Pat Hanrahan

Digital Library

ACM A. M. Turing Award

USA - 2019



For fundamental contributions to 3D computer graphics, and the impact of computer-generated imagery (CGI) in filmmaking and other applications.

Ed Catmull and Pat Hanrahan have fundamentally influenced the field of computer graphics through conceptual innovations and contributions to both software and hardware. Their work has had a revolutionary impact on filmmaking, leading to a new genre of entirely computer-animated feature films that has spanned the past 25 years beginning with "Toy Story".

Dr. Ed Catmull's interest in computer graphics began at the University of Utah under the direction of the 1988 Turing Award Winner, Ivan Sutherland, where Catmull developed his lifelong interest in 3D graphics and its application to making movies. Dr. Pat Hanrahan joined Catmull at Pixar, which Catmull co-founded, in 1986. Catmull's focus of innovation was on how to represent 3D surfaces and their spatial ordering, as would be seen from a given viewpoint. Hanrahan's complementary focus was on algorithms to realistically shade and efficiently render images of these 3D scenes.

Catmull and Hanrahan developed many fundamental 3D graphics algorithms, creating practical tools that graphic artists, filmmakers, and game designers use to create imagery. Catmull began by researching methods to render curved surfaces, later developing the idea of Catmull-Clark subdivision surfaces. In the process of implementing these methods, Catmull developed the Z-buffer algorithm, which determines the objects that are visible from a given viewpoint, as well as texture mapping methods. Catmull and Hanrahan implemented these algorithms in practical systems that are widely used. Catmull teamed up with Rob Cook and Loren Carpenter to develop the REYES architecture (Renders Everything You Ever Saw). REYES became the basis for the RenderMan architecture, which was developed by Hanrahan at Pixar. The pair received several Academy Awards® for Technical Achievement related to rendering technologies for the movies. A key component of the RenderMan system was its shading language; shading languages allowed users to extend the system to achieve more realistic appearances. The language requirements underlying these innovations influenced the development of shading languages such as the OpenGL shading language, and the hardware requirements profoundly impacted the development and design of modern graphics processing units (GPUs).

For their profound impact on 3D computer graphics and its realization in the world, Catmull and Hanrahan have been selected to receive the recognition conferred by the Turing Award.

Press Release

ACM Fellows

USA - 2008


For contributions to rendering theory and systems.