Showing papers in "IEEE Computer Graphics and Applications in 1998"
TL;DR: A system for real-time interpolated animation that addresses some of the problems of simulated figures that alter their actions based on their momentary mood or in response to changes in their goals or environmental stimuli.
Abstract: The article describes a system for real-time interpolated animation that addresses some of these problems. Through creating parameterized motions-which the authors call verbs parameterized by adverbs-a single authored verb produces a continuous range of subtle variations of a given motion at real-time rates. As a result, simulated figures alter their actions based on their momentary mood or in response to changes in their goals or environmental stimuli. For example, they demonstrate a walk verb that can show emotions such as happiness and sadness, and demonstrate subtle variations due to walking up or down hill while turning to the left and right. They also describe verb graphs, which act as the glue to assemble verbs and their adverbs into a runtime data structure. Verb graphs provide the means for seamless transition from verb to verb for the simulated figures within an interactive runtime system. Finally they briefly discuss the discrete event simulator that handles the runtime main loop.
754 citations
TL;DR: The authors present one approach to populating virtual environments-using dynamic simulation to generate the motion of characters, and explore this approach's effectiveness with two virtual environments: the border collie environment, in which the user acts as a border collies to herd robots into a corral, and the Olympic bicycle race environment, where the user participates in a bicycle race with synthetic competitors.
Abstract: Animated characters can play the role of teachers or guides, team mates or competitors, or just provide a source of interesting motion in virtual environments. Characters in a compelling virtual environment must have a variety of complex and interesting behaviors, and be responsive to the user's actions. The difficulty of constructing such synthetic characters currently hinders the development of these environments, particularly when realism is required. The authors present one approach to populating virtual environments-using dynamic simulation to generate the motion of characters. They explore this approach's effectiveness with two virtual environments: the border collie environment, in which the user acts as a border collie to herd robots into a corral, and the Olympic bicycle race environment, in which the user participates in a bicycle race with synthetic competitors.
338 citations
TL;DR: A software system that explicitly attempts to handle much larger graphs than previous systems and support dynamic exploration rather than final presentation is described and the applicability of this system to goals beyond simple exploration is discussed.
Abstract: Drawing graphs as nodes connected by links is visually compelling but computationally difficult. Hyperbolic space and spanning trees can reduce visual clutter, speed up layout, and provide fluid interaction. This article briefly describes a software system that explicitly attempts to handle much larger graphs than previous systems and support dynamic exploration rather than final presentation. It then discusses the applicability of this system to goals beyond simple exploration. A software system that supports graph exploration should include both a layout and an interactive drawing component. I have developed new algorithms for both layout and drawing (H3 and H3Viewer). The H3Viewer drawing algorithm remains under development, so this article presents preliminary results. I have implemented a software library that uses these algorithms. It can handle graphs of more than 100,000 edges by using a spanning tree as the backbone for the layout and drawing algorithms.
230 citations
TL;DR: This work describes vision algorithms for interactive graphics and presents vision-controlled graphics applications using these algorithms to help make computers easier to use.
Abstract: Vision can be a powerful interface device for computers because of its potential for sensing body position, head orientation, direction of gaze, pointing commands, and gestures. Such unencumbered interaction can make computers easier to use. We describe vision algorithms for interactive graphics and present vision-controlled graphics applications using these algorithms. Some applications employ an artificial retina chip for image detection or preprocessing.
227 citations
TL;DR: This article presents a different approach to calculating the global illumination of objects: to achieve a reasonable approximation with high performance, placing global illumination effects within reach of many applications in which visual appearance is more important than absolute numerical accuracy.
Abstract: A major goal in computer graphics is realistic image synthesis. To this end, illumination methods have evolved from simple local shading models to physically based global illumination algorithms. Local illumination methods consider only the light energy transfer between an emitter and a surface (direct lighting), while global methods account for light energy interactions between all surfaces in an environment, considering both direct and indirect lighting. Even though the realistic effects that global illumination algorithms provide are frequently desirable, the computational expense of these methods is too great for many applications. Dynamic environments and scenes containing a very large number of surfaces often pose problems for global illumination methods. This article presents a different approach to calculating the global illumination of objects. Instead of striving for accuracy at the expense of performance, we rephrase the goal: to achieve a reasonable approximation with high performance. This places global illumination effects within reach of many applications in which visual appearance is more important than absolute numerical accuracy.
223 citations
TL;DR: The theory and implementation of low-frequency electric fields as sensing techniques are outlined, then a range of applications developed for interacting with computer graphics are presented.
Abstract: The earliest bit-mapped graphical computers have progressed to bring real-time 3D rendering and digital video to the desktop, but the common physical interface remains unchanged from the first workstations. As a result, many applications, such as modeling or navigating in virtual worlds, are often limited not by processing speed but by the users' difficulty in conveying desired actions to the computer. We outline the theory and implementation of low-frequency electric fields as sensing techniques, then present a range of applications developed for interacting with computer graphics.
222 citations
TL;DR: A single system containing all the modules needed for simulating real-time virtual humans in distant virtual environments (VEs) and letting one rapidly clone any individual and animate the clone in various contexts is developed.
Abstract: The authors have been working on simulating virtual humans for several years. Until recently, these constructs could not act in real time. Today, however, many applications need to simulate in real time virtual humans that look realistic. They have invested considerable effort in developing and integrating several modules into a system capable of animating humans in real-time situations. This includes interactive modules for building realistic individuals and a texture-fitting method suitable for all parts of the head and body. Animating the body, including the hands and their deformations, is the key aspect of the system; to their knowledge, no competing system integrates all these functions. They also included facial animation, as demonstrated below with virtual tennis players. They have developed a single system containing all the modules needed for simulating real-time virtual humans in distant virtual environments (VEs). The system lets one rapidly clone any individual and animate the clone in various contexts. People cannot mistake virtual humans for real ones, but they think them recognizable and realistic.
158 citations
TL;DR: The authors present a model-based algorithm that estimates 3D motion and facial expressions from 2D image sequences showing head and shoulder scenes typical of video telephone and teleconferencing applications.
Abstract: The authors present a model-based algorithm that estimates 3D motion and facial expressions from 2D image sequences showing head and shoulder scenes typical of video telephone and teleconferencing applications.
146 citations
TL;DR: Structuring user interactions using a spreadsheet paradigm creates a powerful tool for information visualization and provides a framework for exploring large and complex data sets.
Abstract: The visualization spreadsheet provides a framework for exploring large and complex data sets. Structuring user interactions using a spreadsheet paradigm creates a powerful tool for information visualization.
141 citations
TL;DR: The author discusses the following issues: sources of imperfection in information; representing the degree of imperfections; intuitive visual metaphors and cues for representing imperfection; imperfect presentation; and notions of managing imperfection and visualization.
Abstract: Visualized data and information can be inaccurate or even wrong. Moreover, in the synthetic digital world anybody can visualize anything in any shape or form, disregarding how users might perceive or get the information. Worse, as technology develops, it becomes easier to do so. Understanding the data and information and reaching sound decisions require knowing what pieces of information or data are accurate, complete, consistent, and certain, identifying which are not and by how much, and making the presentation accurate. The author discusses the following issues: sources of imperfection in information; representing the degree of imperfection; intuitive visual metaphors and cues for representing imperfection; imperfect presentation; and notions of managing imperfection and visualization.
140 citations
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TL;DR: The first step in bringing a computer puppet to life is creating the character's concept, and the author refers to Medialab's methods and procedures to illustrate this process.
Abstract: Computer puppetry is an important form of motion capture that lets animation directors see a character's performance in real time and make immediate corrections to achieve the desired result. The first step in bringing a computer puppet to life is creating the character's concept. How the character will be used forms an important part of its design. To illustrate this process, the author refers to Medialab's methods and procedures. He does this not to single out Medialab, but to draw on experience for concrete examples of principles that prove similar for any computer puppetry system.
TL;DR: In this article, a 3D game engine for varying performance levels is proposed, called NetImmerse, for varying game platforms and demands for reduced development costs, which can be used to reduce development costs.
Abstract: Computer game engine requirements change in response to evolving game platforms and demands for reduced development costs We propose a 3D game engine, marketed as NetImmerse, for varying performance levels
TL;DR: A general framework for polymorphing is presented by extending the traditional image morphing paradigm that applies to two images by forming each input image as a vertex of an (n-1)-dimensional simplex, where n equals the number of input images.
Abstract: Polymorph extends conventional morphing to derive morphed images from more than two images at once, effectively integrating geometric manipulations and color blending. We present a general framework for polymorphing by extending the traditional image morphing paradigm that applies to two images. The authors formulate each input image as a vertex of an (n-1)-dimensional simplex, where n equals the number of input images. They look at the mathematical framework for polymorph, followed by warp function generation and propagation, blending function generation, and the implemented polymorph system. Metamorphosis examples demonstrate the use of polymorph for image composition.
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TL;DR: In this article, the authors discuss volume line integral convolution (LIC) techniques for effectively visualizing 3D flow, including using visibility-impeding halos and efficient asymmetric filter kernels.
Abstract: We discuss volume line integral convolution (LIC) techniques for effectively visualizing 3D flow, including using visibility-impeding halos and efficient asymmetric filter kernels. Specifically, we suggest techniques for selectively emphasizing critical regions of interest in a flow; facilitating the accurate perception of the 3D depth and orientation of overlapping streamlines; efficiently incorporating an indication of orientation into a flow representation; and conveying additional information about related scalar quantities such as temperature or vorticity over a flow via subtle, continuous line width and color variations.
TL;DR: Three high-dimensional glyphs for viewing software project management data assist in perhaps the most challenging engineering task in modern times managing large software projects.
Abstract: Three high-dimensional glyphs for viewing software project management data assist in perhaps the most challenging engineering task in modern times managing large software projects. In data exploration, glyphs refer to graphical objects or symbols that represent data through visual parameters that are either spatial (positions x or y), retinal (color and size), or temporal. Common examples of graphical objects include the bars in a bar chart or the points within a scatter plot. We focus on glyphs for visualizing software project management data. Any large-scale project will have many different classes of resources (lab equipment, staff time, machine cycles, disk resources, interim deliverables, and customer commitments) that must be scheduled and tracked. Inevitably, problems will arise and solutions must be found. To support the management process, information systems collect and maintain large status databases. We aim to support and improve the understanding of this information through visualization. Our glyphs are designed to expose patterns among sets of software artifacts and to help identify differences between items.
TL;DR: This work proposes a method of selectively stimulating only superficial mechanoreceptors and shows that it makes people feel a more realistic, finer virtual texture than possible by adjusting the stimulator spacing.
Abstract: Research in virtual reality has recognized the need for more realistic tactile display in addition to touch and non-touch display and force display. We propose a method of selectively stimulating only superficial mechanoreceptors. We show that it makes people feel a more realistic, finer virtual texture than possible by adjusting the stimulator spacing. The apparatus is simple and we expect this idea to develop into a device to display varieties of tactile feeling.
TL;DR: A 3D scanner developer's viewpoint is taken to review different 3D digitizing techniques to compare existing systems and give special consideration to active optical triangulation-based scanners.
Abstract: The purpose of 3D scanning is to bridge the real world with the virtual world. A practical system would not only produce photorealistic models, but would also be inexpensive and easy to use. We took a 3D scanner developer's viewpoint to review different 3D digitizing techniques. We briefly compare existing systems and give special consideration to active optical triangulation-based scanners.
TL;DR: These experiments in collaborative virtual environments investigated group behavior issues such as relationships between emergent leadership and computational resources, and the sense of presence and copresence among participants.
Abstract: The Collaborative Virtual Environments (Coven) project, a four-year European project launched in October 1995, designs and explores collaborative virtual environment (CVE) technology. It aims to investigate the feasibility of scalable CVE worlds through developing CVE systems and demonstrating prototype applications in a virtual travel rehearsal scenario. Our experiments in collaborative virtual environments investigated group behavior issues such as relationships between emergent leadership and computational resources, and the sense of presence and copresence among participants.
TL;DR: An immersive design application for educational use that focuses on the small, highly specific domain of animal habitat design that doesn't allow general manipulation of all design features and is task-specific and well constrained.
Abstract: The authors present an immersive design application for educational use that takes a different approach. First, they focus on the small, highly specific domain of animal habitat design. Second, the system's users don't have a blank slate-they begin with an existing design. Finally, the design tools don't allow general manipulation of all design features. Instead, they're task-specific and well constrained.
TL;DR: The paper considers a portable 3D scanning system called Autoscan which provides flexibility, reliability and accuracy for scanning 3D surfaces.
Abstract: Quantifying physical abnormalities, guiding corrective and plastic surgery, manufacturing clothing, three-dimensional CAD, and other related fields all benefit from the increasing use of 3D scanners. These scanning systems reconstruct a 3D surface as a large set of polygonal meshes. Although Cyberware scanning systems have become a commercial standard, they have two main drawbacks. First, for large objects they require a mechanical structure that cannot be installed or moved easily. Second, they only allow the scanning of objects within limited size ranges. The paper considers a portable 3D scanning system called Autoscan which provides flexibility, reliability and accuracy for scanning 3D surfaces. Autoscan consists of a pair of video cameras, a real-time image processor and a computer host.
TL;DR: A system which functions as a feature recognizer or a feature model converter depending on whether the input CAD data contains design features, and recognition algorithms for slots and pockets are presented.
Abstract: This article presents a system dubbed IF/sup 2/ (Integrated Incremental Feature Finder), which functions as a feature recognizer or a feature model converter depending on whether the input CAD data contains design features. IF/sup 2/ recognizes three types of machining features: holes, slots and pockets. This article discusses recognition algorithms for slots and pockets. Recognition algorithms for holes are similar to those of slots (Han, 1996).
TL;DR: It is well known that there are only three regular polygons that can tile the plane, but here the verb tile means to cover the infinite plane with a set of polygons so that no gaps or overlaps exist among the polygons.
Abstract: One of the most interesting ways of assembling small units is along one of the lattices that make up crystals. In this column I live entirely in a 2D world, so the crystals are nothing but collections of polygons in the plane. It is well known that there are only three regular polygons that can tile the plane. Here the verb tile means to cover the infinite plane with a set of polygons so that no gaps or overlaps exist among the polygons. Each polygon is called a tile and the composite pattern is called a tiling.
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TL;DR: The author considers how Ptolemy's Theorem can be used to prove that Snell's Law and Fermat's Principle of Least Time both lead to the same geometry of refraction.
Abstract: The author discusses two interesting relationships between circles and lines. There should be a computer graphics application that can use the first topic to run faster or better. The second topic is Ptolemy's Theorem, which is a generalization of the triangle inequality. The author shows how it can be used to derive the angle addition formulas. He considers how Ptolemy's Theorem can be used to prove that Snell's Law and Fermat's Principle of Least Time both lead to the same geometry of refraction.
TL;DR: The article surveys virtual humans and techniques to control the face and body and also covers higher level interfaces for direct speech input and issues of real-time control.
Abstract: The article surveys virtual humans and techniques to control the face and body. It also covers higher level interfaces for direct speech input and issues of real-time control.
TL;DR: The authors discuss Studierstube, a low-cost augmented reality system that features true stereoscopy, 3D interaction, individual viewpoints and customized views for multiple users, and unhindered natural collaboration.
Abstract: The authors discuss Studierstube, a low-cost augmented reality system. The system features true stereoscopy, 3D interaction, individual viewpoints and customized views for multiple users, and unhindered natural collaboration.
TL;DR: This Japanese national R&D scheme is moving toward the realization of mutual telexistence through various kinds of networks, including the Internet, which is called R/sup 3.
Abstract: Many people have longed to project themselves to a remote environment-one where they have the sensation of existing in a different place-while actually remaining where they are. Another dream involves amplifying human muscle power and sensing capabilities with machines while reserving human dexterity through a sensation of direct operation. Virtual reality must have the computer-generated environment or transmitted remote environment's essence of reality to effectively become reality for the user. One of the most promising technologies today is the integration of virtual reality and robotics on the network. The general concept is called networked robotics; in particular, we call it R/sup 3/. This Japanese national R&D scheme is moving toward the realization of mutual telexistence through various kinds of networks, including the Internet. The launch of the five-year MITI "Humanoid and Human Friendly Robotics" project in April 1998 takes the first step toward the realization of R/sup 3/.
TL;DR: The article discusses the application of touch feedback systems to 3D modelling, which requires novel rendering techniques such as volume-based rendering algorithms to achieve a high interactivity level.
Abstract: As we progress into applications that incorporate interactive life-like 3D computer graphics, the mouse falls short as a user interface device, and it becomes obvious that 3D computer graphics could achieve much more with a more intuitive user interface mechanism. Haptic interfaces, or force feedback devices, promise to increase the quality of human-computer interaction by accommodating our sense of touch. The article discusses the application of touch feedback systems to 3D modelling. To achieve a high interactivity level requires novel rendering techniques such as volume-based rendering algorithms.
TL;DR: This case study presents applications of the eigenvector method to recent aeronautical studies at NASA Ames Research Center and Rensselaer Polytechnic Institute and highlights its usefulness for detecting flow features such as vortex cores, vortex bursts, spiral vortex breakdowns, and vortex diffusion.
Abstract: This case study presents applications of the eigenvector method to recent aeronautical studies at NASA Ames Research Center and Rensselaer Polytechnic Institute. We highlight its usefulness for detecting flow features such as vortex cores, vortex bursts, spiral vortex breakdowns, and vortex diffusion. The eigenvector method has also been used as a data analysis tool to guide an automatic mesh refinement program and improve the accuracy of a rotorcraft simulation.
TL;DR: A hierarchical model of human actions based on fine-grained primitives is developed and an associated recognition algorithm identifies simultaneous actions on the fly.
Abstract: Since their inception, interactive virtual environments have not been able to interpret users' gestures. Researchers have investigated a few tentative solutions, but most of them concern a specific set of body parts like hands, arms, or facial expressions. However, when placing a participant in a virtual world to interact with synthetic inhabitants, it would be more convenient and intuitive to use body-oriented actions. To achieve this, we developed a hierarchical model of human actions based on fine-grained primitives. An associated recognition algorithm identifies simultaneous actions on the fly.
TL;DR: This work designed and evaluated three methods for presenting information in a wearable environment and found spatial displays easier and more effective, and spatial audio and visual cues further enhanced performance.
Abstract: Increasing portability of computing power marks a broad emerging trend in advanced human-computer interaction. Wearable computers, the next generation of portable machines, worn on the body, provide constant access to computing and communications resources. However, wide adoption of wearable computers first requires solving unique interface challenges. One of the most important is how to present and interact with information in a wearable environment. We designed and evaluated three methods for presenting information in a wearable environment. Subjects found spatial displays easier and more effective. Spatial audio and visual cues further enhanced performance.