Showing papers in "ACM Transactions on Graphics in 2002"
TL;DR: A new technique for the display of high-dynamic-range images, which reduces the contrast while preserving detail, is presented, based on a two-scale decomposition of the image into a base layer.
Abstract: 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,...
1,715 citations
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TL;DR: The dissimilarities between sampled distributions of simple shape functions provide a robust method for discriminating between classes of objects in a moderately sized database, despite the presence of arbitrary translations, rotations, scales, mirrors, tessellations, simplifications, and model degeneracies.
Abstract: Measuring the similarity between 3D shapes is a fundamental problem, with applications in computer graphics, computer vision, molecular biology, and a variety of other fields. A challenging aspect of this problem is to find a suitable shape signature that can be constructed and compared quickly, while still discriminating between similar and dissimilar shapes.In this paper, we propose and analyze a method for computing shape signatures for arbitrary (possibly degenerate) 3D polygonal models. The key idea is to represent the signature of an object as a shape distribution sampled from a shape function measuring global geometric properties of an object. The primary motivation for this approach is to reduce the shape matching problem to the comparison of probability distributions, which is simpler than traditional shape matching methods that require pose registration, feature correspondence, or model fitting.We find that the dissimilarities between sampled distributions of simple shape functions (e.g., the distance between two random points on a surface) provide a robust method for discriminating between classes of objects (e.g., cars versus airplanes) in a moderately sized database, despite the presence of arbitrary translations, rotations, scales, mirrors, tessellations, simplifications, and model degeneracies. They can be evaluated quickly, and thus the proposed method could be applied as a pre-classifier in a complete shape-based retrieval or analysis system concerned with finding similar whole objects. The paper describes our early experiences using shape distributions for object classification and for interactive web-based retrieval of 3D models.
1,707 citations
TL;DR: In this article, the tone reproduction problem is also considered, which maps the potentially high dynamic range of real world luminances to the low dynamic ranges of the photographic print, which is a classic photographic task.
Abstract: A classic photographic task is the mapping of the potentially high dynamic range of real world luminances to the low dynamic range of the photographic print. This tone reproduction problem is also ...
637 citations
TL;DR: A new method for rendering high dynamic range images on conventional displays that is conceptually simple, computationally efficient, robust, and easy to use is presented.
Abstract: We present a new method for rendering high dynamic range images on conventional displays. Our method is conceptually simple, computationally efficient, robust, and easy to use. We manipulate the gr...
557 citations
TL;DR: A new "strip" treemap algorithm is introduced which addresses shortcomings of previous algorithms, and is shown to be more stable, while maintaining relatively favorable aspect ratios of the constituent rectangles.
Abstract: Treemaps, a space-filling method for visualizing large hierarchical data sets, are receiving increasing attention. Several algorithms have been previously proposed to create more useful displays by controlling the aspect ratios of the rectangles that make up a treemap. While these algorithms do improve visibility of small items in a single layout, they introduce instability over time in the display of dynamically changing data, fail to preserve order of the underlying data, and create layouts that are difficult to visually search. In addition, continuous treemap algorithms are not suitable for displaying fixed-sized objects within them, such as images.This paper introduces a new "strip" treemap algorithm which addresses these shortcomings, and analyzes other "pivot" algorithms we recently developed showing the trade-offs between them. These ordered treemap algorithms ensure that items near each other in the given order will be near each other in the treemap layout. Using experimental evidence from Monte Carlo trials and from actual stock market data, we show that, compared to other layout algorithms, ordered treemaps are more stable, while maintaining relatively favorable aspect ratios of the constituent rectangles. A user study with 20 participants clarifies the human performance benefits of the new algorithms. Finally, we present quantum treemap algorithms, which modify the layout of the continuous treemap algorithms to generate rectangles that are integral multiples of an input object size. The quantum treemap algorithm has been applied to PhotoMesa, an application that supports browsing of large numbers of images.
516 citations
TL;DR: A Texture Atlas is an efficient color representation for 3D Paint Systems that decomposes into charts homeomorphic to discs, each chart is parameterized, and the unfolded charts are mapped to a model to be textured.
Abstract: A Texture Atlas is an efficient color representation for 3D Paint Systems. The model to be textured is decomposed into charts homeomorphic to discs, each chart is parameterized, and the unfolded ch...
449 citations
TL;DR: This work introduces new techniques for modelling with interpolating implicit surfaces that allow the direct specification of both the location of points on the surface and the surface normals, and yields a simple method for converting a polygonal model to a smooth implicit model, as well as a new way to form blends between objects.
Abstract: We introduce new techniques for modelling with interpolating implicit surfaces. This form of implicit surface was first used for problems of surface reconstruction and shape transformation, but the emphasis of our work is on model creation. These implicit surfaces are described by specifying locations in 3D through which the surface should pass, and also identifying locations that are interior or exterior to the surface. A 3D implicit function is created from these constraints using a variational scattered data interpolation approach, and the iso-surface of this function describes a surface. Like other implicit surface descriptions, these surfaces can be used for CSG and interference detection, may be interactively manipulated, are readily approximated by polygonal tilings, and are easy to ray trace. A key strength for model creation is that interpolating implicit surfaces allow the direct specification of both the location of points on the surface and the surface normals. These are two important manipulation techniques that are difficult to achieve using other implicit surface representations such as sums of spherical or ellipsoidal Gaussian functions ("blobbies"). We show that these properties make this form of implicit surface particularly attractive for interactive sculpting using the particle sampling technique introduced by Witkin and Heckbert. Our formulation also yields a simple method for converting a polygonal model to a smooth implicit model, as well as a new way to form blends between objects.
356 citations
TL;DR: In this article, a real-time method for rendering diffuse and glossy objects in low-frequency lighting environments that captures soft shadows, interreflections, and caustics is presented.
Abstract: We present a new, real-time method for rendering diffuse and glossy objects in low-frequency lighting environments that captures soft shadows, interreflections, and caustics. As a preprocess, a nov...
329 citations
TL;DR: In this article, the authors present an algorithm to efficiently and robustly process collisions, contact and friction in cloth simulation, which works with any technique for simulating the internal dynamics of the cloth.
Abstract: We present an algorithm to efficiently and robustly process collisions, contact and friction in cloth simulation. It works with any technique for simulating the internal dynamics of the cloth, and ...
317 citations
TL;DR: A general technique for "colorizing"greyscale images by transferring color between a source, color image and a destination, greyscale image is introduced.
Abstract: We introduce a general technique for "colorizing" greyscale images by transferring color between a source, color image and a destination, greyscale image. Although the general problem of adding chr...
304 citations
TL;DR: In this paper, a new method for the animation and rendering of photo-realistic water effects is presented, which is designed to produce visually plausible three dimensional effects, for example the pouring of...
Abstract: We present a new method for the animation and rendering of photo-realistic water effects. Our method is designed to produce visually plausible three dimensional effects, for example the pouring of ...
TL;DR: In this article, a new 3D model acquisition system that permits the digitization of the 3D shape of real objects is proposed, with applications in entertainment, design, and archaeology.
Abstract: The digitization of the 3D shape of real objects is a rapidly expanding field, with applications in entertainment, design, and archaeology. We propose a new 3D model acquisition system that permits...
TL;DR: In this paper, a new method for contouring a signed grid whose edges are tagged by Hermite data (i.e., exact intersection points and normals) is described.
Abstract: This paper describes a new method for contouring a signed grid whose edges are tagged by Hermite data (i.e; exact intersection points and normals). This method avoids the need to explicitly identif...
TL;DR: This work describes a computational approach to stylizing and abstracting photographs that explicitly responds to the meaningful structure in an image.
Abstract: Good information design depends on clarifying the meaningful structure in an image. We describe a computational approach to stylizing and abstracting photographs that explicitly responds to this de...
TL;DR: A semi-implicit cloth simulation technique that is very stable yet also responsive, and allows the use of a large fixed time step when simulating all types of fabrics.
Abstract: We present a semi-implicit cloth simulation technique that is very stable yet also responsive. The stability of the technique allows the use of a large fixed time step when simulating all types of ...
TL;DR: In this article, a method for creating animations that allows the animator to sketch an animation by setting a small number of keyframes on a fraction of the possible degrees of freedom is discussed.
Abstract: We discuss a method for creating animations that allows the animator to sketch an animation by setting a small number of keyframes on a fraction of the possible degrees of freedom. Motion capture d...
TL;DR: This paper presents an example-based method for calculating skeleton-driven body deformations using range scans of a human body in a variety of poses.
Abstract: This paper presents an example-based method for calculating skeleton-driven body deformations. Our example data consists of range scans of a human body in a variety of poses. Using markers captured...
TL;DR: A novel technique, both flexible and efficient, for interactive remeshing of irregular geometry is presented, in which the original (arbitrary genus) mesh is substituted by a series of 2D maps in parametric models.
Abstract: We present a novel technique, both flexible and efficient, for interactive remeshing of irregular geometry. First, the original (arbitrary genus) mesh is substituted by a series of 2D maps in param...
TL;DR: The bidirectional texture function (BTF) is a 6D function that can describe textures arising from both spatially-variant surface reflectance and surface mesostructures as discussed by the authors.
Abstract: The bidirectional texture function (BTF) is a 6D function that can describe textures arising from both spatially-variant surface reflectance and surface mesostructures. In this paper, we present an...
TL;DR: An implementation of procedural solid texturing that uses the texture atlas, a one-to-one mapping from an object's surface into its texture space, and which supports MIP-mapped minification antialiasing and linear magnification filtering.
Abstract: We describe an implementation of procedural solid texturing that uses the texture atlas, a one-to-one mapping from an object's surface into its texture space. The method uses the graphics hardware to rasterize the solid texture coordinates as colors directly into the atlas. A texturing procedure is applied per-pixel to the texture map, replacing each solid texture coordinate with its corresponding procedural solid texture result. The procedural solid texture is then mapped back onto the object surface using standard texture mapping. The implementation renders procedural solid textures in real time, and the user can design them interactively.The quality of this technique depends greatly on the layout of the texture atlas. A broad survey of texture atlas schemes is used to develop a set of general purpose mesh atlases and tools for measuring their effectiveness at distributing as many available texture samples as evenly across the surface as possible. The main contribution of this paper is a new multiresolution texture atlas. It distributes all available texture samples in a nearly uniform distribution. This multiresolution texture atlas also supports MIP-mapped minification antialiasing and linear magnification filtering.
TL;DR: A novel 3-D warping algorithm is designed: a mesh warp---useful as a modeling and animation tool---that allows users to deform a detailed surface by manipulating a low-resolution mesh of similar shape.
Abstract: We present a framework for geometric warps and deformations. The framework provides a conceptual and mathematical foundation for analyzing known warps and for developing new warps, and serves as a common base for many warps and deformations. Our framework is composed of two components: a generic modular algorithm for warps and deformations; and a concise, geometrically meaningful formula that describes how warps are evaluated. Together, these two elements comprise a complete framework useful for analyzing, evaluating, designing, and implementing deformation algorithms. While the framework is independent of user-interfaces and geometric model representations and is formally capable of describing any warping algorithm, its design is geared toward the most prevalent class of user-controlled deformations: those computed using geometric operations. To demonstrate the expressive power of the framework, we cast several well-known warps in terms of the framework. To illustrate the framework's usefulness for analyzing and modifying existing warps, we present variations of these warps that provide additional functionality or improved behavior. To show the utility of the framework for developing new warps, we design a novel 3-D warping algorithm: a mesh warp---useful as a modeling and animation tool---that allows users to deform a detailed surface by manipulating a low-resolution mesh of similar shape. Finally, to demonstrate the mathematical utility of the framework, we use the framework to develop guarantees of several mathematical properties such as commutativity and continuity for large classes of deformations.
TL;DR: In this paper, a skeleton-driven animation of elastically deformable characters is presented, where a character is embedded in a coarse volumetric control lattice, which provides the structure of the skeleton.
Abstract: This paper presents a framework for the skeleton-driven animation of elastically deformable characters. A character is embedded in a coarse volumetric control lattice, which provides the structure ...
TL;DR: In this article, the authors describe how to create with machine learning techniques a generative, speech animation module, which is first recorded using a videocamera as he/she utters a predetermined speech corpu...
Abstract: We describe how to create with machine learning techniques a generative, speech animation module. A human subject is first recorded using a videocamera as he/she utters a predetermined speech corpu...
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TL;DR: In this article, a light field parameterized on the surface offers a natural and intuitive description of the view-dependent appearance of scenes with complex reflectance properties, and is used to enable the use of surface li...
Abstract: A light field parameterized on the surface offers a natural and intuitive description of the view-dependent appearance of scenes with complex reflectance properties. To enable the use of surface li...
TL;DR: In this paper, an efficient algorithm for compressing geometric data has been developed for closed polyhedral surfaces which are manifold or "nearly manifolds" (nearly manifold) surfaces.
Abstract: Efficient algorithms for compressing geometric data have been widely developed in the recent years, but they are mainly designed for closed polyhedral surfaces which are manifold or "nearly manifol...
TL;DR: In this paper, the authors present an approach for generating coarse-level approximations of topologically complex models by converting a 3D model to and from a volumetric representation.
Abstract: This paper presents a new approach for generating coarse-level approximations of topologically complex models. Dramatic topology reduction is achieved by converting a 3D model to and from a volumetric representation. Our approach produces valid, error-bounded models and supports the creation of approximations that do not interpenetrate the original model, either being completely contained in the input solid or bounding it. Several simple to implement versions of our approach are presented and discussed. We show that these methods perform significantly better than other surface-based approaches when simplifying topologically-rich models such as scene parts and complex mechanical assemblies.
TL;DR: Following simple geometric arguments, a natural and geometrically meaningful definition of square matrices is derived and this definition is applied to matrices in computer graphics.
Abstract: Geometric transformations are most commonly represented as square matrices in computer graphics. Following simple geometric arguments we derive a natural and geometrically meaningful definition of ...
TL;DR: This paper presents a technique which is used to track the motion from traditionally animated cartoons and retarget it onto 3-D models, 2-D drawings, and so on.
Abstract: In this paper, we present a technique we call "cartoon capture and retargeting" which we use to track the motion from traditionally animated cartoons and retarget it onto 3-D models, 2-D drawings, ...
TL;DR: A new procedure for reducing length distortion of an existing parameterization and apply it to ABF results, based on computing a mapping from the plane to itself which has length distortion very similar to that of the ABF parameterization, which yields a new parameterization with low length distortion.
Abstract: Texture is an essential component of computer generated models. For a texture mapping procedure to be effective it has to generate continuous textures and cause only small mapping distortion. The Angle Based Flattening (ABF) parameterization method is guaranteed to provide a continuous (no foldovers) mapping. It also minimizes the angular distortion of the parameterization, including locating the optimal planar domain boundary. However, since it concentrates on minimizing the angular distortion of the mapping, it can introduce relatively large linear distortion.In this paper we introduce a new procedure for reducing length distortion of an existing parameterization and apply it to ABF results. The linear distortion reduction is added as a second step in a texture mapping computation. The new method is based on computing a mapping from the plane to itself which has length distortion very similar to that of the ABF parameterization. By applying the inverse mapping to the result of the initial parameterization, we obtain a new parameterization with low length distortion. We notice that the procedure for computing the inverse mapping can be applied to any other (convenient) mapping from the three-dimensional surface to the plane in order to improve it.The mapping in the plane is computed by applying weighted Laplacian smoothing to a Cartesian grid covering the planar domain of the initial mapping. Both the mapping and its inverse are provably continuous. Since angle preserving (conformal) mappings, such as ABF, locally preserve distances as well, the planar mapping has small local deformation. As a result, the inverse mapping does not significantly increase the angular distortion.The combined texture mapping procedure provides a mapping with low distance and angular distortion, which is guaranteed to be continuous.
TL;DR: A theoretical study of 3D visibility properties for scenes of smooth convex objects in the space of light rays, or more precisely, of maximal free segments that "see" the same object and extends the visibility complex to handle temporal visibility.
Abstract: Visibility problems are central to many computer graphics applications. The most common examples include hidden-part removal for view computation, shadow boundaries, mutual visibility of objects for lighting simulation. In this paper, we present a theoretical study of 3D visibility properties for scenes of smooth convex objects. We work in the space of light rays, or more precisely, of maximal free segments. We group segments that "see" the same object; this defines the 3D visibility complex. The boundaries of these groups of segments correspond to the visual events of the scene (limits of shadows, disappearance of an object when the viewpoint is moved, etc.). We provide a worst case analysis of the complexity of the visibility complex of 3D scenes, as well as a probabilistic study under a simple assumption for "normal" scenes. We extend the visibility complex to handle temporal visibility. We give an output-sensitive construction algorithm and present applications of our approach.