Pub Date : 2001-10-16DOI: 10.1109/PCCGA.2001.962877
E. LaMar, B. Hamann, K. Joy
Volume visualization of large data sets suffers from the same problem that many other visualization modalities suffer from: either one can visualize the entire data set and lose small details or visualize a small region and lose the context. The authors we present a magnification lens technique for volume visualization. While the notion of a magnification-lens is not new, and other techniques attempt to simulate the physical properties of a magnifying lens, our contribution is in developing a magnification lens that is fast, can be implemented using a fairly small software overhead, and has a natural, intuitive appearance. The issue with magnification lens is the border, or transition region. The lens center and exterior have a constant zoom factor, and are simple to render. It is the border region that blends between the external and interior magnification, and has a nonconstant magnification. We use the "perspective-correct textures" capability, available in most current graphics systems, to produce a lens with a tessellated border region that approximates linear compression with respect to the radius of the magnification lens. We discuss how a "cubic" border can mitigate the discontinuities resulting from the use of a linear function, without significant performance loss. We discuss various issues concerning development of a three-dimensional magnification lens.
{"title":"A magnification lens for interactive volume visualization","authors":"E. LaMar, B. Hamann, K. Joy","doi":"10.1109/PCCGA.2001.962877","DOIUrl":"https://doi.org/10.1109/PCCGA.2001.962877","url":null,"abstract":"Volume visualization of large data sets suffers from the same problem that many other visualization modalities suffer from: either one can visualize the entire data set and lose small details or visualize a small region and lose the context. The authors we present a magnification lens technique for volume visualization. While the notion of a magnification-lens is not new, and other techniques attempt to simulate the physical properties of a magnifying lens, our contribution is in developing a magnification lens that is fast, can be implemented using a fairly small software overhead, and has a natural, intuitive appearance. The issue with magnification lens is the border, or transition region. The lens center and exterior have a constant zoom factor, and are simple to render. It is the border region that blends between the external and interior magnification, and has a nonconstant magnification. We use the \"perspective-correct textures\" capability, available in most current graphics systems, to produce a lens with a tessellated border region that approximates linear compression with respect to the radius of the magnification lens. We discuss how a \"cubic\" border can mitigate the discontinuities resulting from the use of a linear function, without significant performance loss. We discuss various issues concerning development of a three-dimensional magnification lens.","PeriodicalId":387699,"journal":{"name":"Proceedings Ninth Pacific Conference on Computer Graphics and Applications. Pacific Graphics 2001","volume":"106 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127774202","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 : 2001-10-16DOI: 10.1109/PCCGA.2001.962883
Jiří Bittner, Peter Wonka, M. Wimmer
We present an algorithm for visibility preprocessing of urban environments. The algorithm uses a subdivision of line space to analytically calculate a conservative potentially visible set for a given region in the scene. We present a detailed evaluation of our method, including a comparison to another recently published visibility preprocessing algorithm. To the best of our knowledge, the proposed method is the first algorithm that scales to large scenes and efficiently handles large view cells.
{"title":"Visibility preprocessing for urban scenes using line space subdivision","authors":"Jiří Bittner, Peter Wonka, M. Wimmer","doi":"10.1109/PCCGA.2001.962883","DOIUrl":"https://doi.org/10.1109/PCCGA.2001.962883","url":null,"abstract":"We present an algorithm for visibility preprocessing of urban environments. The algorithm uses a subdivision of line space to analytically calculate a conservative potentially visible set for a given region in the scene. We present a detailed evaluation of our method, including a comparison to another recently published visibility preprocessing algorithm. To the best of our knowledge, the proposed method is the first algorithm that scales to large scenes and efficiently handles large view cells.","PeriodicalId":387699,"journal":{"name":"Proceedings Ninth Pacific Conference on Computer Graphics and Applications. Pacific Graphics 2001","volume":"121 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124038679","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 : 2001-10-16DOI: 10.1109/PCCGA.2001.962882
Xikun Liang, Mai Ali Nur, B. Wyvill
The paper presents a new method for modeling the structure of sea anemones and sea stars. Two specific invertebrates, the sea anemone, Stomphia coccinea and the sea star, Dermasterias imbricata were modeled using hierarchical implicit surfaces based on the BlobTree. The hierarchy provides both local refinement and global deformation. Local refinement allows the introduction of details on the base surface and global deformations change the overall shape of the model while maintaining the integrity of the surface details. Using a new implicit surface phyllotactic method, we obtain a visually pleasing arrangement of the sea anemone's tentacles. The hierarchical representation of the model provides an easy and efficient way for modeling the many different shape changes of sea anemones.
{"title":"Modeling the structure of the sea anemone and the sea star using hierarchical implicit surfaces","authors":"Xikun Liang, Mai Ali Nur, B. Wyvill","doi":"10.1109/PCCGA.2001.962882","DOIUrl":"https://doi.org/10.1109/PCCGA.2001.962882","url":null,"abstract":"The paper presents a new method for modeling the structure of sea anemones and sea stars. Two specific invertebrates, the sea anemone, Stomphia coccinea and the sea star, Dermasterias imbricata were modeled using hierarchical implicit surfaces based on the BlobTree. The hierarchy provides both local refinement and global deformation. Local refinement allows the introduction of details on the base surface and global deformations change the overall shape of the model while maintaining the integrity of the surface details. Using a new implicit surface phyllotactic method, we obtain a visually pleasing arrangement of the sea anemone's tentacles. The hierarchical representation of the model provides an easy and efficient way for modeling the many different shape changes of sea anemones.","PeriodicalId":387699,"journal":{"name":"Proceedings Ninth Pacific Conference on Computer Graphics and Applications. Pacific Graphics 2001","volume":"147 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129699851","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 : 2001-10-16DOI: 10.1109/PCCGA.2001.962891
Shigenori Mochizuki, DongSheng Cai, T. Komiri, H. Kimura, R. Hori
The authors simulate the time evolution of autumn coloring of both maple leaves and entire trees, and propose both biological and fractal models of this process. We calculate the amount of sunlight received on the leaves and propose the "autumn-coloring-logical-time" that is the temporal indicator of autumn coloring, then we use experimental biological data to calibrate the model parameters. Using the leaf fractalities, we adopt a chaos game algorithm or random iteration algorithm to render natural autumn colorings.
{"title":"Virtual autumn coloring system based on biological and fractal model","authors":"Shigenori Mochizuki, DongSheng Cai, T. Komiri, H. Kimura, R. Hori","doi":"10.1109/PCCGA.2001.962891","DOIUrl":"https://doi.org/10.1109/PCCGA.2001.962891","url":null,"abstract":"The authors simulate the time evolution of autumn coloring of both maple leaves and entire trees, and propose both biological and fractal models of this process. We calculate the amount of sunlight received on the leaves and propose the \"autumn-coloring-logical-time\" that is the temporal indicator of autumn coloring, then we use experimental biological data to calibrate the model parameters. Using the leaf fractalities, we adopt a chaos game algorithm or random iteration algorithm to render natural autumn colorings.","PeriodicalId":387699,"journal":{"name":"Proceedings Ninth Pacific Conference on Computer Graphics and Applications. Pacific Graphics 2001","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132077347","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 : 2001-10-16DOI: 10.1109/PCCGA.2001.962857
Dae-Eun Hyun, B. Jüttler, Myung-Soo Kim
The paper proposes a simple approach to the affine motion interpolation problem, where an affine spline motion is generated that interpolates a given sequence of affine keyframes and approximately satisfies rigidity constraints and certain optimization criteria. An affine spline motion is first generated so as to interpolate the given keyframes; after that, it is progressively refined via knot insertion and degree elevation into an optimal affine motion by an iterative optimization procedure.
{"title":"Minimizing the distortion of affine spline motions","authors":"Dae-Eun Hyun, B. Jüttler, Myung-Soo Kim","doi":"10.1109/PCCGA.2001.962857","DOIUrl":"https://doi.org/10.1109/PCCGA.2001.962857","url":null,"abstract":"The paper proposes a simple approach to the affine motion interpolation problem, where an affine spline motion is generated that interpolates a given sequence of affine keyframes and approximately satisfies rigidity constraints and certain optimization criteria. An affine spline motion is first generated so as to interpolate the given keyframes; after that, it is progressively refined via knot insertion and degree elevation into an optimal affine motion by an iterative optimization procedure.","PeriodicalId":387699,"journal":{"name":"Proceedings Ninth Pacific Conference on Computer Graphics and Applications. Pacific Graphics 2001","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126202614","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 : 2001-10-16DOI: 10.1109/PCCGA.2001.962853
Jianhua Wu, Shimin Hu, Jiaguang Sun, Chiew-Lan Tai
A novel mesh simplification scheme that uses the face constriction process is presented. By introducing a statistical measure that can distinguish triangles having vertices of high local roughness from triangles in flat regions into our weight-ordering equation, along with other heuristics, our scheme can better preserve visually important features in the original mesh. To improve the shape quality of triangles, we adopt nonlinear face area sensitivity in the weight ordering. A learning and feedback mechanism is also utilized to enhance user controllability. The computations are simple, making our scheme time-effective and easy to implement. In addition to comparing our scheme with other mesh simplification algorithms empirically, we compare their performances by establishing a unifying ground among three basic simplification processes: decimate vertex, collapse edge, and constrict face. This unification allows us to analyze the intrinsic merits and demerits of simplification algorithms to help users make better selections.
{"title":"An effective feature-preserving mesh simplification scheme based on face constriction","authors":"Jianhua Wu, Shimin Hu, Jiaguang Sun, Chiew-Lan Tai","doi":"10.1109/PCCGA.2001.962853","DOIUrl":"https://doi.org/10.1109/PCCGA.2001.962853","url":null,"abstract":"A novel mesh simplification scheme that uses the face constriction process is presented. By introducing a statistical measure that can distinguish triangles having vertices of high local roughness from triangles in flat regions into our weight-ordering equation, along with other heuristics, our scheme can better preserve visually important features in the original mesh. To improve the shape quality of triangles, we adopt nonlinear face area sensitivity in the weight ordering. A learning and feedback mechanism is also utilized to enhance user controllability. The computations are simple, making our scheme time-effective and easy to implement. In addition to comparing our scheme with other mesh simplification algorithms empirically, we compare their performances by establishing a unifying ground among three basic simplification processes: decimate vertex, collapse edge, and constrict face. This unification allows us to analyze the intrinsic merits and demerits of simplification algorithms to help users make better selections.","PeriodicalId":387699,"journal":{"name":"Proceedings Ninth Pacific Conference on Computer Graphics and Applications. Pacific Graphics 2001","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128000287","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 : 2001-10-16DOI: 10.1109/PCCGA.2001.962895
Marcelo Magallón, M. Hopf, T. Ertl
The paper describes an architecture that enables the use of commodity off the shelf graphics hardware along with high speed network devices for distributed volume rendering. Several PCs drive a number of graphic accelerator boards using an OpenGL interface. The frame buffers of the cards are read back and blended together for final presentation on a single PC working as front end. We explain how the attainable frame rates are limited by the transfer speeds over the network as well as the overhead implied by having to blend several images together. An initial implementation using four graphic cards achieves frame rates similar to those of high performance visualization systems.
{"title":"Parallel volume rendering using PC graphics hardware","authors":"Marcelo Magallón, M. Hopf, T. Ertl","doi":"10.1109/PCCGA.2001.962895","DOIUrl":"https://doi.org/10.1109/PCCGA.2001.962895","url":null,"abstract":"The paper describes an architecture that enables the use of commodity off the shelf graphics hardware along with high speed network devices for distributed volume rendering. Several PCs drive a number of graphic accelerator boards using an OpenGL interface. The frame buffers of the cards are read back and blended together for final presentation on a single PC working as front end. We explain how the attainable frame rates are limited by the transfer speeds over the network as well as the overhead implied by having to blend several images together. An initial implementation using four graphic cards achieves frame rates similar to those of high performance visualization systems.","PeriodicalId":387699,"journal":{"name":"Proceedings Ninth Pacific Conference on Computer Graphics and Applications. Pacific Graphics 2001","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125754408","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 : 2001-10-16DOI: 10.1109/PCCGA.2001.962881
Jing Hua, Hong Qin
Implicit functions characterized by the zero-set of polynomial-based algebraic equations and other commonly-used analytic equations are extremely powerful in graphics, geometric design, and visualization. But the potential of implicit functions is yet to be fully realized due to the lack of flexible and interactive design techniques. The paper presents a haptic sculpting system founded upon scalar trivariate B-spline functions. All the solids sculpted in our environment are semi-algebraic sets of volumetric implicit functions. We develop a large variety of sculpting toolkits equipped with an intuitive haptic interface to facilitate the direct manipulation of implicit functions in real-time. To facilitate multiresolution editing and different levels of details, we employ three techniques: hierarchical B-splines, CSG-based functional composition, and knot insertion. Our experiments demonstrate that our algorithms and haptics-based techniques can greatly overcome the modeling difficulties associated with implicit functions. The novel modeling techniques and their haptics-based design principle are extensible to the design of arbitrary implicit functions.
{"title":"Haptic sculpting of volumetric implicit functions","authors":"Jing Hua, Hong Qin","doi":"10.1109/PCCGA.2001.962881","DOIUrl":"https://doi.org/10.1109/PCCGA.2001.962881","url":null,"abstract":"Implicit functions characterized by the zero-set of polynomial-based algebraic equations and other commonly-used analytic equations are extremely powerful in graphics, geometric design, and visualization. But the potential of implicit functions is yet to be fully realized due to the lack of flexible and interactive design techniques. The paper presents a haptic sculpting system founded upon scalar trivariate B-spline functions. All the solids sculpted in our environment are semi-algebraic sets of volumetric implicit functions. We develop a large variety of sculpting toolkits equipped with an intuitive haptic interface to facilitate the direct manipulation of implicit functions in real-time. To facilitate multiresolution editing and different levels of details, we employ three techniques: hierarchical B-splines, CSG-based functional composition, and knot insertion. Our experiments demonstrate that our algorithms and haptics-based techniques can greatly overcome the modeling difficulties associated with implicit functions. The novel modeling techniques and their haptics-based design principle are extensible to the design of arbitrary implicit functions.","PeriodicalId":387699,"journal":{"name":"Proceedings Ninth Pacific Conference on Computer Graphics and Applications. Pacific Graphics 2001","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130260391","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 : 2001-10-16DOI: 10.1109/PCCGA.2001.962894
Kei Iwasaki, T. Nishita, Y. Dobashi
The display of realistic natural scenes is one of the most important research areas in computer graphics. The rendering of water is one of the essential components. The paper proposes an efficient method for rendering images of scenes within water. For underwater scenery, the shafts of light and caustics are attractive and important elements. However, computing these effects is difficult and time-consuming, since light refracts when passing through waves. To address the problem, our method makes use of graphics hardware to accelerate the computation. Our method displays the shafts of light by accumulating the intensities of streaks of light by using hardware color blending functions. The rendering of caustics is accelerated by making use of a Z-buffer and a stencil buffer. Moreover, by using a shadow mapping technique, our method can display shafts of light and caustics, taking account of shadows due to objects.
{"title":"Efficient rendering of optical effects within water using graphics hardware","authors":"Kei Iwasaki, T. Nishita, Y. Dobashi","doi":"10.1109/PCCGA.2001.962894","DOIUrl":"https://doi.org/10.1109/PCCGA.2001.962894","url":null,"abstract":"The display of realistic natural scenes is one of the most important research areas in computer graphics. The rendering of water is one of the essential components. The paper proposes an efficient method for rendering images of scenes within water. For underwater scenery, the shafts of light and caustics are attractive and important elements. However, computing these effects is difficult and time-consuming, since light refracts when passing through waves. To address the problem, our method makes use of graphics hardware to accelerate the computation. Our method displays the shafts of light by accumulating the intensities of streaks of light by using hardware color blending functions. The rendering of caustics is accelerated by making use of a Z-buffer and a stencil buffer. Moreover, by using a shadow mapping technique, our method can display shafts of light and caustics, taking account of shadows due to objects.","PeriodicalId":387699,"journal":{"name":"Proceedings Ninth Pacific Conference on Computer Graphics and Applications. Pacific Graphics 2001","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131274595","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 : 2001-10-16DOI: 10.1109/PCCGA.2001.962890
S. Gobron, Norishige Chiba
The paper describes a method for modeling the natural peeling phenomenon over any 3D surface. Using crack input data, precomputed with a semi physical solution, this method allows simulation of peeling on any type of triangulated 3D object. The model's main advantage is that it proposes a method that is intuitive enough to make it easy to understand and convenient to apply, user controllable, and easily extensible, especially to simultaneous natural phenomena. We first introduce the general development of peeling over various materials. Then, we present how to define groups of peeling, how to determine a realistic and natural peeling order, and how to simulate the rendering of two types of special peelings. Finally, a set of graphical results concludes the paper, presenting a series of direct peeling and curling patterns using classical paintings or plastic-paintings simulated materials.
{"title":"Simulation of peeling using 3D-surface cellular automata","authors":"S. Gobron, Norishige Chiba","doi":"10.1109/PCCGA.2001.962890","DOIUrl":"https://doi.org/10.1109/PCCGA.2001.962890","url":null,"abstract":"The paper describes a method for modeling the natural peeling phenomenon over any 3D surface. Using crack input data, precomputed with a semi physical solution, this method allows simulation of peeling on any type of triangulated 3D object. The model's main advantage is that it proposes a method that is intuitive enough to make it easy to understand and convenient to apply, user controllable, and easily extensible, especially to simultaneous natural phenomena. We first introduce the general development of peeling over various materials. Then, we present how to define groups of peeling, how to determine a realistic and natural peeling order, and how to simulate the rendering of two types of special peelings. Finally, a set of graphical results concludes the paper, presenting a series of direct peeling and curling patterns using classical paintings or plastic-paintings simulated materials.","PeriodicalId":387699,"journal":{"name":"Proceedings Ninth Pacific Conference on Computer Graphics and Applications. Pacific Graphics 2001","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132680730","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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