Issue link: http://digital.copcomm.com/i/6179
January 2010 24 n n n n Gaming the details, also insisted that the intensity of the glow should wane when a plant is injured, or wax as it recovers its strength. "For example, when you cut a leaf with a blade or explode one of the many varieties of plants, their biolu- minescence will slowly fade as the plant dies," says Blanche. "We dug pretty deep, pushing Dunia to its limits, to get these effects just right." Indeed, so extraordinary were some of Ubisoft's bioluminescent effects that Cam- eron often asked his Weta team to incorporate them into his film. "I'd often see something really cool that Ubisoft had done, and I'd say to my crew, I want that in the movie—that particular treatment for the bioluminescence, for example," Cameron has said. In addition to the nocturnal biolumines- cence, the player can also use a flamethrower at night to set the forest ablaze, further com- plicating the lighting challenges. "A lot of the fire effects had already been implemented and tested in the Dunia engine back when we made Far Cry 2. However, we made some significant changes to improve on the under- canopy atmosphere during these fires," says Blanche, referring specifically to technological advancements that simulate the dancing, spec- tral shadows and bounce lighting from the fire and luminescent plants. "In addition, Pandora has many expansive and dense rain forests, and we wanted to make sure the light rendering of this under-canopy atmosphere matched Cameron's artistic di- rection," notes Blanche. "If you look closely while you're playing the game—or in certain screenshots—you'll notice that we've added subtle coloration that simulates reflected light on characters, specular lighting in the shadow of the foliage, and ambient colors within the shadows, too. Most of those rendering effects are built into the shaders or into the lighting system itself, using gradients and intensity curves in the Dunia engine." Pandoran Wildlife While meeting Cameron's exacting attention to detail in the plant life was difficult, equally challenging was his demand for the most min- ute details in the Na'vi, humans, Avatars, and wildlife. e notoriously fastidious director wanted the Na'vi to have a specific, graceful way of gliding through the forest, for example; their ears to glow a specific shade of red when backlit; their skin to have a particular, tactile, bioluminescent texture; and they had to shoot their bows with a kind of two-fingered, invert- ed draw beyond the head. Here again, Ubisoft was provided with mocap data from the performance-capture volume at Giant Studios in Los Angeles, and digital assets from Weta. ey had both pho- tos and turntable scans of the actors from the set, including Sigourney Weaver as Dr. Grace Augustine, Giovanni Ribisi as arrogant RDA soldier Parker Selfridge, Michelle Rodriguez as Trudy Chacon, who functions as the player's chopper pilot, and Zoe Saldana as the Na'vi princess—most of whom reprise their roles for the game. Referencing the turntables and photos, the game artists hand-modeled each character using 3ds Max. "e RDA troopers and scientists were easier to animate because of our familiarity with human movement. e Na'vi, however, provided us with a completely new challenge," says animation project lead Xavier Rang. "At first, we weren't sure how to animate them. Poring over reference animations, we studied the Na'vi proportions, skeletal structure, and musculature. eir walk and run cycles were some of the hardest to achieve. Luckily, Light- storm gave us direct access to the animation director from the film, Richard Baneham, who came to Montreal and provided us with a great amount of constructive feedback." Working in 3ds Max, animators keyframed The RDA battles the Hammerhead, modeled and rigged in 3ds Max based on assets provided by Weta Moving in Stereo "Because Avatar was being made in stereoscopic 3D, I urged Ubisoft to offer the game in 3D," director James Cameron has stated. "At first they were dubious, but then they came back six months later and showed us a demo in stereo that blew us away. And then, it was on." Indeed it was, for Avatar is the first major next-gen game to be developed for ste- reoscopic 3D. Thick smoke and mist swirl and drift beyond the screen, as the Ban- shees and twin-propellered helicopters reach out toward you. Ubisoft designed the 3D version of the game specifically for 3D-enabled televisions utilizing stereoscopic technology from Sensio, another growing Montreal company, but it will also work on TVs supporting DLP or RealD technologies. These pricey $4000 sets are capable of running at the 120 hz refresh rate required to project two images at once. To create the stereoscopic effect, the game engine uses two cameras, one for each eye, placed in parallel with a controllable interocular distance—the space be- tween the left- and the right-eye cameras. The images from the two cameras are then rendered in real time. Along with the two cameras that are parallel one to the other, the game develop- ers also used the vertex shader's equivalent of "off-centered projections" to help control the convergence distance—that is, the distance where there is no on-screen separation. Controlling separation and convergence in the vertex shaders enables the artists to correct some special effects and makes them work properly in 3D. "The convergence is positioned farther than our character to have him slight- ly out of the screen and to enhance the 3D effect," says artistic director Pascal Blanche. "As for the left and right images, they are rendered in off-screen buffers and combined for each 3D TV's specific format." –Martin McEachern