The Triangular Computing Scheme Window is used to show the triangular computing scheme of de Casteljau's and de Boor's algorithms. This window has three buttons. Button STEP allows a user to see the computation column-by-column, button RESET resets the current computation and starts over, and button DISMISS closes this window.
The following figures show the final stage of the computation of de Casteljau's algorithm for a Bézier curve of degree 5. Note that all control points of a Bézier curve are listed on the first column, while the point on the curve is shown on the right-most column. Note also that for a B-spline or NURBS curve, not all control points are involved in the computation.
See Tracing the Curve - de Casteljau's and de Boor's Algorithms for the details.