We have developed a technique that extends existing 3-D result visualization methods for use with discretized volumes such as finite element models, where result values are only available at coarsely spaced points throughout the volume. It represents results as smooth isosurfaces within the volume for one or more result values, using visually continuous, bi-cubic polynomials.At each of the points where results are available, result gradients are calculated by a finite difference procedure. The result values and result gradients are used to obtain the location of and the tangents to the isosurfaces on lines connecting the result points. Continuous doubly curved surfaces and surface normals are constructed separately between these discrete isosurface points using bi-cubic polynomials. The isosurfaces are rendered with standard light-source shading and optional levels of translucency, surrounded by translucent free faces of the structure.The method generates isosurfaces on an element-by-element basis, without reference at display time to the behavior of neighboring elements. It is intended for high speed display-time processing of either static or varying isosurface values.
{"title":"An efficient 3-D visualization technique for finite element models and other coarse volumes","authors":"R. Gallagher, J. Nagtegaal","doi":"10.1145/74333.74352","DOIUrl":"https://doi.org/10.1145/74333.74352","url":null,"abstract":"We have developed a technique that extends existing 3-D result visualization methods for use with discretized volumes such as finite element models, where result values are only available at coarsely spaced points throughout the volume. It represents results as smooth isosurfaces within the volume for one or more result values, using visually continuous, bi-cubic polynomials.At each of the points where results are available, result gradients are calculated by a finite difference procedure. The result values and result gradients are used to obtain the location of and the tangents to the isosurfaces on lines connecting the result points. Continuous doubly curved surfaces and surface normals are constructed separately between these discrete isosurface points using bi-cubic polynomials. The isosurfaces are rendered with standard light-source shading and optional levels of translucency, surrounded by translucent free faces of the structure.The method generates isosurfaces on an element-by-element basis, without reference at display time to the behavior of neighboring elements. It is intended for high speed display-time processing of either static or varying isosurface values.","PeriodicalId":422743,"journal":{"name":"Proceedings of the 16th annual conference on Computer graphics and interactive techniques","volume":"76 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123159752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper addresses the problem of simulating deformations between objects and the hand of a synthetic character during a grasping process. A numerical method based on finite element theory allows us to take into account the active forces of the fingers on the object and the reactive forces of the object on the fingers. The method improves control of synthetic human behavior in a task level animation system because it provides information about the environment of a synthetic human and so can be compared to the sense of touch. Finite element theory currently used in engineering seems one of the best approaches for modeling both elastic and plastic deformation of objects, as well as shocks with or without penetration between deformable objects. We show that intrinsic properties of the method based on composition/decomposition of elements have an impact in computer animation. We also state that the use of the same method for modeling both objects and human bodies improves the modeling both objects and human bodies improves the modeling of the contacts between them. Moreover, it allows a realistic envelope deformation of the human fingers comparable to existing methods. To show what we can expect from the method, we apply it to the grasping and pressing of a ball. Our solution to the grasping problem is based on displacement commands instead of force commands used in robotics and human behavior.
{"title":"Simulation of object and human skin formations in a grasping task","authors":"J. Gourret, N. Magnenat-Thalmann, D. Thalmann","doi":"10.1145/74333.74335","DOIUrl":"https://doi.org/10.1145/74333.74335","url":null,"abstract":"This paper addresses the problem of simulating deformations between objects and the hand of a synthetic character during a grasping process. A numerical method based on finite element theory allows us to take into account the active forces of the fingers on the object and the reactive forces of the object on the fingers. The method improves control of synthetic human behavior in a task level animation system because it provides information about the environment of a synthetic human and so can be compared to the sense of touch. Finite element theory currently used in engineering seems one of the best approaches for modeling both elastic and plastic deformation of objects, as well as shocks with or without penetration between deformable objects. We show that intrinsic properties of the method based on composition/decomposition of elements have an impact in computer animation. We also state that the use of the same method for modeling both objects and human bodies improves the modeling both objects and human bodies improves the modeling of the contacts between them. Moreover, it allows a realistic envelope deformation of the human fingers comparable to existing methods. To show what we can expect from the method, we apply it to the grasping and pressing of a ball. Our solution to the grasping problem is based on displacement commands instead of force commands used in robotics and human behavior.","PeriodicalId":422743,"journal":{"name":"Proceedings of the 16th annual conference on Computer graphics and interactive techniques","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117260835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We describe the system architecture and the programming environment of the Pixel Machine - a parallel image computer with a distributed frame buffer.The architecture of the computer is based on an array of asynchronous MIMD nodes with parallel access to a large frame buffer. The machine consists of a pipeline of pipe nodes which execute sequential algorithms and an array of m × n pixel nodes which execute parallel algorithms. A pixel node directly accesses every m-th pixel on every n-th scan line of an interleaved frame buffer. Each processing node is based on a high-speed, floating-point programmable processor.The programmability of the computer allows all algorithms to be implemented in software. We present the mappings of a number of geometry and image-computing algorithms onto the machine and analyze their performance.
{"title":"The pixel machine: a parallel image computer","authors":"M. Potmesil, E. Hoffert","doi":"10.1145/74333.74340","DOIUrl":"https://doi.org/10.1145/74333.74340","url":null,"abstract":"We describe the system architecture and the programming environment of the Pixel Machine - a parallel image computer with a distributed frame buffer.The architecture of the computer is based on an array of asynchronous MIMD nodes with parallel access to a large frame buffer. The machine consists of a pipeline of pipe nodes which execute sequential algorithms and an array of m × n pixel nodes which execute parallel algorithms. A pixel node directly accesses every m-th pixel on every n-th scan line of an interleaved frame buffer. Each processing node is based on a high-speed, floating-point programmable processor.The programmability of the computer allows all algorithms to be implemented in software. We present the mappings of a number of geometry and image-computing algorithms onto the machine and analyze their performance.","PeriodicalId":422743,"journal":{"name":"Proceedings of the 16th annual conference on Computer graphics and interactive techniques","volume":"13 9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126019096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Graphics pipelines are quickly evolving to support multitasking workstations. The driving force behind this evolution is the window system, which must provide high performance graphics within multiple windows, while maintaining interactivity. The virtual graphics system presented by [7] provides a clean solution to the problem of context switching graphics hardware between processes, but does not solve all the problems associated with sharing graphics pipelines.The primary difficulty in context switching a graphics accelerator is the pipeline latency encountered during a pipeline flush. This latency removes the responsiveness and interactivity of the graphics system. As primitives become more complex and pipelines become longer, pipeline latency grows. Hardware solutions are described which further accelerate the window system by eliminating the need for pipeline flushing and resynchronization. An overview of the entire system is presented, highlighting the hardware mechanisms which contribute to window acceleration.
{"title":"Hardware acceleration for Window systems","authors":"D. Rhoden, C. Wilcox","doi":"10.1145/74333.74339","DOIUrl":"https://doi.org/10.1145/74333.74339","url":null,"abstract":"Graphics pipelines are quickly evolving to support multitasking workstations. The driving force behind this evolution is the window system, which must provide high performance graphics within multiple windows, while maintaining interactivity. The virtual graphics system presented by [7] provides a clean solution to the problem of context switching graphics hardware between processes, but does not solve all the problems associated with sharing graphics pipelines.The primary difficulty in context switching a graphics accelerator is the pipeline latency encountered during a pipeline flush. This latency removes the responsiveness and interactivity of the graphics system. As primitives become more complex and pipelines become longer, pipeline latency grows. Hardware solutions are described which further accelerate the window system by eliminating the need for pipeline flushing and resynchronization. An overview of the entire system is presented, highlighting the hardware mechanisms which contribute to window acceleration.","PeriodicalId":422743,"journal":{"name":"Proceedings of the 16th annual conference on Computer graphics and interactive techniques","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123897638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Michel Gangnet, J. Hervé, T. Pudet, Jean-Manuel Van Thong
A planar map is a figure formed by a set of intersecting lines and curves. Such an object captures both the geometrical and the topological information implicitly defined by the data. In the context of 2D drawing it provides a new interaction paradigm, map sketching, for editing graphic shapes.To build a planar map, one must compute curve intersections and deduce from them the map they define. The computed topology must be consistent with the underlying geometry. Robustness of geometric computations is a key issue in this process. We present a robust solution to Bézier curve intersection that uses exact forward differencing and bounded rational arithmetic. Then, we describe data structure and algorithms to support incremental insertion of Bézier curves in a planar map. A prototype illustration tool using this method is also discussed.
{"title":"Incremental computation of planar maps","authors":"Michel Gangnet, J. Hervé, T. Pudet, Jean-Manuel Van Thong","doi":"10.1145/74333.74369","DOIUrl":"https://doi.org/10.1145/74333.74369","url":null,"abstract":"A planar map is a figure formed by a set of intersecting lines and curves. Such an object captures both the geometrical and the topological information implicitly defined by the data. In the context of 2D drawing it provides a new interaction paradigm, map sketching, for editing graphic shapes.To build a planar map, one must compute curve intersections and deduce from them the map they define. The computed topology must be consistent with the underlying geometry. Robustness of geometric computations is a key issue in this process. We present a robust solution to Bézier curve intersection that uses exact forward differencing and bounded rational arithmetic. Then, we describe data structure and algorithms to support incremental insertion of Bézier curves in a planar map. A prototype illustration tool using this method is also discussed.","PeriodicalId":422743,"journal":{"name":"Proceedings of the 16th annual conference on Computer graphics and interactive techniques","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132322515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Deterministic splines and stochastic fractals are complementary techniques for generating free-form shapes. Splines are easily constrained and well suited to modeling smooth, man-made objects. Fractals, while difficult to constrain, are suitable for generating various irregular shapes found in nature. This paper develops constrained fractals, a hybrid of splines and fractals which intimately combines their complementary features. This novel shape synthesis technique stems from a formal connection between fractals and generalized energy-minimizing splines which may be derived through Fourier analysis. A physical interpretation of constrained fractal generation is to drive a spline subject to constraints with modulated white noise, letting the spline diffuse the noise into the desired fractal spectrum as it settles into equilibrium. We use constrained fractals to synthesize realistic terrain models from sparse elevation data.
{"title":"From splines to fractals","authors":"R. Szeliski, Demetri Terzopoulos","doi":"10.1145/74333.74338","DOIUrl":"https://doi.org/10.1145/74333.74338","url":null,"abstract":"Deterministic splines and stochastic fractals are complementary techniques for generating free-form shapes. Splines are easily constrained and well suited to modeling smooth, man-made objects. Fractals, while difficult to constrain, are suitable for generating various irregular shapes found in nature. This paper develops constrained fractals, a hybrid of splines and fractals which intimately combines their complementary features. This novel shape synthesis technique stems from a formal connection between fractals and generalized energy-minimizing splines which may be derived through Fourier analysis. A physical interpretation of constrained fractal generation is to drive a spline subject to constraints with modulated white noise, letting the spline diffuse the noise into the desired fractal spectrum as it settles into equilibrium. We use constrained fractals to synthesize realistic terrain models from sparse elevation data.","PeriodicalId":422743,"journal":{"name":"Proceedings of the 16th annual conference on Computer graphics and interactive techniques","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127171429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present a technique for modeling global illumination which allows a wide variety of reflectance functions. Scene coherence is exploited in a preprocessing step in which the geometry is analyzed using iterative techniques. Memory is traded for speed, in anticipation of the high memory capacities of workstations of the future. The algorithm operates well over a wide range of time and image quality constraints: realistic results may be produced very quickly while very accurate results require more time and space. The method can be extended for animation and parallelization.
{"title":"Illumination networks: fast realistic rendering with general reflectance functions","authors":"Chris Buchalew, D. Fussell","doi":"10.1145/74333.74342","DOIUrl":"https://doi.org/10.1145/74333.74342","url":null,"abstract":"We present a technique for modeling global illumination which allows a wide variety of reflectance functions. Scene coherence is exploited in a preprocessing step in which the geometry is analyzed using iterative techniques. Memory is traded for speed, in anticipation of the high memory capacities of workstations of the future. The algorithm operates well over a wide range of time and image quality constraints: realistic results may be produced very quickly while very accurate results require more time and space. The method can be extended for animation and parallelization.","PeriodicalId":422743,"journal":{"name":"Proceedings of the 16th annual conference on Computer graphics and interactive techniques","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127351794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Fuchs, J. Poulton, J. Eyles, T. Greer, Jack Goldfeather, D. Ellsworth, S. Molnar, Greg Turk, Brice Tebbs, Laura Israel
This paper introduces the architecture and initial algorithms for Pixel-Planes 5, a heterogeneous multi-computer designed both for high-speed polygon and sphere rendering (1M Phong-shaded triangles/second) and for supporting algorithm and application research in interactive 3D graphics. Techniques are described for volume rendering at multiple frames per second, font generation directly from conic spline descriptions, and rapid calculation of radiosity form-factors. The hardware consists of up to 32 math-oriented processors, up to 16 rendering units, and a conventional 1280 × 1024-pixel frame buffer, interconnected by a 5 gigabit ring network. Each rendering unit consists of a 128 × 128-pixel array of processors-with-memory with parallel quadratic expression evaluation for every pixel. Implemented on 1.6 micron CMOS chips designed to run at 40MHz, this array has 208 bits/pixel on-chip and is connected to a video RAM memory system that provides 4,096 bits of off-chip memory. Rendering units can be independently reasigned to any part of the screen or to non-screen-oriented computation. As of April 1989, both hardware and software are still under construction, with initial system operation scheduled for fall 1989.
{"title":"Pixel-planes 5: a heterogeneous multiprocessor graphics system using processor-enhanced memories","authors":"H. Fuchs, J. Poulton, J. Eyles, T. Greer, Jack Goldfeather, D. Ellsworth, S. Molnar, Greg Turk, Brice Tebbs, Laura Israel","doi":"10.1145/74333.74341","DOIUrl":"https://doi.org/10.1145/74333.74341","url":null,"abstract":"This paper introduces the architecture and initial algorithms for Pixel-Planes 5, a heterogeneous multi-computer designed both for high-speed polygon and sphere rendering (1M Phong-shaded triangles/second) and for supporting algorithm and application research in interactive 3D graphics. Techniques are described for volume rendering at multiple frames per second, font generation directly from conic spline descriptions, and rapid calculation of radiosity form-factors. The hardware consists of up to 32 math-oriented processors, up to 16 rendering units, and a conventional 1280 × 1024-pixel frame buffer, interconnected by a 5 gigabit ring network. Each rendering unit consists of a 128 × 128-pixel array of processors-with-memory with parallel quadratic expression evaluation for every pixel. Implemented on 1.6 micron CMOS chips designed to run at 40MHz, this array has 208 bits/pixel on-chip and is connected to a video RAM memory system that provides 4,096 bits of off-chip memory. Rendering units can be independently reasigned to any part of the screen or to non-screen-oriented computation. As of April 1989, both hardware and software are still under construction, with initial system operation scheduled for fall 1989.","PeriodicalId":422743,"journal":{"name":"Proceedings of the 16th annual conference on Computer graphics and interactive techniques","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128738529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Proceedings of the 16th annual conference on Computer graphics and interactive techniques","authors":"","doi":"10.1145/74333","DOIUrl":"https://doi.org/10.1145/74333","url":null,"abstract":"","PeriodicalId":422743,"journal":{"name":"Proceedings of the 16th annual conference on Computer graphics and interactive techniques","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114834328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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