Talk Aid is a communication device that produces a displayed and audio output from a user interface of input speech keys. A scalability feature allows the output of the device to grow along with its user.
Talk Aid is a communication device that produces a displayed and audio output from a user interface of input speech keys. A scalability feature allows the output of the device to grow along with its user.
Web based training systems offer enhanced functionality for co-operative learning. Nevertheless, these system approaches are mostly dedicated to distributed information presentation, exploring the potentials of curren...
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Web based training systems offer enhanced functionality for co-operative learning. Nevertheless, these system approaches are mostly dedicated to distributed information presentation, exploring the potentials of current Internet/WWW technologies (e.g. Java, HTML, VRML). this article describes a research project at the computergraphics Center (ZGDV) in collaboration with small and medium enterprises in the maritime application area withthe objective to enhance the interaction and demonstration quality of training by integrating a distributed simulation environment into the training scenario. this training scenario is based on HLA/RTI while clients are developed using Visual C++ as well as the Java development kit.
Lost motion is a major disturbance to the contouring accuracy of NC machine tools. Although NC machine tools with plain bearing guideways perform high alignment accuracy, they sometimes show exponential-type lost moti...
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Lost motion is a major disturbance to the contouring accuracy of NC machine tools. Although NC machine tools with plain bearing guideways perform high alignment accuracy, they sometimes show exponential-type lost motion. Conventional step-type backlash compensation applied to that lost motion, causes contouring error due to overcompensation. this paper presents a model of a two-body system with a damper and a nonlinear springthat exhibits the exponential-type lost motion, and a compensation method for that lost motion introduced from the model. Experimental results show the improved performance of the proposed method.
the proceedings contain 45 papers. the topics discussed include: a beam tracing approach to acoustic modeling for interactive virtual environments;NeuroAnimator: fast neural network emulation and control of physics-ba...
ISBN:
(纸本)0897919998
the proceedings contain 45 papers. the topics discussed include: a beam tracing approach to acoustic modeling for interactive virtual environments;NeuroAnimator: fast neural network emulation and control of physics-based models;retargetting motion to new characters;subdivision surfaces in character animation;interactive multi-resolution modeling on arbitrary meshes;synthesizing realistic facial expressions from photographs;an anthropometric face model using variational techniques;large steps in cloth simulation;MAPS: multiresolution adaptive parameterization of surfaces;real time compression of triangle mesh connectivity;appearance-preserving simplification;efficiently using graphics hardware in volume rendering applications;the design of a parallel graphics interface;the Clipmap: a virtual Mipmap;a shading language on graphics hardware: the PixelFlow shading system;progressive forest split compression;and the office of the future: a unified approach to image-based modeling and spatially immersive displays.
We describe the clipmap, a dynamic texture representation that efficiently caches textures of arbitrarily large size in a finite amount of physical memory for rendering at real-time rates. Further, we describe a softw...
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ISBN:
(纸本)0897919998
We describe the clipmap, a dynamic texture representation that efficiently caches textures of arbitrarily large size in a finite amount of physical memory for rendering at real-time rates. Further, we describe a software system for managing clipmaps that supports integration into demanding real-time applications. We show the scale and robustness of this integrated hardware/software architecture by reviewing an application virtualizing a 170 gigabyte texture at 60 Hertz. Finally, we suggest ways that other rendering systems may exploit the concepts underlying clipmaps to solve related problems.
this paper presents an algorithm for rendering a static scene from multiple perspectives. While most current computergraphics algorithms render scenes as they appear from a single viewpoint (the location of the camer...
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ISBN:
(纸本)0897919998
this paper presents an algorithm for rendering a static scene from multiple perspectives. While most current computergraphics algorithms render scenes as they appear from a single viewpoint (the location of the camera) multiple viewpoint rendering (MVR) renders a scene from a range of spatially-varying viewpoints. By exploiting perspective coherence, MVR can produce a set of images orders of magnitude faster than conventional rendering methods. Images produced by MVR can be used as input to multiple-perspective displays such as holographic stereograms, lenticular sheet displays, and holographic video. MVR can also be used as a geometry-to-image prefilter for image-based rendering algorithms. MVR techniques are adapted from single viewpoint computergraphics algorithms and can be accelerated using existing hardware graphics subsystems. this paper describes the characteristics of MVR algorithms in general, along withthe design, implementation, and applications of a particular MVR rendering system.
Phong-shaded 3D imagery does not provide geometric information of the same richness as human-drawn technical illustrations. A non-photorealistic lighting model is presented that attempts to narrow this gap. the model ...
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ISBN:
(纸本)0897919998
Phong-shaded 3D imagery does not provide geometric information of the same richness as human-drawn technical illustrations. A non-photorealistic lighting model is presented that attempts to narrow this gap. the model is based on practice in traditional technical illustration, where the lighting model uses both luminance and changes in hue to indicate surface orientation, reserving extreme lights and darks for edge lines and highlights. the lighting model allows shading to occur only in mid-tones so that edge lines and highlights remain visually prominent. In addition, we show how this lighting model is modified when portraying models of metal objects. these illustration methods give a clearer picture of shape, structure, and material composition than traditional computergraphics methods.
computer systems have become powerful enough to process continuous data streams such as video or animated graphics. While processing power and communication bandwidth of today's systems typically are sufficient, q...
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ISBN:
(纸本)0818684917
computer systems have become powerful enough to process continuous data streams such as video or animated graphics. While processing power and communication bandwidth of today's systems typically are sufficient, quality of service (QoS) guarantees as required for handling such data types cannot be provided by these systems in adequate ways. We present Switcherland, a scalable communication architecture based on crossbar switches that provides QoS guarantees for workstation clusters in the form of reserved bandwidth and bounded transmission delays. Similar to the ATM technology Switcherland provides eos guarantees withthe help of service classes, that is, data transfers are characterized as variable bit rate traffic or constant bit rate traffic. However, unlike LAN technologies, Switcherland is optimized for cluster computing in that (i) it serves as a backplane interconnection fabric as well as a LAN, (ii) it extends support for service classes by also covering the end nodes of the network, (iii) it provides low latency in the order of one microsecond per switch, and (iv) it uses a communication model based on a global memory to simplify programming.
Global view-dependent illumination phenomena, in particular reflections, greatly enhance the realism of computer-generated imagery. Current interactive rendering methods do not provide satisfactory support for reflect...
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ISBN:
(纸本)0897919998
Global view-dependent illumination phenomena, in particular reflections, greatly enhance the realism of computer-generated imagery. Current interactive rendering methods do not provide satisfactory support for reflections on curved objects. In this paper we present a novel method for interactive computation of reflections on curved objects. We transform potentially reflected scene objects according to reflectors, to generate virtual objects. these are rendered by the graphics system as ordinary objects, creating a reflection image that is blended withthe primary image. Virtual objects are created by tessellating scene objects and computing a virtual vertex for each resulting scene vertex. Virtual vertices are computed using a novel space subdivision, the reflection subdivision. For general polygonal mesh reflectors, we present an associated approximate acceleration scheme, the explosion map. For specific types of objects (e.g., linear extrusions of planar curves) the reflection subdivision can be reduced to a 2-D one that is utilized more accurately and efficiently.
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