Not only was it artistically stunning, but it was also a technological powerhouse. The short served as a vehicle to demonstrate Pixar s latest addition to its production environment, a surface scheme known as subdivision surfaces.
Subdivision surfaces are a way to describe a surface using a polygonal model.
Like the polygonal model, the surface can be of any shape or size it s not limited to a rectangular patch. Unlike that polygonal model, the surface itself is perfectly smooth. Subdivision surface schemes allow you to take the original polygonal model and produce an approximation of the surface by adding vertices and subdividing existing polygons. The approximation can be as coarse or as detailed as your needs allow. Because Pixar s rendering system requires everything to be broken into polygons that are a half-pixel across, subdivision surfaces allowed them to tessellate automatically to that level everywhere.