Showing papers in "IEEE Computer Graphics and Applications in 1992"
TL;DR: Cue theory, which states that the visual system computes the distances of objects in the environment based on information from the posture of the eyes and from the patterns of light projected onto the retinas by the environment, is presented.
Abstract: The sources of visual information that must be present to correctly interpret spatial relations in images, the relative importance of different visual information sources with regard to metric judgments of spatial relations in images, and the ways that the task in which the images are used affect the visual information's usefulness are discussed Cue theory, which states that the visual system computes the distances of objects in the environment based on information from the posture of the eyes and from the patterns of light projected onto the retinas by the environment, is presented Three experiments in which the influence of pictorial cues on perceived spatial relations in computer-generated images was assessed are discussed Each experiment examined the accuracy with which subjects matched the position, orientation, and size of a test object with a standard by interactively translating, rotating, and scaling the test object >
300 citations
TL;DR: In this article, a generalization of the chamfer distance calculation is proposed, which allows the simultaneous calculation of distances within the object and its background by two consecutive chamfering processes.
Abstract: Extensions to a shape-based interpolation method in which pixels that share a boundary edge (one inside and the other outside the object) are considered to be at a distance between adjacent pixel centers are proposed. Using such an initialization for distance calculations, a generalization of the chamfer distance calculation is developed. The generalization allows the simultaneous calculation of distances within the object and its background by two consecutive chamfering processes. The performances of a number of variants of the methods are evaluated. It is shown that the shape-based interpolation using a near-optimal 3*3 distance and modified cubic spline between-slice interpolation has superior properties to previously proposed methods for estimating object locations in missing slices in tomographic radiology. >
297 citations
TL;DR: In this article, a linearized optimal color scale (LOCS) was proposed for medical image data, and it was found that although observers performed somewhat better with the newly developed LOCS than with the previously advocated heated-object color scale, they performed significantly better with a linearised gray scale than with either of the color scales.
Abstract: Desirable properties of color scales are examined, and a linearized optimal color scale (LOCS) is introduced. The merits of color scales for medical image data were studied, and it was found that, in tests, although observers performed somewhat better with the newly developed LOCS than with the previously advocated heated-object color scale, they performed significantly better with a linearized gray scale than with either of the color scales. After evaluating these results, the authors suggest alternate solutions that might help observers perform better. Nonetheless, they believe that color scales can contribute to the perception of information in images. >
278 citations
TL;DR: A surface manipulation technique that uses distance fields-scalar fields derived geometrically from surface models-to combine, modify, and analyze surfaces is presented, intended for application to complex models arising in scientific visualization.
Abstract: A surface manipulation technique that uses distance fields-scalar fields derived geometrically from surface models-to combine, modify, and analyze surfaces is presented. It is intended for application to complex models arising in scientific visualization. Computing distance from single triangles is discussed, and an optimized algorithm for computing the distance field from an entire closed surface is built. The use of the fields for surface removal, interpolation and blending is examined. The strength of the approach is that it lets simple 3D algorithms substitute for potentially very complex 2D methods. >
236 citations
TL;DR: The algorithm constructs a discontinuity mesh that explicitly represents discontinuities in the radiance function as boundaries between mesh elements, preserving the discontinUities associated with the edges in the mesh.
Abstract: An algorithm for compactly and accurately capturing the illumination of a diffuse polyhedral environment caused by an area light source is presented. The algorithm constructs a discontinuity mesh that explicitly represents discontinuities in the radiance function as boundaries between mesh elements. A piecewise quadratic interpolant is used to approximate the radiance function, preserving the discontinuities associated with the edges in the mesh. >
197 citations
TL;DR: The multimedia video processor (MVP) architecture as mentioned in this paper combines, on a single semiconductor chip, multiple fully programmable processors with multiple data streams connected to shared RAMs through a crossbar network.
Abstract: The multimedia video processor (MVP) architecture, which incorporates a variety of parallel processing techniques to deliver very high performance to a wide range of imaging and graphics applications, is described. The MVP combines, on a single semiconductor chip, multiple fully programmable processors with multiple data streams connected to shared RAMs through a crossbar network. Each of the independent processors can execute many operations in parallel every cycle. The architecture is scalable and supports different numbers of processors to meet the cost and performance requirements of different markets. MVP's target environment and the development of MVP are outlined. >
192 citations
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TL;DR: It is shown that RRT operates in two phases: preprocessing voxel and discrete ray tracing, which employs a discrete variation of the conventional recursive ray tracer in which 3-D discrete rays are traversed through the3-D raster to find the first surface voxels.
Abstract: Discrete ray tracing, or 3-D raster ray tracing (RRT), which, unlike existing ray tracing methods that use geometric representation for the 3-D scene employs a 3-D discrete raster of voxels for representing the 3-D scene in the same way a 2-D raster of pixels represents a 2-D image, is discussed. Each voxel is a small quantum unit of volume that has numeric values associated with it representing some measurable properties or attributes of the real object or phenomenon at that voxel. It is shown that RRT operates in two phases: preprocessing voxel and discrete ray tracing. In the voxel phase, the geometric model is digitized using 3-D scan-conversion algorithms that convert the continuous representation of the model into a discrete representation within the 3-D raster. In the second phase, RRT employs a discrete variation of the conventional recursive ray tracer in which 3-D discrete rays are traversed through the 3-D raster to find the first surface voxel. Encountering a nontransparent voxel indicates a ray-surface hit. Results obtained by running the RRT software one one 20-MIPS (25-GHz) processor of a Silicon Graphics 4D/240GTX are presented in terms of CPU time. >
169 citations
TL;DR: The design and implementation of a virtual environment linked to a graphics workstation for the visualization of complex fluid flows and the performance of the virtual wind tunnel is reviewed.
Abstract: The design and implementation of a virtual environment linked to a graphics workstation for the visualization of complex fluid flows are described. The system user wears a stereo head-tracked display, which effectively displays 3-D information, and an instrumented glove to intuitively position flow-visualization tools. The visualization structures and their interfaces in the virtual environment and the implementation hardware and software are described. The performance of the virtual wind tunnel is reviewed using the flow past a tapered cylinder as an example. Performance issues and future directions for the system are discussed. >
164 citations
Journal Article•
TL;DR: The multimedia video processor architecture, which incorporates a variety of parallel processing techniques to deliver very high performance to a wide range of imaging and graphics applications, is described.
Abstract: We defined the multimedia video processor (MVP) to accelerate applications with heavy image and graphics processing requirements. Here we give an overview of the architecture
144 citations
TL;DR: A survey of the field of solid modeling and an assessment of its strengths and limitations are presented.
Abstract: A survey of the field of solid modeling and an assessment of its strengths and limitations are presented. The survey covers mathematical foundations, representations, algorithms, applications, user interfaces and systems. The primary conferences for each of these five aspects of solid modeling are listed. >
138 citations
TL;DR: A volume model data structure for constructing 3-D anatomical atlases is discussed, providing the look and feel of an actual dissection by visualizing both surface and volume properties of the anatomy and is flexible, letting users easily incorporate extensions both on the level of the spatial primitives and the relational descriptions.
Abstract: A volume model data structure for constructing 3-D anatomical atlases is discussed. The volume model provides the look and feel of an actual dissection by visualizing both surface and volume properties of the anatomy and is flexible, letting users easily incorporate extensions both on the level of the spatial primitives and the relational descriptions. The procedures for filling the data structure, and the visualization, composition, interrogation, and simulation tools used to explore the model are described. The development of a 3-D atlas of the human head to test the framework's performance is also described. >
TL;DR: The interval Bezier curve, which, unlike other curve and surface approximation schemes, can transfer a complete description of approximation errors between diverse CAD/CAM systems that impose fundamentally incompatible constraints on their canonical representation schemes, is described.
Abstract: The interval Bezier curve, which, unlike other curve and surface approximation schemes, can transfer a complete description of approximation errors between diverse CAD/CAM systems that impose fundamentally incompatible constraints on their canonical representation schemes, is described. Interval arithmetic, which offers an essentially infallible way to monitor error propagation in numerical algorithms that use floating-point arithmetic is reviewed. Affine maps, the computations of which are key operations in the de Casteljau subdivision and degree-elevation algorithms for Bezier curves, the floating-point error propagation in such computations, approximation by interval polynomials, and approximation by interval Bezier curves are discussed. >
TL;DR: The main geometric features of the nonuniform rational B-splines (NURBS) curve and surface representations are described and it is shown that most of these features are already exhibited by conics, which are a special case of NURBS.
Abstract: The main geometric features of the nonuniform rational B-splines (NURBS) curve and surface representations are described. It is shown that most of these features are already exhibited by conics, which are a special case of NURBS. The properties typical of NURBS are discussed without dwelling on properties already present in polynomial curves. Conic sections and their representations using rational Bezier curves are reviewed. Cubic NURB curves, geometrical rational splines, rational and B-spline surfaces, and rational Bezier triangles are discussed. >
TL;DR: An efficient method using a trigonal prism model to render individual human hairs is presented and proves effective for rendering eyebrows, eyelashes, beards, moustaches, clothes and personal ornaments such as earrings and hair accessories.
Abstract: The difficulties involved in modeling and rendering hair in computer graphics are described. An efficient method using a trigonal prism model to render individual human hairs is presented. A wisp model easily controls hair shape with a few parameters. The method also proves effective for rendering eyebrows, eyelashes, beards, moustaches, clothes and personal ornaments such as earrings and hair accessories. A double z-buffer generates the backlighting effect. A simple parabola approximates wisp loci for hair animation. The method makes it possible to draw an enormous number of hairs within a reasonably short time. >
TL;DR: Time-multiplexed stereoscopic systems, which present the stereoscopic image by alternating right- and left-eye views of a scene on a CRT, are considered.
Abstract: Time-multiplexed stereoscopic systems, which present the stereoscopic image by alternating right- and left-eye views of a scene on a CRT, are considered. The current technology for stereoscopic computer graphics is introduced, and an overview of factors important to the proper construction and display of computer images in a time-multiplexed environment is provided. The discussion covers the computation of stereoscopic views, stereoscopic display algorithms, horizontal parallax and factors affecting image quality. >
TL;DR: A combination of segmentation tools and fast volume renderers that provides an interactive exploration environment for volume visualization and the flexibility and power of combining volume rendering with region-of-interest selection techniques are demonstrated using examples of medical imaging applications.
Abstract: A combination of segmentation tools and fast volume renderers that provides an interactive exploration environment for volume visualization is discussed. The tools and renderers include mechanisms that distribute volume data across multiple processors, as well as image compositing techniques and solutions to representation problems in the selection and display of subregions within bounding volumes. A volume visualization technique using the interactive control of images rendered directly from volume data coupled with a user-controlled semantic classification tool is described. The variations of parallel volume rendering being explored on the Pixel-Planes 5 system and the region-of-interest selection methods and the interactive tools used by the system are presented. The flexibility and power of combining volume rendering with region-of-interest selection techniques are demonstrated using examples of medical imaging applications. >
TL;DR: Various visualization techniques that identify unwanted curvature regions, such as inflection points and dents, are reviewed.
Abstract: Various visualization techniques that identify unwanted curvature regions, such as inflection points and dents, are reviewed. Orthotomics for the convexity test, isophotes for the geometric continuity test for the boundaries of a patchwork, reflection lines for the aesthetic quality of a surface, and local surfaces for the detection of undesired curvature situations on a surface are discussed. >
IBM1
TL;DR: An algorithm that was designed for the data typically found in reservoir simulation and structural analysis is presented and can be used to visualize scalar volumes of irregular computational meshes.
Abstract: An algorithm that was designed for the data typically found in reservoir simulation and structural analysis is presented. Designed for general applicability and high efficiency, it can be used to visualize scalar volumes of irregular computational meshes. The algorithm accepts as input virtually any 3-D mesh used in computer simulations. Pictures of practical value can be drawn interactively. >
TL;DR: The definition of a Voronoi diagram is extended to arbitrary set-theoretic solid models and a method for approximating such diagrams using recursive subdivision is described, which relies on octrees.
Abstract: The definition of a Voronoi diagram is extended to arbitrary set-theoretic solid models. A method for approximating such diagrams using recursive subdivision is described. The method relies on octrees, which have been used for computing the distances between whole solid models. Two- and three-dimensional images generated using the algorithm are presented. >
TL;DR: A family of techniques for creating intuitively informative shaded images of 4-D mathematical objects is proposed, and results of rendering a Steiner surface, torus, and knotted sphere in four dimensions are presented.
Abstract: A family of techniques for creating intuitively informative shaded images of 4-D mathematical objects is proposed. The rendering of an object in a 4-D world is described by considering step-by-step how objects might be rendered into images in simpler worlds. The mathematical principles needed to compute projected images of objects and their shadows in D dimensions are outlined. The issues involved in producing shaded images of objects in four dimensions, including extending rendering from 3-D to 4-D, smooth shading, and specularity, are discussed. Results of rendering a Steiner surface, torus, and knotted sphere in four dimensions are presented. >
TL;DR: A survey comparing methods for constructing smooth parametric surfaces to interpolate vertices and normal vectors of a triangulated polyhedron is presented, and it is shown that the setting of these remaining free parameters can dramatically affect the shape of the surface.
Abstract: A survey comparing methods for constructing smooth parametric surfaces to interpolate vertices and normal vectors of a triangulated polyhedron is presented. Particular attention is paid to the quality or fairness of the fit, measured by examining how curvature is distributed over the surface. The methods surveyed all generate surfaces composed of one or more surface patches per triangular facet of the input polyhedron. The approaches require an analysis of the number of constraints versus the number of degrees of freedom. Constraints include not only the interpolation conditions, but also continuity conditions imposed where adjacent surface patches abutt. Once the constraints are satisfied, there are generally surplus degrees of freedom. It is shown that the setting of these remaining free parameters can dramatically affect the shape of the surface, so the various methods are classified according to how they assign values to the free parameters. >
TL;DR: The algorithm relies on the convex hull and on the variation diminishing properties of Bezier/B-spline curves to deliver fitting curves that approximate the data with high accuracy even in cases with large tolerances.
Abstract: A geometric method for fitting rational cubic B-spline curves to data representing smooth curves, such as intersection curves or silhouette lines, is presented. The algorithm relies on the convex hull and on the variation diminishing properties of Bezier/B-spline curves. It is shown that the algorithm delivers fitting curves that approximate the data with high accuracy even in cases with large tolerances. The ways in which the algorithm computes the end tangent magnitudes and inner control points, fits cubic curves through intermediate points, checks the approximate error, obtains optimal segmentation using binary search, and obtains appropriate final curve form are discussed. >
TL;DR: A fundamental light reflection model that takes into account the internal structure of cloth to render the peculiar gloss of cloth objects is presented and can express the properties of several kinds of cloth.
Abstract: A fundamental light reflection model that takes into account the internal structure of cloth to render the peculiar gloss of cloth objects is presented. In developing this model, the microscopic structure of textiles was considered. The model represents fabric features such as fiber's cross-sectional shape or weave. By measuring the reflected light intensity from actual cloth objects of several typical materials, it was verified that the model can express the properties of several kinds of cloth, and the parameters in the model were defined. >
TL;DR: It's always a red letter day when I can figure out a new use for homogeneous coordinates, and this time I'll tell you about a way to use them to interpolate various parameters properly when tiling polygons.
Abstract: It's always a red letter day when I can figure out a new use for homogeneous coordinates. This time I'll tell you about a way to use them to interpolate various parameters properly when tiling polygons. The exact definition of "properly" comes from one of those things that homogeneous coordinates are good at-perspective.
TL;DR: It is shown that, using this method, CAD users can generate numerically controlled (NC) tool paths and use them to automatically machine 3-D surface geometries with various cutting tools such as ball-nose or spherical-end cutters and toroidal or flat- end cutters.
Abstract: A feature-based method for designing and representing functional surfaces such as automobile inner panels that lets a user assemble and present complicated, multifeatured surfaces using known, generally simpler component surfaces and information about feature shape is reviewed. It is shown that, using this method, CAD users can generate numerically controlled (NC) tool paths and use them to automatically machine 3-D surface geometries with various cutting tools such as ball-nose or spherical-end cutters and toroidal or flat-end cutters. The method was tested on models involving simple explicit primary and secondary surfaces as well as more complicated B-spline parametric surfaces. Results indicate that the tool-center-generation algorithm is accurate, robust, and computationally efficient. >
TL;DR: The PixelFlow Enhanced Memory Chip (EMC) as mentioned in this paper is a pixel memory on-chip with rasterizing processors that provides the two to three orders of magnitude improvement in access rates needed to support realistic shading models and aliasing in interactive systems.
Abstract: Logic-enhanced memory chips that can remove the rasterizer/frame buffer bottleneck which limits the performance of current image-generation architectures are discussed. Putting pixel memory on-chip with rasterizing processors provides the two to three orders of magnitude improvement in access rates needed to support realistic shading models and aliasing in interactive systems. Current high-performance graphics systems and logic-enhanced memory architectural issues are reviewed. The design of the PixelFlow Enhanced Memory Chip (EMC), which exploits advances in semiconductor technology and circuit techniques to build compact, high-performance rasterizers, is described. >
TL;DR: A particle system technique to model, render, and animate realistic fireworks displays is presented and a rendering engine that consists of various modules which individually handle a particular property of the particle is described.
Abstract: A particle system technique to model, render, and animate realistic fireworks displays is presented. The attributes of the fireworks display that the particle system models are color, brightness, shape, trial, size, particle dynamics, blinking, mousing, star effect, spinning, and elasticity. A rendering engine that consists of various modules which individually handle a particular property of the particle is described. >
TL;DR: The Image chip, which accelerates 3D rendering algorithms base on Bresenham's line drawing and Pineda's parallel polygon drawing algorithms, is discussed and the designs of Image's internal architecture, host interface, and memory interface are described.
Abstract: The Image chip, which accelerates 3D rendering algorithms base on Bresenham's line drawing and Pineda's parallel polygon drawing algorithms, is discussed. With these algorithms, Image can directly draw lines, spans, and triangles in wireframe, hidden-line, and Gouraud-shading modes. Image also directly antialiases vectors or provides antialiasing information to enhance antialiasing of vectors or triangles. Image's operation, separation into layers to maximize performance and simplify the input and output interfaces, and support of advanced rendering effects such as Phong shading and texture mapping are described. The designs of Image's internal architecture, host interface, and memory interface are also described. >
TL;DR: Geometric constructions for computing plane sections of the natural quadric surfaces that operate on planes and natural quadrics in general position and orientation are developed and do not employ coordinate system transformations of any sort.
Abstract: Geometric constructions for computing plane sections of the natural quadric surfaces that operate on planes and natural quadrics in general position and orientation are developed. The procedures separate geometric descriptions of the resulting conic sections. The algorithms are extremely fast, numerically robust, and do not employ coordinate system transformations of any sort. >
TL;DR: Techniques that aid the realistic rendering of lighting effects achieved from linear (1-D) and area ( area) light sources are presented, based on a radiosity model that can be inserted into any traditional ray tracer.
Abstract: Techniques that aid the realistic rendering of lighting effects achieved from linear (1-D) and area (2-D) light sources are presented. They are based on a radiosity model that can be inserted into any traditional ray tracer. The approach is applied to both a 1-D light, analogous to a fluorescent tube, and to a 2-D light, analogous to a light set into the ceiling. >