Weiler-Atherton Polygon Clipping Algorithm The problem encountered in clipping concave polygons in Sutherland-Hodgeman algorithm solved by Weiler-Atherton Polygon Clipping Algorithm. The basic idea in this algorithm is that instead of always proceeding around the polygon edges; as vertices processed, we may sometimes follow the window boundary. Whether to follow polygon boundary (edges) or clipping window… Read More »
Sutherland-Hodgeman Polygon Clipping Algorithm Sutherland-Hodgeman Polygon Clipping Algorithm: This algorithm was purposed by Sutherland and Hodgeman in 1974 to determine which portions of the polygon were visible within a window and clipping out the portions that are outside the window. This algorithm accepts as input a series of polygon vertices, V1, V2, …. Vn. These… Read More »
Polygon Clipping: A polygon is a closed sided figure represented by a number of line segments that are connected to each other end to end. The various line segments are called edges or sides and the points where two edges meet are called vertices or corners. A simplest polygon which exists in the Euclidean plane… Read More »
Line Clipping Line Clipping is a procedure that determines which portion of a line lies inside the clipping window and is displayed. Lines that do not intersect the clipping window are either completely inside the window or completely outside the window. On the other hand, a line that intersects the clipping window is divided by… Read More »
Point clipping Point clipping determines whether the point lies inside the clipping window or not. Thus it determines whether point is visible or not. Assuming that the clip window is a rectangular, we consider a point P(x, y). This point P will be considered inside the window if it satisfies the following two conditions: WXmin… Read More »
Clipping in Computer Graphics Clipping is a process of extracting portion or an object or image that is to be displayed on viewport. Also defined as procedure that identifies whether the portion of any graphics object is within or outside of a specified region or space. The region or space against which an object is… Read More »
Direct Method for Line Drawing Algorithm Direct Method for Line Drawing Algorithm method is the easiest and straightforward method that uses Cartesian slope-intercept equation of a line : y = mx + b –[1] Here x and y are the coordinates of any point of a line, ‘m’ represents the slope of line and ‘b’… Read More »
Difference between Raster Scan Display and Random Scan Display Raster Scan Display In raster scan display the electron beam scans the entire surface of CRT, one row at a time. It starts from the top left corner of the screen then moves horizontally from left to right. It then jump to left side of screen… Read More »
Raster Scan Display The term ‘raster’ is a synonym for the term ‘matrix’. Therefore, a raster scan CRT scans a matrix with an electron beam. Raster scan CRT display is most commonly used in TVs. The various components of raster scan CRT are explained below: Electron Gun Control Electrode Focusing Electrode Deflection Yoke Phosphor Coated… Read More »
Midpoint circle algorithm in an incremental scan conversion method that is similar to Bresenham’s algorithm. This algorithm uses the following function to test the spatial relationship between an arbitrary point (x, y) and a circle with radius r centered at origin. f(x, y) = x2 + y2 – r2 Any point (x, y) on the… Read More »