Julie Dorsey

• PhD
• Professor (Full) at Yale University

Procedural modeling is now the de facto standard of material modeling in industry. Procedural models can be edited and are easily extended, unlike pixel-based representations of captured materials. In this article, we present a semi-automatic pipeline for general material proceduralization. Given Spatially Varying Bidirectional Reflectance Distribu...

Procedural modeling is now the de facto standard of material modeling in industry. Procedural models can be edited and are easily extended, unlike pixel-based representations of captured materials. In this paper, we present a semi-automatic pipeline for general material proceduralization. Given Spatially-Varying Bidirectional Reflectance Distributi...

Non-photorealistic rendering (NPR) and image processing algorithms are widely assumed as a proxy for drawing. However, this assumption is not well assessed due to the difficulty in collecting and registering freehand drawings. Alternatively, tracings are easier to collect and register, but there is no quantitative evaluation of tracing as a proxy f...

Relating small-scale structures to large-scale appearance is a key element in material appearance design. Bi-scale material design requires finding small-scale structures that produce a desired large-scale appearance expressed as a macro-scale BRDF. The adjustment of small-scale geometry and reflectances to achieve a desired appearance can become a...

Procedural textures are powerful tools that have been used in graphics for decades. In contrast to the alternative exemplar-based texture synthesis techniques, procedural textures provide user control and fast texture generation with low-storage cost and unlimited texture resolution. However, creating procedural models for complex textures requires...

Time-based media are used in applications ranging from demonstrating the operation of home appliances to explaining new scientific discoveries. However, creating effective time-based media is challenging. We introduce a new framework for authoring and consuming time-based media. An author encodes an animation in a printed code and affixes the code...

Time-based media (videos, synthetic animations, and virtual reality experiences) are used for communication, in applications such as manufacturers explaining the operation of a new appliance to consumers and scientists illustrating the basis of a new conclusion. However, authoring time-based media that are effective and personalized for the viewer...

We introduce the problem of computing a human-perceived softness measure for virtual 3D objects. As the virtual objects do not exist in the real world, we do not directly consider their physical properties but instead compute the human-perceived softness of the geometric shapes. In an initial experiment, we find that humans are highly consistent in...

Studies on virtual textile have long been an appealing topic in computer graphics and most of the efforts were paid to their distinctive appearances or physically-based simulation. However, stain as one of the most commonly seen phenomena has received little attention so far. This paper introduces techniques for simulating the stain effect on fabri...

A 3D modeling system with all-inclusive functionality is too demanding for a casual 3D modeler to learn. There has been a shift towards more approachable systems, with easy-to-learn, intuitive interfaces. However, most modeling systems still employ mouse and keyboard interfaces, despite the ubiquity of tablet devices and the benefits of multi-touch...

Material design is the process by which artists or designers set the appearance properties of virtual surface to achieve a desiredlook. This process is often conducted in a virtual synthetic environment however, advances in computer vision tracking andinteractive rendering now makes it possible to design materials in augmented reality (AR), rather...

We introduce the problem of computing a human-perceived softness measure for virtual 3D objects. As the virtual objects do not exist in the real world, we do not directly consider their physical properties but instead compute the human-perceived softness of the geometric shapes. We collect crowdsourced data where humans rank their perception of the...

While the concept of visual saliency has been previously explored in the areas of mesh and image processing, saliency detection also applies to other sensory stimuli. In this paper, we explore the problem of tactile mesh saliency, where we define salient points on a virtual mesh as those that a human is more likely to grasp, press, or touch if the...

Texture synthesis is a well-established area, with many important applications in computer graphics and vision. However, despite their success, synthesis techniques are not used widely in practice because the creation of good exemplars remains challenging and extremely tedious. In this paper, we introduce an unsupervised method for analyzing textur...

In early or preparatory design stages, an architect or designer sketches out rough ideas, not only about the object or structure being considered, but its relation to its spatial context. This is an iterative process, where the sketches are not only the primary means for testing and refining ideas, but also for communicating among a design team and...

A system, method and a computer-readable medium for creating texture exemplars from images are provided. The texture exemplars are created by receiving an image containing a plurality of pixels representing a plurality of textures, wherein each texture in the plurality of textures is configured to be selectable by a user, determining a desired text...

This paper examines the following question: given a collection of man-made shapes, e.g., chairs, can we effectively explore and rank the shapes with respect to a given human body - in terms of how well a candidate shape fits the specified human body? Answering this question requires identifying which shapes are more suitable for a prescribed body,...

a) Modeling mode (b) Assembly mode (c) 3D model output Multi-touch gestures 3D components Figure 1. An overview of our novel 3D modeling technique, designed for a multi-touch interface to create 3D models on a tablet device. (a) Users fold 2D sheets of paper in the modeling mode, using gesture-based modeling tools such as folding, bending, extendin...

The BTF data structure was a breakthrough for appearance modeling in computer graphics. More research is needed though to make BTFs practical in rendering applications. We present the first systematic study of the effects of Approximate filtering on the appearance of BTFs, by exploring the spatial, angular and temporal domains over a varied set of...

The paper addresses the following problem: given a set of man-made shapes, e.g., chairs, can we quickly rank and explore the set of shapes with respect to a given avatar pose? Answering this question requires identifying which shapes are more suitable for the defined avatar and pose; and moreover, to provide fast preview of how to alter the input g...

Memory colors refer to those colors recalled in association with familiar objects. While some previous work introduces this concept to assist digital image enhancement, their basis, i.e., on-screen memory colors, are not appropriately investigated. In addition, the resulting adjustment methods developed are not evaluated from a perceptual view of p...

Texture is an essential feature in modeling the appearance of objects and is instrumental in making virtual objects appear interesting and/or realistic. Unfortunately, obtaining textures is a labor intensive task requiring parameter tuning for procedural methods or careful photography and post-processing for natural images. Many texture synthesis t...

One major shortcoming of existing bi-scale material design systems is the lack of support for inverse design: there is no way to directly edit the large-scale appearance and then rapidly solve for the small-scale details that approximate that look. Prior work is either too slow to provide quick feedback, or limited in the types of small-scale detai...

Directors employ a process called “color grading” to add color styles to feature films. Color grading is used for a number of reasons, such as accentuating a certain emotion or expressing the signature look of a director. We collect a database of feature film clips and label them with tags such as director, emotion, and genre. We then learn a model...

Memory colors refer to those colors recalled in association with familiar objects [Hering 1961]. The deficiency with existing research in this area is that a) screen memory colors have not been rigorously established and b) existing studies do not include extensive human judgements when evaluating image edits based on memory colors. We first perfor...

Sophisticated methods for true spectral rendering have been developed in computer graphics to produce highly accurate images. In addition to traditional applications in visualizing appearance, such methods have potential applications in many areas of scientific study. In particular, we are motivated by the application of studying avian vision and a...

Compositing is one of the most commonly performed operations in computer graphics. A realistic composite requires adjusting the appearance of the foreground and background so that they appear compatible; unfortunately, this task is challenging and poorly understood. We use statistical and visual perception experiments to study the realism of image...

Architecture is design in spatial context. The only current methods for representing context involve designing in a heavyweight computer-aided design system, using a full model of existing buildings and landscape, or sketching on a panoramic photo. The former is too cumbersome; the latter is too restrictive in viewpoint and in the handling of occlu...

We present the first physically-based interactive system to facilitate the appearance design at different scales consistently, through manipulations of both small-scale geometry and materials. The core of our system is a novel reflectance filtering algorithm, which rapidly computes the large-scale appearance from small-scale details, by exploiting...

Architecture is design in spatial context. The only current methods for representing context involve designing in a heavyweight computer-aided design system, using a full model of existing buildings and landscape, or sketching on a panoramic photo. The former is too cumbersome; the latter is too restrictive in viewpoint and in the handling of occlu...

We present the first physically-based interactive system to facilitate the appearance design at different scales consistently, through manipulations of both small-scale geometry and materials. The core of our system is a novel reflectance filtering algorithm, which rapidly computes the large-scale appearance from small-scale details, by exploiting...

Architecture is design in spatial context. The only current methods for representing context involve designing in a heavyweight computer-aided design system, using a full model of existing buildings and landscape, or sketching on a panoramic photo. The former is too cumbersome; the latter is too restrictive in viewpoint and in the handling of occlu...

Digital libraries have now become by far the preferred method for storing large image collections, making it increasingly important to improve issues of search and discovery within these databases. Content-based annotations of images, for classification purposes, have been a particularly significant area of research; however, even the best of such...

The appearance of weathering effects on stone is important for creating outdoor scenes in computer graphics. To achieve them, previous research has built upon physical simulation, which, while yielding a degree of realism, is computationally expensive and inapplicable to the situation when the object geometry is unknown. Also, physical simulation r...

The simulation of weathered appearance is essential in the realistic modeling of urban environments. A representative and particularly difficult effect to produce on a large scale is the effect of fluid flow. Changes in appearance due to flow are the result of both the global effect of large-scale shape, and local effects, such as the detailed roug...

Abstract Bidirectional texture functions (BTFs) represent the appearance of complex materials. Three major shortcomings with BTFs are the bulky storage, the difficulty in editing and the lack of efficient rendering methods. To reduce storage, many compression techniques have been applied to BTFs, but the results are difficult to edit. To facilitate...

We introduce a tool for organizing images and drawings of archaeological sites. The tool is based on a 3D sketching system developed for conceptual architectural design. The sketching system for design allows a user to represent structures as strokes located on 2D canvases situated in 3D space. The design of a consistent 3D structure evolves as the...

Abstract Papercraft models can serve as inexpensive prototypes in shape design applications. However, in making the models some geometric detail is necessarily lost, and artificial creases may be visible, thereby limiting the utility of these models. To compensate for these practical limitations, we introduce the use of printed patterns on papercra...

Extremely dense spatial sampling is often needed to prevent aliasing when rendering objects with high frequency variations in geometry and reflectance. To accelerate the rendering process, we introduce characteristic point maps (CPMs), a hierarchy of view-independent points, which are chosen to preserve the appearance of the original model across d...

Texture synthesis techniques require nearly uniform texture samples, ho wever identifying suitable texture samples in an image requires significant data preprocessing. To eliminate this work , we introduce a fully automatic pipeline to detect dominant texture samples based on a manifold generated using the diffusion distance. We define the characte...

Images of everyday scenes are frequently used as input for texturing 3D models in computer graphics. Such images include both the texture desired and other extraneous information. In our previous work [Lu et al. 2009], we defined dominant texture as a large homogeneous region in an input sample image and proposed an automatic method to detect domin...

While many materials can be defined as simple combinations of the general material models, other materials require specific models of small-scale geometric structure and multiple spatially varying layers. This chapter provides a guide to these specific models, which have been published in diverse, more specialized, conference documents and journals...

This chapter presents how material models are integrated into complete systems for generating images. Different representations of models are used for different rendering approaches. Different models can be appropriate for offline and real-time systems. The process of creating images with realistic appearance necessarily involves taking into accoun...

Materials have a temporal, as well as a spatial, dimension. Material appearance depends on the history of usage and environment and the basic chemical components and surface finish. Materials may be purposefully treated to achieve particular end results or may change as the result of natural aging or weathering. This chapter presents methods that e...

Whichever model is used for materials, one needs some means to determine the parameters for it. In a design setting, parameters may be selected to achieve a particular effect. In many other cases, a model of a particular existing material that matches suitable benchmarks is needed. This chapter discusses the different techniques available for obtai...

This chapter emphasizes, in a technical framework, the way appearance is affected by how light rays reach the eye from a source to develop a computer model. Modeling materials begins with observation. One needs to observe what makes each material in the real world look different from other materials. The observation skills needed are similar to tho...

This chapter reviews the various approaches to specification and discusses how material properties can be represented in the computer for efficient processing and rendering. The most common approaches to the specification of complex appearance characteristics relies on interactive tools and visual inspection by users, while others use the power of...

This chapter defines the basic terms, concepts, and notations used in describing light and materials. One needs physically based models with parameters with physical meaning so that measuring materials, adjusting, and reusing them in scenes produce effects consistent with what one observes in the real world. To make physically based numerical defin...

This chapter introduces some basic principles from other disciplines used as a starting point for modeling. Modeling the appearance of an object's material gives the capability to simulate what an object would look like. How the object will look depends on both physical and psychological phenomena. In generating images from digital models, the disp...

This chapter presents the basic models for how materials scatter light. One approach for representation of material models is to store values of the reflectance for densely sampled values of position, wavelength, and direction. A table of such densely sampled models would require an enormous amount of storage for even simple objects. In addition to...

The level of accuracy required for physical models of materials and their interaction with light in virtual city models is an open question. We consider work that has been done to date on mod-eling architectural materials, the measurement of such materials in situ, and modeling of natural materials found in urban environments (e.g. snow, ice, and m...

For many years, appearance models in computer graphics focused on general models for reflectance functions coupled with texture maps. Recently, it has been recognized that even very common materials such as hair, skin, fabric, and rusting metal require more sophisticated models to appear realistic. This course begins with a brief review of basic re...

In this article, we introduce sketching reality , the process of converting a freehand sketch into a realistic-looking model. We apply this concept to architectural designs. As the sketch is being drawn, our system periodically interprets its 2.5D-geometry by identifying new junctions, edges, and faces, and then analyzing the extracted topology. Th...

In this paper, we introduce \sketching reality," the process of converting a free-hand sketch to a realistic-looking model. We apply this concept to architectural designs. As the sketch is being drawn, our system periodically interprets its 2.5D geometry by identifying new junctions, edges, and faces, and then analyzing the extracted topology. The...

In modern computer graphics applications, textures play an important role in conveying the appearance of real-world materials. But while surface appearance can often be effectively captured with a photograph, it is difficult to use example imagery to synthesize fully three-dimensional (3D) solid textures that are perceptually similar to their input...

Computer graphics systems are capable of generating stunningly realistic images of objects that have never physically existed. In order for computers to create these accurately detailed images, digital models of appearance must include robust data to give viewers a credible visual impression of the depicted materials. In particular, digital models...

Computer graphics systems are capable of generating stunningly realistic images of objects that have never physically existed. In order for computers to create these accurately detailed images, digital models of appearance must include robust data to give viewers a credible visual impression of the depicted materials. In particular, digital models...

We describe a computer graphics system that supports conceptual architectural design and analysis. We use as a starting point the traditional sketchbook drawings that architects use to experiment with various views, sections, and details. Rather than interpret or infer 3D structure from drawings, our system is designed to allow the designer to orga...

Interesting textures form on the surfaces of objects as the result of external chemical, mechanical, and biological agents. Simulating these textures is necessary to generate models for realistic image synthesis. The textures formed are progressively variant, with the variations depending on the global and local geometric context. We present a meth...

We present new techniques for capturing the shape of physical objects using simple tools. From a set of caliper distance measurements between object points, we reconstruct a three dimensional structure. We show that we can refine the model using planar contours obtained with a gage that are placed in three dimensions using the caliper measurements....

We present an image-based modeling and editing system that takes a single photo as input. We represent a scene as a layered collection of depth images, where each pixel encodes both color and depth. Starting from an input image, we employ a suite of user-assisted techniques, based on a painting metaphor, to assign depths and extract layers. We intr...

We describe a computer graphics system that supports conceptual architectural design and analysis. We use as a starting point the traditional sketchbook drawings that architects use to experiment with various views, sections, and details. Rather than interpret or infer 3D structure from drawings, our system is designed to allow the designer to orga...

We describe a discrete model for the dynamics of thin flexible structures, such as hats, leaves, and aluminum cans, which are characterized by a curved undeformed configuration. Previously such thin shell models required complex continuum mechanics formulations ...

We consider the problem of creating integrated texture maps of large structures scanned with a time-of-flight laser scanner and imaged with a digital camera. The key issue in creating integrated textures is correcting for the spatially varying illumination across the structure. In most cases, the illumination cannot be controlled, and dense spatial...

We introduce a new method for filling holes in geometry obtained from 3D range scanners. Our method makes use of 2D images of the areas where geometric data is missing. The 2D images guide the filling using the relationship between the images and geometry learned from the existing 3D scanned data. Our method builds on existing techniques for using...

This paper presents a framework for the real-time rendering of plant leaves with global illumination effects. Realistic rendering of leaves requires a sophisticated appearance model and accurate lighting computation. For leaf appearance we introduce a parametric model that describes leaves in terms of spatially-variant BRDFs and BTDFs. These BRDFs...

We consider the problem of the spatio-temporal variations in material appearance due to the wetting and drying of materials. We conducted a series of experiments that capture the appearance history of surfaces drying. We reduce this history to two parameters that control the shape of a drying curve. We relate these drying parameters to the shape of...

Figure 1. Sample images of a time sequence with synthesized time-varying textures for cracking paint and growing grass.

An abstract is not available.

Essentially all computer graphics rendering assumes that the reflectance and texture of surfaces is a static phe- nomenon. Yet, there is an abundance of materials in nature whose appearance varies dramatically with time, such as cracking paint, growing grass, or ripening banana skins. In this paper, we take a significant step towards ad- dressing t...

We describe the use of traditional stereological methods to synthesize 3D solid textures from 2D images of existing materials. We first illustrate our approach for aggregate materials of spherical particles, and then extend the technique to apply to particles of arbitrary shapes. We demonstrate the effectiveness of the approach with side-by-side co...

Most 3D mesh generation techniques require simplification and mesh improvement stages to prepare a tetrahedral model for efficient simulation. We have developed an algorithm that both reduces the number of tetrahedra in the model to permit interactive manipulation and removes the most poorly shaped tetrahedra to allow for stable physical simulation...

Most 3D mesh generation techniques require simplification and mesh improvement stages to prepare a tetrahedral model for efficient simulation. We have developed an algorithm that both reduces the number of tetrahedra in the model to permit interactive manipulation and removes the most poorly shaped tetrahedra to allow for stable physical simulation...

This thesis investigates the creation, representation, and manipulation of volumetric geometry suitable for computer graphics applications. In order to capture and reproduce the appearance and behavior of many objects, it is necessary to model the internal structures and materials, and how they change over time. However, producing real-world effect...

We introduce billboard clouds -- a new approach for extreme simplification in the context of real-time rendering. 3D models are simplified onto a set of planes with texture and transparency maps. We present an optimization approach to build a billboard cloud given a geometric error threshold. After computing an appropriate density function in plane...

The linear strain measures that are commonly used in real-time animations of deformable objects yield fast and stable simulations. However, they are not suitable for large deformations. Recently, more realistic results have been achieved in computer graphics by using Green's non-linear strain tensor, but the non-linearity makes the simulation more...

Classical ray-tracing algorithms compute radiance returning to the eye along one or more sample rays through each pixel of an image. The output of a ray-tracing algorithm, although potentially photorealistic, is a two-dimensional quantity — an image array of radiance values — and is not directly useful from any viewpoint other than the one for whic...

Existing techniques for real-time simulation of object deformation are well suited for animating soft materials like human tissue or two-dimensional systems such as cloth. However, simulation of deformation in malleable materials and fracture in brittle materials has only been done offline because the underlying equations of motion are numerically...

Freehand sketching has long had appeal as an artistic medium for conceptual design because of its immediacy in capturing and communicating design intent and visual experience. We present a sketching paradigm that supports the early stages of design by preserving the fluidity of traditional freehand drawings. In addition, it attempts to fill the gap...

We present a procedural approach to authoring layered, solid models. Using a simple scripting language, we define the internal structure of a volume from one or more input meshes. Sculpting and simulation operators are applied within the context of the language to shape and modify the model. Our framework treats simulation as a modeling operator ra...

We present a new technique for the display of high-dynamic-range images, which reduces the contrast while preserving detail. It is based on a two-scale decomposition of the image into a base layer, encoding large-scale variations, and a detail layer. Only the base layer has its contrast reduced, thereby preserving detail. The base layer is obtained...

We present a new technique for the display of high-dynamic-range images, which reduces the contrast while preserving detail. It is based on a two-scale decomposition of the image into a base layer, encoding large-scale variations, and a detail layer. Only the base layer has its contrast reduced, thereby preserving detail. The base layer is obtained...

This paper presents an efficient data structure that facilitates high-speed haptic (force feedback) interaction with detailed digital models. Models are partitioned into coarse slabs, which collectively define a piecewise continuous vector field over a thick volumetric region surrounding the surface of the model. Within each slab, the surface is re...

We describe a system for interactively acquiring depth for an image-based representation consisting of a single input image. We use layers of images with depth to represent the scene. Unlike traditional 3D modeling and rendering systems that require precise information that are usually difficult to model and manipulate, our system's emphasis is on...

Computer generated models are often conspicuously clean and lack the rich detail of the real world. Biological growth on a real object provides a compelling reminder that the object exists in a complex and dynamic environment. Of these biological agents, lichen flora form some of the most beautiful and intricate patterns, often completely covering...

The linear strain measures that are commonly used in real-time animations of deformable objects yield fast and stable simulations. However, they are not suitable for large deformations. Recently, more realistic results have been achieved in computer graphics by using Green’s non-linear strain tensor, but the non-linearity makes the simulation more...

Cellular patterns are all around us, in masonry, tiling, shingles, and many other materials. Such patterns, especially in architectural settings, are influenced by geometric features of the underlying shape. Bricks turn corners, stones frame windows and doorways, and patterns on disconnected portions of a building align to achieve a particular aest...

Our computer modeling technique reproduces a tree's 3D volume and skeleton from instrumented photographs. The technique involves first constructing the skeleton (trunk and the major branches) of the tree, and then applying an L-system starting from this skeleton. L-systems are one of the better known procedural models in the graphics community, esp...

We present a novel drawing system for composing and rendering perspective scenes. Our approach uses a projective 2D representation for primitives rather than a conventional 3D description. This allows drawings to be composed with the same ease as traditional illustrations, while providing many of the advantages of a 3D model. We describe a range of...

Ray tracing, which computes radiance, is traditionally regarded as an off-line rendering algorithm that is too slow for interactive use. In this paper, we present an interactive system that uses 4D interpolants to approximate radiance, while providing guaranteed error bounds. Our system exploits the object-space, ray-space, image-space and temporal...

We present a new framework for rendering virtual environments. This framework is proposed as a complete scene description, which embodies the space of all possible renderings, under all possible lighting scenarios of the given scene. In effect, this hypothetical rendering space includes all possible light sources as part of the geometric model. Whi...

We present a method for the efficient re-rendering of a scene under a directional illuminant at an arbitrary orientation. We take advantage of the linearity of the rendering operator with respect to illumination for a fixed scene and camera geometry. Re-rendering is accomplished via linear combination of a set of pre-rendered "basis" images. The th...

In this article, we present an approach for employing a particular procedural modeling technique, L-systems, to produce a tree resembling one occurring in a set of input photographs. Our approach involves reconstructing the 3D volume occupied by the tree, constructing a plausible skeleton of the tree - its trunk and major branches - for this volume...

This paper presents a physically-based model of the night sky for realistic image synthesis. We model both the direct appearance of the night sky and the illumination coming from the Moon, the stars, the zodiacal light, and the atmosphere. To accurately predict the appearance of night scenes we use physically-based astronomical data, both for posit...

. We present an interactive system, which allows the user to produce drawings in a variety of traditional styles. It takes as input an image and performs semi-automatic tonal modeling. Our system shifts tedious technical aspects to the computer side, while providing the user with freedom on the creative and aesthetic side. The user has low-level co...

Existing techniques for real-time simulation of object deformation are well suited for animating soft materials like human tissue or two-dimensional systems such as cloth. However. simulation of deformation in malleable materials and fracture in brittle materials has only been done offline because the underlying equations of motion are numerically...