PPT-3D Viewing and Clipping Ming

Ouhyoung 歐陽明 Professor Dept of CSIE and GINM NTU 3D Viewing Process Transform into viewport in 2D device coordinates for display Project onto projection plane Clip against view. 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 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 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. 411 Carnahan,ReynoldsandBrogan Simulation Viewing,MakingcoercibleI. Viewing,Editing,CoercingII. Viewing,LoggingEvaluatin g III. modificationExtract forInsert coercedsimulation Figure1:LifeCycleofCoerc 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:. 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:. Zhu Yuanzhang. In 1368, a rebellion led by a warlord named Zhu Yuanzhang brought an end to the Yuan Empire. Zhu Yuanzhang went on to establish one . of . the longest-lasting and most famous dynasties in Chinese history: the Ming (1368-1644). Preview. Chinese Ideas Spread. - . After the Ming dynasty took control of China back from the Mongols, Chinese ideas and goods spread across the world.. As Trade Expands, the Empire Grows. - . The expansion of trade led to the growth of the Ming dynasty’s empire and its people.. 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 .