361 research outputs found
L-systems in Geometric Modeling
We show that parametric context-sensitive L-systems with affine geometry
interpretation provide a succinct description of some of the most fundamental
algorithms of geometric modeling of curves. Examples include the
Lane-Riesenfeld algorithm for generating B-splines, the de Casteljau algorithm
for generating Bezier curves, and their extensions to rational curves. Our
results generalize the previously reported geometric-modeling applications of
L-systems, which were limited to subdivision curves.Comment: In Proceedings DCFS 2010, arXiv:1008.127
A variational model for data fitting on manifolds by minimizing the acceleration of a B\'ezier curve
We derive a variational model to fit a composite B\'ezier curve to a set of
data points on a Riemannian manifold. The resulting curve is obtained in such a
way that its mean squared acceleration is minimal in addition to remaining
close the data points. We approximate the acceleration by discretizing the
squared second order derivative along the curve. We derive a closed-form,
numerically stable and efficient algorithm to compute the gradient of a
B\'ezier curve on manifolds with respect to its control points, expressed as a
concatenation of so-called adjoint Jacobi fields. Several examples illustrate
the capabilites and validity of this approach both for interpolation and
approximation. The examples also illustrate that the approach outperforms
previous works tackling this problem
A projective invariant generalization of the de Casteljau algorithm
A projective invariant generalization of the de Casteljau algorithm is described by using the cross ratio and an auxiliary line. We describe the implicit form of the section conics obtained by the algorithm proposed in this paper. Finally, we show how to construct specific conic sections using this approach. © 2010 Elsevier Ltd. All rights reserved.Benítez López, J. (2011). A projective invariant generalization of the de Casteljau algorithm. Computer-Aided Design. 43(1):3-11. doi:10.1016/j.cad.2010.09.005S31143
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