Editing Non-uniform rational B-spline (section)

=== Knot insertion ===
As the term suggests, '''knot insertion''' inserts a knot into the knot vector. If the degree of the curve is <math>n</math>, then <math>n-1</math> control points are replaced by <math>n</math> new ones. The shape of the curve stays the same.

A knot can be inserted multiple times, up to the maximum multiplicity of the knot. This is sometimes referred to as '''knot refinement''' and can be achieved by an algorithm that is more efficient than repeated knot insertion.