MATERIC은 기계공학 연구의 교류와 홍보를 위해 관련학회들과 협약을 맺어 학술대회를 매년 촬영해오고 있습니다. 촬영에 동의해주신 학회와 발표자 분들에게 감사드립니다. 학술대회 촬영에 관심있으신 학회는 연락(firstname.lastname@example.org, Tel: 051-510-3345)을 부탁드립니다.
동영상 게시판 내용
2004년 한국 CAD/CAM학회 학술대회
현재까지 614명 읽었습니다.
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Offset curve/surface may self-intersect locally when the absolute value of the offset distance exceeds the minimum radius of curvature in the concave regions, and self-intersect globally when the distance between two distinct points on the curve/surface reaches a local minimum. These local and global self-intersections can appear as machining a part using a cylindrical/spherical cutter with too large radius for 2.5D/3D milling. In this paper, a new method for obtaining a planar offset curve based on implicit function is given. For a planar curve ) (t C , first, generate a distance surface, which is one of implicit models (blobs, metaballs, distance surfaces, convolution surfaces) by using the curve ) (t C as the skeleton of the distance surface, then obtain offset curve) (t d C of the curve ) (t C from the intersection curve ) (t i C between the distance surface and the plane where the curve ) (t C is located. The intersection curve is a planar implicit curve, and a planar implicit curve 0 ) , ( = y x f has the property that it partitions a plane into three domains: point sets of 0 ) , ( > y x f , 0 ) , ( = y x f and 0 ) , ( < y x f , therefore, based on the property of the planar implicit curve, we present an algorithm for rendering the intersection curve. Using the algorithm, we can render 0 C planar implicit curves, however the Newton method can not. While the curve ) (t C is closed, the offset curve is just the intersection curve ) (t i C and while the curve ) (t C is open, the offset curve is obtained by clipping the intersection curve ) (t i C . The advantages of our method are (1) automatically to remove these local and global self-intersections in an offset curve, (2) robustly to render 0 C continuous offset curves which may be generated by boolean sum of many primitives as well as n C continuous ones. Key Words : : planar curve, offset, self-intersection, implicit surface, geometric modelling