Papers by Robert L. Cook


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Stochastic Simplification of Aggregate Detail

Robert L. Cook, John Halstead, Maxwell Planck, David Ryu
May 2007

Many renderers perform poorly on scenes that contain a lot of detailed geometry. The load on the renderer can be alleviated by simplification techniques, which create less expensive representations of geometry that is small on the screen. Current simplification techniques for high-quality surface-based rendering tend to work best with element ... more

Additional materials: [SiggraphSlides.pdf], [WithAndWithoutSimplification.mov]

Available in the Proceedings of Siggraph 2007.

Available as Pixar Technical Memo #06-05a

Other versions:


3D Paint Baking Proposal

Robert L. Cook
May 2007

3d paint has long been one of the most expensive parts of rendering at Pixar. This proposal is for a new baking technique that would greatly reduce the run-time cost of 3d paint and require no changes to the existing workflow. The implementation makes heavy use of existing code, which ... more

Available as Pixar Technical Memo #07-16


Wavelet Noise

Robert L. Cook, Tony DeRose
August 2005

Noise functions are an essential building block for writing procedural shaders in 3D computer graphics. The original noise function introduced by Ken Perlin is still the most popular because it is simple and fast, and many spectacular images have been made ... more

Additional materials: [RapLyrics.txt]

Available in the Proceedings of SIGGRAPH 2005


Rendering Antialiased Shadows with Depth Maps

William T. Reeves, David H. Salesin, Robert L. Cook
July 1987

We present a solution to the aliasing problem for shadow algorithms that use depth maps. The solution is based on a new filtering technique called percentage closer filtering. In addition to antialiasing, the improved algorithm provides soft shadow boundaries that resemble penumbrae. We describe ... more

Available in the Proceedings of SIGGRAPH 1987.


The Reyes Rendering Architecture

Robert L. Cook, Loren Carpenter, Edwin Catmull
July 1987

An architecture is presented for fast high-quality rendering of complex images. All objects are reduced to common world-space geometric entities called micropolygons, and all of the shading and visibility calculations operate on these micropolygons. Each type of calculation is performed in a coordinate system that is ... more


Stochastic Sampling in Computer Graphics

Robert L. Cook
January 1986

Ray tracing, ray casting, and other forms of point sampling are important techniques in computer graphics, but their usefulness has been undermined by aliasing artifacts. In this paper it is shown that these artifacts are not an inherent part of point sampling, but a consequence of ... more

Available in ACM Transactions on Graphics, Volume 6, Number 1, January 1996.


Distributed Ray Tracing

Robert L. Cook, Thomas Porter, Loren Carpenter
July 1984

Ray tracing is one of the most elegant techniques in computer graphics. Many phenomena that are difficult or impossible with other techniques are simple with ray tracing, including shadows, reflections, and refracted light. Ray directions, however, have been determined precisely, and this had limited the capabilities of ray tracing. By ... more

Available in the Proceedings of SIGGRAPH 1984


Shade Trees

Robert L. Cook
July 1984

Shading is an important part of computer imagery, but shaders have been based on fixed models to which all surfaces must conform. As computer imagery becomes more sophisticated, surfaces have more complex shading characteristics and thus require a less rigid shading model. This paper presents a flexible tree-structured shading model ... more

Available in the Proceedings of SIGGRAPH 1984.


A Reflectance Model for Computer Graphics

Robert L. Cook, Kenneth E. Torrance
January 1982

A new reflectance model for rendering computer sythesized images is presented. The model accounts for the relative brightness of different materials and light sources in the same scene. It describes the directional distribution of the reflected light and a color shift that occurs as ... more

Published in Transactions on Graphics, Vol. 1, No. 1, January 1982.