Spherical nu-spline interpolation.
Implementation based on the paper "ν-Quaternion Splines for the Smooth Interpolation of Orientations" by Gregory M. Nielson, IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS, VOL. 10, NO. 2, MARCH/APRIL 2004.
The code is based on the Boost framework, in particular the Geometry package. Different running configurations are to be implemented via configuration files, refer to the example present.
In subsequent versions the structure of the branch will hopefully improve.
The configuration is quite simplistic and allows for some parameterization of the program without requiring recompilation of the source. The switches supported are below:
| Parameter | Example | Description |
|---|---|---|
| points_file | tests/helix15/points | File containing the points to interpolate (Spherical Equatorial 2D coordinates) |
| tensions_file | tests/helix15/tensions | File containing the tension values (ν-values in the paper) |
| tolerance | 1e-10 | Error below which the solution is acceptable |
| iterations | 10000 | Max iterations before interrupting execution (if convergence is not achieved) |
| spline_points | 43 | Now many points to produce in each interval (more = smoother curve) |
| uniform | 0 | Uniform knot spacing (set to 1) or non-uniform (set to 0), refer to the paper |
| plot_knots | 0 | Whether to plot the control points (set to 1) or not (set to 0) |
| plot_sphere_file | plot/sphere | File containing the points of the reference sphere |
| plot_points_file | plot/points | Where to write the interpolation points in Cartesian 3D coordinates |
| plot_spline_file | plot/spline | Where to write the points of the interpolating spline |
| plot_control_pts_file | plot/control_points | Where to write the control points |