Pub Date : 1997-06-09DOI: 10.1109/DAGSTUHL.1997.1423108
W. Hibbard, C. Rueden, T. Rink, S. Emmerson, D. Fulker, John Anderson
VisAD is a Java class library for interactive and collaborative visualization and analysis of numerical data. It is designed to support distributed computing and data sharing on the Internet through the use of distributed objects and a very general numerical data model. The data model integrates metadata for data organization, units, coordinate systems, sampling geometries and topoligies, missing data indicators, and error estimates. When data are combined in computations or visualizations, unit conversion, coordinate transforms and resampling are done implicitly as needed.
{"title":"The VisAD Java Class Library for Scientific Data and Visualization","authors":"W. Hibbard, C. Rueden, T. Rink, S. Emmerson, D. Fulker, John Anderson","doi":"10.1109/DAGSTUHL.1997.1423108","DOIUrl":"https://doi.org/10.1109/DAGSTUHL.1997.1423108","url":null,"abstract":"VisAD is a Java class library for interactive and collaborative visualization and analysis of numerical data. It is designed to support distributed computing and data sharing on the Internet through the use of distributed objects and a very general numerical data model. The data model integrates metadata for data organization, units, coordinate systems, sampling geometries and topoligies, missing data indicators, and error estimates. When data are combined in computations or visualizations, unit conversion, coordinate transforms and resampling are done implicitly as needed.","PeriodicalId":268314,"journal":{"name":"Scientific Visualization Conference (dagstuhl '97)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132232856","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}
Pub Date : 1997-06-09DOI: 10.1109/DAGSTUHL.1997.1423112
S. Klimenko, I. Nikitin, Valery V. Burkin
In this paper we present a several topics in visualization and animation of topologically non-trivial objects: the open strings in 3D space; a process of un-coupling of 2 coupled handles on a sphere in 3D space by means of a homotopy in the class of embedding; the projective plane and the projective 3D space. Various properties of these objects are visualized: their non-orientability and non-trivial connectivity, and two representations of the projective plane in 3D space are examined: the cross-cap and the Boy immersion.Visualization in string theory and some results obtained from visual study of strings demonstrates the benefits of this approach.Problems are discussed that arise in computer assisted visualization of topologically non-trivial objects, and in their integration in virtual environments, in particular: fast rendering of self-crossing transparent surfaces, and smooth mapping of colors and textures onto topologically complex surfaces.
{"title":"Visualization of Complex Physical Phenomena and Mathematical Objects in Virtual Environment","authors":"S. Klimenko, I. Nikitin, Valery V. Burkin","doi":"10.1109/DAGSTUHL.1997.1423112","DOIUrl":"https://doi.org/10.1109/DAGSTUHL.1997.1423112","url":null,"abstract":"In this paper we present a several topics in visualization and animation of topologically non-trivial objects: the open strings in 3D space; a process of un-coupling of 2 coupled handles on a sphere in 3D space by means of a homotopy in the class of embedding; the projective plane and the projective 3D space. Various properties of these objects are visualized: their non-orientability and non-trivial connectivity, and two representations of the projective plane in 3D space are examined: the cross-cap and the Boy immersion.Visualization in string theory and some results obtained from visual study of strings demonstrates the benefits of this approach.Problems are discussed that arise in computer assisted visualization of topologically non-trivial objects, and in their integration in virtual environments, in particular: fast rendering of self-crossing transparent surfaces, and smooth mapping of colors and textures onto topologically complex surfaces.","PeriodicalId":268314,"journal":{"name":"Scientific Visualization Conference (dagstuhl '97)","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131824704","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}
Pub Date : 1997-06-09DOI: 10.1109/DAGSTUHL.1997.1423107
Bjørn Heckel, A. Uva, B. Hamann
We present a highly efficient, automatic method for the generation of hierarchical surface triangulations. Given a set of scattered points in three-dimensional space, without known connectivity information, our method reconstructs a valid triangulated surface model in a two-step procedure. First, we apply clustering to the set of given points and identify point subsets in locally nearly planar regions. Second, we construct a surface triangulation from the output of the clustering step. The output of the clustering step is a set of 2-manifold tiles, which locally approximate the underlying, unknown surface. We construct the triangulation of the entire surface by triangulating the individual tiles and triangulating the gaps between the tiles. Since we apply point clustering in a hierarchical fashion we can generate model hierarchies by triangulating various levels resulting from the hierarchical clustering step.
{"title":"Cluster-Based Generation of Hierarchical Surface Models","authors":"Bjørn Heckel, A. Uva, B. Hamann","doi":"10.1109/DAGSTUHL.1997.1423107","DOIUrl":"https://doi.org/10.1109/DAGSTUHL.1997.1423107","url":null,"abstract":"We present a highly efficient, automatic method for the generation of hierarchical surface triangulations. Given a set of scattered points in three-dimensional space, without known connectivity information, our method reconstructs a valid triangulated surface model in a two-step procedure. First, we apply clustering to the set of given points and identify point subsets in locally nearly planar regions. Second, we construct a surface triangulation from the output of the clustering step. The output of the clustering step is a set of 2-manifold tiles, which locally approximate the underlying, unknown surface. We construct the triangulation of the entire surface by triangulating the individual tiles and triangulating the gaps between the tiles. Since we apply point clustering in a hierarchical fashion we can generate model hierarchies by triangulating various levels resulting from the hierarchical clustering step.","PeriodicalId":268314,"journal":{"name":"Scientific Visualization Conference (dagstuhl '97)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127474614","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}
Pub Date : 1997-06-09DOI: 10.1109/DAGSTUHL.1997.1423114
M. Lin
A realistic simulation system, which couples geometry and physics, can provide a useful toolkit for virtual environments. Interactions among moving objects in the virtual worlds are modeled by dynamic constraints and contact analysis. In order to portray the geometric interaction in a dynamical system or to simulate physical behaviors of entities in the virtual environments, it is essential to perform collision detection at interactive rate with minimal computation possible. In this paper, we present efficient algorithms for contact determination and interference detection between geometric models undergoing rigid motion. The set of models includes polyhedra and surfaces described by B-splines. The algorithms make use of temporal and spatial coherence between successive instances to reduce the number of pairwise tests and hierarchical data structures for checking overlaps between a pair of objects. Their running time is a function of the motion between successive instances. The main characteristics of these algorithms are their simplicity and efficiency. They have been implemented. A subset of these implementations, including I-Collide, RAPID and V-Collide are available as part of the collision detection packages at the UNC-CH website.
{"title":"Fast and Accurate Collision Detection for Virtual Environments","authors":"M. Lin","doi":"10.1109/DAGSTUHL.1997.1423114","DOIUrl":"https://doi.org/10.1109/DAGSTUHL.1997.1423114","url":null,"abstract":"A realistic simulation system, which couples geometry and physics, can provide a useful toolkit for virtual environments. Interactions among moving objects in the virtual worlds are modeled by dynamic constraints and contact analysis. In order to portray the geometric interaction in a dynamical system or to simulate physical behaviors of entities in the virtual environments, it is essential to perform collision detection at interactive rate with minimal computation possible. In this paper, we present efficient algorithms for contact determination and interference detection between geometric models undergoing rigid motion. The set of models includes polyhedra and surfaces described by B-splines. The algorithms make use of temporal and spatial coherence between successive instances to reduce the number of pairwise tests and hierarchical data structures for checking overlaps between a pair of objects. Their running time is a function of the motion between successive instances. The main characteristics of these algorithms are their simplicity and efficiency. They have been implemented. A subset of these implementations, including I-Collide, RAPID and V-Collide are available as part of the collision detection packages at the UNC-CH website.","PeriodicalId":268314,"journal":{"name":"Scientific Visualization Conference (dagstuhl '97)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131324660","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}
Pub Date : 1997-06-09DOI: 10.1109/DAGSTUHL.1997.1423119
H. Müller, Michael Wehle
Implicitly defined surfaces f(x,y,z)=0 are usually visualized by an approximating mesh of polygons. One approach of calculating an approximating mesh, practiced in the past, is to subdivide the regions of interests into spatial cells from which the surface is extracted by compiling surface patterns of those cells which are traversed by the surface. Our solution basically follows this approach, but improves it with respect to several aspects. The space is partitioned adaptively using a scheme which neither requires multiple passes nor storing neighborhood information. Furthmore, the cells of the approximating surface mesh are part of the resulting spatial cell decomposition. A post-processing step of ''vertex snapping'' in order to improve the surface mesh is not required.
{"title":"Visualization of Implicit Surfaces Using Adaptive Tetrahedrizations","authors":"H. Müller, Michael Wehle","doi":"10.1109/DAGSTUHL.1997.1423119","DOIUrl":"https://doi.org/10.1109/DAGSTUHL.1997.1423119","url":null,"abstract":"Implicitly defined surfaces f(x,y,z)=0 are usually visualized by an approximating mesh of polygons. One approach of calculating an approximating mesh, practiced in the past, is to subdivide the regions of interests into spatial cells from which the surface is extracted by compiling surface patterns of those cells which are traversed by the surface. Our solution basically follows this approach, but improves it with respect to several aspects. The space is partitioned adaptively using a scheme which neither requires multiple passes nor storing neighborhood information. Furthmore, the cells of the approximating surface mesh are part of the resulting spatial cell decomposition. A post-processing step of ''vertex snapping'' in order to improve the surface mesh is not required.","PeriodicalId":268314,"journal":{"name":"Scientific Visualization Conference (dagstuhl '97)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115823737","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}
Pub Date : 1997-06-09DOI: 10.1109/DAGSTUHL.1997.1423105
M. Gross, David Kleiner
We describe an alternative way of constructing interpolating B-spline curves, surfaces or volumes in Fourier space which can be used for visualization. In our approach the interpolation problem is considered from a signal processing point of view and is reduced to finding an inverse B-spline filter sequence. The Fourier approach encompasses some advantageous features, such as successive approximation, compression, fast convolution and hardware support. In addition, optimal Wiener filtering can be applied to remove noise and distortions from the initial data points and to compute a smooth, least-squares fitting "lq Wiener spline". Unlike traditional fitting methods, the described algorithm is simple and easy to implement. The performance of the presented method is illustrated by some examples showing the restoration of surfaces corrupted by various types of distortions.
{"title":"Wiener Splines","authors":"M. Gross, David Kleiner","doi":"10.1109/DAGSTUHL.1997.1423105","DOIUrl":"https://doi.org/10.1109/DAGSTUHL.1997.1423105","url":null,"abstract":"We describe an alternative way of constructing interpolating B-spline curves, surfaces or volumes in Fourier space which can be used for visualization. In our approach the interpolation problem is considered from a signal processing point of view and is reduced to finding an inverse B-spline filter sequence. The Fourier approach encompasses some advantageous features, such as successive approximation, compression, fast convolution and hardware support. In addition, optimal Wiener filtering can be applied to remove noise and distortions from the initial data points and to compute a smooth, least-squares fitting \"lq Wiener spline\". Unlike traditional fitting methods, the described algorithm is simple and easy to implement. The performance of the presented method is illustrated by some examples showing the restoration of surfaces corrupted by various types of distortions.","PeriodicalId":268314,"journal":{"name":"Scientific Visualization Conference (dagstuhl '97)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125460985","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}
Pub Date : 1997-06-09DOI: 10.1109/DAGSTUHL.1997.1423109
Lichan Hong, A. Kaufman
In this paper we study the computational-space-based (C-space-based) ray-casting algorithm for rendering curvilinear volumes. With a simple counter example, we demonstrate that a proposed C-space-based method may not generate rendering results as accurately as ray-casting in the physical space. We also analyze what needs to be improved and discuss several other issues related to the C-space-based approach.
{"title":"Notes on Computational-Space-Based Ray-Casting for Curvilinear Volumes","authors":"Lichan Hong, A. Kaufman","doi":"10.1109/DAGSTUHL.1997.1423109","DOIUrl":"https://doi.org/10.1109/DAGSTUHL.1997.1423109","url":null,"abstract":"In this paper we study the computational-space-based (C-space-based) ray-casting algorithm for rendering curvilinear volumes. With a simple counter example, we demonstrate that a proposed C-space-based method may not generate rendering results as accurately as ray-casting in the physical space. We also analyze what needs to be improved and discuss several other issues related to the C-space-based approach.","PeriodicalId":268314,"journal":{"name":"Scientific Visualization Conference (dagstuhl '97)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125045108","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}
Pub Date : 1997-06-09DOI: 10.1109/DAGSTUHL.1997.1423125
J. Trapp, H. Pagendarm, B. Walter, A. A. Wouden, I. Sadarjoen, F. Post
Vis-à-Web was designed as a distributed visualization software on the word-wide-web (WWW). Using Vis-à-Web, owners of visualization algorithms may offer their visualization tool as a service on the WWW without giving away their code. Users can access such a service as simply as ordinary WWW-pages. Data may be processed on a variety of servers and the resulting visualization may be combined to a single complex scene. A prototype application using two distributed servers at the DLR in Germany and the TU Delft in the Netherlands was successfully demonstrated.
{"title":"Vis-à-Web: An On-line Distributed Visualization Service","authors":"J. Trapp, H. Pagendarm, B. Walter, A. A. Wouden, I. Sadarjoen, F. Post","doi":"10.1109/DAGSTUHL.1997.1423125","DOIUrl":"https://doi.org/10.1109/DAGSTUHL.1997.1423125","url":null,"abstract":"Vis-à-Web was designed as a distributed visualization software on the word-wide-web (WWW). Using Vis-à-Web, owners of visualization algorithms may offer their visualization tool as a service on the WWW without giving away their code. Users can access such a service as simply as ordinary WWW-pages. Data may be processed on a variety of servers and the resulting visualization may be combined to a single complex scene. A prototype application using two distributed servers at the DLR in Germany and the TU Delft in the Netherlands was successfully demonstrated.","PeriodicalId":268314,"journal":{"name":"Scientific Visualization Conference (dagstuhl '97)","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133018483","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}
Pub Date : 1997-06-09DOI: 10.1109/DAGSTUHL.1997.1423099
P. Bunyk, A. Kaufman, Cláudio T. Silva
In this paper we describe a simple and efficient ray casting engine that is suitable for the rapid exploration of irregular grids composed of tetrahedra cells, or other cell complexes where cells have been broken up into faces. In our method, in a preprocessing phase, all the cells are broken into their corresponding faces. Visibility determination is performed after all the faces have been transformed into screen space; here we compute for each pixel an ordered list of the stabbing boundary faces. The final phase is the actual ray casting, which is performed independently for each pixel, and is basically a walk in the cell complex inside each component of the stabbing ordered list. For color calculations, a simple analytical lighting model is applied to each intersection of ray and cell. Our algorithm is simple, and our implementation fast and robust.
{"title":"Simple, Fast, and Robust Ray Casting of Irregular Grids","authors":"P. Bunyk, A. Kaufman, Cláudio T. Silva","doi":"10.1109/DAGSTUHL.1997.1423099","DOIUrl":"https://doi.org/10.1109/DAGSTUHL.1997.1423099","url":null,"abstract":"In this paper we describe a simple and efficient ray casting engine that is suitable for the rapid exploration of irregular grids composed of tetrahedra cells, or other cell complexes where cells have been broken up into faces. In our method, in a preprocessing phase, all the cells are broken into their corresponding faces. Visibility determination is performed after all the faces have been transformed into screen space; here we compute for each pixel an ordered list of the stabbing boundary faces. The final phase is the actual ray casting, which is performed independently for each pixel, and is basically a walk in the cell complex inside each component of the stabbing ordered list. For color calculations, a simple analytical lighting model is applied to each intersection of ray and cell. Our algorithm is simple, and our implementation fast and robust.","PeriodicalId":268314,"journal":{"name":"Scientific Visualization Conference (dagstuhl '97)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114501205","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}
Pub Date : 1997-06-09DOI: 10.1109/DAGSTUHL.1997.1423104
E. Gröller, Helwig Löffelmann, R. Wegenkittl
The visualization of analytically defined dynamical systems is important for a thorough understanding of the underlying system behavior. An overview of theoretical concepts concerning analytically defined dynamical systems is given. Various visualization techniques for dynamical systems are discussed. Three current research directions concerning the visualization of dynamical systems are treated in more detail. These are: texture based techniques, visualization of high-dimensional dynamical systems, and advanced streamsurface representations.
{"title":"Visualization of Analytically Defined Dynamical Systems","authors":"E. Gröller, Helwig Löffelmann, R. Wegenkittl","doi":"10.1109/DAGSTUHL.1997.1423104","DOIUrl":"https://doi.org/10.1109/DAGSTUHL.1997.1423104","url":null,"abstract":"The visualization of analytically defined dynamical systems is important for a thorough understanding of the underlying system behavior. An overview of theoretical concepts concerning analytically defined dynamical systems is given. Various visualization techniques for dynamical systems are discussed. Three current research directions concerning the visualization of dynamical systems are treated in more detail. These are: texture based techniques, visualization of high-dimensional dynamical systems, and advanced streamsurface representations.","PeriodicalId":268314,"journal":{"name":"Scientific Visualization Conference (dagstuhl '97)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114641426","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：