DreamWorks' five-year investment in Spirit: Stallion of the Cimarron typifies the studio's philosophy regarding so-called “traditional” animated feature films. The movie, after all, is hardly standard fare — it's essentially a painterly, epic tale about a young horse coming of age, featuring non-speaking lead characters, long stretches without dialogue (only a narrator and a few human characters speak), extensive scenes that highlight stylized landscapes, and a hybrid animation approach that combines hand-drawn and CG images to a far greater extent than most animated features.

The film's attempt to meld the 2D and 3D worlds is the most aggressive step to date in DreamWorks' strategic quest to incorporate digital technology into all aspects of the traditional animation process at its Glendale studio, following on the heels of earlier steps taken with Prince of Egypt and The Road to El Dorado (see the April 2000 issue Millimeter).

On the artistic side, the film has conjured up a host of technical solutions designed to serve a specific goal: “To tell a moving story while emulating the emotions expressed in the works of the great Western artists of the 20^th century — Frederick Remington, Charles Russell, Frank Tenney-Johnson, James Reynolds, and others,” explains Kelly Asbury, who directed Spirit with Lorna Cook.

According to Asbury, “There was a certain drama, a quality of light in those old paintings that really captured the mood of those Old West landscapes. That's why we decided to present the movie in Cinemascope — to highlight the panoramic concept of those landscapes and to emphasize the long, horizontal bodies of the horses. Early on, we realized we needed to rely on human artists to create the characters and that basic, stylized look. That's why we had our artists take extensive field trips to national parks all over the United States.” The film is directly influenced by those field trips, Asbury says, part of the team's commitment to letting the landscapes help tell the story.

“At the same time, we also realized that CG imagery, used subtly, could help us make those landscapes even more visually stunning,” Asbury continues, adding that the studio developed new tools to manipulate both the 2D and the 3D imagery more efficiently.

Thus, all the main characters in Spirit are hand-drawings, and they retain that 2D look throughout the film, even as the light, shadows, and effects that interact with them are mainly CG. Many of those characters, however, also experience 2D/3D “takeovers” in certain scenes, whereby close shots of 2D characters seamlessly transition into 3D versions of those characters for wide shots that don't require detailed performances. Most of the backgrounds, meanwhile, are heavily CG, but with subtle 2D elements also mixed in periodically.

Digital technology also enabled filmmakers to create extensive camera moves as viewers follow 2D characters through 3D landscapes, including the extended “homeland pan” sequence, joining the flight of a bald eagle, that opens the film. Asbury estimates that approximately 35% of the film is totally CG, and about 20% consists of mixed-and-matched 2D and 3D elements with the rest featuring more traditional 2D artistry.

“But virtually every shot in the film was extensively manipulated in some way using computers,” says Doug Cooper, digital supervisor on the film. “The homeland pan shot typifies the approach — 2D characters and 3D characters passing through a 3D environment, with an extended camera move that lasts about three minutes — 4,183 frames, to be exact. Something like that is very unusual in an animated film that has a traditional look.”

Cooper credits the success of those shots largely to extensive pre-viz work done using a proprietary, integrated, 2D/3D camera exposure plug-in for Maya, developed at DreamWorks, called “Toonstage,” which is an update of an earlier tool used on Prince of Egypt and The Road to El Dorado, called “Exposure.”

“Essentially, Toonstage lets us insert into the 3D world representations of 2D pieces of paper with flat characters on them, called peg bars,” Cooper explains. “The peg bars have coordinate numbers associated with them, which allow us to position them where we like them and then render out those images as digital references for the artists creating the final camera move. We can print it all out on animation paper and let the layout artists draw to that guide exactly. The improvement in the system is that we have now integrated it with Maya, so that layout artists can work with rough models and camera motion at the same time, rather than using it as a standalone tool, like in the past.”

Spirit also builds directly on earlier work from Prince of Egypt and The Road to El Dorado in terms of its extensive use of organic CG effects involving wind, fire, water, dust, grass, trees, etc — mainly made possible using particle systems through Maya.

“We leveraged the approach to the organic effects off our work on earlier movies using a sprite rendering technique,” explains Wendy Rogers, CG picture supervisor for the film. “For the earlier films, we had already developed the concept of having Maya particles act as if they were splashes of water, and then on each particle, attaching a little sprite card that plays back a textured, 2D animated movement of the water. For this film, though, one of our artists, Yancy Lindquist, helped us advance the approach by having the splashes feel more like they were joining the surface of the water, not just sitting on it. Yancy spent time working on a shape language to develop the foam on the surface of the water so that it would fit the hand-drawn look, and on ways to add additional 2D hand-drawn effects that could be played back in the midst of this volumetric splash. Another artist, Fernando Benitez, developed a similar approach for fire, which was very important considering there is an important fire sequence in this film.”

Cooper says Spirit also featured improved processes for adding digital tweaks to 2D elements, including an image tracking system called “Patch Tracking” that permitted DreamWorks' artists to track realistic CG horse brands, Indian paint, and shadows onto the moving bodies of 2D horses. “Animators would just define a box on the area where they wanted the U.S. Cavalry brand to go, and it would automatically curve around the muscles of the horse,” says Cooper. “Then, the ink-and-paint department would assign particular colors to that box, with each color representing a custom image processing code that would automatically texture map that particular image, making it more accurate frame-to-frame as the horse moved along.”

Similarly, the production developed a tool Cooper calls “Super Tone” to define areas of light and shadow on moving 2D characters, permitting the effects animator to more easily control those effects in terms of thickness and blurring.

“With this approach, the animator could just draw two lines on the horse's belly and the software would blur the shadow area between them,” he says. “This gave us smooth shading around the belly, shoulders, and bones, and a realistic lighting model for a traditionally drawn animal. That's another example of how the 2D and 3D approaches were blended for this film.”

To learn more about the history of the DreamWorks animation pipeline, read “Inside DreamWorks Animation” on Millimeter.com.