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A Material Point Method For Snow Simulation

Siggraph 2013

Alexey Stomakhin, Craig Schroeder, Lawrence Chai, Joseph Teran, Andrew Selle - 08/2013

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Snow is a challenging natural phenomenon to visually simulate. While the graphics community has previously considered accumulation and rendering of snow, animation of snow dynamics has not been fully addressed. Additionally, existing techniques for solids and fluids have difficulty producing convincing snow results. Specifically, wet or dense snow that has both solid- and fluid-like properties is difficult to handle. Consequently, this paper presents a novel snow simulation method utilizing a usercontrollable elasto-plastic constitutive model integrated with a hybrid Eulerian/Lagrangian Material Point Method. The method is continuum based and its hybrid nature allows us to use a regular Cartesian grid to automate treatment of self-collision and fracture. It also naturally allows us to derive a grid-based semi-implicit integration scheme that has conditioning independent of the number of Lagrangian particles. We demonstrate the power of our method with a variety of snow phenomena including complex character interactions.

Modeling and Estimation of Internal Friction in Cloth

Siggraph 2013

Eder Miguel, Rasmus Tamstorf, Derek Bradley, Sara C. Schvartzman, Bernhard Thomaszewski, Bernd Bickel, Wojciech Matusik, Steve Marschner, Miguel A. Otaduy - 07/2013

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Force-deformation measurements of cloth exhibit significant hysteresis, and many researchers have identified internal friction as the source of this effect. However, it has not been incorporated into computer animation models of cloth. In this paper, we propose a model of internal friction based on an augmented reparameterization of Dahl’s model, and we show that this model provides a good match to several important features of cloth hysteresis even with a minimal set of parameters. We also propose novel parameter estimation procedures that are based on simple and inexpensive setups and need only sparse data, as opposed to the complex hardware and dense data acquisition of previous methods. Finally, we provide an algorithm for the efficient simulation of internal friction, and we demonstrate it on simulation examples that show disparate behavior with and without internal friction.

Discrete bending forces and their Jacobians

GMOD 2013

Rasmus Tamstorf, Eitan Grinspun - 07/2013

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Computation of bending forces on triangle meshes is required for numerous simulation and geometry processing applications. A common quantity in many bending models is the hinge angle between two adjacent triangles. This angle is straightforward to compute, and its gradient with respect to vertex positions (required for the forces) is easily found in the literature. However, its Hessian, which is required for efficient numerics (e.g., implicit time stepping, Newton-based energy minimization) is not documented in the literature. Readily available computations of the Hessian, such as those produced by symbolic algebra systems, or by autodifferentiation codes, are expensive to compute. We present compact, easily reproducible, closed form expressions for the Hessian. Compared to the automatic differentiation, we measure up to 7 speedup for the evaluation of the bending forces and their gradients.

Sorted Deferred Shading for Production Path Tracing

EGSR 2013 Paper - Received "Best Paper" distinction

Christian Eisenacher, Gregory Nichols, Andrew Selle, Brent Burley - 06/2013


Ray-traced global illumination is becoming widespread. However, incoherent ray traversal and shading has traditionally limited ray tracing to scenes that fit in memory. To combat these issues, we introduce a sorting strategy for large, potentially out-of-core ray batches, and we sort and defer shading of ray hits. As a result, we achieve perfectly coherent shading and texture access, removing the need for a shading cache.

Speculative Parallel Asynchronous Contact Mechanics

Siggraph Asia 2012

Samantha Ainsley, Etienne Vouga, Eitan Grinspun, Rasmus Tamstorf - 12/2012

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We extend the Asynchronous Contact Mechanics algorithm [Harmon et al. 2009] and improve its performance by two orders of magnitude, using only optimizations that do not compromise ACM’s three guarantees of safety, progress, and correctness. The key to this speedup is replacing ACM’s timid, forward-looking mechanism for detecting collisions—locating and rescheduling separating plane kinetic data structures—with an optimistic speculative method inspired by Mirtich’s rigid body Time Warp algorithm [2000].

Reflections on Simultaneous Impact

Siggraph 2012 Paper

Breannan Smith - Danny M. Kaufman - Etienne Vouga - Rasmus Tamstorf - Eitan Grinspun - 08/2012

PDF Video Supplemental Material

We present a simple generalized impact model motivated by both the successes and pitfalls of two popular approaches: pair-wise propagation and linear complementarity models. Our algorithm is the first to satisfy all identified desiderata, including simultaneously guaranteeing symmetry preservation, kinetic energy conservation, and allowing break-away.

Topology-Driven Vectorization of Clean Line Drawings

ACM Transactions on Graphics Paper

Gioacchino Noris - Alexander Hornung - Robert W. Sumner - Maryann Simmons - Markus Gross - 06/2012

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Vectorization provides a link between raster scans of pencil-and-paper drawings and modern digital processing algorithms that require accurate vector representations. We propose a vectorization algorithm specialized for clean line drawings that analyzes the drawing's topology in order to overcome junction ambiguities.

Asynchronous Contact Mechanics

Communications of the ACM Paper

David Harmon - Etienne Vouga - Breannan Smith - Rasmus Tamstorf - Eitan Grinspun - 04/2012

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The principled, faithful simulation of complex collisions for deformable objects, such as cloth and other flexible materials, remains an open, challenging, and important problem. We propose to place safety and correctness on an equal footing with progress. To overcome the fundamental opposition between these requirements, we turn to asynchronous integration, which integrates each geometric element of a discrete shape (e.g., the stretching resistance of cloth defined across a triangle) at its own pace, not in lockstep with the entire object.

Ball-morph: Definition, Implementation and Comparative Evaluation

IEEE TVCG, June 2011, 17:6, pp 757-769, © 2011 IEEE Paper

G. Noris - D. Sýkora - S. Coros - B. Whited - M. Simmons - A. Hornung - M. Gross - R. W. Sumner - 08/2011


Ball-morphs use the automatic ball-map correspondence, proposed by Chazal et al., from which we derive different vertex trajectories (linear, circular, and parabolic). All three morphs are symmetric, meeting both curves with the same angle, which is a right angle for the circular and parabolic. We provide simple constructions for these ball-morphs and compare them to each other and other simple morphs.

Perceptually-Based Compensation of Light Pollution in Display Systems

APGV 2011 Paper

Jeroen van Baar - Steven Poulakos - Wojciech Jarosz - Derek Nowrouzezahrai - Rasmus Tamstorf - Markus Gross - 08/2011

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This paper addresses the problem of unintended light contributions due to physical properties of display systems. We propose an automatic, perceptually-based computational compensation framework, which formulates pollution elimination as a minimization problem. Our method aims to distribute the error introduced by the pollution in a perceptually optimal manner.

A Programmable System for Artistic Volumetric Lighting

Siggraph 2011 Paper

Derek Nowrouzezahrai - Jared Johnson - Andrew Selle - Dylan Lacewell - Michael Kaschalk - Wojciech Jarosz - 08/2011

PDF Video Supplemental Material

We present a method for generating art-directable volumetric effects, ranging from physically-accurate to non-physical results. Our system mimics the way experienced artists think about volumetric effects by using an intuitive lighting primitive, and decoupling the modeling and shading of this primitive. We integrate our approach into a real-world production pipeline and couple our volumetric effects to surface shading.

Efficient Elasticity for Character Skinning with Contact and Collisions

Siggraph 2011 Paper

Aleka McAdams - Yongning Zhu - Andrew Selle - Mark Empey - Rasmus Tamstorf - Joseph Teran - Eftychios Sifakis - 08/2011

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We present a new algorithm for near-interactive simulation of skeleton driven, high resolution elasticity models. Our methodology is used for soft tissue deformation in character animation. The algorithm targets performance through parallelism using a fully vectorized and branch-free SVD algorithm as well as a stable one-point quadrature scheme on a hexahedral grid.

Collision-Driven Volumetric Deformation on the GPU

Eurographics 2011 Paper

G. Aldrich - D. Pinskiy - B. Hamann - 04/2011

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A novel parallel algorithm to animate the deformation of a soft body in response to collision. The algorithm incorporates elements of physically-based methods, and at the same time, it allows artistic control of general deformation behavior. The proposed solver has important benefits for practical use, such as evaluation of animation frames in an arbitrary order and effective approximation of volume preservation.

An Artist Friendly Hair Shading System

Siggraph 2010 Paper

Iman Sadeghi - Heather Pritchett - Henrik Wann Jensen - Rasmus Tamstorf - - 07/2010

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This paper introduces a novel approach for creating an art-directable hair shading model from existing physically based models. Through an informal user study we show that this system is easier to use compared to existing systems. In practice, the new approach has been integrated into our production pipeline and is being used in the production of the upcoming feature film Tangled.

Sliding Deformation: Shape Preserving Per-Vertex Displacement

Eurographics 2010 Paper

Dmitriy Pinskiy - 05/2010


We present a novel algorithm for deforming a locally smooth polygonal mesh by sliding its vertices over the surface. This sliding deformation creates the visual appearance of texture animation without requiring an explicit global surface parameterization or the overhead of storing texture coordinates.

CASE STUDY - Beauty and the Beast 3D Benefits of 3D Viewing for 2D to 3D Conversion

SPIE Electronic Imaging 2010/Stereoscopic Displays and Applications XXI Paper

Tara Handy Turner - 01/2010


While designing the stereoscopic conversion process for Beauty and the Beast 3D, the engineering team at Walt Disney Animation Studios quickly recognized the benefit of desk-side 3D viewing for 2D to 3D conversion artists. This paper outlines the technical and creative requirements of the project that supported that opinion along with the criteria established to analyze available solutions. The evolution of internal prototypes as well as 3rd party devices are then explored along with a description of the final choices made and wish-lists for future development.

Synthetic Turbulence using Artificial Boundary Layers

Siggraph Asia 2009 Paper

Tobias Pfaff - Nils Thuerey - Andrew Selle - Markus Gross - 12/2009


We build upon work from classical fluid mechanics to design an algorithm that allows us to accurately precompute the turbulence being generated around an object immersed in a flow. This is made possible by modeling turbulence formation based on an averaged flow field, and relying on universal laws describing the flow near a wall.

Detail Preserving Continuum Simulation of Straight Hair Siggraph 2009 Paper

Siggraph 2009 Paper

Aleka McAdams - Andrew Selle - Kelly Ward - Eftychios Sifakis - Joseph Teran - 08/2009


This paper presents a hybrid Eulerian/Lagrangian approach to handling both self and body collisions with hair efficiently while still maintaining detail.

Asynchronous Contact Mechanics

Siggraph 2009 and CMAME Journal Paper

David Harmon - Etienne Vouga - Brennan Smith - Rasmus Tamstorf - Eitan Grinspun - 08/2009

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We develop a method for reliable simulation of elastica in complex contact scenarios. Our focus is on firmly establishing three parameter-independent guarantees: that simulations of well-posed problems (a) have no interpenetrations, (b) obey causality, momentum and energy conservation laws, and (c) complete in finite time.

Dent Removal: Geodesic Curve-Based Mesh Fairing

Eurographics 2009 Paper

Dmitriy Pinskiy - 04/2009


This paper presents a novel mesh fairing method to remove unwanted geometric artifacts such as dents. The key element of the proposed method is our unique algorithm for the assignment of weights in the discrete Laplacian.

Implicit Contact Handling for Deformable Objects

Eurographics 2009 Paper

Miguel A. Otaduy - Rasmus Tamstorf - Denis Steinemann - Markus Gross - 04/2009


We present an algorithm for robust and efficient contact handling of deformable objects. By being aware of the internal dynamics of the colliding objects, our algorithm provides smooth rolling and sliding, stable stacking, robust impact handling, and seamless coupling of heterogeneous objects, all in a unified manner.

Robust Treatment of Simultaneous Collisions

Siggraph 2008 Paper

David Harmon - Etienne Vouga - Rasmus Tamstorf - Eitan Grinspun - 08/2008

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Robust treatment of complex collisions is a challenging problem in cloth simulation. We present a fail-safe that cancels impact but not sliding motion. This reduces artificial dissipation considerably. We equip the proposed fail-safe with an approximation of Coulomb friction, allowing finer control of sliding dissipation.

Motorcycle Graphs: Canonical Quad Mesh Partitioning

Symposium on Geometry Processing 2008 Paper

David Eppstein - Michael T. Goodrich - Ethan Kim - Rasmus Tamstorf - 08/2008


We describe algorithms for canonically partitioning semi-regular quadrilateral meshes into structured submeshes, using an adaptation of the geometric motorcycle graph of Eppstein and Erickson to quad meshes.

Raytracing Prefiltered Occlusion for Aggregate Geometry

IEEE Symposium on Interactive Raytracing 2008 Paper

Dylan Lacewell - Brent Burley - Solomon Boulos - Peter Shirley - 08/2008


We prefilter occlusion of aggregate geometry, e.g., foliage or hair, storing local occlusion as a directional opacity in each node of a bounding volume hierarchy (BVH). During intersection, we terminate rays early at BVH nodes based on ray differential, and composite the stored opacities.

Approximate Topological Matching of Quadrilateral Meshes

The Visual Computer 2009 and Shape Modeling International 2008 Paper

David Eppstein - Michael T. Goodrich - Ethan Kim - Rasmus Tamstorf - 08/2008


We study approximate topological matching of quadrilateral meshes; that is, the problem of finding as large a set as possible of matching portions of two quadrilateral meshes.

The Hybrid Theatre

Stereoscopic Displays and Applications Paper

Ron Gillen - 08/2008


Old cinema dead, Digital cinema now, hybrid theatre future.

Ptex: Per-Face Texture Mapping for Production Rendering

Eurographics Symposium on Rendering 2008 Paper

Brent Burley - Dylan Lacewell - 04/2008

PDF Supplemental Material

We propose a new texture mapping method for Catmull-Clark subdivision surfaces that requires no explicit parameterization. Our method, Ptex, stores a separate texture per quad face of the subdivision control mesh, along with a novel per-face adjacency map, in a single texture file per surface.

Fast Collision Detection for Deformable Models using Representative-Triangles

i3D 2008 Paper

Sean Curtis - Rasmus Tamstorf - Dinesh Manocha - 02/2008


We present a new approach to accelerate collision detection for deformable models. Our formulation applies to all triangulated models and significantly reduces the number of elementary tests between features of the mesh, i.e., vertices, edges and faces. We introduce the notion of Representative-Triangles, and use this representation to achieve better collision query performance.

Exact Evaluation of Catmull-Clark Subdivision Surfaces Near B-spline Boundaries

Journal of Graphics Tools 2007 Paper

Dylan Lacewell - Brent Burley - 08/2007


We extend the eigenbasis method of Jos Stam to evaluate Catmull-Clark subdivision surfaces near extraordinary vertices on B-spline boundaries.

Interactive Collision Detection between Deformable Models using Chromatic Decomposition

Siggraph 2005 Paper

Naga K. Govindaraju - David Knott - Nitin Jain - Ilknur Kabul - Rasmus Tamstorf - Russell Gayle - Ming C. Lin - Dinesh Manocha - 08/2005

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We present a novel algorithm for accurately detecting all contacts, including self-collisions, between deformable models. We precompute a chromatic decomposition of a mesh into non-adjacent primitives using graph coloring algorithms. This enables us to check for collisions between non-adjacent primitives using a linear-time culling algorithm.

Texture Mapping for Cel Animation

Siggraph 1998 Paper

Wagner Toledo Correa - Robert J. Jensen - Craig E. Thayer - Adam Finkelstein - 08/1998


We present a method for applying complex textures to hand-drawn characters in cel animation. The method correlates features in a simple, textured, 3-D model with features on a hand-drawn figure, and then distorts the model to conform to the hand-drawn artwork.

Multiperspective Panoramas for Cel Animation

Siggraph 1997 Paper

Daniel N. Wood - Adam Finkelstein - John F. Hughes - Craig E. Thayer - David H. Salesin - 08/1997


The approach is motivated by a traditional technique used in 2D cel animation, in which a single background image, which we call a multiperspective panorama, is used to incorporate multiple views of a 3D environment as seen from along a given camera path. In this paper, we explore how such backdrops can be created from 3D models and camera paths.

Painterly Rendering for Animation

Siggraph 1996 Paper

Barbara J. Meier - 08/1996


We present a technique for rendering animations in a painterly style. The difficulty in using existing still frame methods for animation is getting the paint to “stick” to surfaces rather than randomly change with each frame, while still retaining a hand-crafted look.


A Deformer-Based Approach to Facial Rigging


John Kahwaty, Gene Lee, Greg Smith, Andy Lin, Matthew Schiller - 07/2013


Facial rigging is the process of adding controls to a face for animating facial expressions. These controls are commonly bound to either deformers or blendshapes, both of which modify the face’s shape, scale, or orientation. Facial rigs created with complex deformers are intuitive, yet commonly slow and less tunable. Facial rigs created with blendshapes are fast, yet memory intensive and sensitive to model changes. This paper introduces a rapid, deformer-based approach to facial rigging using only skin clusters, (in-house) wire deformers, and pose space deformation (PSD)

Pixels to Parks: New Animation Techniques for Fantasyland


Gene Lee, Aaron Adams, Evan Goldberg, Justin Walker - 07/2013


We present the innovative techniques that brought to life an audio-animatronic Lumiere for Disney World’s newest attraction- -Enchanted Tales With Belle. Walt Disney Imagineering and Walt Disney Animation Studios collaborated to create a pipeline that was flexible and intuitive for feature film animators. First, motion was digitally choreographed on the computer with a virtual rig. Next, the software detected constraints and motion limitations that would exist on the physical audio-animatronic. This allowed the artist to resolve them and animate physically plausible motions. Finally, the performance was transferred to the audio-animatronic, faithfully recreating the artist-produced motion using motors and machinery.

Enhanced Dual Quaternion Skinning for Production Use


Gene Lee, Andy Lin, Matt Schiller, Scott Peters, Mark McLaughlin, Frank Hanner - 07/2013


Dual Quaternion Skinning (DQS) is an advanced rigging technique that binds a mesh to skeletal joints. Unlike the popular alternative, Linear Blend Skinning (LBS), DQS avoids the undesirable “candy-wrapper effect” and effectively simulates volume preservation. DQS is a powerful technique, but to get desirable results, it must be extended to meet the needs of production environments, and is therefore not a simple drop-in replacement for LBS. This paper presents an extension to DQS that successfully met the rigging requirements of Disney’s feature Frozen. In particular, DQS is configured with LBS to handle non-rigid transformations, hierarchies of differing joints, and arbitrary support joints.

Physically-Based Shading at Disney

Part of SIGGRAPH 2012 Course: Practical Physically Based Shading in Film and Game Production

Brent Burley - 08/2012


In these course notes we describe the development of a new BRDF model used on Wreck-It Ralph and subsequent productions at Walt Disney Animation Studios. We begin with observations from studying measured materials along with insights we've gleaned about which models fit the measured data and where they fall short. We then present our new model, describe our experience of adopting this new model in production, and discuss how we were able to add the right level of artistic control while preserving simplicity and robustness.

dRig: An Artist-Friendly, Object-Oriented Approach to Rig Building

Siggraph 2012 Talk

Greg Smith - Mark McLaughlin - Andy Lin - Evan Goldberg - Frank Hanner - 08/2012


We present dRig, Disney Animation's novel approach to rigging that allows for efficient reuse and extension of assets, fast authoring of per-element variations, and accessibility of rig code through a proprietary language and user interface.

Directing Hair Motion on Tangled

Siggraph 2011 Talk

Maryann Simmons - Kelly Ward - Hidetaka Yosumi - Hubert Leo - Xinmin Zhao - 08/2011


We describe a hybrid approach leveraging the power of custom hair dynamics with the artistic control of key-framed animation that was key to the success of directing hair motion on Tangled.

Gaussian Quadrature for Photon Beams in Tangled

Siggraph 2011 Talk

Jared M. Johnson - Dylan Lacewell - Andrew Selle - Wojciech Jarosz - 08/2011


We implemented the recent Photon Beams algorithm in Photorealistic RenderMan to efficiently render artistically-directed volumetric lighting effects for the feature-length animated movie Tangled. With the knowledge that most fall-off functions defined by our artists would be polynomial-smooth, we use Gaussian Quadrature to accurately and efficiently estimate the lighting contribution of these camera-containing beams.

Tangled Choreographing Destruction: Art Directing a Dam Break

Siggraph 2011 Talk

Brett Boggs - Lawrence Chai - Michael Kaschalk - Andrew Selle - 08/2011


Much like the character animation in Tangled, the goal of the dam break sequence was to bring classic Disney 2D sensibilities to CG effects. Hand-drawn effects animation in films such as Pinocchio and Fantasia served as inspiration. The water shapes drawn in these films were very stylized yet conveyed recognizable forms of nature. The concept was to emulate these shapes and then enhance them with the modern benefits of CG rendering such as ray traced reflections and ambient occlusion.

Automated Target Selection for DrivenShape

Siggraph Asia 2010 Talk

Gene S. Lee - 12/2010


This paper presents an automated means to select targets for DrivenShape. These targets enable DrivenShape to produce the lowest error in common contexts.

A Hybrid Approach to Facial Rigging

Siggraph Asia 2010 Talk

David Komorowski - Vinod Melapudi - Darren Mortillaro - Gene S. Lee - 12/2010


This paper presents a hybrid approach to facial rigging that uses Pose Space Deformation (PSD) to seamlessly combine both geometric deformations and blendshapes.

Point-based Hair Global Illumination

Siggraph Asia 2010 Talk

Ramón Montoya-Vozmediano - 12/2010


A point based representation was extensively used on "Tangled" to generate occlusion and indirect illumination involving the characters' hair.

Example-based Texture Synthesis on Disney’s Tangled

Siggraph 2010 Talk

Christian Eisenacher - Chuck Tappan - Brent Burley - Daniel Teece - Arthur Shek - 07/2010


Look development on Walt Disney's Tangled called for artists to paint hundreds of organic elements with high resolution textures on a tight schedule. We found that example-based texture synthesis, where an artist paints a small exemplar texture, indicating the desired pattern that the system synthesizes over arbitrary surfaces, would alleviate some of the burden. In this talk we describe how we adapted existing synthesis methods to our Ptex-based workflow, scaled them to production sized methods and expose it to artists using a one click interface.

Art-directing Disney’s Tangled Procedural Trees

Siggraph 2010 Talk

Arthur Shek - Dylan Lacewell - Andrew Selle - Daniel Teece - Tom Thompson - 07/2010


We designed a system of authoring trees based around a language of hierarchical curves. Our system lets artists interactively sketch out a base skeleton representation of a tree and grow procedural twigs and leaves out to a canopy shell by tweaking a limited number of parameters.

Simulating Rapunzel’s Hair in Disney’s Tangled

Siggraph 2010 Talk

Kelly Ward - Maryann Simmons - Andy Milne - Hidetaka Yosumi - Xinmin Zhao - 07/2010


We present several key techniques used for simulating Rapunzel's 70 feet of hair for the animated feature “Tangled”; these techniques range from methods to improve the run-time efficiency of the simulations to achieving the desired art direction of the hair.

Set’m and Forget’m: A Motion Graphics Pipeline for Effects

Siggraph 2010 Talk

Ian J. Coony - Brian Silva - Bruce Wright - Andrew Kinney - 07/2010


For the creation of brilliant light displays, flickering control tower buttons and vibrant computer monitors, the Effects Department goal was to build a motion graphics pipeline capable of running nearly unattended - all while maintaining the flexibility of downstream artist input, should problems arise.

Christmas in July: The Effects Snow Process

Siggraph 2010 Talk

Ian J. Coony - David Hutchins - Kevin Lee - Mike Harris - Tim Molinder - Kee Suong - 07/2010


Prep and Landing had multiple snow variants in a large number of shots - ranging from gentle falling snow outside windows, to near blizzard-like conditions. Snowfall was necessary to help the world the characters inhabited feel believable. Managing the workflow and complexity involved in creating snow variety was the challenge.

Evaluation of the Radial Basis Function Space

Siggraph Asia 2009 Talk

Gene S. Lee - 12/2009


We suggest a method for artists to better understand RBF behavior through visualization and to evaluate RBF functions according to the requirements of a production environment.

Practical Experiences with Pose Space Deformation

Siggraph Asia 2009 Talk

Gene S. Lee - Frank Hanner - 12/2009

Pose Space Deformation (PSD) [Lewis2000] is a shape interpolation technique for animation. This paper presents some practical experience with PSD acquired while creating the film "BOLT."

Geometric Fracture Modeling in BOLT

Siggraph 2009 Talk

Jeffrey Hellrung - Andrew Selle - Arthur Shek - Eftychios Sifakis - Joseph Teran - 08/2009


We designed a system to facilitate the modeling of cracked and shattered objects, enabling the automatic generation of a large number of fragments while retaining the flexibility to artistically control the density and complexity of the crack formation.

Medial Axis Techniques for Stereoscopic Extraction

Siggraph 2009 Talk

Evan Goldberg - 08/2009


To perform the stereoscopic conversion of Disney’s Beauty and the Beast, we developed novel extensions to standard medial axis techniques.

Applying Painterly Concepts in a CG Film - BOLT

Siggraph 2009 Talk

Adolph Lusinsky - Paul Felix - Ernie Petti - Sean Jenkins - Adrienne Othon - Patrick Dalton - Hank Driskill - John Murrah - 08/2009


We focused on fundamental ideas such as massing, a term in painting which refers to the process of editing detail into bigger shapes, and also edge quality, the use of the painter's brush to vary edges of shapes which can bring emphasis to the image and/or direct the eye. This led to the development of new algorithms and tools for the film "Bolt".

Rhino-Palooza: Procedural Animation and Mesh Smoothing

Siggraph 2009 Talk

Evan Goldberg - Dmitriy Pinskiy - 08/2009


In Disney’s Bolt, the character of Rhino poses many technical challenges. He spends a majority of the movie inside a plastic ball, frequently contacts the ground surface, and presents a complicated skinning problem. Innovative tools and technology were developed to solve these issues for the production.

Realistic Eye Motion Using Procedural Geometric Methods

Siggraph 2009 Talk

Dmitriy Pinskiy - Erick Miller - 08/2009


Using an anatomically motivated approach, our method to produce realistic convincing deformations of the skin and flesh surrounding the eye is unique, not only due to the novel approaches employed, but also because our method is entirely procedural.

Interactive Lighting of Effects Using Point Clouds in "Bolt"

Siggraph 2009 Talk

Dale Mayeda - 08/2009

PDF Video

We explore the use of point cloud data to provide interactive lighting effects for an environment.

iBind: Smooth Indirect Binding using Segmented Thin-Layers

Siggraph 2009 Talk

Chung-An Lin - Erick Miller - Gene S. Lee - 08/2009


iBind smoothly deforms vertices using a control cage by uniquely leveraging heat diffusion on closed, thin layers across a structured set of mean value coordinates. Dynamic rebinding is still useful, so iBind implements it, but for most cases of character articulation, a static binding option is used.

Composite Based Refraction for Fur and Other Complex Objects

Siggraph 2009 Talk

Lewis Siegel - Sean Jenkins - 08/2009


Rendering hair and simulating refraction, when performed separately, are both time and memory intensive. To overcome these problems, a process was developed for "Bolt" which involved exporting 3D data from the render stage so that the calculation of the refraction could be delayed until the composite stage.