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Liang–Barsky Algorithm
In computer graphics, the Liang–Barsky algorithm (named after You-Dong Liang and Brian A. Barsky) is a line clipping algorithm. The Liang–Barsky algorithm uses the parametric equation of a line and inequalities describing the range of the clipping window to determine the intersections between the line and the clip window. With these intersections it knows which portion of the line should be drawn. So this algorithm is significantly more efficient than Cohen–Sutherland. The idea of the Liang–Barsky clipping algorithm is to do as much testing as possible before computing line intersections. Consider first the usual parametric form of a straight line: :x = x_0 + t (x_1 - x_0) = x_0 + t \Delta x, :y = y_0 + t (y_1 - y_0) = y_0 + t \Delta y. A point is in the clip window, if :x_\text \le x_0 + t \Delta x \le x_\text and :y_\text \le y_0 + t \Delta y \le y_\text, which can be expressed as the 4 inequalities :t p_i \le q_i, \quad i = 1, 2, 3, 4, where : \begin p_1 &= -\Delt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Graphics
Computer graphics deals with generating images with the aid of computers. Today, computer graphics is a core technology in digital photography, film, video games, cell phone and computer displays, and many specialized applications. A great deal of specialized hardware and software has been developed, with the displays of most devices being driven by computer graphics hardware. It is a vast and recently developed area of computer science. The phrase was coined in 1960 by computer graphics researchers Verne Hudson and William Fetter of Boeing. It is often abbreviated as CG, or typically in the context of film as computer generated imagery (CGI). The non-artistic aspects of computer graphics are the subject of computer science research. Some topics in computer graphics include user interface design, sprite graphics, rendering, ray tracing, geometry processing, computer animation, vector graphics, 3D modeling, shaders, GPU design, implicit surfaces, visualization, scientific c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
You-Dong Liang
You-Dong Liang () is a mathematician and educator, best known for his contributions in geometric modeling and the Liang-Barsky algorithm. Education and teaching You-Dong Liang was born on July 19, 1935, in Fuzhou, Fujian Province, China. Liang pursued his graduate degree in Fudan University, where he worked under the supervision of Professor Su Buqing and specialized in geometric theory. After graduating in 1960, he joined the mathematics teaching faculty at Zhejiang University, where he actively promoted the development of geometric design and graphics. From 1984–1990, he was the chairman of the mathematics department, and on several occasions, was a visiting scholar and visiting professor at the University of California at Berkeley, University of Utah, and University of Berlin. Liang helped form the Computational Geometry Collaborative Group in China. As the leader of this group, Liang supported the collaboration of scholars in geometric design and computational graphics. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brian A
Brian (sometimes spelled Bryan in English) is a male given name of Irish and Breton origin, as well as a surname of Occitan origin. It is common in the English-speaking world. It is possible that the name is derived from an Old Celtic word meaning "high" or "noble". For example, the element ''bre'' means "hill"; which could be transferred to mean "eminence" or "exalted one". The name is quite popular in Ireland, on account of Brian Boru, a 10th-century High King of Ireland. The name was also quite popular in East Anglia during the Middle Ages. This is because the name was introduced to England by Bretons following the Norman Conquest. Bretons also settled in Ireland along with the Normans in the 12th century, and 'their' name was mingled with the 'Irish' version. Also, in the north-west of England, the 'Irish' name was introduced by Scandinavian settlers from Ireland. Within the Gaelic speaking areas of Scotland, the name was at first only used by professional families of Irish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Line Clipping
In computer graphics, line clipping is the process of removing (clipping) lines or portions of lines outside an area of interest (a viewport or view volume). Typically, any part of a line which is outside of the viewing area is removed. There are two common algorithms for line clipping: Cohen–Sutherland and Liang–Barsky. A line-clipping method consists of various parts. Tests are conducted on a given line segment to find out whether it lies outside the view area or volume. Then, intersection calculations are carried out with one or more clipping boundaries. Determining which portion of the line is inside or outside of the clipping volume is done by processing the endpoints of the line with regards to the intersection. Cohen–Sutherland In computer graphics, the Cohen–Sutherland algorithm (named after Danny Cohen and Ivan Sutherland) is a line-clipping algorithm. The algorithm divides a 2D space into 9 regions, of which only the middle part (viewport) is visible. In 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clip Window
This is a glossary of terms relating to computer graphics. For more general computer hardware terms, see glossary of computer hardware terms. 0–9 A B C D E F G H I K L M N O P Q R S T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyrus–Beck Algorithm
In computer graphics, the Cyrus–Beck algorithm is a generalized algorithm for line clipping. It was designed to be more efficient than the Cohen–Sutherland algorithm, which uses repetitive clipping. Cyrus–Beck is a general algorithm and can be used with a convex polygon clipping window, unlike Cohen-Sutherland, which can be used only on a rectangular clipping area. Here the of a line in the view plane is where . Now to find the intersecti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicholl–Lee–Nicholl Algorithm
In computer graphics, the Nicholl–Lee–Nicholl algorithm is a fast algorithm for line clipping that reduces the chances of clipping a single line segment multiple times, as may happen in the Cohen–Sutherland algorithm. Description Using the Nicholl–Lee–Nicholl algorithm, the area around the clipping window is divided into a number of different areas, depending on the position of the initial point of the line to be clipped. This initial point should be in three predetermined areas; thus the line may have to be translated and/or rotated to bring it into the desired region. The line segment may then be re-translated and/or re-rotated to bring it to the original position. After that, straight line segments are drawn from the line end point, passing through the corners of the clipping window. These areas are then designated as L, LT, LB, or TR, depending on the location of the initial point. Then the other end point of the line is checked against these areas. If a line starts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fast Clipping
In computer graphics, line clipping is the process of removing ( clipping) lines or portions of lines outside an area of interest (a viewport or view volume). Typically, any part of a line which is outside of the viewing area is removed. There are two common algorithms for line clipping: Cohen–Sutherland and Liang–Barsky. A line-clipping method consists of various parts. Tests are conducted on a given line segment to find out whether it lies outside the view area or volume. Then, intersection calculations are carried out with one or more clipping boundaries. Determining which portion of the line is inside or outside of the clipping volume is done by processing the endpoints of the line with regards to the intersection. Cohen–Sutherland In computer graphics, the Cohen–Sutherland algorithm (named after Danny Cohen and Ivan Sutherland) is a line-clipping algorithm. The algorithm divides a 2D space into 9 regions, of which only the middle part (viewport) is visible. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
