Boundary Representation in Solid Modeling|Geometric Modeling Techniques| ENGINEERING STUDY MATERIALS

Boundary Representation in Solid Modeling B Rep |Geometric Modeling Techniques| ENGINEERING STUDY MATERIALS Solid Modeling and computer-aided design, boundary representation—often abbreviated as B-rep or BREPis a method for representing shapes using the limits. A solid is represented as a collection of connected surface elements, the boundary between solid and non-solid. Boundary representation of models are composed of two parts: topology and geometry (surfaces, curves and points). The main topological items are: faces, edges and vertices. A face is a bounded portion of a surface; an edge is a bounded piece of a curve and a vertex lies at a point. Other elements are the shell (a set of connected faces), the loop (a circuit of edges bounding a face) and loop-edge links (also known as winged edge links or half-edges) which are used to create the edge circuits. The edges are like the edges of a table, bounding a surface portion. Compared to the constructive solid geometry (CSG) representation, which uses only primitive objects and Boolean operations to combine them, boundary representation is more flexible and has a much richer operation set. In addition to the Boolean operations, B-rep has extrusion (or sweeping), chamfer, blending, drafting, shelling, tweaking and other operations which make use of these. The basic method for BREP was developed independently in the early 1970s by both Ian C. Braid in Cambridge (for CAD) and Bruce G. Baumgart at Stanford (for computer vision). Braid continued his work with the research solid modeller BUILD which was the forerunner of many research and commercial solid modelling systems. Braid worked on the commercial systems ROMULUS, the forerunner of Parasolid, and on ACIS. Parasolid and ACIS are the basis for many of today's commercial CAD systems. Following Braid's work for solids, a Swedish team led by Professor Torsten Kjellberg, developed the philosophy and methods for working with hybrid models, wire-frames, sheet objects and volumetric models during the early 1980s. In Finland, Martti Mäntylä produced a solid modelling system called GWB. In the USA Eastman and Weiler were also working on Boundary Representation and in Japan Professor Fumihiko Kimura and his team at Tokyo University also produced their own B-rep modelling system. Initially CSG was used by several commercial systems because it was easier to implement. The advent of reliable commercial B-rep kernel systems like Parasolid and ACIS, mentioned above, as well as OpenCASCADE and C3D that were later developed, has led to widespread adoption of B-rep for CAD. Tags: boundary representation in solid modelling,boundary representation in computer graphics,boundary representation in digital image processing,boundary representation ppt,boundary representation in solid modelling in hindi,boundary representation example,b rep in cad,b rep in computer graphics,constructive solid geometry,computer aided design,computer aided design of electrical machines,brep,cad,geometric modelling,computer graphics,3d modeling,cad modellingboundary representation in solid modelling,boundary representation in computer graphics,boundary representation in digital image processing,boundary representation ppt,boundary representation in solid modelling in hindi,boundary representation example,b rep in cad,b rep in computer graphics,constructive solid geometry,computer aided design,computer aided design of electrical machines,brep,cad,geometric modelling,computer graphics,3d modeling,cad modelling #Engineering_Study_Materials