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":null,"pages":null},"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.2001.962881
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":null,"pages":null},"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.2001.962890
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":null,"pages":null},"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}
Pub Date : 2001-05-01DOI: 10.1109/PCCGA.2001.962860
D. Steiner, A. Fischer
Reverse engineering (RE) deals with an enormous number of irregular and scattered digitized points that require intensive processing in order to reconstruct the surfaces of an object. Surface reconstruction of freeform objects is based on geometrical and topological criteria. Current fitting methods reconstruct an object using a bottom-up approach, from points to a dense mesh, and finally into smoothed connected freeform sub-surfaces. This type of reconstruction, however, can cause topological problems that lead to undesired surface fitting results. Such problems are particularly common with concave shapes. To avoid problems of this type, the paper proposes a new method that automatically detects the topological structure of an object as a base for surface fitting. The topological reconstruction method described in the paper is based on two stages: (1) creating 3D non-self-intersecting iso-curves from a 3D triangular mesh and (2) extracting a topological graph. The feasibility of the proposed topological reconstruction method is demonstrated on several examples using freeform objects with complex topologies.
{"title":"Topology recognition of 3D closed freeform objects based on topological graphs","authors":"D. Steiner, A. Fischer","doi":"10.1109/PCCGA.2001.962860","DOIUrl":"https://doi.org/10.1109/PCCGA.2001.962860","url":null,"abstract":"Reverse engineering (RE) deals with an enormous number of irregular and scattered digitized points that require intensive processing in order to reconstruct the surfaces of an object. Surface reconstruction of freeform objects is based on geometrical and topological criteria. Current fitting methods reconstruct an object using a bottom-up approach, from points to a dense mesh, and finally into smoothed connected freeform sub-surfaces. This type of reconstruction, however, can cause topological problems that lead to undesired surface fitting results. Such problems are particularly common with concave shapes. To avoid problems of this type, the paper proposes a new method that automatically detects the topological structure of an object as a base for surface fitting. The topological reconstruction method described in the paper is based on two stages: (1) creating 3D non-self-intersecting iso-curves from a 3D triangular mesh and (2) extracting a topological graph. The feasibility of the proposed topological reconstruction method is demonstrated on several examples using freeform objects with complex topologies.","PeriodicalId":387699,"journal":{"name":"Proceedings Ninth Pacific Conference on Computer Graphics and Applications. Pacific Graphics 2001","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129838272","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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