Abstract: From the Publisher: Implicit surfaces offer special effects animators, graphic designers, CAD engineers, graphics students, and hobbyists a new range of capabilities for the modeling of complex geometric objects. In contrast to traditional parametric surfaces, implicit surfaces can easily describe smooth, intricate, and articulatable shapes. These powerful yet easily understood surfaces are finding use in a growing number of graphics applications. This comprehensive introduction develops the fundamental concepts and techniques of implicit surface modeling, rendering, and animating in terms accessible to anyone with a basic background in computer graphics. provides a thorough overview of implicit surfaces with a focus on their applications in graphics explains the best methods for designing, representing, and visualizing implicit surfaces surveys the latest research With contributions from seven graphics authorities, this innovative guide establishes implicit surfaces as a powerful and practical tool for animation and rendering.

Abstract: Force feedback coupled with visual display allows people to interact intuitiv ely with complex virtual environments. For this synergy of haptics and graphics to flourish, however, haptic systems must be capable of modeling environments with the same richness, complexity and interactivity that can be found in existing graphic systems. To help meet this challenge, we have developed a haptic rendering system that allows for the efficient tactile display of graphical information. The system uses a common high-level framework to model contact constraints, surface shading, friction and tex ture. The multilevel control system also helps ensure that the haptic device will remain stable even as the limits of the renderer’s capabilities are reached.

Abstract: Image rendering maps scene parameters to output pixel values; animation maps motion-control parameters to trajectory values. Because these mapping functions are usually multidimensional, nonlinear, and discontinuous, finding input parameters that yield desirable output values is often a painful process of manual tweaking. Interactive evolution and inverse design are two general methodologies for computer-assisted parameter setting in which the computer plays a prominent role. In this paper we present another such methodology. Design GalleryTM (DG) interfaces present the user with the broadest selection, automatically generated and organized, of perceptually different graphics or animations that can be produced by varying a given input-parameter vector. The principal technical challenges posed by the DG approach are dispersion, finding a set of input-parameter vectors that optimally disperses the resulting output-value vectors, and arrangement, organizing the resulting graphics for easy and intuitive browsing by the user. We describe the use of DG interfaces for several parameter-setting problems: light selection and placement for image rendering, both standard and image-based; opacity and color transfer-function specification for volume rendering; and motion control for particle-system and articulated-figure animation. CR Categories: I.2.6 [Artificial Intelligence]: Problem Solving, Control Methods and Search—heuristic methods; I.3.6 [Computer Graphics]: Methodology and Techniques—interaction techniques; I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism.

Abstract: A pair of rendered images and their Z-buffers contain almost all of the information necessary to re-render from nearby viewpoints. For the small changes in viewpoint that occur in a fraction of a second, this information is sufficient for high quality re-rendering with cost independent of scene complexity. Re-rendering from previously computed views allows an order-of-magnitude increase in apparent frame rate over that provided by conventional rendering alone. It can also compensate for system latency in local or remote display. We use McMillan and Bishop’s image warping algorithm to re-render, allowing us to compensate for viewpoint translation as well as rotation. We avoid occlusion-related artifacts by warping two different reference images and compositing the results. This paper explains the basic design of our system and provides details of our reconstruction and multi-image compositing algorithms. We present our method for selecting reference image locations and the heuristic we use for any portions of the scene which happen to be occluded in both reference images. We also discuss properties of our technique which make it suitable for real-time implementation, and briefly describe our simpler real-time remote display system. CR

Abstract: Dynamically adapting the layout of a document to a particular output device. The layout of a document can be adapted to a particular output device so that the document fully utilizes the capabilities of the output device. A layout generator interrogates the output device to determine the capabilities of the output device. Based upon the capabilities of the output device, the layout generator selects a style sheet to accommodate the particular output device. The style sheet assigns values to format properties such as font properties, color and background properties, and text properties. The layout of the document is adapted to the particular output device by rendering the document on the output device using the values defined in the style sheet.

Abstract: Virtual colonoscopy is a non-invasive computerized medical procedure for examining the entire colon to detect polyps. We present an interactive virtual colonoscopy method, which uses a physicallybased camera control model and a hardware-assisted visibility algorithm. By employing a potential field and rigid body dynamics, our camera control supplies a convenient and intuitive mechanism for examining the colonic surface while avoiding collisions. Our Zbuffer-assisted visibility algorithm culls invisible regions based on their visibility through a chain of portals, thus providing interactive rendering speed. We demonstrate our method with experimental results on a plastic pipe phantom, the Visible Human, and several patients. CR Categories: I.3.3 [Picture/Image Generation]: Display Algorithms; I.3.5 [Computational Geometry and Object Modeling]: Physically Based Modeling; I.3.6 [Methodologies and Techniques]: Interaction Techniques; I.3.7 [Three-Dimensional Graphics and Realism]: Hidden Line/Surface Removal; I.3.8 [Applications];

Abstract: This paper presents a new evenly-spaced streamlines placement algorithm to visualize 2D steady flows. The main technical contribution of this work is to propose a single method to compute a wide variety of flow field images, ranging from texture-like to hand-drawing styles. Indeed the control of the density of the field is very easy since the user only needs to set the separating distance between adjacent streamlines, which is related to the overall density of the image. We show that our method produces images of a quality at least as good as other methods but that it is computationally less expensive and offers a better control on the rendering process.

Abstract: Simulating realistic lighting and rendering complex scenes are usually considered separate problems with incompatible solutions. Accurate lighting calculations are typically performed using ray tracing algorithms, which require that the entire scene database reside in memory to perform well. Conversely, most systems capable of rendering complex scenes use scan-conversion algorithms that access memory coherently, but are unable to incorporate sophisticated illumination. We have developed algorithms that use caching and lazy creation of texture and geometry to manage scene complexity. To improve cache performance, we increase locality of reference by dynamically reordering the rendering computation based on the contents of the cache. We have used these algorithms to compute images of scenes containing millions of primitives, while storing ten percent of the scene description in memory. Thus, a machine of a given memory capacity can render realistic scenes that are an order of magnitude more complex than was previously possible. CR Categories: I.3.3 [Computer Graphics]: Picture/Image Generation; I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism—Raytracing

Abstract: In this paper we develop a computational model of visual masking based on psychophysical data. The model predicts how the presence of one visual pattern affects the detectability of another. The model allows us to choose texture patterns for computer graphics images that hide the effects of faceting, banding, aliasing, noise and other visual artifacts produced by sources of error in graphics algorithms. We demonstrate the utility of the model by choosing a texture pattern to mask faceting artifacts caused by polygonal tesselation of a flat-shaded curved surface. The model predicts how changes in the contrast, spatial frequency, and orientation of the texture pattern, or changes in the tesselation of the surface will alter the masking effect. The model is general and has uses in geometric modeling, realistic image synthesis, scientific visualization, image compression, and image-based rendering. CR Categories: I.3.0 [Computer Graphics]: General;

Abstract: Most existing visualization applications use 3D geometry as their basic rendering primitive. As users demand more complex data sets, the memory requirements for retrieving and storing large 3D models are becoming excessive. In addition, the current 3D rendering hardware is facing a large memory bus bandwidth bottleneck at the processor to graphics pipeline interface. Rendering 1 million triangles with 24 bytes per triangle at 30 Hz requires as much as 720 MB/sec memory bus bandwidth. This transfer rate is well beyond the current low-cost graphics systems. A solution is to compress the static 3D geometry as an off-line pre-process. Then, only the compressed geometry needs to be stored in main memory and sent down to the graphics pipeline for real-time decompression and rendering. The author presents several new techniques for compression of 3D geometry that produce 2 to 3 times better compression ratios than existing methods. They first introduce several algorithms for the efficient encoding of the original geometry as generalized triangle meshes. This encoding allows most of the mesh vertices to be reused when forming new triangles. Their second contribution allows various parts of a geometric model to be compressed with different precision depending on the level of details present. Together, the meshifying algorithms and the variable compression method achieve compression ratios of 30 and 37 to one over ASCII encoded formats and 10 and 15 to one over binary encoded triangle strips. The experimental results show a dramatically lowered memory bandwidth required for real-time visualization of complex data sets.

Abstract: Modeling arbitrary real objects is difficult and rendering textured models typically does not result in realistic images We describe a new method for displaying scanned real objects, called view-based rendering The method takes as input a collection of colored range images covering the object and creates a collection of partial object models These partial models are rendered separately using traditional graphics hardware and blended together using various weights and soft z-buffering We demonstrate interactive viewing of real, non-trivial objects that would be difficult to model using traditional methods

Abstract: This paper describes ‘Quick-sketch’, a 2D and 3D modelling tool for pen-based computers Users of this system define a model by simple pen strokes, drawn directly on the screen of a pen-based PC Exact shapes and geometric relationships are interpreted from the sketch The system can also be used to sketch 3D solid objects and B-spline surfaces These objects may be refined by defining 2D and 3D geometric constraints A novel graph-based constraint solver is used to establish the geometric relationships, or to maintain them when manipulating the objects interactively The approach presented here is a first step towards a conceptual design system Quick-sketch can be used as a hand sketching front-end to more sophisticated modelling, rendering or animation systems

Abstract: The present invention provides a system, apparatus and method for transmitting logging data from a primary location to a remote location in near real time. The logs can be viewed almost simultaneously at the primary and remote locations, as data is being acquired. The present invention also provides for a system for viewing logs in near real time at a primary location and a remote location which includes a first means for reading while writing at the primary location, a second means for reading while writing at the remote location which is identical to the first means for reading while writing, a first file system at the primary location, the first file system having data written to it by the first means for reading while writing as numerical data or graphics data, a first rendering means for reading the graphics data from the first file system and rendering the graphics data so that it can be displayed, a first display means for displaying the rendered graphics data, a first file transfer utility means for transmitting the data from the primary location to the remote location over a communications system, a second file transfer utility means for receiving the data at the remote location, a second file system at the remote location, to which the second file transfer utility means writes the received data using the second means for reading while writing, a second rendering means for reading graphics data from the second file system and rendering the graphics data so that it can be displayed, an input interface means which directs signals from a user input to the second rendering means to adjust the display of the log, and a second display means for displaying the rendered graphics data at the remote location.

Abstract: We present a bump mapping method that requires minimal hardware beyond that necessary for Phong shading. We eliminate the costly per-pixel steps of reconstructing a tangent space and perturbing the interpolated normal vector by a) interpolating vectors that have been transformed into tangent space at polygon vertices and b) storing a precomputed, perturbed normal map as a texture. This represents a considerable savings in hardware or rendering speed compared to a straightforward implementation of bump mapping. CR categories and subject descriptors: I.3.3 [Computer Graphics]: Picture/Image generation; I.3.7 [Image Processing]: Enhancement

Abstract: A method and apparatus for creating and rendering multiple-view images A camera includes an image sensor to receive images, sampling logic to digitize the images and a processor programmed to combine the images based upon a spatial relationship between the images

Abstract: A layered graphics rendering pipeline for real time 3D animation independently renders terms in a shading model to separate image layers. The layered pipeline factors the shading model into separate image layers and renders geometry to these layers independently. Each layer can have an independent update rate and a spatial resolution different than the resolution of the output images. A compositor that supports one or more image operators composites the factored layers into an output image to generate frames of animation. To reduce rendering overhead, factored terms can be rendered once and then re-used in later frames by warping the initial rendering.

Abstract: A new image-based rendering method, based on the light field and Lumigraph system, allows illumination to be changed interactively. It does not try to recover or use any geometrical information (e.g., depth or surface normals) to calculate the illumination, but the resulting images are physically correct. The scene is first sampled from different viewpoints and under different illuminations. Treating each pixel on the back plane of the light slab as a surface element,the sampled images are used to find an apparent BRDF of each surface element. The tabular BRDF data of each pixel is further transformed to the spherical harmonic domain for efficient storage. Whenever the user changes the illumination setting, a certain number of views are reconstructed. The correct user perspective view is then displayed using the texture mapping technique of the Lumigraph system. Hence, the intensity, the type and the number of the light sources can be manipulated interactively.

Abstract: A print rendering server system in a network computing environment perform many of the most compute intensive tasks in the overall print process for a plurality of resource limited clients. In response to a print request from the client, a print job in a print ready format is produced and sent back for local printing by the resource limited client system.

Abstract: A photographic apparatus is disclosed combining an image capturing apparatus and image rendering apparatus, the image capturing apparatus operating as an electronic camera and having an integral liquid crystal display panel for viewing acquired images prior to printing the images onto photosensitive media. The images are individually selectable to adjust image properties prior to printing the image on the image rendering apparatus. The image rendering apparatus is preferably a photographic recorder adapted to print the images such that the images are readily viewable on a photosensitive medium.

Abstract: A fly-through, three-dimensional computer aided design system is provided. Computational requirements are bounded, at least in part by defining a bounded volume or world defining the volume which may be displayed, in whole or in part. Preprocessing the data assists in organizing the data for high performance display. Full detail rendering is available. However in some situations, such as during fly-through, some or all portions of the image are rendered in a simplified fashion, e.g. to maintain a high frame rate. The volume-based simplification involves rendering faces of cells or collections of cells which are at least partly intersected by components of the item or system being displayed. A plurality of granularities, preferably organized as an octree, provide multiple levels of detail. Unnecessary rendering load is reduced by view frustum culling and considering certain cell face occlusion situations. As the scene is rendered, preferably slicewise, the level of detail for slices can be adjusted based on predictions of time-to-complete, in order to meet a frame rate target.

Abstract: A medical diagnostic ultrasound system is described in which ultrasonic B mode tissue information and Doppler flow information is acquired from a volumetric region of the body and processed together to render a three dimensional image. The three dimensional rendering processes the B mode and Doppler flow information as a function of the spatial location of B mode and Doppler pixels in the volumetric region. The rendering utilizes separate three dimensional rendering parameters for the tissue and flow information, respectively.

Abstract: A video broadcast system includes a broadcast source that broadcasts a video stream and provides accompanying supplemental data files. Each supplemental data file is an HTML file having instructions for rendering a hyperlink overlay on the video stream. A receiver is configured to receive the video stream and accompanying supplemental data files and to display the hyperlink overlays in conjunction with the video stream. The overlays are designed having backgrounds of a pre-determined value which is used as a color key in receiving equipment. Specifically, the receiving equipment is configured to render video only in display areas that are set to the color key value. Thus, the video stream is rendered “behind” the hyperlink overlays, and the backgrounds of the overlays appears transparent. Control data is provided with the HTML files to indicate when the overlays should be rendered and to provide other instructions on how the HTML files should be handled by the receiving equipment.

Abstract: Voxelization algorithms that convert a 3D continuous line representation into a discrete line representation have a dual role in graphics. First, these algorithms synthesize voxel-based objects in volume graphics. The 3D line itself is a fundamental primitive, also used as a building block for voxelizing more complex objects. For example, sweeping a 3D voxelized line along a 3D voxelized circle generates a voxelized cylinder. The second application of 3D line voxelization algorithms is for ray traversal in voxel space. Rendering techniques that cast rays through a volume of voxels are based on algorithms that generate the set of voxels visited (or pierced) by the continuous ray. Discrete ray algorithms have been developed for traversing a 3D space partition or a 3D array of sampled or computed data. These algorithms produce one discrete point per step, in contrast to ray casting algorithms for volume rendering, which track a continuous ray at constant intervals, and to voxelization algorithms that generate nonbinary voxel values (for example, partial occupancies). Before considering algorithms for generating discrete lines, we introduce the topology and geometry of discrete lines.

Abstract: Line Integral Convolution (LIC) is a common approach for the visualisation of 2D vector fields. It is well suited for visualizing the direction of a flow field, but it gives no information about the orientation of the underlying vectors. We introduce Oriented Line Integral Convolution (OLIC), where direction as well as orientation are encoded within the resulting image. This is achieved by using a sparse input texture and a ramp like (anisotropic) convolution kernel. This method can be used for animations, whereby the computation of so called pixel traces fastens the calculation process. Various OLICs illustrating simple and real world vector fields are shown.

Abstract: A probabilistic lighting model is presented for thin coats of fur over skin. Previous methods for rendering furry objects and creatures have addressed the case where individual strands or tufts of hair may be resolvable at the pixel level. These methods are often computationally intensive. However, a large class of realworld cases where individual hairs are much smaller than the size of a pixel can be addressed using a probabilistic model for the expected value of reflected light within a small surface area. Under the assumption that hair parameters are slowly varying across the skin, lighting calculations are performed on a reference hair with prefiltered parameters. The reflected light from individual hairs and from the skin below is blended using the expectation of a ray striking a hair in that area as the opacity of the fur coating. Approximations for hair-to-hair shadowing and hair-to-skin shadowing can be made using the same hit-expectation model. Our system can be implemented in existing commercial surfacerendering software at a much lower computational cost than typical resolvable-hair methods. CR

Abstract: A processor is provided with a first set of digital information that includes a first, resolution-independent structured representation of a document. This first representation is one from which various image collections (e.g., sets of page images) can be obtained, each such image in each such collection having a characteristic resolution. From the first set of digital information, the processor produces a second set of digital information that includes a second, resolution-dependent structured representation of the document. The second structured representation is a lossless representation of a particular one of the image collections obtainable from the first structured representation, and it includes a set of tokens and a set of positions. The second set of digital information is produced by extracting the tokens from the first structured representation, and by determining the positions from the first structured representation. Each extracted token includes pixel data representing a subimage of the particular image collection. Each position is a position of a token subimage in the particular image collection. At least one of the token subimages contains multiple pixels and occurs at more than one position in the image collection. The second set of digital information thus produced can be made available for further use (e.g., distribution, transmission, storage, subsequent reconversion into page images). Applications of the invention include high-speed printing and Internet (World Wide Web) document display.

Abstract: A layered graphics rendering pipeline measures image fidelity ("fiducials") to determine how accurately a transformed image layer approximates a rendering of a 3D object. The graphics rendering pipeline approximates the change in position or color of 3D object by transforming a rendering of the 3D object from a previous frame. The pipeline uses the fiducials to control rendering of factored scene elements to independent image layers. The pipeline then combines the layers to compute frames of animation. The types of fiducials include sampling, visibility, and photometric fiducials. The sampling fiducial measures the distortion of an image sample when warped to screen coordinates. The visibility fiducial measures the change in visibility of a scene element since a previous rendering of the scene element. The photometric fiducial measures either the change in lighting from the time of the previous rendering to the current time, or it measures the difference between warped color samples and actual color samples of the scene element for a current frame.

Abstract: An image processing system for imaging a scene to mosaic, selecting a new viewpoint of the scene, and rendering a synthetic image from the mosaic of the scene from that new viewpoint. The synthesized image is then combined with a second image. The combination of the second image and the synthetic image generates a composite image containing a realistic combination of objects in the second image and the scene. Using this system, a production set or other scene need only be created once, then imaged by the system. Thereafter, through image processing, any view of the scene can be synthesized and combined with separately imaged performers or other objects to generate the composite image. As such, a production set or other scene can be repetitively reused without recreating the physical scene.

Abstract: A graphic display system includes a set of rendering engines and a plurality of data storage units. Each data storage unit in the set of data storage units is coupled to at least one rendering engine in the set of rendering engines. A selection means is included in the graphic display system for selecting a data storage unit in the plurality of data storage units. The selected data storage unit is to be used for storing data representing an object to be displayed by the graphic display system and is selected based on a validity period of the object. The selection means includes means for determining a size validity period of the object and means for determining a translational validity period of the object. The translational validity period is a time required for the object to change by a predetermined translational threshold, wherein the predetermined translational threshold is a first angle extending from a line that passes through both a reference point and the object. The size validity period is a time required for the object to change by a predetermined size threshold, wherein the predetermined size threshold is a second angle extending from the line.