Find inflection points

Turn on the Inflection Points option in the Information window. Inflection points are marked approximately with blue arrows. To find the exact inflection point, zoom in to the point where the comb outline crosses the curve.

What are inflection points?

Inflection points, also called ogees, are the points on the curve where the curvature changes direction.

Measure torsion

Turn on the Torsion option in the Information window to plot secondary quills showing the torsion.

What is torsion?

Torsion is the amount the curve bends out of the plane of curvature.

Find tangent discontinuities

Tangent discontinuities appear as two separate Unit Normal quills originating from the same point on the curve but pointing in different directions.

The telltale quills are always at an edit point. To see them clearly, set the Plot value option to Unit Normal in the Information window, and increase the Samples density to have at least 2 samples per span.

Make sure the Scale is high enough to tell whether there is more than one quill.

What are tangent discontinuities?

Tangent discontinues occur when two curves are not properly aligned. It can also happen at a multi-knot, or because of CV multiplicity.

Find curvature discontinuities

Curvature discontinuities appear as sudden steps in the outline of the curvature comb. You will need to use a high sampling rate to detect curvature discontinuities.

What are curvature discontinuities?

Curvature discontinuities between curves occur when two curves do not have the same curvature at their end, or because of multiplicity. The curve join may be smooth, but the curvature values do not change smoothly.