دانلود مقاله ISI انگلیسی شماره 61351
ترجمه فارسی عنوان مقاله

تشخیص تقارن تقریبی از زیر مجموعه های نقطه گسسته

عنوان انگلیسی
Detecting approximate symmetries of discrete point subsets ☆
کد مقاله سال انتشار تعداد صفحات مقاله انگلیسی
61351 2008 18 صفحه PDF
منبع

Publisher : Elsevier - Science Direct (الزویر - ساینس دایرکت)

Journal : Computer-Aided Design, Volume 40, Issue 1, January 2008, Pages 76–93

ترجمه کلمات کلیدی
تقارن تقریبی محلی؛ قصد طراحی ؛ مهندسی معکوس
کلمات کلیدی انگلیسی
Local approximate symmetry; Design intent; Reverse engineering
پیش نمایش مقاله
پیش نمایش مقاله  تشخیص تقارن تقریبی از زیر مجموعه های نقطه گسسته

چکیده انگلیسی

Detecting approximate symmetries of parts of a model is important when attempting to determine the geometrical design intent of approximate boundary-representation (B-rep) solid models produced e.g. by reverse engineering systems. For example, such detected symmetries may be enforced exactly on the model to improve its shape, to simplify its analysis, or to constrain it during editing. We give an algorithm to detect local approximate symmetries in a discrete point set derived from a B-rep model: the output comprises the model’s potential local symmetries at various automatically detected tolerance levels. Non-trivial symmetries of subsets of the point set are found as unambiguous permutation cycles  , i.e. vertices of an approximately regular polygon or an anti-prism, which are sufficiently separate from other points in the point set. The symmetries are detected using a rigorous, tolerance-controlled, incremental approach, which expands symmetry seed sets by one point at a time. Our symmetry cycle detection approach only depends on inter-point distances. The algorithm takes time O(n4)O(n4) where nn is the number of input points. Results produced by our algorithm are demonstrated using a variety of examples.