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 gradient field of the luminance image by attenuating the magnitudes of large gradients. A new, low dynamic range image is then obtained by solving a Poisson equation on the modified gradient field. Our results demonstrate that the method is capable of drastic dynamic range compression, while preserving fine details and avoiding common artifacts, such as halos, gradient reversals, or loss of local contrast. The method is also able to significantly enhance ordinary images by bringing out detail in dark regions.

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 novel global transport simulator creates functions over the object's surface representing transfer of arbitrary, low-frequency incident lighting into transferred radiance which includes global effects like shadows and interreflections from the object onto itself. At run-time, these transfer functions are applied to actual incident lighting. Dynamic, local lighting is handled by sampling it close to the object every frame; the object can also be rigidly rotated with respect to the lighting and vice versa. Lighting and transfer functions are represented using low-order spherical harmonics. This avoids aliasing and evaluates efficiently on graphics hardware by reducing the shading integral to a dot product of 9 to 25 element vectors for diffuse receivers. Glossy objects are handled using matrices rather than vectors. We further introduce functions for radiance transfer from a dynamic lighting environment through a preprocessed object to neighboring points in space. These allow soft shadows and caustics from rigidly moving objects to be cast onto arbitrary, dynamic receivers. We demonstrate real-time global lighting effects with this approach.

Abstract: Presents a framework for three-dimensional model-based tracking. Graphical rendering technology is combined with constrained active contour tracking to create a robust wire-frame tracking system. It operates in real time at video frame rate (25 Hz) on standard hardware. It is based on an internal CAD model of the object to be tracked which is rendered using a binary space partition tree to perform hidden line removal. A Lie group formalism is used to cast the motion computation problem into simple geometric terms so that tracking becomes a simple optimization problem solved by means of iterative reweighted least squares. A visual servoing system constructed using this framework is presented together with results showing the accuracy of the tracker. The paper then describes how this tracking system has been extended to provide a general framework for tracking in complex configurations. The adjoint representation of the group is used to transform measurements into common coordinate frames. The constraints are then imposed by means of Lagrange multipliers. Results from a number of experiments performed using this framework are presented and discussed.

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...

Abstract: Most direct volume renderings produced today employ 1D transfer functions which assign color and opacity to the volume based solely on the single scalar quantity which comprises the data set. Though they have not received widespread attention, multi-dimensional transfer functions are a very effective way to extract materials and their boundaries for both scalar and multivariate data. However, identifying good transfer functions is difficult enough in 1D, let alone 2D or 3D. This paper demonstrates an important class of 3D transfer functions for scalar data, and describes the application of multi-dimensional transfer functions to multivariate data. We present a set of direct manipulation widgets that make specifying such transfer functions intuitive and convenient. We also describe how to use modern graphics hardware to both interactively render with multidimensional transfer functions and to provide interactive shadows for volumes. The transfer functions, widgets and hardware combine to form a powerful system for interactive volume exploration.

Abstract: A fundamental measure of progress in computing involves rendering it as an inseparable part of our everyday experience while simultaneously making it disappear [2]. Radical improvements in microprocessor cost-performance ratios have pushed this process forward while drastically reducing computing-device form factors, enabling us to embed computers in many parts of our environments. In 40 years this change has transformed the early large “computing machines” into compact devices that enable, mediate, support, and organize our daily activities.

Abstract: Construct3D is a three-dimensional geometric construction tool specifically designed for mathematics and geometry education. It is based on the mobile collaborative augmented reality system "Studierstube." We describe our efforts in developing a system for the improvement of spatial abilities and maximization of transfer of learning. In order to support various teacher-student interaction scenarios we implemented flexible methods for context and user dependent rendering of parts of the construction. Together with hybrid hardware setups they allow the use of Construct3D in today's classrooms and provide a test bed for future evaluations. Means of application and integration in mathematics and geometry education at the high school, as well as the university, level are being discussed. Anecdotal evidence supports our claim that Construct3D is easy to learn, encourages experimentation with geometric constructions, and improves spatial skills.

Abstract: In the past decade, the field of non-photorealistic computer graphics (NPR) has developed as the product of research marked by diverse and sometimes divergent assumptions, approaches, and aims. This book is the first to offer a systematic assessment of this work, identifying and exploring the underlying principles that have given the field its cohesion. In the course of this assessment, the authors provide detailed accounts of today's major non-photorealistic algorithms, along with the background information and implementation advice you need to put them to productive use. As NPR finds new applications in a broadening array of fields, Non-Photorealistic Computer Graphics is destined to be the standard reference for researchers and practitioners alike.

Abstract: The present invention is directed to a method and system for disaggregating and connecting A/V components, and communicating A/V content stream information. An A/V stream from a source device is packaged for transmission over an IP network to one or more output devices. A brick device enables the integration of legacy A/V systems into the network supported A/V system. The brick device operates to provide analog signal and IP protocol conversion, along with the synchronization of received A/V stream data packets. The rendering and play of the A/V stream content on multiple output devices is synchronized to overcome distortions and other network idiosyncrasy and to facilitate a pleasant user experience.

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...

Abstract: We present a system for interactive shape and appearance editing of 3D point-sampled geometry. By generalizing conventional 2D pixel editors, our system supports a great variety of different interaction techniques to alter shape and appearance of 3D point models, including cleaning, texturing, sculpting, carving, filtering, and resampling. One key ingredient of our framework is a novel concept for interactive point cloud parameterization allowing for distortion minimal and aliasing-free texture mapping. A second one is a dynamic, adaptive resampling method which builds upon a continuous reconstruction of the model surface and its attributes. These techniques allow us to transfer the full functionality of 2D image editing operations to the irregular 3D point setting. Our system reads, processes, and writes point-sampled models without intermediate tesselation. It is intended to complement existing low cost 3D scanners and point rendering pipelines for efficient 3D content creation.

Abstract: We describe a general framework for out-of-core rendering and management of massive terrain surfaces. The two key components of this framework are: view-dependent refinement of the terrain mesh and a simple scheme for organizing the terrain data to improve coherence and reduce the number of paging events from external storage to main memory. Similar to several previously proposed methods for view-dependent refinement, we recursively subdivide a triangle mesh defined over regularly gridded data using longest-edge bisection. As part of this single, per-frame refinement pass, we perform triangle stripping, view frustum culling, and smooth blending of geometry using geomorphing. Meanwhile, our refinement framework supports a large class of error metrics, is highly competitive in terms of rendering performance, and is surprisingly simple to implement. Independent of our refinement algorithm, we also describe several data layout techniques for providing coherent access to the terrain data. By reordering the data in a manner that is more consistent with our recursive access pattern, we show that visualization of gigabyte-size data sets can be realized even on low-end, commodity PCs without the need for complicated and explicit data paging techniques. Rather, by virtue of dramatic improvements in multilevel cache coherence, we rely on the built-in paging mechanisms of the operating system to perform this task. The end result is a straightforward, simple-to-implement, pointerless indexing scheme that dramatically improves the data locality and paging performance over conventional matrix-based layouts.

Abstract: A method and system for synchronizing the rendering of content at various rendering devices. Each rendering device has a device time and a rendering time. The synchronization system designates one of the rendering devices as a master rendering device and designates all other rendering devices as slave rendering devices. Each slave rendering device adjusts the rendering of its content to keep it in synchronization with the rendering of the content at the master rendering device. The master rendering device sends a message with its rendering time and corresponding device time to the slave rendering devices. Each slave rendering device, upon receiving the message from the master rendering device, determines whether it is synchronized with the master rendering time. If not, the slave rendering device adjusts the rendering of its content to compensate for the difference between the master rendering time and the slave rendering time.

Abstract: We present a system that lets a designer directly annotate a 3D model with strokes, imparting a personal aesthetic to the non-photorealistic rendering of the object. The artist chooses a "brush" style, then draws strokes over the model from one or more viewpoints. When the system renders the scene from any new viewpoint, it adapts the number and placement of the strokes appropriately to maintain the original look.

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 ...

Abstract: We propose a highly efficient hierarchical representation for point sampled geometry that automatically balances sampling density and point coordinate quantization. The representation is very compact with a memory consumption of far less than 2 bits per point position which does not depend on the quantization precision. We present an efficient rendering algorithm that exploits the hierarchical structure of the representation to perform fast 3D transformations and shading. The algorithm is extended to surface splatting which yields high quality anti-aliased and water tight surface renderings. Our pure software implementation renders up to 14 million Phong shaded and textured samples per second and about 4 million anti-aliased surface splats on a commodity PC. This is more than a factor 10 times faster than previous algorithms.

Abstract: Elliptical weighted average (EWA) surface splatting is a technique for high quality rendering of point-sampled 3D objects. EWA surface splatting renders water-tight surfaces of complex point models with high quality, anisotropic texture filtering. In this paper we introduce a new multi-pass approach to perform EWA surface splatting on modern PC graphics hardware, called object space EWA splatting. We derive an object space formulation of the EWA filter, which is amenable for acceleration by conventional triangle-based graphics hardware. We describe how to implement the object space EWA filter using a two pass rendering algorithm. In the first rendering pass, visibility splatting is performed by shifting opaque surfel polygons backward along the viewing rays, while in the second rendering pass view-dependent EWA prefiltering is performed by deforming texture mapped surfel polygons. We use texture mapping and alpha blending to facilitate the splatting process. We implement our algorithm using programmable vertex and pixel shaders, fully exploiting the capabilities of today’s graphics processing units (GPUs). Our implementation renders up to 3 million points per second on recent PC graphics hardware, an order of magnitude more than a pure software implementation of screen space EWA surface splatting.

Abstract: n the past seven years, the adjective image-based has become a common fixture in the computer graphics vernacular. As a result, we've witnessed an explosion of new and original uses for photographs and other forms of acquired images in computer graphics applications. We can use collections of images to relight scenes, capture the subtle appearance qualities of real-world objects, derive geometric models, and synthesize images from original viewpoints. Not coincidentally, this explosion has occurred in conjunction with the availability of affordable digital photography. This special issue of IEEE Computer Graphics and Applications spotlights both the progress and recent advances in image-based approaches to computer graphics. It brings together a range of diverse points of view and demonstrates the indelible impact these approaches have had on our field. The introduction of image-based approaches exemplifies one of many dramatic yet, in hindsight, obvious departures in computer graphics. The quest for photo-realistic renderings has long been the holy grail of computer graphics. Prior to the introduction of image-based methods, the most popular approach to achieving improved realism was to incorporate more and more knowledge of physics into simulation-based rendering systems. Generally, these improvements came with the costs of increased simulation times and the introduction of new, often difficult to obtain, material parameters. Image-based rendering is a refreshing alternative because it suggests that we might distill the essence of realism from example photographs. Furthermore, it's turned the computational focus away from simulation, toward a more manageable interpolation-based approach. Image-based computer graphics techniques started gaining traction as a result of two important leaps. First was the realization that we could incorporate images as first-class components of an underlying scene representation. This contrasted with the prevailing practice where images played a more subordinate role, most frequently as static texture maps draped over geometry. A second realization was the recognition that we could treat images as actual measurements of both geometric and radiometric information. This new interpretation has proven to be rich with new opportunities, including new approaches to visibility, improved methods for modeling view-dependent variations in the appearance of materials, and the possibility of combining radiant energy measurements from different images to reilluminate scenes. Furthermore, this interpretation of images as measurements has fostered new connections between the computer graphics and computer vision communities, as well as provided new perspectives on the problems of inverse rendering. This special issue demonstrates the wide-ranging impact that image-based approaches have …

Abstract: The ultimate aim of realistic graphics is the creation of images that provoke the same responses that a viewer would have to a real scene. This STAR addresses two related key problem areas in this effort which are located at opposite ends of the rendering pipeline, namely the data structures used to describe light during the actual rendering process, and the issue of displaying such radiant intensities in a meaningful way. The interest in the first of these subproblems stems from the fact that it is common industry practice to use RGB colour values to describe light intensity and surface reflectancy. While viable in the context of methods that do not strive to achieve true realism, this approach has to be replaced by more physically accurate techniques if a prediction of nature is intended. The second subproblem is that while research into ways of rendering images provides us with better and faster methods, we do not necessarily see their full effect due to limitations of the display hardware. The low dynamic range of a standard computer monitor requires some form of mapping to produce images that are perceptually accurate. Tone reproduction operators attempt to replicate the effect of real-world luminance intensities. This STAR report will review the work to date on spectral rendering and tone reproduction techniques. It will include an investigation into the need for spectral imagery synthesis methods and accurate tone reproduction, and a discussion of major approaches to physically correct rendering and key tone mapping algorithms. The future of both spectral rendering and tone reproduction techniques will be considered, together with the implications of advances in display hardware.

Abstract: A system and method for platform and language-independent delivery of page-based content. Content defined in a relatively abstract format is rendered into multiple platform formats in client-side applications' user interfaces in multiple human languages. The relatively abstract format is a subset of XML and is used to define user interface elements to be displayed on a page. A Model-View-Controller architecture is implemented comprising a plurality of servlet filters, a servlet pipeline and a plurality of rendering processors for client detection, client tracking, relatively abstract format preprocessing, relatively abstract format processing and validating, and transforming and rendering of the relatively abstract format into multiple platform formats in client-side applications' user interfaces in multiple human languages. A creation, modification and management tool is also disclosed for creating, modifying and managing platform and language-independent page-based content.

Abstract: A proxy subsystem for a media renderer comprises a network interface, a content transfer subsystem coupled to the network interface, a format transcoder coupled to the content transfer subsystem and capable of coupling to a rendering hardware. The proxy subsystem further comprises a connection manager service coupled to the content transfer subsystem and the format transcoder subsystem, and a rendering controller capable of coupling to the rendering hardware.

Abstract: This book contains the proceedings of the 13th Eurographics Workshop on Rendering, which took place between the 26th to the 28th of June, 2002, in Pisa, Italy. Over the past 12 years, the Rendering Workshop has become the premier forum dedicated to research in rendering. Much of the work in the field now appearing in other conferences and journals builds on ideas originally presented at this event.This year we received a record number of submissions, 112 in all. Each paper was carefully reviewed by two of the 28 international programme committee members, as well as external reviewers, selected by the co-chairs from a pool of over 180 individuals. In this review process, all submissions of papers and reviews were handled electronically, with the exception of video tapes submitted with a few of the papers.The overall quality of the submissions was exceptionally high. Space and time constraints forced the committee to make some difficult decisions. In the end, 29 submissions were accepted as full papers, and they appear here. Almost all papers are accompanied by color images, which appear at the end of the book. The papers treat the following varied topics: interactive and non-interactive global illumination algorithms, point-based rendering, methods for capturing dynamic models and light-fields, texture mapping and synthesis, colour and tone reproduction, interactive walkthroughs, non-photorealism, appearance modelling, transparency, and algorithms for shading and shadowing.Each year, in addition to the reviewed contributions, the workshop includes invited presentations from internationally recognized experts. This year we were pleased to have Doug Roble from Digital Domain, and Hans-Peter Seidel from the Max-Planck-Institut fur Informatik as invited speakers. As in previous years, we expect these proceedings to become an invaluable resource for both rendering researchers and practitioners.

Abstract: We present a framework for high quality splatting based on elliptical Gaussian kernels. To avoid aliasing artifacts, we introduce the concept of a resampling filter, combining a reconstruction kernel with a low-pass filter. Because of the similarity to Heckbert's (1989) EWA (elliptical weighted average) filter for texture mapping, we call our technique EWA splatting. Our framework allows us to derive EWA splat primitives for volume data and for point-sampled surface data. It provides high image quality without aliasing artifacts or excessive blurring for volume data and, additionally, features anisotropic texture filtering for point-sampled surfaces. It also handles nonspherical volume kernels efficiently; hence, it is suitable for regular, rectilinear, and irregular volume datasets. Moreover, our framework introduces a novel approach to compute the footprint function, facilitating efficient perspective projection of arbitrary elliptical kernels at very little additional cost. Finally, we show that EWA volume reconstruction kernels can be reduced to surface reconstruction kernels. This makes our splat primitive universal in rendering surface and volume data.

Abstract: We present a method for interactive rendering of large outdoor scenes. Complex polygonal plant models and whole plant populations are represented by relatively small sets of point and line primitives. This enables us to show landscapes faithfully using only a limited percentage of primitives. In addition, a hierarchical data structure allows us to smoothly reduce the geometrical representation to any desired number of primitives. The scene is hierarchically divided into local portions of geometry to achieve large reduction factors for distant regions. Additionally, the data reduction is adapted to the visual importance of geometric objects. This allows us to maintain the visual fidelity of the representation while reducing most of the geometry drastically. With our system, we are able to interactively render very complex landscapes with good visual quality.

Abstract: Level-of-detail rendering is essential for rendering very large, detailed worlds in real-time. Unfortunately, level-of-detail computations can be expensive, creating a bottleneck at the CPU.This paper presents the CABTT algorithm, an extension to existing binary-triangle-tree-based level-of-detail algorithms. Instead of manipulating triangles, the CABTT algorithm instead operates on clusters of geometry called aggregate triangles. This reduces CPU overhead, eliminating a bottleneck common to level-of-detail algorithms. Since aggregate triangles stay fixed over several frames, they may be cached on the video card. This further reduces CPU load and fully utilizes the hardware accelerated rendering pipeline on modern video cards. These improvements result in a fourfold increase in frame rate over ROAM [7] at high detail levels. Our implementation renders an approximation of an 8 million triangle heightfield at 42 frames per second with an maximum error of 1 pixel on consumer hardware.

Abstract: A method and system for converting an attachment in an e-mail for delivery to a client device of limited rendering capability. The method includes downloading the e-mail and the attachment in response to a request from a client device for the e-mail, transforming the attachment into a plurality of sub-documents, each sub-document being expressed in a format that is compatible with the client device and being a size not greater than a maximum rendering size capability of the client device, wherein a first sub-document includes a link to a second sub-document, and serving the first sub-document to the client device.

Abstract: A conferencing system provides an interactive virtual world representing a real or imaginary place using graphics, images, multimedia, and audio data. The system includes a communications network, at least one local client processor/server operatively connected to the communications network operable for virtual environment and avatar rendering using a descriptive computer markup language and further operable for coordinating virtual environment and avatar state changes, at least one input device operable for performing the virtual environment and avatar state changes, and an output device operable for displaying the virtual conference environment. The system operates using a low bandwidth dependency. A virtual conference is created using human, environment, gesture, voice, and phonetic descriptive markup languages. A software-based virtual conferencing system that does not require cameras, video translation devices, or any other additional equipment.

Abstract: Various described embodiments provide for per-pixel functionality in connection with pixel data that is processed by a video card for rendering on a display monitor. That is, pixel data that is associated with individual pixels that are to be rendered on a display monitor are imparted with a characteristic that enables various functionalities to be implemented at the pixel level. In one embodiment, per-pixel functionality is provided by including, in the pixel data itself, a specification of an auxiliary function that is to be performed on the pixel data associated with the individual pixels. For example, the security of the pixel data associated with each pixel can be enhanced by providing the ability to encrypt and decrypt the pixel data for individual pixels. A specification of a key that can be used for decrypting the pixel data can then be included in the pixel data itself such that when the pixel data is processed for rendering, a suitably configured decryptor can access the key specification and decrypt the pixel data.

Abstract: We propose texture maps that contain at each texel all the parameters of a Lafortune representation BRDF as a compact, but quite general surface appearance representation. We describe a method for rendering such surfaces rapidly on current graphics hardware and demonstrate the method with real, measured surfaces and hand-painted surfaces.We also propose a method of rendering such spatial bi-directional reflectance distribution functions using prefiltered environment maps. Only one set of maps is required for rendering the different BRDFs stored at each texel over the surface.