As the sun rises over the quiet Indiana countryside, we hear the sounds of a farm waking up. An optimistic but not overly bright chicken happens along, and looks out across a two-lane country road. Directly across the road from him stands a farmhouse and silo. The silo has lost one of its slats, and a tall pile of golden grain has spilled out. Upon seeing this grain, the chicken becomes ecstatic. He has found that his purpose in life: to eat some of that delicious grain! With joy in his heart, the chicken steps out into the road... and his adventure begins.

Chicken Crossing looks like a tradtionally rendered 3D animated film (the images in this section are reduced and compressed versions of unretouched frames from the film). That is, each frame is rich in models, textures, and visual effects. Typically a film like this is modeled and animated over a course of weeks or months, and then rendered one frame at a time by several computers; it is not unusual for each frame of a modern 3D animation to take minutes or even hours.

But Chicken Crossing is different. This movie can be rendered in real time, on a PC, using a board that costs two or three hundred dollars. The architecture behind this board is code-named Talisman (see the More Info section below for more details). Although there are no Talisman boards available, we do have an instrumented, detailed simulator of the architecture. Every one of the over 7000 frames of Chicken Crossing was rendered within time and memory budgets by this simulator.

In Talisman, individually animated objects are rendered into independent image layers which are composited together at video refresh rates to create the final display. During the compositing process, a full affine transformation is applied to the layers to allow translation, rotation, scaling and skew to simulate 3D motion of objects. Image compression is broadly exploited for textures and image layers to reduce image capacity and bandwidth requirements. Performance rivaling high-end 3D graphics workstations can be achieved at a cost point of two to three hundred dollars.

Chicken Crossing represents the collaboration of a unique group of artists, researchers, and implementers throughout Microsoft. In all, a half-dozen divisions in three different countries cooperated to create the software and run the simulator to create this movie.

Chicken Crossing was modeled and animated using SoftImage 3D Version 3.5, running on Unix platforms. At the time, this was a Microsoft product. We rendered the images using our software simulator of the Talisman architecture. The final images were produced on a render farm of over 400 PCs running Microsoft NT; these computers were distributed across the US, Canada, and Ireland.

Chicken Crossing is included in the Siggraph 96 volume of the Siggraph Video Review, which you can order online or buy at the conference. I talked about the production process for the film, and the unusual technical issues we faced, in "The Making of Chicken Crossing", a talk given at the July 23 meeting of Seattle SIGGRAPH.

You can learn more about Talisman from the paper "Talisman: Commodity Realtime 3D Graphics for the PC" by Jay Torborg and Jim Kajiya, presented at Siggraph 96 .