Geri's Game is featured in the Computer Animation Festival

 

 

 

 

 

 

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Cont...

Surface Subdivision Improves Character Modeling

One of Barsky's former students, Tony DeRose, now a software researcher at Pixar, has developed a new algorithm for modeling based not on spline surfaces but rather surface subdivision. A spline surface is a mathematical representation of a curved surface, like a piece of checkerboard cloth with each checker having a formula. While these would work well for, say, an airplane wing, there are limitations in using them for more complex shapes. "Imagine trying to wrap a piece of cloth around your hand-- at some places the squares wouldn't meet, at others they would be bunched up," says DeRose. Surface subdivision is a new approach to modeling using a different mathematical direction, which requires less software, less time to model, and less effort required of the model builder. Unlike spline-based modeling that relies on complex algebraic expressions to describe surfaces, subdivision instead describes surfaces using an infinite sequence of two simple geometric operations: splitting and averaging. The inherently geometric nature of subdivision allows modelers to create their shapes with far more flexibility.



Begun as an in-house project to develop surface subdivision software suitable for a production environment, "Geri's Game" gained momentum and attracted some of Pixar's best creative talent.

Surface subdivsion modeling gives skin and clothing a more realistic look, as seen in Pixar's animated short, "Geri's Game." (c ) Pixar 1997

DeRose's work can be seen in Pixar's new animated short, "Geri's Game." Begun as an in-house project to develop surface subdivision software suitable for a production environment, "Geri's Game" gained momentum and attracted some of Pixar's best creative talent. The efforts did not go unrewarded; Pixar won an Oscar for Best Short Animation.

Surface subdivision modeling will also play a starring role in Pixar's next full-length feature animation release this fall, "A Bug's Life." With "Geri's Game "as a testing ground, Pixar has spent considerable effort to integrate subdivision surfaces into "Marionette," its proprietary animation software, and "RenderMan Artist Tools," its commercially available rendering software.

"A Bug's Life," opening this fall, exploits Pixar's new developments in more organic modeling, (c ) Pixar 1997

 

 


Modeling | Rendering | Animation | Interaction | Virtual Reality | Synthetic Actors