|
Visibility (geometry)
In geometry, visibility is a mathematical abstraction of the real-life notion of visibility. Given a set of obstacles in the Euclidean space, two points in the space are said to be visible to each other, if the line segment that joins them does not intersect any obstacles. (In the Earth's atmosphere light follows a slightly curved path that is not perfectly predictable, complicating the calculation of actual visibility.) Computation of visibility is among the basic problems in computational geometry and has applications in computer graphics, motion planning, and other areas. Concepts and problems * Point visibility * Edge visibilityE. Roth, G. Panin and A. Knoll,Sampling feature points for contour tracking with graphics hardware, "In International Workshop on Vision, Modeling and Visualization (VMV)", Konstanz, Germany, October 2008. * Visibility polygon * Weak visibility *Art gallery problem or museum problem *Visibility graph ** Visibility graph of vertical line segments * Wat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geometry
Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is called a ''geometer''. Until the 19th century, geometry was almost exclusively devoted to Euclidean geometry, which includes the notions of point, line, plane, distance, angle, surface, and curve, as fundamental concepts. During the 19th century several discoveries enlarged dramatically the scope of geometry. One of the oldest such discoveries is Carl Friedrich Gauss' ("remarkable theorem") that asserts roughly that the Gaussian curvature of a surface is independent from any specific embedding in a Euclidean space. This implies that surfaces can be studied ''intrinsically'', that is, as stand-alone spaces, and has been expanded into the theory of manifolds and Riemannian geometry. Later in the 19th century, it appeared that geometries ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hidden Line Removal
In 3D computer graphics, solid objects are usually modeled by polyhedra. A face of a polyhedron is a planar polygon bounded by straight line segments, called edges. Curved surfaces are usually approximated by a polygon mesh. Computer programs for line drawings of opaque objects must be able to decide which edges or which parts of the edges are hidden by an object itself or by other objects, so that those edges can be clipped during rendering. This problem is known as hidden-line removal. The first known solution to the hidden-line problem was devised by L. G. Roberts in 1963. However, it severely restricts the model: it requires that all objects be convex. Ruth A. Weiss of Bell Labs documented her 1964 solution to this problem in a 1965 paper. In 1966 Ivan E. Sutherland listed 10 unsolved problems in computer graphics. Problem number seven was ''"hidden-line removal"''. In terms of computational complexity, this problem was solved by Devai in 1986.F. Devai. Quadratic bou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otfried Schwarzkopf
Otfried Cheong (formerly Otfried Schwarzkopf) is a German computational geometer working in South Korea at KAIST. He is known as one of the authors of the widely used computational geometry textbook ''Computational Geometry: Algorithms and Applications'' (with Mark de Berg, Marc van Kreveld, and Mark Overmars) and as the developer of Ipe, a vector graphics editor. Cheong completed his doctorate from the Free University of Berlin in 1992 under the supervision of Helmut Alt. He joined KAIST in 2005, after previously holding positions at Utrecht University, Pohang University of Science and Technology, Hong Kong University of Science and Technology, and the Eindhoven University of Technology. Cheong was co-chair of the Symposium on Computational Geometry in 2006, with Nina Amenta. In 2017 he was recognized by the Association for Computing Machinery The Association for Computing Machinery (ACM) is a US-based international learned society for computing. It was founded in 1947 an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mark Overmars
Markus Hendrik Overmars (; born 29 September 1958 in Zeist, Netherlands) is a Dutch computer scientist and teacher of game programming known for his game development application GameMaker. GameMaker lets people create computer games using a drag-and-drop interface. He is the former head of the ''Center for Geometry, Imaging, and Virtual Environments'' at Utrecht University, in the Netherlands. This research center concentrates on computational geometry and its application in areas like computer graphics, robotics, geographic information systems, imaging, multimedia, virtual environments, and games. Overmars received his Ph.D. in 1983 from Utrecht University under the supervision of Jan van Leeuwen, and continued to be a member of the faculty of the same university until September 2013. Overmars has published over 100 journal papers, largely on computational geometry, and is the co-author of several books including a widely used computational geometry text. Overmars has also wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marc Van Kreveld
Marc Johan van Kreveld is a Dutch computational geometer, known as one of the authors of the textbook ''Computational Geometry: Algorithms and Applications'' (with Mark de Berg, Otfried Cheong, and Mark Overmars, Springer, 1997; 3rd ed., 2008). Van Kreveld completed his Ph.D. in 1992 at Utrecht University. His dissertation, ''New Results on Data Structures in Computational Geometry'', was supervised by Mark Overmars. He is a professor of computer science at Utrecht University. With Ferran Hurtado, van Kreveld was co-chair of the 2011 Symposium on Computational Geometry The International Symposium on Computational Geometry (SoCG) is an academic conference in computational geometry. It was founded in 1985, and was originally sponsored by the SIGACT and SIGGRAPH Special Interest Groups of the Association for Computi .... He has also worked in geographic information systems, and (with Jürg Nievergelt, Thomas Roos, and Peter Widmayer) is the author of the textbook ''Algorithmic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mark De Berg
Mark de Berg is a Dutch computational geometer, known as one of the authors of the textbook ''Computational Geometry: Algorithms and Applications'' (with Otfried Cheong, Marc van Kreveld, and Mark Overmars, Springer, 1997; 3rd ed., 2008). De Berg completed his Ph.D. in 1992 at Utrecht University. His dissertation, ''Efficient Algorithms for Ray Shooting and Hidden Surface Removal'', was supervised by Mark Overmars. He is a professor of computer science at the Eindhoven University of Technology. With David Mount, de Berg was co-chair of the 2003 Symposium on Computational Geometry The International Symposium on Computational Geometry (SoCG) is an academic conference in computational geometry. It was founded in 1985, and was originally sponsored by the SIGACT and SIGGRAPH Special Interest Groups of the Association for Computin .... References External linksHome page* {{DEFAULTSORT:Berg, Mark De Year of birth missing (living people) Living people Dutch computer scientists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambridge University Press
Cambridge University Press is the university press of the University of Cambridge. Granted letters patent by Henry VIII of England, King Henry VIII in 1534, it is the oldest university press A university press is an academic publishing house specializing in monographs and scholarly journals. Most are nonprofit organizations and an integral component of a large research university. They publish work that has been reviewed by schola ... in the world. It is also the King's Printer. Cambridge University Press is a department of the University of Cambridge and is both an academic and educational publisher. It became part of Cambridge University Press & Assessment, following a merger with Cambridge Assessment in 2021. With a global sales presence, publishing hubs, and offices in more than 40 Country, countries, it publishes over 50,000 titles by authors from over 100 countries. Its publishing includes more than 380 academic journals, monographs, reference works, school and uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxford University Press
Oxford University Press (OUP) is the university press of the University of Oxford. It is the largest university press in the world, and its printing history dates back to the 1480s. Having been officially granted the legal right to print books by decree in 1586, it is the second oldest university press after Cambridge University Press. It is a department of the University of Oxford and is governed by a group of 15 academics known as the Delegates of the Press, who are appointed by the vice-chancellor of the University of Oxford. The Delegates of the Press are led by the Secretary to the Delegates, who serves as OUP's chief executive and as its major representative on other university bodies. Oxford University Press has had a similar governance structure since the 17th century. The press is located on Walton Street, Oxford, opposite Somerville College, in the inner suburb of Jericho. For the last 500 years, OUP has primarily focused on the publication of pedagogical texts and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Painter's Algorithm
The painter’s algorithm (also depth-sort algorithm and priority fill) is an algorithm for visible surface determination in 3D computer graphics that works on a polygon-by-polygon basis rather than a pixel-by-pixel, row by row, or area by area basis of other Hidden Surface Removal algorithms. The painter’s algorithm creates images by sorting the polygons within the image by their depth and placing each polygon in order from the farthest to the closest object. The painter's algorithm was initially proposed as a basic method to address the Hidden-surface determination problem by Martin Newell, Richard Newell, and Tom Sancha in 1972, while all three were working at CADCentre. The name "painter's algorithm" refers to the technique employed by many painters where they begin by painting distant parts of a scene before parts that are nearer, thereby covering some areas of distant parts. Similarly, the painter's algorithm sorts all the polygons in a scene by their depth and then p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zone Of Visual Influence
A viewshed is the geographical area that is visible from a location. It includes all surrounding points that are in line-of-sight with that location and excludes points that are beyond the horizon or obstructed by terrain and other features (e.g., buildings, trees). Conversely, it can also refer to area from which an object can be seen. A viewshed is not necessarily "visible" to humans; the same concept is used in radio communications to indicate where a specific combination of transmitter, antenna, and terrain allow reception of signal. Viewsheds are commonly used in terrain analysis, which is of interest to urban planning, archaeology, and military science. In urban planning, for example, viewsheds tend to be calculated for areas of particular scenic or historic value that are deemed worthy of preservation against development or other change. Viewsheds are often calculated for public areas — for example, from public roadways, public parks, or high-rise buildings. The preservat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viewshed
A viewshed is the geographical area that is visible from a location. It includes all surrounding points that are in line-of-sight with that location and excludes points that are beyond the horizon or obstructed by terrain and other features (e.g., buildings, trees). Conversely, it can also refer to area from which an object can be seen. A viewshed is not necessarily "visible" to humans; the same concept is used in radio communications to indicate where a specific combination of transmitter, antenna, and terrain allow reception of signal. Viewsheds are commonly used in terrain analysis, which is of interest to urban planning, archaeology, and military science. In urban planning, for example, viewsheds tend to be calculated for areas of particular scenic or historic value that are deemed worthy of preservation against development or other change. Viewsheds are often calculated for public areas — for example, from public roadways, public parks, or high-rise buildings. The preserva ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isovist
A single isovist is the volume of space visible from a given point in space, together with a specification of the location of that point. It is a geometric concept coined by Clifford Tandy in 1967 and further refined by the architect Michael Benedikt. Isovists are naturally three-dimensional, but they may also be studied in two dimensions: either in horizontal section ("plan") or in other vertical sections through the three-dimensional isovist. Every point in physical space has an isovist associated with it. Concept The isovist is one of the two representations of the structure of space, along with the spatial-envelope representation. It is an approach in describing space from the point of view of a person within an environment. It refers to the drawn polygon that covers an area that can be seen or reached when he walks in a straight line from a particular position. The boundary-shape of an isovist may or may not vary with location in, say, a room. If the room is convex (for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Oxford University Press")
