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A Fast Shadow Algorithm for Area Light Sources Using Backprojection
, 1994
"... The fast identification of shadow regions due to area light sources is necessary for realistic rendering and for discontinuity meshing for global illumination. A new shadowdetermination algorithm is presented that uses a data structure, called a backprojection, to represent the visible portion of a ..."
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Cited by 116 (13 self)
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The fast identification of shadow regions due to area light sources is necessary for realistic rendering and for discontinuity meshing for global illumination. A new shadowdetermination algorithm is presented that uses a data structure, called a backprojection, to represent the visible portion of a light source from any point in the scene. A complete discontinuity meshing algorithm is described for polyhedral scenes and area light sources, which includes an important class of light/geometry interactions that have not been implemented before. A fast incremental algorithm for computing backprojections is also described. The use of spatial subdivision, and heuristics based on computed statistics of typical scenes, results in efficient mesh and backprojection computation. Results of the implementation show that the use of the backprojection and discontinuity meshing permits accelerated highquality rendering of shadows using both raycasting and polygonrendering with interpolants. CR C...
Mesh Generation
 Handbook of Computational Geometry. Elsevier Science
, 2000
"... this article, we emphasize practical issues; an earlier survey by Bern and Eppstein [24] emphasized theoretical results. Although there is inevitably some overlap between these two surveys, we intend them to be complementary. ..."
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Cited by 55 (8 self)
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this article, we emphasize practical issues; an earlier survey by Bern and Eppstein [24] emphasized theoretical results. Although there is inevitably some overlap between these two surveys, we intend them to be complementary.
Using Generic Programming for Designing a Data Structure for Polyhedral Surfaces
 Comput. Geom. Theory Appl
, 1999
"... Appeared in Computational Geometry  Theory and Applications 13, 1999, 6590. Software design solutions are presented for combinatorial data structures, such as polyhedral surfaces and planar maps, tailored for program libraries in computational geometry. Design issues considered are flexibility, ..."
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Cited by 49 (4 self)
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Appeared in Computational Geometry  Theory and Applications 13, 1999, 6590. Software design solutions are presented for combinatorial data structures, such as polyhedral surfaces and planar maps, tailored for program libraries in computational geometry. Design issues considered are flexibility, time and space efficiency, and easeofuse. We focus on topological aspects of polyhedral surfaces and evaluate edgebased representations with respect to our design goals. A design for polyhedral surfaces in a halfedge data structure is developed following the generic programming paradigm known from the Standard Template Library STL for C++. Connections are shown to planar maps and facebased structures. Key words: Library design; Generic programming; Combinatorial data structure; Polyhedral surface; Halfedge data structure 1 Introduction Combinatorial structures, such as planar maps, are fundamental in computational geometry. In order to be useful in practice, a solid library for compu...
Designing a Data Structure for Polyhedral Surfaces
 In Proc. 14th Annu. ACM Sympos. Comput. Geom
, 1998
"... Design solutions for a program library are presented for combinatorial data structures in computational geometry, such as planar maps and polyhedral surfaces. Design issues considered are genericity, flexibility, time and space efficiency, and easeofuse. We focus on topological aspects of polyhedr ..."
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Cited by 34 (2 self)
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Design solutions for a program library are presented for combinatorial data structures in computational geometry, such as planar maps and polyhedral surfaces. Design issues considered are genericity, flexibility, time and space efficiency, and easeofuse. We focus on topological aspects of polyhedral surfaces. Edgebased representations for polyhedrons are evaluated with respect to the design goals. A design for polyhedral surfaces in a halfedge data structure is developed following the generic programming paradigm known from the Standard Template Library STL for C++. Connections are shown to planar maps and facebased structures managing holes in facets. 1 Introduction Combinatorial structures, such as planar maps, are fundamental in computational geometry. In order to use computational geometry in practice, a solid library must provide generic and flexible solutions as one of its fundamental cornerstones. Other design criteria are time and space efficiency. Easeofuse is necessar...
Fast 3D Cartoon Rendering with Improved Quality by Exploiting Graphics Hardware
 In Proceedings of Image and Vision Computing New Zealand (IVCNZ) 2001
, 2001
"... Our work in the area of nonphotorealistic rendering (NPR) focuses on visualising 3D models in a cartoon rendering style: the geometrical objects are internally coloured using two or three colours, while simultaneously using an explicit outline. Many NPR techniques are timeconsuming processes, wher ..."
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Cited by 12 (2 self)
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Our work in the area of nonphotorealistic rendering (NPR) focuses on visualising 3D models in a cartoon rendering style: the geometrical objects are internally coloured using two or three colours, while simultaneously using an explicit outline. Many NPR techniques are timeconsuming processes, whereas we aim at realtime rendering performance on mainstream graphics PC hardware without losing a high image quality. Particular emphasis is also put on getting smooth transition borders between the bitonal cartooncolours by applying an object precision triangle subdivision technique. Rapidly finding these transition borders as well as silhouette edges is a topic of a new algorithm. As silhouette lines and light effects are useful indicators for computer vision, this algorithm also looks interesting for applications in that field.
Computer Sculpting of Polygonal Models using Virtual Tools
, 1994
"... vii Acknowledgements viii 1. Introduction 1 1.1 What is Computer Sculpting? : : : : : : : : : : : : : : : : : : : : : : : : : : 1 1.2 The FreeForm Design Problem in Computer Graphics : : : : : : : : : : : : 2 1.3 Contributions of this Thesis : : : : : : : : : : : : : : : : : : : : : : : : : : : 4 2 ..."
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Cited by 11 (0 self)
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vii Acknowledgements viii 1. Introduction 1 1.1 What is Computer Sculpting? : : : : : : : : : : : : : : : : : : : : : : : : : : 1 1.2 The FreeForm Design Problem in Computer Graphics : : : : : : : : : : : : 2 1.3 Contributions of this Thesis : : : : : : : : : : : : : : : : : : : : : : : : : : : 4 2. Related Work 6 2.1 Polygonal Mesh Sculpting : : : : : : : : : : : : : : : : : : : : : : : : : : : : 6 2.2 Virtual Tools : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 9 2.3 Other Approaches to Sculpting : : : : : : : : : : : : : : : : : : : : : : : : : 11 2.3.1 FFDBased Systems : : : : : : : : : : : : : : : : : : : : : : : : : : : 11 2.3.2 Hierarchical BSpline Refinement : : : : : : : : : : : : : : : : : : : : 12 2.3.3 2 1/2 D Paint Systems : : : : : : : : : : : : : : : : : : : : : : : : : : 13 3. Features of the System 14 3.1 Polygonal Mesh Modeling : : : : : : : : : : : : : : : : : : : : : : : : : : : : 14 3.2 Mesh Refinement Operations : : : : : : : : : : : : : ...
Graphics Education
"... The winged and half edge data structures are commonly used representations for polyhedron models. Due to the complexity, students in an introductory to computer graphics course usually have difficulty in handling these data structures and developing applications. This paper describes the authors ’ ..."
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The winged and half edge data structures are commonly used representations for polyhedron models. Due to the complexity, students in an introductory to computer graphics course usually have difficulty in handling these data structures and developing applications. This paper describes the authors ’ effort in the development of a visualization and animation tool for teaching and learning these data structures. This tool also includes a simple pseudo codelike language for algorithm design. Instructors may employ this tool for presentation and demonstration purposes. Students may use the simple language to develop and experiment with new algorithms before their actual implementation. The visualization and animation system may be used to explore and understand the relationship among mesh elements and algorithm execution.
A Fast Shadow Algorithm for Area Light Sources Using Backprojection
"... The fast identification of shadow regions due to area light sources is necessary for realistic rendering and for discontinuity meshing for global illumination. A new shadowdetermination algorithm is presented that uses a data structure, called a backprojection, to represent the visible portion of a ..."
Abstract
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The fast identification of shadow regions due to area light sources is necessary for realistic rendering and for discontinuity meshing for global illumination. A new shadowdetermination algorithm is presented that uses a data structure, called a backprojection, to represent the visible portion of a light source from any point in the scene. A complete discontinuity meshing algorithm is described for polyhedral scenes and area light sources, which includes an important class of light/geometry interactions that have not been implemented before. A fast incremental algorithm for computing backprojections is also described. The use of spatial subdivision, and heuristics based on computed statistics of typical scenes, results in efficient mesh and backprojection computation. Results of the implementation show that the use of the backprojection and discontinuity meshing permits accelerated highquality rendering of shadows using both raycasting and polygonrendering with interpolants.