PPT-Clipping

1 Clipping Clipping is a process of dividing an object into visible and invisible portions and displaying the visible portion and discarding the invisible portion Types of Clipping Generally we have Clipping algorithm for the following primitive type. In rendering complex 3D images it has to be done several thousand times Ef64257cient algorithms are therefore very important We present such an ef64257cient algorithm for clipping arbitrary 2D polygons The algorithm can handle arbitrary closed polyg Clipping. CMSC 435/634. Graphics Pipeline. Object-order approach to rendering. Sequence of operations. Vertex processing. Transforms. Vertex components of shading/texture. Clipping. Find the visible parts of any primitives. Computer Graphics . :. Viewing In 2D. Contents. Windowing Concepts. Clipping. Introduction . Brute Force. Cohen-Sutherland Clipping Algorithm. Area Clipping. Sutherland-Hodgman Area Clipping Algorithm. Viewing In 2D. Contents. *. Windowing Concepts. *. Clipping. Point Clipping . Line Clipping. . -Cohen-Sutherland Clipping Algorithm. *. Area Clipping. Sutherland-. Hodgman. Area Clipping Algorithm. Images were taken from the book: “Interactive Computer Graphics” by Angel and Shreiner. Normal Vectors. How to compute the normal per . planar. face?.  . Normal Vectors. However, vertex normals are not well defined. 網媒所. 林宏祥. . 2012.10.02. Overview. Orthogonal Projection. -Z. X. x. camera. x. viewport. Perspective . P. rojection. -Z. X. x. camera. x. viewport. d. z. View Volume—orthogonal projection. 1 Clipping Transform intoframe bufferin frame buffer Clipping in the 2D pipeline Clipping references Clipping references Hearn and Baker Hearn and Baker C C - - S (lines): p 317 S (lines): p 317 L Clipping. CMSC 435/634. Graphics Pipeline. Object-order approach to rendering. Sequence of operations. Vertex processing. Transforms. Vertex components of shading/texture. Clipping. Find the visible parts of any primitives. Department of Computing and Information Sciences, . KSU. KSOL course pages: . http://bit.ly/hGvXlH. / . http://bit.ly/eVizrE. . Public mirror web site: . http://www.kddresearch.org/Courses/CIS636. Instructor home page: . CSCI 440. textbook section 8.3-8.7. Starter Question. How do we clip these lines?. X=-5. Y. =-5. Y=5. X=5. [0,0]. [3,3]. [7,-3]. [0,-3]. formula from . wikipedia. Goals of Clipping. Reject, Accept, or Accept a portion. 1. of 16 . Clipping - 10/12/17. Clipping endpoints. If . x. min. ≤ x ≤ . x. max. . . and. . y. min. . ≤ . y . ≤ . y. max. . , . the point is inside the clip rectangle.. Endpoint analysis for lines:. CMSC 435/634. Graphics Pipeline. Object-order approach to . rendering. Vertex Processing. Clipping. Rasterization. Fragment Processing. Visibility & Blending. Transformations. Vertex components of shading. Types of Clipping:. Generally we have Clipping algorithm for the following primitive type:. Point Clipping. Line Clipping . Area Clipping (Polygon). Curve Clipping. Text Clipping. . 2. Point Clipping. Clip Coordinates vs. NDC. Clip space (left-handed). Clip. coordinate. Normalized device. coordinate . (NDC). Culling: discarding . invisible. polygons. Back-face culling. Discarding all faces (i.e., polygons) that face “backward” (i.e., whose .