Spiral fat arcs - Bounding regions with cubic convergence
نویسندگان
چکیده
A bounding region for spiral curve segments shaped by two circular arcs, parts of the osculating circles at the spiral’s endpoints, and two lines is introduced. This bounding region, denoted Spiral Fat Arc (SFA) is simple to construct and process, and shows a cubic approximation order to a given spiral curve. Given a general planar parametric curve, it can be split at curvature extrema (and inflection points), solving for the parametric locations for which κ′ = 0 (and κ = 0), κ being the signed curvature field, to yield a set of spiral curves. Each of the spirals is then fitted with a bounding SFA. Finding the intersection locations of two free-form planar curves is a fundamental task in geometric computing and computer aided design, and can immediately benefit from this new SFA bounding region. A recursive curve-curve intersection (CCI) algorithm that efficiently computes the intersection location of two parametric curves using SFAs is also introduced.
منابع مشابه
An example on approximation by fat arcs and fat biarcs
Fat arcs form bounding boxes for planar curves. An example on approximation by fat arcs, provided by Qun and Rokne, is corrected. The third derivative of the given curve segment under the polar coordinate system is increasing only at the beginning of the curve segment, and then decreasing, rather than monotonically increasing for the whole curve segment. Some numerical data are corrected as well.
متن کاملEfficient Collision Detection for Curved Solid Objects
The design-for-assembly technique requires realistic physically based simulation algorithms and in particular efficient geometric collision detection routines. Instead of approximating mechanical parts by large polygonal models, we work with the much smaller original CAD-data directly, thus avoiding precision and tolerance problems. We present a generic algorithm, which can decide whether two s...
متن کاملAn involute spiral that matches G2 Hermite data in the plane
A construction is given for a planar rational Pythagorean hodograph spiral which interpolates any two-point G Hermite data that a spiral can match. When the curvature at one of the points is zero, the construction gives the unique interpolant that is the involute of a rational Pythagorean hodograph curve of the form cubic over linear. Otherwise, the spiral comprises an involute of a Tschirnhaus...
متن کاملSpherical Shell: A Higher Order Bounding Volume for Fast Proximity Queries
Hierarchical data structures have been widely used to design e cient algorithms for interference detection for robot motion planning and physically-based modeling applications. Most of the hierarchies involve use of bounding volumes which enclose the underlying geometry. These bounding volumes are used to test for interference or compute distance bounds between the underlying geometry. The e ci...
متن کاملThe Asymptotics of Wilkinson's Shift: Loss of Cubic Convergence
One of the most widely used methods for eigenvalue computation is the QR iteration with Wilkinson’s shift: here the shift s is the eigenvalue of the bottom 2 × 2 principal minor closest to the corner entry. It has been a long-standing conjecture that the rate of convergence of the algorithm is cubic. In contrast, we show that there exist matrices for which the rate of convergence is strictly qu...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Graphical Models
دوره 73 شماره
صفحات -
تاریخ انتشار 2011