Serge LAROCQUE <sgl### [at] hotmailcom> wrote:
> So you mean your new spline system will let you specify through points
rather
> than control points?

The difficulty of specifying the Bezier control points in my previous spline
include file was one of the main issues people raised.  The new macro file
actually gives you the choice of creating a range of cubic interpolating
splines, namely Kochanek-Bartels splines (which includes the cardinal
splines, which include Catmull-Rom splines, the default), Bezier curves, and
hermite splines.  The first is specified as a list of interpolated points
only, the second as a list of points with every third point interpolated,
the last as a list of points and tangents.

Depending on the spline type you can adjust the curvature using tension,
continuity and/or bias controls.  You can also specify a desired length and
the macro will adjust the spline tension so that the curve passes through
the points as specified, tightened or loosened to fit the length given.

Before writing the macros I also wrote code for cubic approximating splines
(beta and b-splines), and even started working on some code for NURBS
(curves, not surfaces).  In the end, though, I decided that interpolating
splines would make most sense when hand-coded in POV-Ray.

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