Abstract
An advanced geometric modeler GEMS4.0 has been developed, in which feature representation is used at the highest level abstraction of a product model. Boundary representation is used at the bottom level, while CSG model is adopted at the median level. A BRep data structure capable of modeling non-manifold is adopted. NURBS representation is used for all curved surfaces. Quadric surfaces have dual representations consisting of their geometric data such as radius, center point, and center axis. Boundary representation of free form surfaces is easily built by sweeping and skinning method with NURBS geometry. Set operations on curved solids with boundary representation are performed by an evaluation process consisting of four steps. A file exchange facility is provided for the conversion between product data described by STEP and product information generated by GEMS4.0.
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Yang Changgui received his Ph.D. degree in computer science from Hull University, UK, in 1988. He is now an Associate Professor of CAD Center, Tsinghua University. His research interests include computer graphics, computer aided design and computer aided manufacturing.
Chen Yujian is an Associate Professor. His research interests include computer graphics and computer aided drafting.
Sun Jiaguang is a Professor. His research interests include computer graphics, CAD/CAM and engineering database management.
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Yang, C., Chen, Y. & Sun, J. Advanced geometric modeler with hybrid representation. J. of Compt. Sci. & Technol. 11, 1–8 (1996). https://doi.org/10.1007/BF02943516
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DOI: https://doi.org/10.1007/BF02943516