#curve #derivative #spline #nalgebra #graphics #b-spline

no-std bsplines

N-dimensional B-spline curves and their derivatives built on top of nalgebra

9 releases

0.0.1-alpha.8 Feb 9, 2024
0.0.1-alpha.7 Feb 8, 2024

#580 in Math

Apache-2.0

150KB
3K SLoC

bsplines Rust Library

Crates.io Docs.rs License

Rust library for vectorized, N-dimensional B-spline curves and their derivatives based on nalgebra.

🚧 This Library is Under Construction 🚧

  • Use iterators and simplify loops
  • Use thiserror
  • Refactor visibility and folder structure
  • Refactor method selection and settings structs
  • Add benchmarks and improve performance

lib.rs:

bsplines is a library for vectorized, N-dimensional B-spline curves and their derivatives based on [nalgebra].

Features

What are B-Splines?

B-splines are parametric functions composed of piecewise, polynomial basis functions of degree p > 0. These piecewise polynomials are joined so that the parametric function is p-1 times continuously differentiable. The overall functions are parametrized over finite domains with a so-called knot vector with the co-domain being an N-dimensional vector space, that is defined by control points. They can describe [curves][curve], but also surfaces. These characteristics lead to many desirable properties. The piecewise definition makes B-spline functions versatile allowing to interpolate or approximate complex-shaped and high-dimensional data, while maintaining a low polynomial degree. Because of the polynomial nature, all possible derivatives are accessible.

![A 2D B-Spline curve.][img-curve]

Still, evaluations or spatial manipulations can be executed fast because only local polynomial segments must be considered and the associated numerical procedures are stable. Lastly, polynomials represent a memory-efficient way of storing spatial information as few polynomial coefficients suffice to describe complex shapes.

Literature:

Piegl1997 Piegl, L., Tiller, W. The NURBS Book. Monographs in Visual Communication. Springer, Berlin, Heidelberg, 2nd ed., 1997.
Eilers1996 Eilers, P. H. C., Marx, B. D., Flexible smoothing with B -splines and penalties, Stat. Sci., 11(2) (1996) 89–121.
Tai2003 Tai, C.-L., Hu, S.-M., Huang, Q.-X., Approximate merging of B-spline curves via knot adjustment and constrained optimization, Comput. Des., 35(10) (2003) 893–899.

Dependencies

~3.5MB
~78K SLoC