### Seeing Is Believing: Do People Fail to Identify Fake Images on the Web?

Mona Kasra, Cuihua Shen, James F. O'Brien

*AoIR 2016*

Images have historically been perceived as photographic proof of the depicted events. However, the growing ease with which digital images can be convincingly manipulated ... [more]

### Repurposing Hand Animation for Interactive Applications

Stephen Bailey, Martin Watt, James F. O'Brien

*SCA 2016*

In this paper we describe a method for automatically animating interactive characters based on an existing corpus of key-framed hand-animation. The method learns separate ... [more]

### Interactive Detailed Cutting of Thin Sheets

Pierre-Luc Manteaux, Wei-Lun Sun, Francois Faure, Marie-Paule Cani, James F. O'Brien

*MIG 2015*

In this paper we propose a method for the interactive detailed cutting of deformable thin sheets. Our method builds on the ability of frame-based simulation to solve for ... [more]

### View-Dependent Adaptive Cloth Simulation with Buckling Compensation

Woojong Koh, Rahul Narain, James F. O'Brien

*TVCG 2015*

This paper describes a method for view-dependent cloth simulation using dynamically adaptive mesh refinement and coarsening. Given a prescribed camera motion, the method ... [more]

### Optimal Presentation of Imagery with Focus Cues on Multi-Plane Displays

Rahul Narain, Rachel A. Albert, Abdullah Bulbul, Gregory J. Ward, Marty Banks, James F. O'Brien

*SIGGRAPH 2015*

We present a technique for displaying three-dimensional imagery of general scenes with nearly correct focus cues on multi-plane displays. These displays present an additive ... [more]

### Resampling Adaptive Cloth Simulations onto Fixed-Topology Meshes

George Brown, Armin Samii, James F. O'Brien, Rahul Narain

*SCA 2015 Poster*

We describe a method for converting an adaptively remeshed simulation of cloth into an animated mesh with fixed topology. The topology of the mesh may be specified by the ... [more]

### Exposing Photo Manipulation from Shading and Shadows

Eric Kee, James F. O'Brien, Hany Farid

*TOG 2014*

We describe a method for detecting physical inconsistencies in lighting from the shading and shadows in an image. This method imposes a multitude of shading- and shadow-based ... [more]

### Mirror Mirror: Crowdsourcing Better Portraits

Jun-Yan Zhu, Aseem Agarwala, Alexei A. Efros, Eli Shechtman, Jue Wang

*SIGGRAPH Asia 2014*

We describe a method for providing feedback on portrait expressions, and for selecting the most attractive expressions from large video/photo collections. We capture a ... [more]

### Eyeglasses-free Display: Towards Correcting Visual Aberrations with Computational Light Field Displays

Fu-Chung Huang, Gordon Wetzstein, Brian A. Barsky, Ramesh Raskar

*ACM SIGGRAPH 2014*

Millions of people worldwide need glasses or contact lenses to see or read properly. We introduce a computational display technology that predistorts the presented content ... [more]

### Adaptive Tearing and Cracking of Thin Sheets

Tobias Pfaff, Rahul Narain, Juan Miguel de Joya, James F. O'Brien

*SIGGRAPH 2014*

This paper presents a method for adaptive fracture propagation in thin sheets. A high-quality triangle mesh is dynamically restructured to adaptively maintain detail ... [more]

### Self-Refining Games using Player Analytics

Matt Stanton, Ben Humberston, Brandon Kase, James F. O'Brien, Kayvon Fatahalian, Adrien Treuille

*SIGGRAPH 2014*

Data-driven simulation demands good training data drawn from a vast space of possible simulations. While fully sampling these large spaces is infeasible, we observe that ... [more]

### View-Dependent Adaptive Cloth Simulation

Woojong Koh, Rahul Narain, James F. O'Brien

*SCA 2014*

This paper describes a method for view-dependent cloth simulation using dynamically adaptive mesh refinement and coarsening. Given a prescribed camera motion, the method ... [more]

### AverageExplorer: Interactive Exploration and Alignment of Visual Data Collections

Jun-Yan Zhu, Yong Jae Lee, Alexei A. Efros

*SIGGRAPH 2014*

This paper proposes an interactive framework that allows a user to rapidly explore and visualize a large image collection using the medium of average images. Average images ... [more]

### User-Assisted Video Stabilization

Jiamin Bai, Aseem Agarwala, Maneesh Agrawala, Ravi Ramamoorthi

*EGSR 2014*

We present a user-assisted video stabilization algorithm that is able to stabilize challenging videos when state-of-the-art automatic algorithms fail to generate ... [more]

### Can 3D Shape be Estimated from Focus Cues Alone?

Rachel A. Albert, Abdullah Bulbul, Rahul Narain, James F. O'Brien, Martin S. Banks

*VSS 2014*

Focus cues—blur and accommodation—have generally been regarded as very coarse, ordinal cues to depth. This assessment has been largely determined by the inability to display ... [more]

### Correct blur and accommodation information is a reliable cue to depth ordering.

Marina Zannoli, Rachel A. Albert, Abdullah Bulbul, Rahul Narain, James F. O'Brien, Martin Banks

*VSS 2014*

Marshall et al. (1996) showed that blur could in principle also be used to determine depth ordering of two surfaces across an occlusion boundary from the correlation between ... [more]

### The Perception of Surface Material from Disparity and Focus Cues

Martin Banks, Abdullah Bulbul, Rachel Albert, Rahul Narain, James F. O'Brien, Gregory Ward

*VSS 2014*

The visual properties of surfaces reveal many things including a floor's cleanliness and a car's age. These judgments of material are based on the spread of light reflected ... [more]

### External mask based depth and light field camera

Dikpal Reddy, Jiamin Bai, Ravi Ramamoorthi

*ICCV 2013 Workshop*

We present a method to convert a digital single-lensreflex (DSLR) camera into a high resolution consumer depth and light field camera by affixing an external aperture mask ... [more]

### Depth from Combining Defocus and Correspondence Using light-Field Cameras

Michael W. Tao, Sunil Hadap, Jitendra Malik, Ravi Ramamoorthi

*ICCV 2013*

Light-field cameras have recently become available to the consumer market. An array of micro-lenses captures enough information that one can refocus images after acquisition ... [more]

### Fast Simulation of Mass-Spring Systems

Tiantian Liu, Adam Bargteil, James F. O'Brien, Ladislav Kavan

*SIGGRAPH Asia 2013*

We describe a scheme for time integration of mass-spring systems that makes use of a solver based on block coordinate descent. This scheme provides a fast solution for classical ... [more]

### Exposing Photo Manipulation with Inconsistent Shadows

Eric Kee, James F. O'Brien, Hany Farid

*TOG 2013*

We describe a geometric technique to detect physically inconsistent arrangements of shadows in an image. This technique combines multiple constraints from cast and attached ... [more]

### Folding and Crumpling Adaptive Sheets

Rahul Narain, Tobias Pfaff, James F. O'Brien

*SIGGRAPH 2013*

We present a technique for simulating plastic deformation in sheets of thin materials, such as crumpled paper, dented metal, and wrinkled cloth. Our simulation uses a framework ... [more]

### Near-exhaustive Precomputation of Secondary Cloth Effects

Doyub Kim, Woojong Koh, Rahul Narain, Kayvon Fatahalian, Adrien Treuille, James F. O'Brien

*SIGGRAPH 2013*

The central argument against data-driven methods in computer graphics rests on the curse of dimensionality: it is intractable to precompute "everything" about a complex ... [more]

### Axis-Aligned Filtering for Interactive Physically-Based Diffuse Indirect Lighting

Soham Uday Mehta, Brandon Wang, Ravi Ramamoorthi, Fredo Durand

*SIGGRAPH 2013*

We introduce an algorithm for interactive rendering of physically-based global illumination, based on a novel frequency analysis of indirect lighting. Our method combines ... [more]

### Type-Constrained Direct Fitting of Quadric Surfaces

James Andrews, Carlo H. Séquin

*CAD 2013*

We present a catalog of type-specific, direct quadric fitting methods: Given a selection of a point cloud or triangle mesh, and a desired quadric type (e.g. cone, ellipsoid, paraboloid ... [more]

### Automatic Cinemagraph Portraits

Jiamin Bai, Aseem Agarwala, Maneesh Agrawala, Ravi Ramamoorthi

*EGSR 2013*

Cinemagraphs are a popular new type of visual media that lie in-between photos and video; some parts of the frame are animated and loop seamlessly, while other parts of the ... [more]

### Sharpening Out of Focus Images using High-Frequency Transfer

Michael Tao, Jitendra Malik, Ravi Ramamoorthi

*EG 2013*

Focus misses are common in image capture, such as when the camera or the subject moves rapidly in sports and macro photography. One option to sharpen focus-missed photographs ... [more]

### Simulating Liquids and Solid-Liquid Interactions with Lagrangian Meshes

Pascal Clausen, Martin Wicke, Jonathan Shewchuk, James F. O'Brien

*TOG 2013*

This paper describes a Lagrangian finite element method that simulates the behavior of liquids and solids in a unified framework. Local mesh improvement operations maintain ... [more]

### Generalized, Basis-Independent Kinematic Surface Fitting

James Andrews, Carlo H. Séquin

*JCAD 2013*

Kinematic surfaces form a general class of surfaces, including surfaces of revolution, helices, spirals, and more. Standard methods for fitting such surfaces are either specialized ... [more]

### Interactive Albedo Editing in Path-Traced Volumetric Materials

Miloš Hašan, Ravi Ramamoorthi

*TOG 2013*

Materials such as clothing or carpets, or complex assemblies of small leaves, flower petals or mosses, do not fit well into either BRDF or BSSRDF models. Their appearance is ... [more]

### Gloss Perception in Painterly and Cartoon Rendering

Adrien Boussean, James P. O'Shea, Frédo Durand, Ravi Ramamoorthi, Maneesh Agrawala

*TOG 2013*

Depictions with traditional media such as painting and drawing represent scene content in a stylized manner. It is unclear however how well stylized images depict scene ... [more]

### Axis-Aligned Filtering for Interactive Sampled Soft Shadows

Soham Mehta, Brandon Wang, Ravi Ramamoorthi

*Siggraph Asia 2012*

We develop a simple and efficient method for soft shadows from planar area light sources, based on explicit occlusion calculation by raytracing, followed by adaptive image-space ... [more]

### Adaptive Anisotropic Remeshing for Cloth Simulation

Rahul Narain, Armin Samii, James F. O'Brien

*SIGGRAPH Asia 2012*

We present a technique for cloth simulation that dynamically refines and coarsens triangle meshes so that they automatically conform to the geometric and dynamic detail ... [more]

### Correcting for Optical Aberrations using Multilayer Displays

Fu-Chung Huang, Douglas Lanman, Brian A. Barsky, Ramesh Raskar

*SIGGRAPH ASIA 2012*

Optical aberrations of the human eye are currently corrected using eyeglasses, contact lenses, or surgery. We describe a fourth option: modifying the composition of displayed ... [more]

### Frequency-Space Decomposition and Acquisition of Light Transport under Spatially Varying Illumination

Dikpal Reddy, Ravi Ramamoorthi, Brian Curless

*ECCV 2012*

We show that, under spatially varying illumination, the light transport of diffuse scenes can be decomposed into direct, near-range (subsurface scattering and local inter-reflections ... [more]

### On Differential Photometric Reconstruction for Unknown, Isotropic BRDFs

Manmohan Chandraker, Jiamin Bai, Ravi Ramamoorthi

*PAMI 2012*

This paper presents a comprehensive theory of photometric surface reconstruction from image derivatives, in the presence of a general, unknown isotropic BRDF. We derive ... [more]

### Selectively De-Animating Video

Jiamin Bai, Aseem Agarwala, Maneesh Agrawala, Ravi Ramamoorthi

*SIGGRAPH 2012*

We present a semi-automated technique for selectively de-animating video to remove the large-scale motions of one or more objects so that other motions are easier to see ... [more]

### Updated Sparse Cholesky Factors for Corotational Elastodynamics

Florian Hecht, Yeon Jin Lee, Jonathan Shewchuk, James F. O'Brien

*TOG 2012*

We present warp-canceling corotation, a nonlinear finite element formulation for elastodynamic simulation that achieves fast performance by making only partial or ... [more]

### Compressive Structured Light for Recovering Inhomogeneous Participating Media

Jinwei Gu, Shree K. Nayar, Eitan Grinspun, Peter N. Belhumeur, Ravi Ramamoorthi

*PAMI 2012*

We propose a new method named compressive structured light for recovering inhomogeneous participating media. Whereas conventional structured light methods emit coded ... [more]

### Analytic Tangent Irradiance Environment Maps for Anisotropic Surfaces

Soham Mehta, Ravi Ramamoorthi, Mark Meyer, Christophe Hery

*EGSR 2012*

We extend spherical harmonic irradiance maps to anisotropic surfaces, replacing Lambertian reflectance with the diffuse term of the popular Kajiya-Kay model. We show ... [more]

### Interactive Inverse 3D Modeling

James Andrews, Hailin Jin, Carlo H. Séquin

*CAD 2012*

“Interactive Inverse 3D Modeling” is a user-guided approach to shape construction and redesign that extracts well-structured, parameterized, procedural descriptions ... [more]

### Importance Sampling of Reflection from Hair Fibers

Christophe Hery, Ravi Ramamoorthi

*JCCT 2012*

Hair and fur are increasingly important visual features in production rendering, and physically-based light scattering models are now commonly used. In this paper, we enable ... [more]

### SimpleFlow: A Non-iterative, Sublinear Optical Flow Algorithm

Michael Tao, Jiamin Bai, Pushmeet Kohli, Sylvain Paris

*EG 2012*

Optical flow is a critical component of video editing applications, e.g. for tasks such as object tracking, segmen- tation, and selection. In this paper, we propose an optical ... [more]

### Exposing Digital Forgeries in Ballistic Motion

Valentina Conotter, James F. O'Brien, Hany Farid

*TIFS 2012*

We describe a geometric technique to detect physically implausible trajectories of objects in video sequences. This technique explicitly models the three-dimensional ... [more]

### Real-Time Rendering of Rough Refraction

Charles de Rousiers, Adrien Bousseau, Kartic Subr, Nicolas Holzschuch, Ravi Ramamoorthi

*TVCG 2012*

We present an algorithm to render objects made of transparent materials with rough surfaces in real-time, under all-frequency distant illumination. Rough surfaces cause ... [more]

### A Theory of Monte Carlo Visibility Sampling

Ravi Ramamoorthi, John Anderson, Mark Meyer, Derek Nowrouzezahrai

*TOG 2012*

Soft shadows from area lights are one of the most crucial effects in high quality and production rendering, but Monte Carlo sampling of visibility is often the main source ... [more]

### Exposing Photo Manipulation with Inconsistent Reflections

James F. O'Brien, Hany Farid

*TOG 2012*

The advent of sophisticated photo editing software has made it increasingly easier to manipulate digital images. Often visual inspection cannot definitively distinguish ... [more]

### Practical Filtering for Efficient Ray-Traced Directional Occlusion

Kevin Egan, Fredo Durand, Ravi Ramamoorthi

*SIGGRAPH Asia 2011*

Ambient occlusion and directional (spherical harmonic) occlusion have become a staple of production rendering because they capture many visually important qualities ... [more]

### What An Image Reveals About Material Reflectance

Manmohan Chandraker, Ravi Ramamoorthi

*ICCV 2011*

We derive precise conditions under which material reflectance properties may be estimated from a single image of a homogeneous curved surface (canonically a sphere), lit ... [more]

### A Linear Variational System for Modeling From Curves

James Andrews, Pushkar P. Joshi, Nathan Carr

*CGF 2011*

We present a linear system for modelling 3D surfaces from curves. Our system offers better performance, stability and precision in control than previous non-linear systems ... [more]

### Data-Driven Elastic Models for Cloth: Modeling and Measurement

Huamin Wang, Ravi Ramamoorthi, James F. O'Brien

*SIGGRAPH 2011*

Cloth often has complicated nonlinear, anisotropic elastic behavior due to its woven pattern and fiber properties. However, most current cloth simulation techniques simply ... [more]

### Perceptually Based Tone Mapping for Low-Light Conditions

Adam Kirk, James F. O'Brien

*SIGGRAPH 2011*

In this paper we present a perceptually based algorithm for modeling the color shift that occurs for human viewers in low-light scenes. Known as the Purkinje effect, this ... [more]

### Illumination Decomposition for Material Recoloring with Consistent Interreflections

Robert Carroll, Ravi Ramamoorthi, Maneesh Agrawala

*SIGGRAPH 2011*

Changing the color of an object is a basic image editing operation, but a high quality result must also preserve natural shading. A common approach is to first compute reflectance ... [more]

### Interactive Furniture Layout Using Interior Design Guidelines

Paul Merrell, Eric Schkufza, Zeyang Li, Maneesh Agrawala, Vladlen Koltun

*SIGGRAPH 2011*

We present an interactive furniture layout system that assists users by suggesting furniture arrangements that are based on interior design guidelines. Our system incorporates ... [more]

### Sparse Reconstruction of Visual Appearance for Computer Graphics and Vision

Ravi Ramamoorthi

*Wavelets and Sparsity 2011*

A broad range of problems in computer graphics rendering, appearance acquisition for graphics and vision, and imaging, involve sampling, reconstruction, and integration ... [more]

### Optimizing Environment Maps for Material Depiction

Adrien Bousseau, Emmanuelle Chapoulie, Ravi Ramamoorthi, Maneesh Agrawala

*EGSR 2011*

We present an automated system for optimizing and synthesizing environment maps that enhance the appearance of materials in a scene. We first identify a set of lighting ... [more]

### A Theory of Differential Photometric Stereo for Unknown BRDFs

Manmohan Chandraker, Jiamin Bai, Ravi Ramamoorthi

*CVPR 2011*

We present a comprehensive theory of photometric surface reconstruction from image derivatives. For unknown isotropic BRDFs, we show that two measurements of spatial ... [more]

### On the Duality of Forward and Inverse Light Transport

Manmohan Chandraker, Jiamin Bai, Tian-Tsong Ng, Ravi Ramamoorthi

*PAMI 2011*

Inverse light transport seeks to undo global illumination effects, such as interreflections, that pervade images of most scenes. This paper presents the theoretical and ... [more]

### From the Rendering Equation to Stratified Light Transport Inversion

Tian-Tsong Ng, Ramampreet Singh Pahwa, Jiamin Bai, Kar-Han Tan, Ravi Ramamoorthi

*IJCV 2011*

Recent advances in fast light transport acquisition have motivated new applications for forward and inverse light transport. While forward light transport enables image ... [more]

### Interactive Extraction and Re-Design of Sweep Geometries

James Andrews, Pushkar P. Joshi, Carlo H. Séquin

*CGI 2011*

We introduce two interactive extraction modules that can fit the parameters of generalized sweeps to large, unstructured meshes for immediate, high-level, detail-preserving ... [more]

### Bringing Clothing into Desired Configurations with Limited Perception

Marco Cusumano-Towner, Arjun Singh, Stephen Miller, James F. O'Brien, Pieter Abbeel

*ICRA 2011*

We consider the problem of autonomously bringing an article of clothing into a desired configuration using a general-purpose two-armed robot. We propose a hidden Markov ... [more]

### Modeling and Perception of Deformable One-Dimensional Objects

Shervin Javdani, Sameep Tandon, Jie Tang, James F. O'Brien, Pieter Abbeel

*ICRA 2011*

Recent advances in the modeling of deformable one-dimensional objects (DOOs) such as surgical suture, rope, and hair show significant promise for improving the simulation ... [more]

### Frequency Analysis and Sheared Filtering for Shadow Light Fields of Complex Occluders

Kevin Egan, Florian Hecht, Frédo Durand, Ravi Ramamoorthi

*TOG 2011*

Monte Carlo ray tracing of soft shadows produced by area lighting and intricate geometries, such as the shadows through plant leaves or arrays of blockers, is a critical challenge ... [more]

### Design Principles for Visual Communication

Maneesh Agrawala, Wilmot Li, Floraine Berthouzoz

*CACM*

Design principles connect the visual design of a visualization with the viewer’s perception and cognition of the underlying information the visualization is meant to ... [more]

### Real-Time Rough Refraction

Charles De Rousiers, Adrien Bousseau, Kartic Subr, Nicolas Holzschuch, Ravi Ramamoorthi

*I3D 2011*

We present an algorithm to render objects of transparent materials with rough surfaces in real-time, under distant illumination. Rough surfaces cause wide scattering ... [more]

### Eden: A Professional Multitouch Tool for Constructing Virtual Organic Environments

Kenrick Kin, Tom Miller, Björn Bollensdorff, Tony DeRose, Björn Hartmann, Maneesh Agrawala

*CHI 2011*

Set construction is the process of selecting and positioning virtual geometric objects to create a virtual environment used in a computer-animated film. Set construction ... [more]

### FingerGlass: Efficient Multiscale Interaction on Multitouch Screens

Dominik Käser, Maneesh Agrawala, Mark Pauly

Many tasks in graphical user interfaces require users to inter- act with elements at various levels of precision. We present FingerGlass, a bimanual technique designed ... [more]

### CommentSpace: Structured Support for Collaborative Visual Analysis

Wesley Willett, Jeffrey Heer, Joseph Hellerstein, Maneesh Agrawala

Collaborative visual analysis tools can enhance sensemaking by facilitating social interpretation and parallelization of effort. These systems enable distributed ... [more]

### Computer generation of ribbed sculptures

James Hamlin, Carlo H. Séquin

*JMA 2010*

Charles Perry's monumental sculpture Solstice is analysed and its generative geometrical logic based on a twisted toroidal sweep is captured in a computer programme with ... [more]

### Multi-Resolution Isotropic Strain Limiting

Huamin Wang, James F. O'Brien, Ravi Ramamoorthi

*SIGGRAPH Asia 2010*

In this paper we describe a fast strain-limiting method that allows stiff, incompliant materials to be simulated efficiently. Unlike prior approaches, which act on springs ... [more]

### Automatic Generation of Destination Maps

Johannes Kopf, Maneesh Agrawala, David Bargeron, David Salesin, Michael F. Cohen

*SIGGRAPH Asia 2010*

Destination maps are navigational aids designed to show anyone within a region how to reach a location (the destination). Hand-designed destination maps include only the ... [more]

### Symmetrical Embeddings of Regular Maps R5.13 and R5.6

Carlo H. Séquin

This report is a documentation of my trial-and-error design process to find a symmetrical embedding of the regular map R5.13 on a genus-5 2-manifold. It documents the non-linear ... [more]

### Personalized Photograph Ranking and Selection System

Che-Hua Yeh, Yuan-Chen Ho, Brian A. Barsky, Ming Ouhyoung

*ACM MM 2010*

In this paper, we propose a novel personalized ranking system for amateur photographs. Although some of the features used in our system are similar to previous work, new features ... [more]

### A Dual Theory of Inverse and Forward Light Transport

Jiamin Bai, Manmohan Chandraker, Tian-Tsong Ng, Ravi Ramamoorthi

*ECCV 2010*

We present the theoretical and computational foundations for inverse light transport as a dual of forward rendering. Inverse light transport seeks to undo global illumination ... [more]

### Error-tolerant Image Compositing

Michael W. Tao, Micah K. Johnson, Sylvain Paris

*ECCV 2010*

Gradient-domain compositing is an essential tool in computer vision and its applications, e.g., seamless cloning, panorama stitching, shadow removal, scene completion and ... [more]

### Example-Based Wrinkle Synthesis for Clothing Animation

Huamin Wang, Florian Hecht, Ravi Ramamoorthi, James F. O'Brien

*SIGGRAPH 2010*

This paper describes a method for animating the appearance of clothing, such as pants or a shirt, that fits closely to a figure's body. Compared to flowing cloth, such as loose ... [more]

### Dynamic Local Remeshing for Elastoplastic Simulation

Martin Wicke, Daniel Ritchie, Bryan Klingner, Sebastian Burke, Jonathan Shewchuk, James F. O'Brien

*SIGGRAPH 2010*

We propose a finite element simulation method that addresses the full range of material behavior, from purely elastic to highly plastic, for physical domains that are substantially ... [more]

### My Search for Symmetrical Embeddings of Regular Maps

Carlo H. Séquin

*Bridges 2010*

Various approaches are discussed for obtaining highly symmetrical and aesthetically pleasing space models of regular maps embedded in surfaces of genus 2 to 5. For many ... [more]

### Image Warps for Artistic Perspective Manipulation

Robert Carroll, Aseem Agarwala, Maneesh Agrawala

Painters and illustrators commonly sketch vanishing points and lines to guide the construction of perspective images. We present a tool that gives users the ability to ... [more]

### Illustrating How Mechanical Assemblies Work

Niloy J. Mitra, Yong-Liang Yang, Dong-Ming Yan, Wilmot Li, Maneesh Agrawala

How things work visualizations use a variety of visual techniques to depict the operation of complex mechanical assemblies. We present an automated approach for generating ... [more]

### Sparsely Precomputing The Light Transport Matrix for Real-Time Rendering

Fu-Chung Huang, Ravi Ramamoorthi

*EGSR 2010*

Precomputation-based methods have enabled real-time rendering with natural illumination, all-frequency shadows, and global illumination. However, a major bottleneck ... [more]

### Common Sense Community: Scaffolding Mobile Sensing and Analysis for Novice Users

Wesley Willett, Paul Aoki, Neil Kumar, Sushmita Subramanian, Allison Woodruff

As sensing technologies become increasingly distributed and democratized, citizens and novice users are becoming responsible for the kinds of data collection and analysis ... [more]

### Two New Approaches to Depth of Field Post-Processing: Pyramid Spreading and Tensor Filtering

Todd J. Kosloff, Brian A. Barsky

*VISIGRAPP 2010*

Depth of field refers to the swath that is imaged in sharp focus through an optics system, such as a camera lens. Control over depth of field is an important artistic tool, which ... [more]

### Simulation of Needle Insertion and Tissue Deformation for Modeling Prostate Brachytherapy

Nuttapong Chentanez, Ron Alterovitz, Daniel Ritchie, Lita Cho, Kris Hauser, Ken Goldberg, Jonathan Shewchuk, James F. O'Brien

*ABS 2010*

Realistic modeling of needle insertion during brachytherapy can be used for training and in automated planning to reduce errors between intended and actual placement ... [more]

### Using Blur to Affect Perceived Distance and Size

Robert (Robin) Held, Emily Cooper, James F. O'Brien, Marty Banks

*TOG 2010*

We present a probabilistic model of how viewers may use defocus blur in conjunction with other pictorial cues to estimate the absolute distances to objects in a scene. Our ... [more]

### An intuitive explanation of third-order surface behavior

Pushkar P. Joshi, Carlo H. Séquin

*CAGD*

We present a novel parameterization-independent exposition of the third-order geometric behavior of a surface point. Unlike existing algebraic expositions, our work ... [more]

### Perceptual Guidelines for Creating Rectangular Treemaps

Nicholas Kong, Jeffrey Heer, Maneesh Agrawala

Treemaps are space-filling visualizations that make efficient use of limited display space to depict large amounts of hi- erarchical data. Creating perceptually effective ... [more]

### Exploded View Diagrams of Mathematical Surfaces

Olga Karpenko, Wilmot Li, Niloy J. Mitra, Maneesh Agrawala

We present a technique for visualizing complicated mathematical surfaces that is inspired by hand-designed topological illustrations. Our approach generates exploded ... [more]

### Removing Image Artifacts Due to Dirty Camera Lenses and Thin Occluders

Jinwei Gu, Ravi Ramamoorthi, Peter Belhumeur, Shree Nayar

*SIGGRAPH ASIA 09*

Dirt on camera lenses, and occlusions from thin objects such as fences, are two important types of artifacts in digital imaging systems. These artifacts are not only an annoyance ... [more]

### Adaptive Wavelet Rendering

Ryan Overbeck, Craig Donner, Ravi Ramamoorthi

*SIGGRAPH ASIA 09*

Effects such as depth of field, area lighting, antialiasing and global illumination require evaluating a complex high-dimensional integral at each pixel of an image. We ... [more]

### User-Assisted Intrinsic Images

Adrien Bousseau, Sylvain Paris, Fredo Durand

*SIGGRAPH Asia 2009*

For many computational photography applications, the lighting and materials in the scene are critical pieces of information. We seek to obtain intrinsic images, which decompose ... [more]

### Edge-Based Image Coarsening

Raanan Fattal, Robert Carroll, Maneesh Agrawala

This paper presents a new dimensionally-reduced linear image space that allows a number of recent image manipulation techniques to be performed efficiently and robustly ... [more]

### Generating Surface Crack Patterns

Hayley Iben, James F. O'Brien

*Graphical Models*

We present a method for generating surface crack patterns that appear in materials such as mud, ceramic glaze, and glass. To model these phenomena, we build upon existing physically ... [more]

### Simulating Gaseous Fluids with Low and High Speeds

Yue Gao, Chen-Feng Li, Shi-Min Hu, Brian A. Barsky

*Pacific Graphics 09*

Gaseous fluids may move slowly, as smoke does, or at high speed, such as occurs with explosions. High-speed gas flow is always accompanied by low-speed gas flow, which produces ... [more]

### Three Techniques for Rendering Generalized Depth of Field Effects

Todd J. Kosloff, Brian A. Barsky

*MI 09*

Depth of field refers to the swath that is imaged in sufficient focus through an optics system, such as a camera lens. Control over depth of field is an important artistic tool ... [more]

### Radiometric Compensation Using Stratified Inverses

Tian-Tsong Ng, Ramanpreet S. Pahwa, Jiamin Bai, Tony Q. S. Quek, Kar-han Tan

*ICCV 2009*

Through radiometric compensation, a projector-camera system can project a desired image onto a non-flat and non-white surface. This can be achieved by computing the inverse ... [more]

### Interactive Simulation of Surgical Needle Insertion and Steering

Nuttapong Chentanez, Ron Alterovitz, Daniel Ritchie, Lita Cho, Kris Hauser, Ken Goldberg, Jonathan Shewchuk, James F. O'Brien

*SIGGRAPH 2009*

We present algorithms for simulating and visualizing the insertion and steering of needles through deformable tissues for surgical training and planning. Needle insertion ... [more]

### Real-Time Deformation and Fracture in a Game Environment

Eric G. Parker, James F. O'Brien

*SCA 2009*

This paper describes a simulation system that has been developed to model the deformation and fracture of solid objects in a real-time gaming context. Based around a corotational ... [more]

### 3D Clothing Fitting Based on the Geometric Feature Matching

Zhong Li, Xiaogang Jin, Brian Barsky, Jun Liu

*CAD/Graphics 2009*

The 3D clothing fitting on a body model is an important research topic in the garment computer aided design (GCAD). During the fitting process, the match between the clothing ... [more]

### Optimizing Content-Preserving Projections for Wide-Angle Images

Robert Carroll, Maneesh Agrawala, Aseem Agarwala

*SIGGRAPH 2009*

Any projection of a 3D scene into a wide-angle image unavoidably results in distortion. Current projection methods either bend straight lines in the scene, or locally distort ... [more]

### Generating Photo Manipulation Tutorials by Demonstration

Floraine Grabler, Maneesh Agrawala, Wilmot Li, Mira Dontcheva, Takeo Igarashi

We present a demonstration-based system for automatically generating succinct step-by-step visual tutorials of photo manipulations. An author first demonstrates ... [more]

### An Empirical BSSRDF Model

Craig Donner, Jason Lawrence, Ravi Ramamoorthi, Toshiya Hachisuka, Henrik Wann Jensen, Shree Nayar

*SIGGRAPH 09*

We present a new model of the homogeneous BSSRDF based on large-scale simulations. Our model captures the appearance of materials that are not accurately represented using ... [more]

### Frequency Analysis and Sheared Reconstruction for Rendering Motion Blur

Kevin Egan, Yu-Ting Tseng, Nicolas Holzschuch, Fredo Durand, Ravi Ramamoorthi

*SIGGRAPH 09*

Motion blur is crucial for high-quality rendering, but is also very expensive. Our first contribution is a frequency analysis of motionblurred scenes, including moving ... [more]

### Moving Gradients: A Path-Based Method for Plausible Image Interpolation

Dhruv Mahajan, Fu-Chung Huang, Wojciech Matusik, Ravi Ramamoorthi, Peter Belhumeur

*SIGGRAPH 09*

We describe a method for plausible interpolation of images, with a wide range of applications like temporal up-sampling for smooth playback of lower frame rate video, smooth ... [more]

### Tubular Sculptures

Carlo H. Séquin

*Bridges 2009*

This paper reviews ways in which many artists have constructed large sculptures from tubular elements, ranging from single cylinders to toroidal or knotted structures ... [more]

### Visualizing High-Order Surface Geometry

Pushkar P. Joshi, Carlo H. Séquin

*CAD&A 2009*

We have derived parameters that describe the higher-order geometric behavior of smooth surfaces. Our parameters are similar in spirit to the principal directions and ... [more]

### An Effective Third-order Local Fitting Patch and Its Application

Zhong Li, Brian Barsky, Xiaogang Jin

*SMI 2009*

In this paper, we extend Razdan and Bae’s second-order local fitting method [11] to construct an effective third-order fitting patch. Compared to other estimation algorithms ... [more]

### Ribbed Surfaces for Art, Architecture, and Visualization

James Hamlin, Carlo H. Séquin

*CAD&A 2009*

Sequences of parameterized Hermite curves following with their endpoints along two guide rails are used to create "transparent" surfaces and tubular sculptures. This parameterized ... [more]

### CAD Tools for Creating Space-filling 3D Escher Tiles

Mark Howison, Carlo H. Séquin

*CAD&A 2009*

We discuss the design and implementation of CAD tools for creating decorative solids that tile 3-space in a regular, isohedral manner. Starting with the simplest case of ... [more]

### Interpolating Splines: Which is the fairest of them all?

Raph Levien, Carlo H. Séquin

*CAD&A 2009*

Interpolating splines are a basic primitive for designing planar curves. There is a wide diversity in the literature but no consensus on a "best" spline, or even criteria for ... [more]

### Depth of Field Postprocessing For Layered Scenes Using Constant-Time Rectangle Spreading

Todd Kosloff, Michael W. Tao, Brian Barsky

*GI 2009*

Control over what is in focus and what is not in focus in an image is an important artistic tool. The range of depth in a 3D scene that is imaged in sufficient focus through an optics ... [more]

### Determining the Benefits of Direct-Touch, Bimanual, and Multifinger Input on a Multitouch Workstation

Kenrick Kin, Maneesh Agrawala, Tony DeRose

Multitouch workstations support direct-touch, bimanual, and multifinger interaction. Previous studies have separately examined the benefits of these three interaction ... [more]

### Parallax Photography: Creating 3D Cinematic Effects from Stills

Ke Colin Zheng, Alex Colburn, Aseem Agarwala, Maneesh Agrawala, Brian Curless, David Salesin, Michael Cohen

We present an approach to convert a small portion of a light field with extracted depth information into a cinematic effect with simulated, smooth camera motion that exhibits ... [more]

### Precomputation-Based Rendering

Ravi Ramamoorthi

*Foundations and Trends*

High quality image synthesis is a long-standing goal in computer graphics. Complex lighting, reflection, shadow and global illumination effects can be rendered with modern ... [more]

### Affine Double and Triple Product Wavelet Integrals for Rendering

Bo Sun, Ravi Ramamoorthi

*TOG*

Many problems in computer graphics involve integrations of products of functions. Double- and triple-product integrals are commonly used in applications such as all-frequency ... [more]

### Refolding Planar Polygons

Hayley Iben, James F. O'Brien, Erik Demaine

*DCG*

This paper describes an algorithm for generating a guaranteed intersection-free interpolation sequence between any pair of compatible polygons. Our algorithm builds ... [more]

### Compressive Light Transport Sensing

Pieter Peers, Dhruv Mahajan, Bruce Lamond, Abhijeet Ghosh, Wojciech Matusik, Ravi Ramamoorthi, Paul Debevec

*TOG*

In this article we propose a new framework for capturing light transport data of a real scene, based on the recently developed theory of compressive sensing. Compressive ... [more]

### Sizing the Horizon: The Effects of Chart Size and Layering on the Graphical Perception of Time Series Visualizations

Jeffrey Heer, Nicholas Kong, Maneesh Agrawala

We investigate techniques for visualizing time series data and evaluate their effect in value comparison tasks. We compare line charts with

### Perceptual Interpretation of Ink Annotations on Line Charts

Nicholas Kong, Maneesh Agrawala

Asynchronous collaborators often use freeform ink annotations to point to visually salient perceptual features of line charts such as peaks or humps, valleys, rising slopes ... [more]

### A layered, heterogeneous reflectance model for acquiring and rendering human skin

Craig Donner, Tim Weyrich, Eugene d'Eon, Ravi Ramamoorthi, Szymon Rusinkiewicz

*SIGGRAPH ASIA 08*

We introduce a layered, heterogeneous spectral reflectance model for human skin. The model captures the inter-scattering of light among layers, each of which may have an ... [more]

### Interactive 3D Architectural Modeling from Unordered Photo Collections

Sudipta Sinha, Drew Steedly, Rick Szeliski, Maneesh Agrawala, Marc Pollefeys

We present an interactive system for generating photorealistic, textured, piecewise-planar 3D models of architectural structures and urban scenes from unordered sets ... [more]

### Video Puppetry: A Performative Interface for Cutout Animation

Connelly Barnes, David E. Jacobs, Jason Sanders, Dan B Goldman, Szymon Rusinkiewicz, Adam Finkelstein, Maneesh Agrawala

We present a video-based interface that allows users of all skill levels to quickly create cutout-style animations by performing the character motions. The puppeteer ... [more]

### Searching the World's Herbaria: A System for Visual Identification of Plant Species

Peter N. Belhumeur, Daozheng Chen, Steven Feiner, David W. Jacobs, W. John Kress, Haibin Ling, Ida Lopez, Ravi Ramamoorthi, Sameer Sheorey, Sean White, Ling Zhang

*ECCV 2008*

We describe a working computer vision system that aids in the identification of plant species. A user photographs an isolated leaf on a blank background, and the system extracts ... [more]

### Compressive Structured Light for Recovering Inhomogeneous Participating Media

Jinwei Gu, Shree Nayar, Eitan Grinspun, Peter Belhumeur, Ravi Ramamoorthi

*ECCV 2008*

We propose a new method named compressive structured light for recovering inhomogeneous participating media. Whereas conventional structured light methods emit coded ... [more]

### Large Ray Packets for Real-time Whitted Ray Tracing

Ryan Overbeck, Ravi Ramamoorthi, William R. Mark

*IRT 2008*

In this paper, we explore large ray packet algorithms for acceleration structure traversal and frustum culling in the context of Whitted ray tracing, and examine how these ... [more]

### Light Field Transfer: Global Illumination Between Real and Synthetic Objects

O. Cossairt, S. K. Nayar, Ravi Ramamoorthi

*SIGGRAPH 08*

We present a novel image-based method for compositing real and synthetic objects in the same scene with a high degree of visual realism. Ours is the first technique to allow ... [more]

### Multiscale Texture Synthesis

Charles Han, Eric Risser, Ravi Ramamoorthi, Eitan Grinspun

*SIGGRAPH 2008*

Example-based texture synthesis algorithms have gained widespread popularity for their ability to take a single input image and create a perceptually similar non-periodic ... [more]

### Automatic Generation of Tourist Maps

Floraine Grabler, Maneesh Agrawala, Robert W. Sumner, Mark Pauly

Tourist maps are essential resources for visitors to an unfamiliar city because they visually highlight landmarks and other points of interest. Yet, hand-designed maps ... [more]

### The Assumed Light Direction for Perceiving Shape from Shading

James P. O'Shea, Martin S. Banks, Maneesh Agrawala

Recovering 3D shape from shading is an ill-posed problem that the visual system can solve only by making use of additional information such as the position of the light source ... [more]

### Automated Generation of Interactive 3D Exploded View Diagrams

Wilmot Li, Maneesh Agrawala, Brian Curless, David Salesin

We present a system for creating and viewing interactive exploded views of complex 3D models. In our approach, a 3D input model is organized into an explosion graph that encodes ... [more]

### Intricate Isohedral Tilings of 3D Euclidean Space

Carlo H. Séquin

*Bridges 2008*

Various methods to create intricate tilings of 3D space are presented. They include modulated extrusions of 2D Escher tilings, free-form deformations of the fundamental ... [more]

### An Analysis of the In-Out BRDF Factorization for View-Dependent Relighting

Dhruv Mahajan, Yu-Ting Tseng, Eugene d'Eon, Ravi Ramamoorthi

*ESR 08*

Interactive rendering with dynamic natural lighting and changing view is a long-standing goal in computer graphics. Recently, precomputation-based methods for all-frequency ... [more]

### Making Big Things Look Small: Blur combined with other depth cues affects perceived size and distance

Robert (Robin) Held, Emily Cooper, James F. O'Brien, Marty Banks

*VSS 2008*

Blur is commonly considered a weak distance cue, but photographic techniques that manipulate blur cause significant and compelling changes in the perceived distance ... [more]

### A Precomputed Polynomial Representation for Interactive BRDF Editing with Global Illumination

Aner Ben-Artzi, Kevin Egan, Kevin Egan, Frédo Durand, Ravi Ramamoorthi

*TOG*

The ability to interactively edit BRDFs in their final placement within a computer graphics scene is vital to making informed choices for material properties. We significantly ... [more]

### A Theory of Frequency Domain Invariants: Spherical Harmonic Identities for BRDF/Lighting Transfer and Image Consistency

Dhruv Mahajan, Ravi Ramamoorthi, Brian Curless

*PAMI 2008*

This work develops a theory of frequency domain invariants in computer vision. We derive novel identities using spherical harmonics, which are the angular frequency domain ... [more]

### Geometrically exact dynamic splines

Adrien Theetten, Laurent Grisoni, Claude Andriot, Brian Barsky

*Computer-Aided Design 2008*

We propose a complete model handling the physical simulation of deformable 1D objects. We formulate continuous expressions for stretching, bending and twisting energies ... [more]

### Design Considerations for Collaborative Visual Analytics

Jeffrey Heer, Maneesh Agrawala

Visualizations leverage the human visual system to support the process of sensemaking, in which information is collected, organized, and analyzed to generate knowledge ... [more]

### Generalized Selection via Interactive Query Relaxation

Jeffrey Heer, Maneesh Agrawala, Wesley Willett

Selection is a fundamental task in interactive applications, typically performed by clicking or lassoing items of interest. However, users may require more nuanced forms ... [more]

### Graphical Histories for Visualization: Supporting Analysis, Communication, and Evaluation

Jeffrey Heer, Jock D. Mackinlay, Chris Stolte, Maneesh Agrawala

Interactive history tools, ranging from basic undo and redo to branching timelines of user actions, facilitate iterative forms of interaction. In this paper, we investigate ... [more]

### Effect of Character Animacy and Preparatory Motion on Perceptual Magnitude of Errors in Ballistic Motion

Paul Reitsma, James Andrews, Nancy Pollard

*EG 2008*

An increasing number of projects have examined the perceptual magnitude of visible artifacts in animated motion. These studies have been performed using a mix of character ... [more]

### Agressive Tetrahedral Mesh Improvement

Bryan Klingner, Jonathan Shewchuk

*2007 Meshing Roundtable*

We present a tetrahedral mesh improvement schedule that usually creates meshes whose worst tetrahedra have a level of quality substantially better than those produced ... [more]

### Liquid Simulation on Lattice-Based Tetrahedral Meshes

Nuttapong Chentanez, Bryan Feldman, François Labelle, James F. O'Brien, Jonathan Shewchuk

*SCA 2007*

This paper describes a simulation method for animating the behavior of incompressible liquids with complex free surfaces. The region occupied by the liquid is discretized ... [more]

### A Theory of Locally Low Dimensional Light Transport

Dhruv Mahajan, Ira Kemelmacher Shlizerman, Ravi Ramamoorthi, Peter Belhumeur

*SIGGRAPH 2007*

Blockwise or Clustered Principal Component Analysis (CPCA) is commonly used to achieve real-time rendering of shadows and glossy reflections with precomputed radiance ... [more]

### An Algorithm for Rendering Generalized Depth of Field Effects Based on Simulated Heat Diffusion

Todd Kosloff, Brian Barsky

*ICCSA 2007*

Depth of field refers to the swath through a 3Dscene that is imaged in acceptable focus through an optics system, such as a camera lens. Control over depth of field is an important ... [more]

### Isosurface Stuffing: Fast Tetrahedral Meshes with Good Dihedral Angles

François Labelle, Jonathan Shewchuk

*SIGGRAPH 2007*

The *isosurface stuffing* algorithm fills an isosurface
with a uniformly sized tetrahedral mesh whose dihedral angles
are bounded between 10.7^{o} and 164.8^{o}, or
(with a change ...
[more]

### Frequency Domain Normal Map Filtering

Charles Han, Bo Sun, Ravi Ramamoorthi, Eitan Grinspun

*SIGGRAPH 2007*

Filtering is critical for representing image-based detail, such as textures or normal maps, across a variety of scales. While mipmapping textures is commonplace, accurate ... [more]

### Symmetric Embedding of Locally Regular Hyperbolic Tilings

Carlo H. Séquin

*Bridges 2007*

Various methods to create intricate tilings of 3D space are presented. They include modulated extrusions of 2D Escher tilings, free-form deformations of the fundamental ... [more]

### Energy Minimizers for Curvature-Based Surface Functionals

Pushkar P. Joshi, Carlo H. Séquin

We compare curvature-based surface functionals by comparing the aesthetic properties of their minimizers. We introduce an enhancement to the original inline curvature ... [more]

### Computer-Aided Design and Realization of Geometrical Sculptures

Carlo H. Séquin

The use of computer-aided design tools in the conception and realization of large-scale geometrical bronze sculptures is described. An inspirational piece of sculpture ... [more]

### Viewpoint-Coded Structured Light

Mark Young, Erik Beeson, James Davis, Szymon Rusinkiewicz, Ravi Ramamoorthi

*CVPR 2007*

We introduce a theoretical framework and practical algorithms for replacing time-coded structured light patterns with viewpoint codes, in the form of additional camera ... [more]

### Dirty Glass: Rendering Contamination on Transparent Surfaces

Jinwei Gu, Ravi Ramamoorthi, Peter N. Belhumeur, Shree Nayar

*EGSR 2007*

Rendering of clean transparent objects has been well studied in computer graphics. However, real-world transparent objects are seldom clean--their surfaces have a variety ... [more]

### A Real-Time Beam Tracer with Application to Exact Soft Shadows

Ryan Overbeck, Ravi Ramamoorthi, William R. Mark

*EGSR 2007*

Efﬁciently calculating accurate soft shadows cast by area light sources remains a difﬁcult problem. Ray tracing based approaches are subject to noise or banding, and most ... [more]

### A Method for Cartoon-Style Rendering of Liquid Animations

Ashley M. Eden, Adam Bargteil, Tolga Goktekin, Sara Beth Eisinger, James F. O'Brien

*GI 2007*

In this paper we present a visually compelling and informative cartoon
rendering style for liquid animations. Our style is inspired by animations
such as *Futurama,* *The Little ...*
[more]

### Hyper-Seeing the Regular Hendeca-choron

Carlo H. Séquin

*ISAMA 2007*

The hendecachoron is an abstract 4-dimensional polytope composed of eleven cells in the form of hemi-icosahedra. This paper tries to foster an understanding of this intriguing ... [more]

### Design and Implementation of Pax Mundi II

Carlo H. Séquin

On January 18, 2007 a ten foot tall bronze sculpture Pax Mundi II was installed in the courtyard of the H&R Block headquarters in Kansas City. This paper describes the computer-aided ... [more]

### Time-Varying BRDFs

Bo Sun, Kalyan Sunkavalli, Ravi Ramamoorthi, Peter Belhumeur, Shree Nayar

*TVCG 2007*

The properties of virtually all real-world materials change with time, causing their bidirectional reflectance distribution functions (BRDFs) to be time varying. However ... [more]

### Real-Time Ambient Occlusion for Dynamic Character Skins

Adam Kirk, Okan Arikan

*I3D 2007*

We present a single-pass hardware accelerated method to reconstruct compressed ambient occlusion values in real-time on dynamic character skins. This method is designed ... [more]

### A first-order analysis of lighting, shading, and shadows

Ravi Ramamoorthi, Dhruv Mahajan, Peter Belhumeur

*TOG*

The shading in a scene depends on a combination of many factors---how the lighting varies spatially across a surface, how it varies along different directions, the geometric ... [more]

### 4D compression and relighting with high-resolution light transport matrices

Ewen Cheslack-Postava, Nolan Goodnight, Ren Ng, Ravi Ramamoorthi, Greg Humphreys

*I3D 2007*

This paper presents a method for efficient compression and relighting with high-resolution, precomputed light transport matrices. We accomplish this using a 4D wavelet ... [more]

### A semi-Lagrangian contouring method for fluid simulation

Adam Bargteil, Tolga Goktekin, James F. O'Brien, John A. Strain

*ACM Trans. Graphics*

In this paper we present a semi-Lagrangian surface tracking method for use with fluid simulations. Our method maintains an explicit polygonal mesh that defines the surface ... [more]

### Optimization of HDR brachytherapy dose distributions using linear programming with penalty costs

Ron Alterovitz, Etienne Lessard, Jean Pouliot, I-Chow Joe Hsu, James F. O'Brien, Ken Goldberg

*J. Medical Physics*

Prostate cancer is increasingly treated with high-dose-rate (HDR) brachytherapy, a type of radiotherapy in which a radioactive source is guided through catheters temporarily ... [more]

### Efficient Shadows from Sampled Environment Maps

Aner Ben-Artzi, Ravi Ramamoorthi, Maneesh Agrawala

*JGT 06*

This paper addresses the problem of efficiently calculating shadows from environment maps. Since accurate rendering of shadows from environment maps requires hundreds ... [more]

### A Texture Synthesis Method for Liquid Animations

Adam Bargteil, Funshing Sin, Jonathan E. Michaels, Tolga Goktekin, James F. O'Brien

*SCA 2006*

In this paper we present a method for synthesizing textures on animated liquid surfaces generated by a physically based fluid simulation system. Rather than advecting ... [more]

### Generating Surface Crack Patterns

Hayley Iben, James F. O'Brien

*SCA 2006*

We present a method for generating surface crack patterns that appear in materials such as mud, ceramic glaze, and glass. To model these phenomena, we build upon existing physically ... [more]

### Simultaneous Coupling of Fluids and Deformable Bodies

Nuttapong Chentanez, Tolga Goktekin, Bryan Feldman, James F. O'Brien

*SCA 2006*

This paper presents a method for simulating the two-way interaction between fluids and deformable solids. The fluids are simulated using an incompressible Eulerian formulation ... [more]

### Fluid Animation with Dynamic Meshes

Bryan Klingner, Bryan Feldman, Nuttapong Chentanez, James F. O'Brien

*SIGGRAPH 2006*

This paper presents a method for animating fluid with unstructured tetrahedral meshes that change at each time step. Meshes that conform well to changing boundaries and ... [more]

### A Texture Synthesis Method for Liquid Animations

Adam Bargteil, Funshing Sin, Jonathan Michaels, James F. O'Brien

*SIGGRAPH 2006 Tech Sketch*

In this sketch we present a method for synthesizing textures on animated liquid surfaces generated by a physically based fluid simulation system. Rather than advecting ... [more]

### Acquiring Scattering Properties of Participating Media by Dilution

Srinivasa G. Narasimhan, Mohit Gupta, Craig Donner , Ravi Ramamoorthi, Shree Nayar, Henrik Wann Jensen

*SIGGRAPH 2006*

The visual world around us displays a rich set of volumetric effects due to participating media. The appearance of these media is governed by several physical properties ... [more]

### Reflectance Sharing: Predicting Appearance from a Sparse Set of Images of a Known Shape

Todd Zickler, Sebastian Enrique, Ravi Ramamoorthi, Peter Belhumeur

*PAMI 2006 Aug*

When the shape of an object is known, its appearance is determined by the spatially-varying reflectance function defined on its surface. Image-based rendering methods ... [more]

### Time-varying surface appearance: acquisition, modeling and rendering

Jinwei Gu, Chien-I Tu, Ravi Ramamoorthi, Peter Belhumeur, Wojciech Matusik, Shree Nayar

*SIGGRAPH 2006*

In this project, we take a significant step towards measuring, modeling and rendering time-varying surface appearance. Traditional computer graphics rendering generally ... [more]

### A Compact Factored Representation of Heterogeneous Subsurface Scattering

Pieter Peers, Karl vom Berge, Wojciech Matusik, Ravi Ramamoorthi, Jason Lawrence, Szymon Rusinkiewicz, Philip Dutr{\'e}

*SIGGRAPH 2006*

Heterogeneous subsurface scattering in translucent materials is one of the most beautiful but complex effects. We acquire spatial BSSRDF datasets using a projector, and ... [more]

### Simultaneous Coupling of Fluids and Deformable Bodies

Nuttapong Chentanez, Tolga Goktekin, Bryan Feldman, James F. O'Brien

*SIGGRAPH 2006 Tech Sketch*

We describe a method for simultaneous two-way coupling of fluid and deformable bodies. The interaction between a fluid and deformable body can create complex and interesting ... [more]

### Inverse shade trees for non-parametric material representation and editing

Jason Lawrence, Aner Ben-Artzi, Christopher DeCoro, Wojciech Matusik, Hanspeter Pfister, Ravi Ramamoorthi, Szymon Rusinkiewicz

*SIGGRAPH 2006*

Recent progress in the measurement of surface reflectance has created a demand for non-parametric appearance representations that are accurate, compact, and easy to use ... [more]

### Real-Time BRDF Editing in Complex Lighting

Aner Ben-Artzi, Ryan Overbeck, Ravi Ramamoorthi

*SIGGRAPH 06*

Current systems for editing BRDFs typically allow users to adjust analytic parameters while visualizing the results in a simplified setting (e.g. unshadowed point light ... [more]

### Patterns on the Genus-3 Klein Quartic

Carlo H. Séquin

*Bridges 2006*

Projections of Klein's quartic surface of genus 3 into 3D space are used as canvases on which we present regular tessellations, Escher tilings, knot- and graph-embedding ... [more]

### Refolding Planar Polygons

Hayley Iben, James F. O'Brien, Erik Demaine

*SoCG 2006*

This paper describes an algorithm for generating a guaranteed-intersection-free interpolation sequence between any pair of compatible polygons. Our algorithm builds ... [more]

### Extensions for 3D Graphics Rendering Engine used for Direct Tessellation of Spline Surfaces

Adrien Sfarti, Brian Barsky, Todd Kosloff, Egon Pasztor, Alex Kozlowski, Eric Roman, Alex Perelman

*ICCS 2006*

In current 3D graphics architectures, the bus between the triangle server and the rendering engine GPU is clogged with triangle vertices and their many attributes (normal ... [more]

### New 3D Graphics Rendering Engine Architecture for Direct Tessellation of Spline Surfaces

Adrien Sfarti, Brian Barsky, Todd Kosloff, Egon Pasztor, Alex Kozlowski, Eric Roman, Alex Perelman

*3IA 2006*

In current 3D graphics architectures, the bus between the triangle server and the rendering engine GPU is clogged with triangle vertices and their many attributes (normal ... [more]

### Human Vision Based Detection of Non-Uniform Brightness on LCD Panels

Jee Hong Kim, Brian Barsky

*MVAII 2004*

We propose a method to detect defects due to spatially non-uniform brightness on LCD panels by using a machine vision technique. The detection method is based on human vision ... [more]

### Exploiting Temporal Coherence for Incremental All-Frequency Relighting

Ryan Overbeck, Aner Ben-Artzi, Ravi Ramamoorthi, Eitan Grinspun

*EGSR 2006*

Current PRT methods exploit spatial coherence of the lighting (such as with wavelets) and of light transport (such as with CPCA). We consider a significant, yet unexplored form ... [more]

### Modeling Illumination Variation with Spherical Harmonics

Ravi Ramamoorthi

The appearance of objects including human faces can vary dramatically with the lighting. We present results that use spherical harmonic illumination basis functions ... [more]

### Computational Studies of Human Motion: Tracking and Motion Synthesis

David Forsyth, Okan Arikan, Leslie Ikemoto, James F. O'Brien, Deva Ramanan

*Foundations and Trends*

We review methods for kinematic tracking of the human body in video. The review is part of a projected book that is intended to cross-fertilize ideas about motion representation ... [more]

### Interactive Procedural Computer-Aided Design

Carlo H. Séquin

*CAD/Graphics 2005*

The typical engineering design process can be decomposed into several phases: creative exploration of ideas, testing soundness of proposed concepts, refining concepts ... [more]

### Semi-Automated Ultrasound Interpretation System Using Anatomical Knowledge Representation

Michael S. Downes, Brian Barsky

*VC 2005*

Interpreting ultrasound data presents a significant challenge to medical personnel, which limits the clinical applications of the technology. We have addressed this ... [more]

### Elimination of Artifacts Due to Occlusion and Discretization Problems in Image Space Blurring Techniques

Brian Barsky, Michael Tobias, Derrick P. Chu, Daniel R. Horn

*GM 2005*

Traditional computer graphics methods render images that appear sharp at all depths. Adding blur can add realism to a scene, provide a sense of scale, and draw a viewerÕs attention ... [more]

### Animating Gases with Hybrid Meshes

Bryan Feldman, James F. O'Brien, Bryan Klingner

*SIGGRAPH 2005*

This paper presents a method for animating gases on unstructured tetrahedral meshes to efficiently model the interaction of the fluids with irregularly shaped obstacles ... [more]

### Efficiently Combining Positions and Normals for Precise 3D Geometry

Diego Nehab, Szymon Rusinkiewicz, James Davis, Ravi Ramamoorthi

*SIGGRAPH 2005*

Range scanning, manual 3D editing, and other modeling approaches can provide information about the geometry of surfaces in the form of either 3D positions (e.g., triangle meshes ... [more]

### A Practical Analytic Single Scattering Model for Real Time Rendering

Bo Sun, Ravi Ramamoorthi, Srinivasa Narasimhan, Shree Nayar

*SIGGRAPH 2005*

We consider real-time rendering of scenes in participating media, capturing the effects of light scattering in fog, mist and haze. While a number of sophisticated approaches ... [more]

### Provably Good Moving Least Squares

Ravi Kolluri

*SODA 2005*

We analyze a moving least squares algorithm for reconstructing a surface from point cloud data. Our algorithm defines an implicit function I whose zero set U is the reconstructed ... [more]

### Fast and Detailed Approximate Global Illumination by Irradiance Decomposition

Okan Arikan, David A. Forsyth, James F. O'Brien

*SIGGRAPH 2005*

In this paper we present an approximate method for accelerated computation of the final gathering step in a global illumination algorithm. Our method operates by decomposing ... [more]

### Fluids in Deforming Meshes

Bryan Feldman, James F. O'Brien, Bryan Klingner, Tolga Goktekin

*SCA 2005*

This paper describes a simple modification to an Eulerian fluid simulation that permits the underlying mesh to deform independent of the simulated fluid's motion. The modification ... [more]

### Pushing People Around

Okan Arikan, David Forsyth, James F. O'Brien

*SCA 2005*

We present an algorithm for animating characters being pushed by an external source such as a user or a game environment. We start with a collection of motions of a real person ... [more]

### A semi-Lagrangian contouring method for fluid simulation

Adam Bargteil, Tolga Goktekin, James F. O'Brien, John A. Strain

*SIGGRAPH 2005 Tech Sketch*

In this sketch we present a semi-Lagrangian surface tracking method for use with fluid simulations. Our method main- tains an explicit polygonal mesh that defines the surface ... [more]

### Symmetrical Hamiltonian Manifolds on Regular 3D and 4d Polytopes

Carlo H. Séquin

*Coxeter Day 2005*

Hamiltonian cycles on the edge graphs of the regular polytopes in three and four dimensions are investigated with the primary goal of finding complete multi-colored coverages ... [more]

### Splitting Tori, Knots, and Moebius Bands

Carlo H. Séquin

*Bridges 2005*

A study of sculptures and puzzles resulting from splitting lengthwise, tori, Moebius bands, various knots and graphs, illustrated with many models made on rapid prototyping ... [more]

### Adaptive Numerical Cumulative Distribution Functions for Efficient Importance Sampling

Jason Lawrence, Szymon Rusinkiewicz, Ravi Ramamoorthi

*EGSR 2004*

As image-based surface reflectance and illumination gain wider use in physically-based rendering systems, it is becoming more critical to provide representations that ... [more]

### Skeletal Parameter Estimation from Optical Motion Capture Data

Adam Kirk, James F. O'Brien, David Forsyth

*CVPR 2005*

In this paper we present an algorithm for automatically estimating a subject’s skeletal structure from optical mo- tion capture data. Our algorithm consists of a series ... [more]

### New 3D Graphics Rendering Engine Architecture for Direct Tessellation of Spline Surfaces

Adrien Sfarti, Brian Barsky, Todd Kosloff, Egon Pasztor, Alex Kozlowski, Eric Roman, Alex Perelman

*ICCS 2005*

In current 3D graphics architectures, the bus between the triangle server and the rendering engine GPU is clogged with triangle vertices and their many attributes (normal ... [more]

### A Fourier Theory for Cast Shadows

Ravi Ramamoorthi, Melissa Koudelka, Peter Belhumeur

*PAMI 2005*

Cast shadows can be significant in many computer vision applications, such as lighting-insensitive recognition and surface reconstruction. Nevertheless, most algorithms ... [more]

### Spacetime Stereo: A Unifying Framework for Depth from Triangulation

James Davis, Diego Nehab, Ravi Ramamoorthi, Szymon Rusinkiewicz

*PAMI 2005*

Depth from triangulation has traditionally been treated in a number of separate threads in the computer vision literature, with methods like stereo, laser scanning, and ... [more]

### Reflectance Sharing: Image-based Rendering from a Sparse Set of Images

Todd Zickler, Sebastian Enrique, Ravi Ramamoorthi, Peter Belhumeur

*EGSR 2005*

When the shape of an object is known, its appearance is determined by the spatially-varying reflectance function defined on its surface. Image-based rendering methods ... [more]

### A Signal-Processing for Reflection

Ravi Ramamoorthi, Pat Hanrahan

*TOG 2004*

We present a signal-processing framework for analyzing the reflected light field from a homogeneous convex curved surface under distant illumination. This analysis ... [more]

### A Method for Animating Viscoelastic Fluids

Tolga Goktekin, Adam Bargteil, James F. O'Brien

*SIGGRAPH 2004*

This paper describes a technique for animating the behavior of viscoelastic fluids, such as mucus, liquid soap, pudding, toothpaste, or clay, that exhibit a combination of both ... [more]

### Skeletal Parameter Estimation from Optical Motion Capture Data

Adam Kirk, James F. O'Brien, David Forsyth

*SIGGRAPH 2004 Tech Sketch*

In this sketch we present an algorithm for automatically estimating a subject's skeletal structure from optical motion capture data without using any a priori skeletal ... [more]

### Refolding Planar Polygons

Hayley Iben, James F. O'Brien, Erik Demaine

*SIGGRAPH 2004 Tech Sketch*

This sketch describes a guaranteed technique for generating intersection-free interpolation sequences between arbitrary, non-intersecting, planar polygons. The computational ... [more]

### Interpolating and Approximating Implicit Surfaces from Polygon Soup

Chen Shen, James F. O'Brien, Jonathan Shewchuk

*SIGGRAPH 2004*

This paper describes a method for building interpolating or approximating implicit surfaces from polygonal data. The user can choose to generate a surface that exactly ... [more]

### Radiance Caching and Local Geometry Correction

Okan Arikan, David A. Forsyth, James F. O'Brien

*SIGGRAPH 2004 Tech Sketch*

We present a final gather algorithm which splits the irradiance integral into two components. One component captures the incident radiance due to distant surfaces. This ... [more]

### An Opponent Process Approach to Modeling the Blue Shift of the Human Color Vision System

Brian Barsky, Todd Kosloff, Steven D. Upstill

*APGV 2004*

Low light level affects human visual perception in various ways. Visual acuity is reduced and scenes appear bluer, darker, less saturated, and with reduced contrast. We confine ... [more]

### Rendering Skewed Plane of Sharp Focus and Associated Depth of Field

Brian Barsky, Egon Pasztor

*SIGGRAPH 2004*

Depth of field is the region of a scene that is in focus in an image. This is measured relative to a plane-of-sharp focus. When using a physical camera, this plane is perpendicular ... [more]

### Vision-Realistic Rendering: Simulation of the Scanned Foveal Image from Wavefront Data of Human Subjects

Brian Barsky

*APGV 2004*

We introduce the concept of vision-realistic rendering – the com- puter generation of synthetic images that incorporate the charac- teristics of a particular individual ... [more]

### Efficient BRDF Importance Sampling Using a Factored Representation

Jason Lawrence, Szymon Rusinkiewicz, Ravi Ramamoorthi

*SIGGRAPH 2004*

High-quality Monte Carlo image synthesis requires the ability to importance sample realistic BRDF models. However, analytic sampling algorithms exist only for the Phong ... [more]

### Triple Product Wavelet Integrals for All-Frequency Relighting

Ren Ng, Ravi Ramamoorthi, Pat Hanrahan

*SIGGRAPH 2004*

This paper focuses on efficient rendering based on pre-computed light transport, with realistic materials and shadows under all-frequency direct lighting such as environment ... [more]

### Spectral Surface Reconstruction from Noisy Point Clouds

Ravi Kolluri, Jonathan Shewchuk, James F. O'Brien

*SGP 2004*

We introduce a noise-resistant algorithm for reconstructing a watertight surface from point cloud data. It forms a Delaunay tetrahedralization, then uses a variant of ... [more]

### Practical Rendering of Multiple Scattering Effects in Participating Media

Simon Premože, Michael Ashikhmin, Ravi Ramamoorthi, Shree K. Nayar

*EGSR 2004*

Volumetric light transport effects are significant for many materials like skin, smoke, clouds, snow or water. In particular, one must consider the multiple scattering of ... [more]

### An Energy-Driven Approach to Linkage Unfolding

Jason Cantarella, Erik Demaine, Hayley Iben, James F. O'Brien

*SoCG 2004*

We present a new algorithm for unfolding planar polygonal linkages without self-intersection based on following the gradient flow of a "repulsive" energy function. This ... [more]

### A Fourier Theory for Cast Shadows

Ravi Ramamoorthi, Melissa Koudelka, Peter Belhumeur

*ECCV 2004*

Cast shadows can be significant in many computer vision applications such as lighting-insensitive recognition and surface reconstruction. However, most algorithms ... [more]

### Motion Synthesis from Anotations

Okan Arikan, David Forsyth, James F. O'Brien

*SIGGRAPH 2003*

This paper describes a framework that allows a user to synthesize human motion while retaining control of its qualitative properties. The user paints a timeline with annotations ... [more]

### Animating Suspended Particle Explosions

Bryan Feldman, James F. O'Brien, Okan Arikan

*SIGGRAPH 2003*

This paper describes a method for animating suspended particle explosions. Rather than modeling the numerically troublesome, and largely invisible blast wave, the method ... [more]

### All-Frequncy Shadows Using Non-linear Wavelet Lighting Approximation

Ren Ng, Ravi Ramamoorthi, Pat Hanrahan

*SIGGRAPH 2003*

We present a method, based on pre-computed light transport, for real-time rendering of objects under all-frequency, time-varying illumination represented as a high-resolution ... [more]

### Spectral Watertight Surface Reconstruction

Ravi Kolluri, Jonathan Shewchuk, James F. O'Brien

*SIGGRAPH 2003 Tech Sketch*

We use spectral partitioning to reconstruct a watertight surface from point cloud data. This method is particularly effective for noisy and undersampled point sets with ... [more]

### Investigating Occlusion and Discretization Problems in Image Space Blurring Techniques

Brian Barsky, Michael J. Tobias, Daniel R. Horn, Derrick P. Chu

*VVG 2003*

Traditional computer graphics methods render images that appear sharp at all depths. Adding blur can add realism to a scene, provide a sense of scale, and draw a viewer’s attention ... [more]

### Interactive Deformation Using Modal Analysis with Constraints

Kris Hauser, Chen Shen, James F. O'Brien

*Graphics Interface 2003*

Modal analysis provides a powerful tool for efficiently simulating the behavior of deformable objects. This paper shows how manipulation, collision, and other constraints ... [more]

### Camera Models and Optical Systems Used in Computer Graphics: Part I, Object Based Techniques

Brian Barsky, Daniel R. Horn, Stanley A. Klein, Jeffrey A. Pang, Meng Yu

*ICCSA 03*

Images rendered with traditional computer graphics techniques, such as scanline rendering and ray tracing, appear focused at all depths. However, there are advantages to ... [more]

### Camera Models and Optical Systems Used in Computer Graphics: Part II, Image Based Techniques

Brian Barsky, Daniel R. Horn, Stanley A. Klein, Jeffrey A. Pang, Meng Yu

*ICCSA 03*

In our companion paper [5], we described the optics underlying camera models that have been used in computer graphics, and presented object space techniques for rendering ... [more]

### Structured Importance Sampling of Environment Maps

Sameer Agarwal, Ravi Ramamoorthi, Serge J. Belongie, Henrik Wann Jensen

*SIGGRAPH 2003*

We introduce structured importance sampling, a new technique for efficiently rendering scenes illuminated by distant natural illumination given in an environment map ... [more]

### Spacetime Stereo: A Unifying Framework for Depth from Triangulation

James Davis, Ravi Ramamoorthi, Szymon Rusinkiewicz

*CVPR 2003*

Depth from triangulation has traditionally been treated in a number of separate threads in the computer vision literature, with methods like stereo, laser scanning, and ... [more]

### Using Specularities for Recognition

Margarita Osadchy, David Jacobs, Ravi Ramamoorthi

*ICCV 2003*

Recognition systems have generally treated specular highlights as noise. We show how to use these highlights as a positive source of information that improves recognition ... [more]

### An Energy-Driven Approach to Linkage Unfolding

Jason Cantarella, Erik Demaine, Hayley Iben, James F. O'Brien

*DIMACS 2002*

In this paper, we introduce a new energy-driven approach for straightening polygonal arcs and convexifying polygonal cycles without self-intersection based on following ... [more]

### Modelling with Implicit Surfaces that Interpolate

Greg Turk, James F. O'Brien

*TOG*

We introduce new techniques for modelling with interpolating implicit surfaces. This form of implicit surface was first used for problems of surface reconstruction and ... [more]

### Graphical Modeling and Animation of Ductile Fracture

James F. O'Brien, Adam Bargteil, Jessica Hodgins

*SIGGRAPH 2002*

In this paper, we describe a method for realistically animating ductile fracture in common solid materials such as plastics and metals. The effects that characterize ductile ... [more]

### Synthesizing sounds from rigid-body simulations

James F. O'Brien, Chen Shen, Christine Gatchalian

*SCA 2002*

This paper describes a real-time technique for generating realistic and compelling sounds that correspond to the motions of rigid objects. By numerically precomputing ... [more]

### Modal Analysis for Real-Time Viscoelastic Deformation

Chen Shen, Kris Hauser, Christine Gatchalian, James F. O'Brien

*SIGGRAPH 2002 Tech Sketch*

This technical sketch describes how a standard analysis technique known as modal decomposition can be used for real-time model- ing of viscoelastic deformation. While ... [more]

### Modeling the Accumulation of Wind-Driven Snow

Bryan Feldman, James F. O'Brien

*SIGGRAPH 2002 Tech Sketch*

This technical sketch presents a method for modeling the appearance of snow drifts formed by the accumulation of wind-blown snow near buildings and other obstacles. Our ... [more]

### Frequency Space Environment Map Rendering

Ravi Ramamoorthi, Pat Hanrahan

*SIGGRAPH 2002*

We present a new method for real-time rendering of objects with complex isotropic BRDFs under distant natural illumination, as specified by an environment map. Our approach ... [more]

### Analytic PCA construction for theoretical analysis of lighting variability in images of a Lambertian object

Ravi Ramamoorthi

*PAMI 2001*

We analyze theoretically the subspace best approximating images of a convex Lambertian object taken from the same viewpoint, but under different distant illumination ... [more]

### Synthesizing Sounds from Physically Based Motion

James F. O'Brien, Perry R. Cook, Georg Essl

*SIGGRAPH 2001*

The goal of this work is to develop techniques for approximating sounds that are generated by the motions of solid objects. Our methods builds on previous work in the field ... [more]

### Image Based Rendering and Illumination Using Spherical Mosaics

Chen Shen, Heung-Yeung Shum, James F. O'Brien

*SIGGRAPH 2001 Tech Sketch*

The work described here extends the concentric mosaic representation developed by Shum and He to spherical mosaics that allow the viewer greater freedom of movement. Additionally ... [more]

### Implicit Surfaces that Interpolate

Greg Turk, GHuong Quynh Dinh, James F. O'Brien, Gary Yngve

*Shape Modeling International 2001*

Implicit surfaces are often created by summing a collection of radial basis functions. Recently, researchers have begun to create implicit surfaces that exactly interpolate ... [more]

### Analysis of Planar Light Fields From Homogeneous Convex Curved Surfaces Under Distant Illumination

Ravi Ramamoorthi, Pat Hanrahan

We consider the flatland or 2D properties of the light field generated when a homogeneous convex curved surface reflects a distant illumination field. Besides being of ... [more]

### An Efficient Representation for Irradiance Environment Maps

Ravi Ramamoorthi, Pat Hanrahan

*SIGGRAPH 2001*

We consider the rendering of diffuse objects under distant illumination, as specified by an environment map. Using an analytic expression for the irradiance in terms of ... [more]

### A Signal-Processing Framework for Inverse Rendering

Ravi Ramamoorthi, Pat Hanrahan

*SIGGRAPH 2001*

Realism in computer-generated images requires accurate input models for lighting, textures and BRDFs. One of the best ways of obtaining high-quality data is through measurements ... [more]

### On the relationship between Radiance and Irradiance: Determining the illumination from images of a convex Lambertian object

Ravi Ramamoorthi, Pat Hanrahan

*JOSA 2001*

We present a theoretical analysis of the relationship between incoming radiance and irradiance. Specifically, we address the question of whether it is possible to compute ... [more]

### Animating Fracture

James F. O'Brien, Jessica Hodgins

*CACM*

We have developed a simulation technique that uses non-linear finite element analysis and elastic fracture mechanics to compute physically plausible motion for three-dimensional ... [more]

### Combining Active and Passive Simulations for Secondary Motion

James F. O'Brien, Victor Zordan, Jessica Hodgins

*CG&A*

Objects that move in response to the actions of a main character often make an important contribution to the visual richness of an animated scene. We use the term "secondary ... [more]

### Animating Explosions

Gary D. Yngve, James F. O'Brien, Jessica K. Hodgins

*SIGGRAPH 2000*

In this paper, we introduce techniques for animating explosions and their effects. The primary effect of an explosion is a disturbance that causes a shock wave to propagate ... [more]

### Automatic Joint Parameter Estimation from Magnetic Motion Capture Data

James F. O'Brien, Robert Bodenheimer, Gabriel Brostow, Jessica Hodgins

*GI 2000*

This paper describes a technique for using magnetic motion capture data to determine the joint parameters of an articulated hierarchy. This technique makes it possible ... [more]

### Efficient Image-Based Methods for Rendering Soft Shadows

Maneesh Agrawala, Ravi Ramamoorthi, Alan Heirich, Laurent Moll

*SIGGRAPH 2000*

We present two efficient image-based approaches for computation and display of high-quality soft shadows from area light sources. Our methods are related to shadow maps ... [more]

### Graphical Modeling and Animation of Brittle Fracture

James F. O'Brien, Jessica Hodgins

*SIGRAPH 1999*

In this paper, we augment existing techniques for simulating flexible objects to include models for crack initiation and propagation in three-dimensional volumes. By ... [more]

### Shape Transformation Using Variational Implicit Functions

James F. O'Brien, Greg Turk

*SIGGRAPH 1999*

Traditionally, shape transformation using implicit functions is performed in two distinct steps: 1) creating two implicit functions, and 2) interpolating between these ... [more]

### Animating Sand, Mud, and Snow

Robert Sumner, James F. O'Brien, Jessica Hodgins

*CGF*

Computer animations often lack the subtle environmental changes that should occur due to the actions of the characters. Squealing car tires usually leave no skid marks ... [more]

### Creating Generative Models from Range Images

Ravi Ramamoorthi, James Arvo

*SIGGRAPH '99*

We describe a new approach for creating concise high-level generative models from range images or other methods of obtaining approximate point clouds. Using a variety ... [more]

### Perception of Human Motion with Different Geometric Models

Jessica Hodgins, James F. O'Brien, Jack Tumblin

*TVCG 1998*

Human figures have been animated using a variety of geometric models including stick figures, polygonal models, and NURBS-based models with muscles, flexible skin, or clothing ... [more]

### Animating Sand, Mud, and Snow

Robert Sumner, James F. O'Brien, Jessica Hodgins

*GI 98*

Computer animations often lack the subtle environmental changes that should occur due to the actions of the char- acters. Squealing car tires usually leave no skid marks ... [more]

### Combining Active and Passive Simulations for Secondary Motion

James F. O'Brien, Victor Zordan, Jessica Hodgins

*SIGGRAPH 1997 Tech Sketch*

The secondary motion of passive objects in the scene is essential for appealing and natural-looking animated characters, but because of the difficulty of controlling ... [more]

### Do Geometric Models Affect Judgments of Human Motion?

Jessica Hodgins, James F. O'Brien, Jack Tumblin

*GI 97*

Human figures have been animated using a wide variety of geometric models including stick figures, polygonal models, and NURBS-based models with muscles, flexible skin ... [more]

### Fast Construction of Accurate Quaternion Splines

Ravi Ramamoorthi, Alan H. Barr

*SIGGRAPH '97*

In 1992, Barr et al proposed a method for interpolating orientations with unit quaternion curves by minimizing covariant acceleration. This paper presents a simple improved ... [more]

### Animating Human Athletics

Jessica Hodgins, Wayne Wooten, David Brogan, James F. O'Brien

*SIGGRAPH 1995*

This paper describes algorithms for the animation of men and women performing three dynamic athletic behaviors: running, bicycling, and vaulting. We animate these behaviors ... [more]

### Dynamic Simulation of Splashing Fluids

James F. O'Brien, Jessica Hodgins

*Computer Animation 95*

In this paper we describe a method for modeling the dynamic behavior of splashing fluids. The model simulates the behavior of a fluid when objects impact or float on its surface ... [more]