality, one of director Stephen Fangmeier’s mandates, and Bolte’s preference. “I like taking texture and color from nature,” she says. “Nature is astonishing; we can’t improve on it. It’s better if we don’t change it too much to keep the essence real. So, viewpainting is like collage.”
|For Saphira’s body, one tricky bit was in making the scales. “We had to place each one just so with the knowledge of how it fit to the body and how it moved,” she says. To place the scales, CG supervisors John Helms devised a directional displacement shader. Essentially, this technique uses a directional flow field to slant the displacements. Kevin Reuter’s shader handled the rendering. “When they’re rendered, the scales look like they overlap even though they don’t,” says Bolte. She reaches into a brown grocery sack and pulls out several plastic bags filled with papery snake skins, reference for the texture.|
She found the snake skins in Berkeley at the East Bay Vivarium, which claims to be the nation’s largest and oldest retail herpetological store. “I scanned the snake skins on a flatbed scanner and applied them to her body,” Bolte says, “by bending them in Photoshop.” She also painted colors into the scanned textures, a task complicated by Saphira’s color, one of the challenges Bolte needed to address. The book of the same name, on which 20th Century Fox based the movie, has a bright blue dragon on its cover. “She’s big,” Bolte says of Saphira. “But in nature, brightly colored animals are small and really big ones are muted.
As much as we wanted her to be stunning, her color is the least organic thing about her.”
| Bolte started with scans of a rusty dumpster, changing the colors to give the winged reptile a gold-toned underbelly with a monochromatic grayish-blue over the rest of her body. She often painted the textures with a one-pixel brush. “Each scale has enough high resolution detail so that if the camera goes close, there is something to see,” she says. An iridescence map added hits of blue, and gray scale maps painted by Bolte controlled the hits; light areas on the map catch the iridescence, darker areas don’t. Bolte also painted a bump map. “It’s sort of a noisy pattern,” she says. “I looked at fish, the way their scales don’t always reflect light.” |
And, a map for specularity - the highlight - that, like the other maps that control aspects of lighting, is in grayscale. This map has random spots of gray. “Specularity is what kicks the light,” she says. “We didn’t want her to have a big sheen because each scale is different. We wanted angle kicks in chunks.” For Saphira’s claws, Bolte referenced raptor talons; for her horns, a buffalo horn that she photographed; for her wings, at least in the beginning, bat wings. Before painting the wing textures, she spread the wings of several captive bats, guests at a nearby bat conservancy, on a light table. Then, the filmmakers asked for bird-like wings.