Computer Graphics World

July 2009 58 n n n n Gaming the game. Nevertheless, most performances were a combination of auto recognition and hand animation, or were completely hand keyed. ough the game uses only two base heads, both are robust and flexible, with more than 40 bones. Because all the heads share the same mesh and Maya joint system, they were also able to share skin weights. Most heads are capable of more than 50 base shapes, which, in turn, can be combined into myriad shapes in FaceFX or Maya. e crew also wrote a MEL script to import the base auto-recognized lip sync into Maya, where artists could hand key a large amount of upper face movement into the eyes and brows, for example, on top of the FaceFX animation. "is allowed us to choose key moments to add more expressiveness to the characters," adds Gonzalez. While all the creatures and ghosts were hand keyed, Terminal Reality mocapped almost all the human-based animations us- ing a Vicon motion-capture system, refin- ing them in Maya before exporting them to Infernal. e title contains more than 2600 individual animations, including 40 blended animations on each ghostbuster, which facilitated transitions between nor- mal and combat walks and runs, or even when driving the Ecto-1 vehicle. e node-based blending system created specifically for this title enables animators and programmers to combine hundreds of raw animations using control variables and different blending techniques to cre- ate output states. e group also created a tool that would transfer all the mocap data from the joints onto the studio's animation controllers, enabling the animators to add to the performance of the mocap while still using a rig they were familiar with. Packing Protons Each ghostbuster comprises just over 31,000 triangles, give or take 16,000 de- pending on the equipment the character is hauling. "e proton pack started as a one- Ghostly Weather Signs of impending doom are everywhere in Ghostbusters, manifested in the surreal weather and lighting. Ominous clouds loom low overhead, casting an otherworldly light as they whip into a swirling vault at the opening of the portal to the beyond. Almost all the lighting effects were done inside Terminal Reality's Infernal Engine. "The creation of lightmaps and the radiosity pass can be set up to run like a renderfarm, so that one person's machine is not tied up with the process," says art director Adam Norton. "You can place and adjust lights in your scene, as you would do in most 3D packages, or you can use any emissive material in the game to cast light from an object, which will be calculated into the radios- ity pass. If you place a model of a lightbulb in your set and that model uses an emissive material, the model will actually cast light. You don't need to place any additional lights in the engine. This approach, combined with our radiosity, al- lows for the creation of some realistic lighting solutions." That said, Norton acknowledges that the group is making a video game—one based on a very popular Hollywood movie, at that. So a lot of the time the crew preferred to use Hollywood-style (three-point) cinematic lighting, rather than go for true realism. To that end, the artists placed lights to achieve maximum drama with colors, shadows, and so forth. Times Square was the most difficult to light, with the seemingly endless maze of buildings reaching far into the gauzy haze, the dazzling neon signage min- gling with flaring police lights, and the usually complex weather and sky effects. "Because it's a large outdoor set, you can see much farther, meaning we have much more geometry visible throughout most of that set than we do in others. This meant we had to vertex-light a lot more geometry, which, in most cases, doesn't look as nice," says Norton. "The artists had to build the geometry with this in mind to make sure the lighting would be effective." The group still light-mapped the streets since the player is standing directly on top of them. Intelligently built geometry and the use of a robust radiosity solution— which generates the lightmaps and calculates them into vertex radiosity—helped make the set look as nice as the others, contends Norton. –Martin McEachern Artists had to contend with a range of environments, from indoor scenes to outdoor locales.

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