Papers by Michael Kass

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Efficient, Fair Interpolation using Catmull-Clark Surfaces

Mark Halstead, Michael Kass, Tony DeRose
July 1993

We describe an efficient method for constructing a smooth surface that interpolates the vertices of a mesh of arbitrary topological type. Normal vectors can also be interpolated at an arbitrary subset of the vertices. The method improves on existing interpolation techniques in that it is fast, robust and general.

Paper (PDF)

Appeared in SIGGRAPH 1993.

Subdivision Surfaces in Character Animation

Tony DeRose, Michael Kass, Tien Truong
August 1998

The creation of believable and endearing characters in computer graphics presents a number of technical challenges, including the modeling, animation and rendering of complex shapes such as heads, hands, and clothing. Traditionally, these shapes have been modeled ... more

Paper (PDF)

Available in the Proceedings of SIGGRAPH 1998.

Untangling Cloth

David Baraff, Andrew Witkin, Michael Kass
August 2003

Deficient cloth-to-cloth collision response is the most serious shortcoming of most cloth simulation systems. Past approaches to cloth-cloth collision have used history to decide wheter nearby cloth regions have interpenetrated. The biggest pitfall of history-based methods is that an error anywhere along the way can give rise to persistent tangles...This ... more

Paper (PDF)

Available in the Proceedings of SIGGRAPH 2003

Interactive Depth of Field

Michael Kass, Aaron Lefohn, John Owens
January 2006

Accurate computation of depth-of-field effects in computer graphics rendering is generally very time consuming, creating a problematic workflow for film authoring. The computation is particularly challenging because it depends on large-scale spatially-varying filtering that must accurately respect complex boundaries. Here we introduce an approximate depth-of-field computation that is good enough for film preview, yet ... more

Paper (PDF)

Additional materials: [movie.avi]

Available as Pixar Technical Memo #06-01

Animating Oscillatory Motion With Overlap: Wiggly Splines

Michael Kass, John Anderson
June 2008

Oscillatory motion is ubiquitous in computer graphics, yet existing animation techniques are ill-suited to its authoring. We introduce a new type of spline for this purpose, known as a ``Wiggly Spline.'' The spline generalizes traditional piecewise cubics when its resonance and damping are set to zero, but creates oscillatory animation when its resonance and damping ... more

Paper (PDF)

Available in SIGGRAPH 2008

Available as Pixar Technical Memo #06-06a

Other versions:

Smoothed Local Histogram Filters

Michael Kass, Justin Solomon
May 2010

Local image histograms contain a great deal of information useful for applications in computer graphics, computer vision and computational photography. Making use of that information has been challenging because of the expense of computing histogram properties over large neighborhoods. Efficient algorithms exist for some specific computations like the bilateral filter, but not others. ... more

Paper (PDF)

To appear in the Proceedings of SIGGRAPH 2010

Available as Pixar Technical Memo #10-02

Coherent Noise for Non-Photorealistic Rendering

Michael Kass, Davide Pesare
July 2011

A wide variety of non-photorealistic rendering techniques make use of random variation in the placement or appearance of primitives. In order to avoid the "shower-door" effect, this random variation should move with the objects in the scene. Here we present coherent noise tailored to this purpose. We compute the coherent ... more

Paper (PDF)

Available in the Proceedings of SIGGRAPH 2011

Stylizing Animation By Example

Pierre Benard, Forrester Cole, Michael Kass, Igor Mordatch, James Hegarty, Martin Sebastian Senn, Kurt Fleischer, Davide Pesare, Katherine Breeden
April 2013

Skilled artists, using traditional media or modern computer painting tools, can create a variety of expressive styles that are very appealing in still images, but have been unsuitable for animation. The key difficulty is that existing techniques lack adequate temporal coherence to animate these styles effectively. Here we augment the ... more

Paper (PDF)

Additional materials: [ComputerGraphicsWorldArticle.pdf], [PaintTweenWorkingSets.tgz], [], [PaintTweenDistro.tgz], []

Available in the proceedings of SIGGRAPH 2013.

Available as Pixar Technical Memo #13-03

Computing Smooth Surface Contours with Accurate Topology

Pierre Benard, Aaron Hertzmann, Michael Kass
March 2014

This paper introduces a method for accurately computing the visible contours of a smooth 3D surface for stylization. This is a surprisingly difficult problem, and previous methods are prone to topological errors, such as gaps in the outline. Our approach is to generate, for each viewpoint, a new triangle mesh with contours that are topologically-equivalent ... more

Paper (PDF)

To appear in ACM Transactions on Graphics

Geometry into Shading

Christophe Hery, Michael Kass, Junyi Ling
October 2014

Sometimes, when 3D CG objects are viewed from a distance, a great deal of geometry can end up inside a single pixel. When this happens, full-sized facets, or pixels in a displacement map should play the role of traditional micro-facets. Here we describe how to alter traditional shading calculations to ... more

Paper (PDF)

Additional materials: [Bump2Roughness.tar.gz]

Available as Pixar Technical Memo #14-04