Abstract: A number of techniques have been proposed for flying through scenes by redisplaying previously rendered or digitized views. Techniques have also been proposed for interpolating between views by warping input images, using depth information or correspondences between multiple images. In this paper, we describe a simple and robust method for generating new views from arbitrary camera positions without depth information or feature matching, simply by combining and resampling the available images. The key to this technique lies in interpreting the input images as 2D slices of a 4D function the light field. This function completely characterizes the flow of light through unobstructed space in a static scene with fixed illumination. We describe a sampled representation for light fields that allows for both efficient creation and display of inward and outward looking views. We hav e created light fields from large arrays of both rendered and digitized images. The latter are acquired using a video camera mounted on a computer-controlled gantry. Once a light field has been created, new views may be constructed in real time by extracting slices in appropriate directions. Since the success of the method depends on having a high sample rate, we describe a compression system that is able to compress the light fields we have generated by more than a factor of 100:1 with very little loss of fidelity. We also address the issues of antialiasing during creation, and resampling during slice extraction. CR Categories: I.3.2 [Computer Graphics]: Picture/Image Generation — Digitizing and scanning, Viewing algorithms; I.4.2 [Computer Graphics]: Compression — Approximate methods Additional keywords: image-based rendering, light field, holographic stereogram, vector quantization, epipolar analysis

Abstract: Highly detailed geometric models are rapidly becoming commonplace in computer graphics. These models, often represented as complex triangle meshes, challenge rendering performance, transmission bandwidth, and storage capacities. This paper introduces the progressive mesh (PM) representation, a new scheme for storing and transmitting arbitrary triangle meshes. This efficient, lossless, continuous-resolution representation addresses several practical problems in graphics: smooth geomorphing of level-of-detail approximations, progressive transmission, mesh compression, and selective refinement. In addition, we present a new mesh simplification procedure for constructing a PM representation from an arbitrary mesh. The goal of this optimization procedure is to preserve not just the geometry of the original mesh, but more importantly its overall appearance as defined by its discrete and scalar appearance attributes such as material identifiers, color values, normals, and texture coordinates. We demonstrate construction of the PM representation and its applications using several practical models

Abstract: This paper discusses a new method for capturing the complete appearance of both synthetic and real world objects and scenes, representing this information, and then using this representation to render images of the object from new camera positions. Unlike the shape capture process traditionally used in computer vision and the rendering process traditionally used in computer graphics, our approach does not rely on geometric representations. Instead we sample and reconstruct a 4D function, which we call a Lumigraph. The Lumigraph is a subset of the complete plenoptic function that describes the flow of light at all positions in all directions. With the Lumigraph, new images of the object can be generated very quickly, independent of the geometric or illumination complexity of the scene or object. The paper discusses a complete working system including the capture of samples, the construction of the Lumigraph, and the subsequent rendering of images from this new representation.

Abstract: We present a new approach for modeling and rendering existing architectural scenes from a sparse set of still photographs. Our modeling approach, which combines both geometry-based and imagebased techniques, has two components. The first component is a photogrammetricmodeling method which facilitates the recovery of the basic geometry of the photographed scene. Our photogrammetric modeling approach is effective, convenient, and robust because it exploits the constraints that are characteristic of architectural scenes. The second component is a model-based stereo algorithm, which recovers how the real scene deviates from the basic model. By making use of the model, our stereo technique robustly recovers accurate depth from widely-spaced image pairs. Consequently, our approach can model large architectural environments with far fewer photographs than current image-based modeling approaches. For producing renderings, we present view-dependent texture mapping, a method of compositing multiple views of a scene that better simulates geometric detail on basic models. Our approach can be used to recover models for use in either geometry-based or image-based rendering systems. We present results that demonstrate our approach’s ability to create realistic renderings of architectural scenes from viewpoints far from the original photographs. CR Descriptors: I.2.10 [Artificial Intelligence]: Vision and Scene Understanding Modeling and recovery of physical attributes; I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism Color, shading, shadowing, and texture I.4.8 [Image Processing]: Scene Analysis Stereo; J.6 [Computer-Aided Engineering]: Computer-aided design (CAD).

Abstract: This paper presents a two pass global illumination method based on the concept of photon maps. It represents a significant improvement of a previously described approach both with respect to speed, accuracy and versatility. In the first pass two photon maps are created by emitting packets of energy (photons) from the light sources and storing these as they hit surfaces within the scene. We use one high resolution caustics photon map to render caustics that are visualized directly and one low resolution photon map that is used during the rendering step. The scene is rendered using a distribution ray tracing algorithm optimized by using the information in the photon maps. Shadow photons are used to render shadows more efficiently and the directional information in the photon map is used to generate optimized sampling directions and to limit the recursion in the distribution ray tracer by providing an estimate of the radiance on all surfaces with the exception of specular and highly glossy surfaces.

Abstract: We present an algorithm for real-time level of detail reduction and display of high-complexity polygonal surface data. The algorithm uses a compact and efficient regular grid representation, and employs a variable screen-space threshold to bound the maximum error of the projected image. A coarse level of simplification is performed to select discrete levels of detail for blocks of the surface mesh, followed by further simplification through repolygonalization in which individual mesh vertices are considered for removal. These steps compute and generate the appropriate level of detail dynamically in real-time, minimizing the number of rendered polygons and allowing for smooth changes in resolution across areas of the surface. The algorithm has been implemented for approximating and rendering digital terrain models and other height fields, and consistently performs at interactive frame rates with high image quality.

Abstract: Recent progress in acquiring shape from range data permits the acquisition of seamless million-polygon meshes from physical models. While dense polygon meshes are an adequate representation for some applications, many users prefer smooth surface representations for reasons of compactness, control, manufacturability, or appearance. In this thesis, we present algorithms and an end-to-end software system for converting dense irregular polygon meshes of arbitrary topology into tensor product B-spline surface patches with accompanying displacement maps. This choice of representation yields a coarse but efficient model suitable for interactive modification and animation and a fine but more expensive model suitable for rendering. The first step in our process consists of interactively painting patch boundaries onto the polygonal surface. In many applications, the placement of patch boundaries is considered part of the creative process and is not amenable to automation. We present efficient techniques for representing, creating and editing curves on dense polygonal surfaces. The second step in our process consists of finding a gridded resampling of each bounded section of the mesh. Our resampling algorithm lays a grid of springs across the polygon mesh, then iterates between relaxing this grid and subdividing it. This grid provides a parameterization for the mesh section, which is initially unparameterized. Our parameterization algorithm is automatic, efficient, and robust, even for complex polygonal surfaces. Prior algorithms have lacked one or more of these properties, making them unusable for dense meshes. Our strategy also provides the user a flexible method to design parameterizations--an ability that previous literature in surface approximation does not address. The third and final step of our process consists of fitting a hybrid of B-spline surfaces and displacement maps to our gridded re-sampling. The displacement map is an image representation of the error between the fitted B-spline surfaces and our spring grid. Since displacement maps are just images our hybrid representation facilitates the use of image processing operators for manipulating the geometric detail of an object. Our resampling and fitting steps are fast enough to surface a million polygon mesh in under 10 minutes--important for an interactive system.

Abstract: Imagine visiting your favorite place, taking a few pictures, and then turning those pictures into a photorealisic three-dimensional computer model The work presented in this thesis combines techniques from computer vision and computer graphics to make this possible The applications range from architectural planning and archaeological reconstructions to virtual environments and cinematic special effects This thesis presents an approach for modeling and rendering existing architectural scenes from sparse sets of still photographs The modeling approach, which combines both geometry-based and image-based techniques, has two components The first component is an interactive photogrammetric modeling method which facilitates the recovery of the basic geometry of the photographed scene The photogrammetric modeling approach is effective, convenient, and robust because it exploits the constraints that are characteristic of architectural scenes The second component is a model-based stereo algorithm, which recovers how the real scene deviates from the basic model By making use of the model, this new technique robustly recovers accurate depth from widely-spaced image pairs Consequently, this approach can model large architectural environments with far fewer photographs than current image-based modeling approaches For producing renderings, this thesis presents view-dependent texture mapping, a method of compositing multiple views of a scene that better simulates geometric detail on basic models This approach can be used to recover models for use in either geometry-based or image-based rendering systems This work presents results that demonstrate the approach's ability to create realistic renderings of architectural scenes from viewpoints far from the original photographs This thesis concludes with a presentation of how these modeling and rendering techniques were used to create the interactive art installation Rouen Revisited, presented at the SIGGRAPH '96 art show

Abstract: We present a new method for digitally interpolating images to higher resolution. It consists of two phases: rendering and correction. The rendering phase is edge-directed. From the low resolution image data, we generate a high resolution edge map by first filtering with a rectangular center-on-surround-off filter and then performing piecewise linear interpolation between the zero crossings in the filter output. The rendering phase is based on bilinear interpolation modified to prevent interpolation across edges, as determined from the estimated high resolution edge map. During the correction phase, we modify the mesh values on which the rendering is based to account for the disparity between the true low resolution data, and that predicted by a sensor model operating on the high resolution output of the rendering phase. The overall process is repeated iteratively. We show experimental results which demonstrate the efficacy of our interpolation method.

Abstract: Sphere tracing is a new technique for rendering implicit surfaces that uses geometric distance. Sphere tracing marches along the ray toward its first intersection in steps guaranteed not to penetrate the implicit surface. It is particularly adept at rendering pathological surfaces. Creased and rough implicit surfaces are defined by functions with discontinuous or undefined derivatives. Sphere tracing requires only a bound on the magnitude of the derivative, robustly avoiding problems where the derivative jumps or vanishes. It is an efficient direct visualization system for the design and investigation of new implicit models. Sphere tracing efficiently approximates cone tracing, supporting symbolic-prefiltered antialiasing. Signed distance functions for a variety of primitives and operations are derived.

Abstract: The present invention relates to methods and systems for maintaining application programs on a client computer in a client-server network environment. The task of dynamically upgrading components in the application program running on a client is greatly simplified by rendering control to the individual client rather than to a central server. The version updating procedures of the present invention further provides steps to ensure speedy and error-free transfer of the required files and components through an open network environment, such as the Internet.

Abstract: We propose a new algorithm for automatically computing approximations of a given polyhedral object at different levels of details. The applications for this algorithm is the display of very complex scenes. Our approach is similar to the region-merging method used in image segmentation. We iteratively collapse edges based on a measure of the geometric deviation from the initial shape. when edges are merged in the right order, this strategy produces a continuum of valid approximations of the original object, which can be used for faster rendering at vastly different scales.

Abstract: A system for improved shadowing of images using a multiple pass, depth buffer approach includes rendering a scene from the perspective of a light source to construct a shadow depth map in a rasterization buffer. The system computes depth values for the two nearest geometric primitives to the light source for pixels, and stores these depth values in the rasterization buffer. Once the shadow map is constructed, it is stored in shared memory, where it can be retrieved for subsequent rendering passes. The two depth values for each element in the shadow map can be used in combination with a global bias to eliminate self-shadowing artifacts and avoid artifacts in the terminator region. The system supports linear or higher order filtering of data from the shadow depth map to produce smoother transitions from shadowed and un-shadowed portions of an image. In addition, the system supports the re-use of the shadow map and shadowed images for more than one frame.

Abstract: A process control system includes an alarm and event monitoring and display system for which various users of the system can easily prioritize the alarm and event information that is displayed. The alarm and event configuration is highly flexible and is configured by a user to display particular events in a hierarchical manner, as directed by the user. The user sets a desired alarm priority, selecting high importance alarms for more urgent display and annunciation and rendering a lower display status to less urgent events. At log-on, a particular system user is associated with a display configuration for displaying alarm and event information that is pertinent to that user and the process control system is automatically "primed" with current alarms and initiate process information about new alarm and event occurrences.

Abstract: We present a new method that utilizes path coherence to accelerate walkthroughs of geometrically complex static scenes. As a preprocessing step, our method constructs a BSP-tree that hierarchically partitions the geometric primitives in the scene. In the course of a walkthrough, images of nodes at various levels of the hierarchy are cached for reuse in subsequent frames. A cached image is reused by texture-mapping it onto a single quadrilateral that is drawn instead of the geometry contained in the corresponding node. Visual artifacts are kept under control by using an error metric that quantifies the discrepancy between the appearance of the geometry contained in a node and the cached image. The new method is shown to achieve speedups of an order of magnitude for walkthroughs of a complex outdoor scene, with little or no loss in rendering quality. CR

Abstract: A new and easy-to-implement method for direct volume rendering that uses 3D texture maps for acceleration, and incorporates directional lighting, is described. The implementation, called Voltx, produces high-quality images at nearly interactive speeds on workstations with hardware support for three-dimensional texture maps. Previously reported methods did not incorporate a light model, and did not address issues of multiple texture maps for large volumes. Our research shows that these extensions impact performance by about a factor of ten. Voltx supports orthographic, perspective, and stereo views. This paper describes the theory and implementation of this technique, and compares it to the shear-warp factorization approach. A rectilinear data set is converted into a three-dimensional texture map containing color and opacity information. Quantized normal vectors and a lookup table provide efficiency. A new tesselation of the sphere is described, which serves as the basis for normal-vector quantization. A new gradient-based shading criterion is described, in which the gradient magnitude is interpreted in the context of the field-data value and the material classification parameters, and not in isolation. In the rendering phase, the texture map is applied to a stack of parallel planes, which effectively cut the texture into many slabs. The slabs are composited to form an image.

Abstract: Almost all scientific visualization involving surfaces is currently done via triangles. The speed at which such triangulated surfaces can be displayed is crucial to interactive visualization and is bounded by the rate at which triangulated data can be sent to the graphics subsystem for rendering. Partitioning polygonal models into triangle strips can significantly reduce rendering times over transmitting each triangle individually. We present new and efficient algorithms for constructing triangle strips from partially triangulated models, and experimental results showing these strips are on average 15% better than those from previous codes. Further, we study the impact of larger buffer sizes and various queuing disciplines on the effectiveness of triangle strips.

Abstract: We present a simple method for rendering directly from compressed textures in hardware and software rendering systems. Textures are compressed using a vector quantization (VQ) method. The advantage of VQ over other compression techniques is that textures can be decompressed quickly during rendering. The drawback of using lossy compression schemes such as VQ for textures is that such methods introduce errors into the textures. We discuss techniques for controlling these losses. We also describe an extension to the basic VQ technique for compressing mipmaps. We have observed compression rates of up to 35 : 1, with minimal loss in visual quality and a small impact on rendering time. The simplicity of our technique lends itself to an efficient hardware implementation. CR categories: I.3.7 [Computer Graphics]: 3D Graphics and Realism Texture; I.4.2 [Image Processing]: Compression Coding

Abstract: A self-service kiosk system is provided which includes a monitor having a display screen, a microprocessor electrically coupled to the monitor for controlling the display screen, a browser software executable on the microprocessor for accessing and displaying documents in response to user input, the graphical user interface (GUI) of the browser software including controls for the browser software and a document viewing area, and at least one image positioned for display on the screen so as to mask the controls for the browser software, the image thus rendering the controls inaccessible to a user of the kiosk system to resist tampering with the browser software. The self-service kiosk system may also include a security control software which is programmed to disable system functions available to the user of the kiosk system to resist tampering with operation of the kiosk system.

Abstract: In an image processing system, a method for generating a images includes rendering graphical models comprising a scene to separate image layers called "gsprites," and then compositing these image layers to generate an image. An image processor can retrieve gsprites from memory, transform them, and composite them for display at video rates. Gsprites can be re-rendered or updated at different rates. Reducing the rendering overhead of the system, the image processor can perform an affine transformation on the gsprite to approximate motion of the graphical object that it represents, rather than re-render the object. Objects in a scene can be queued for re-rendering based on a predefined update rate, or based on the accuracy of representing the object with a transformed gsprite, rendered for a previously displayed image.

Abstract: In this paper we show how bidirectional path tracing can be extended to handle global illumination effects due to participating media. The resulting image-based algorithm is computationally expensive but more versatile than previous solutions. It correctly handles multiple scattering in non-homogeneous, anisotropic media in complex illumination situations. We illustrate its specific advantages by means of examples.

Abstract: A method for improved multi-pass rendering in a graphics system includes rendering geometry in a scene to generate rendered image data and then feeding back this rendered image data for a subsequent rendering pass for the same or other geometry in a scene. Geometric primitives are rasterized to generate pixel data, which is stored in a rasterization buffer. The pixel data, including lists of fragment records, is resolved and stored in a shared memory. Resolved pixel data can be combined to generate a display image at real-time, interactive rates. The resolved pixel data can also be used as a texture for subsequent rendering operations. Geometry in a scene can be rasterized in more than one pass to generate pixel data including fragments for partially covered pixels. Fragments from subsequent passes can be blended with corresponding fragments stored in the rasterization buffer from a previous pass.

Abstract: A method for rendering graphical objects in a scene to generate a display images includes dividing the geometric primitives of models in a scene among portions or "chunks" of the view space to which the primitives will be rendered, and then rendering geometry referenced to the chunks in series in a common depth buffer. Geometry for a chunk can be rendered, including sophisticated anti-aliasing and translucency computations, using a minimum of memory. Serially rendering object geometry in chunks provides an effective form of compression because pixel fragments can be generated for one chunk at a time and then resolved. Pixel fragments can be resolved in a post-processing step for one chunk while primitives for another chunk are rasterized.

Abstract: Despite recenl advances in rendering hardware, large and complex virtual environments cannot be displayed with a sufficiently high frame rate, because of limitations in the available rendering performance. This paper presents a new approach of software accelerated rendering which draws from the concepts of impostors, hierarchical scene subdivision and levels of detail. So far software optimization in real-time rendering has merely considered individual objects. This work is actually optimizing the rendering of the whole virtual environment by implementing a three dimensional image cache. It speeds up rendering for large portions of the scene by exploiting the coherence inherent in any smooth frame sequence. The implementation of the three dimensional image cache is discussed and the savings in rendering load achievable on a suitable hardware platform are presented.

Abstract: Figures. Examples. Foreword. Acknowledgments. About This Book. What This Book Contains. How to Use This Book. Conventions Used in This Book. Related Reading. About the Aztec Site. Credits. The Changing VRML World. 1. Introduction. 3D Models versus 2D Images. Cutting-Edge Technology. A Brief Look at the Development of VRML. What's New in VRML 2.0? Enhanced Static Worlds. Interaction. Animation and Behavior Scripting. Prototyping. VRML File Information. 2. Getting Plugged Into the World Wide Web. Locating Documents on the Web. Browser and Server. Viewing VRML Scenes. Types of Internet Access. Gateway Service. Dial-Up Direct Connection. Dedicated Direct Connection. Finding an Internet Service Provider (ISP). VRML Browsers. Creating VRML Scenes. Publishing Your Work. 3. Exploring and Building a World. Exploring Aztec City. Do-It-Yourself Tour. Guided Tour. On Your Way. The Eagle Lands. Temple of Quetzalcoatl. At the Base of the Temple. Texture Mapping to Add Details. View from the Top. Reusing Objects. Exploring the Shrines. Traveling through Time. Building a World. Creating Objects. Using External Files: Inline Nodes. Using Multiple Instances of an Object. Linking to Other Objects. Combining Objects into Worlds. Looking at the Scene. Interacting with the Scene. Starting from Scratch. Develop a Story Board. Build Objects. Add Animation and Scripts. Refine and Test. Moving On. 4. Building Objects. Starting Your Temple. Transformations. Translation and the Standard Unit of Distance. Rotation. Scaling. Combining Transformations. Order of Transformations. Geometry. Simple Geometry Nodes. Irregular Geometry. Text (Flat). Appearances. Appearance Nodes. Materials. Textures. Prototypes. Fields Versus Events. EXTERNPROTO. 5. Lighting, Sound, and Complex Shapes. Lights. Scope of Lights. Common Attributes of Lights. Attenuation. DirectionalLight Nodes. PointLight Nodes. SpotLight Nodes. Sound. AudioClip. Complex Shapes. Terrain Modeling with the ElevationGrid Node. Extrusions. What's Next? 6. Animation and User Interaction. Events and Routes Revisited. The Animation Event Path. Triggers and Targets. Timers. Engines. Animation Hints. 7. Scripting. Script Node Syntax. How Scripts Handle Events. Special Functions. Field Types in JavaScript. Scripting and Animation. Locate-Highlighting: A Glowing Skull. Switching among Choices: The Eagle Has Landed. Other Fittings. Logic. Computed Animation. Advanced Scripting. The Browser Script Interface (Browser API). Scene Hierarchy Manipulation. Binding the Browser to a Node. Network Access. Multiuser Worlds. 8. Using Colors, Normals, and Textures. Colors. Specifying Colors Per Face. Specifying Colors Per Vertex. Lines and Points. Normals. Using Default Normals. Specifying Normals Per Face. Specifying Normals Per Vertex. Advanced Textures. What Is a Texture Map? Movie Textures. Components of a Texture. Combining Textures, Colors, and Materials. Specifying Texture Coordinates. Transforming a Texture. Repeating or Clamping a Texture. How to Specify a Pixel Texture. Backgrounds with Textures. Creating the Panorama Scene. Adding Ground and Sky Colors. Combining a Panorama with Ground and Sky Color. 9. Publishing Your Work. Setting Up a Server. Security Issues. Configuring a Server to Recognize VRML Files. Your URL. Organizing and Publishing Your Files. Use Relative Addresses. Use MIME Type Extensions. Verify Remote URLs. Add Information Nodes. Compress the Files. Announce Your Work on the Web. Using the Common Gateway Interface (CGI). HTML Form. Script. Putting Form and Script Files on the Server. 10. Improving Performance. Reducing File Size. Use Instancing. Use Prototypes. Use the Text Node. Use Space-Efficient Geometry Nodes. Use Automatic Normals. Eliminate White Space. Round Floating Point Numbers. Compress Files. Increasing Rendering Speed. Simplify the Scene. Divide and Conquer. Let the Browser Do Its Job. Turn Off Collision Detection and Use Collision Proxies. Use Scripts Efficiently. 11. Node Reference. Suggested Structure of a VRML File. Rules for Names. Anchor. Appearance. AudioClip. Background. Billboard. Box. Collision. Color. ColorInterpolator. Cone. Coordinate. CoordinateInterpolator. Cylinder. CylinderSensor. DirectionalLight. ElevationGrid. Extrusion. Fog. FontStyle. Group. ImageTexture. IndexedFaceSet. IndexedLineSet. Inline. LOD. Material. MovieTexture. NavigationInfo. Normal. NormalInterpolator. OrientationInterpolator. PixelTexture. PlaneSensor. PointLight. PointSet. PositionInterpolator. ProximitySensor. ScalarInterpolator. Script. Shape. Sound. Sphere. SphereSensor. SpotLight. Switch. Text. TextureCoordinate. TextureTransform. TimeSensor. TouchSensor. Transform. Viewpoint. VisibilitySensor. WorldInfo. 12. Field Reference. SFBool. SFColor and MFColor. SFFloat and MFFloat. SFImage. SFInt 32 and MFInt 32. SFNode and MFNode. SFRotation and MFRotation. SFString and MFString. SFTime and MFTime. SFVec2f and MFVec2f. SFVec3f and MFVec3f. A. Obsolete Nodes. B. Java Notes and Examples. Java Notes. Examples. Locate-Highlighting. Integer Interpolator. State Retention. Viewpoint Binding. Glossary. Index. 0201479443T04062001

Abstract: A graphics rendering chip serially renders a stream of geometric primitives to image regions called chunks. A set-up processor in the chip parses rendering commands and the stream of geometric primitives and computes edge equation parameters. A scan-convert processor receives the edge equation parameters from the set-up processor and scan converts the geometric primitives to produce pixel records and fragment records. An internal, double-buffered pixel buffer stores pixel records for fully covered pixel addresses and also stores references to fragment lists stored in a fragment buffer. A pixel engine performs hidden surface removal and controls storage of pixel and fragment records to the pixel and fragment buffers, respectively. An anti-aliasing engine resolves pixel data for one pixel buffer while the pixel engine fills the other pixel buffer with pixel data for the next chunk.

Abstract: We present Cube-4, a special-purpose volume rendering architecture that is capable of rendering high-resolution (e.g., 1024/sup 3/) datasets at 30 frames per second. The underlying algorithm, called slice-parallel ray-casting, uses tri-linear interpolation of samples between data slices for parallel and perspective projections. The architecture uses a distributed interleaved memory, several parallel processing pipelines, and an innovative parallel data flow scheme that requires no global communication, except at the pixel level. This leads to local, fixed bandwidth interconnections and has the benefits of high memory bandwidth, real-time data input, modularity, and scalability. We have simulated the architecture and have implemented a working prototype of the complete hardware on a configurable custom hardware machine. Our results indicate true real-time performance for high-resolution datasets and linear scalability of performance with the number of processing pipelines.

Abstract: A system for providing a primarily audio environment for world wide web access includes a system for rendering structured documents using audio, an interface for information exchange to users, a non-keyword based WWW search system and a few miscellaneous features. The system for rendering structured documents using audio includes a pre-rendering system which converts a HTML document into an intermediate document and a rendering system which actually generates an audio output. The interface includes a non-visual browsing system and an interface to users for visual browsing environments.

Abstract: This paper presents a new method of rendering for interaction with 3D virtual space with the use of gaze detection devices In this method, hierarchical geometric models of graphic objects are constructed prior to the rendering process The rendering process first calculates the visual acuity, which represents the importance of a graphic object for a human operator, from the gaze position of the operator Second, the process selects a level from the set of hierachical geometric models depending on the value of visual acuity That is, a simpler level of detail is selected where the visual acuity is lower, and a more complicated level is used where it is higher Then, the selected graphic models are rendered on the display This paper examines three visual characteristics to calculate the visual acuity: the central/peripheral vision, the kinetic vision, and the fusional vision The actual implementation and our testbed system are described, as well as the details of the visual acuity model