MicroStation PowerDraft CONNECT Edition Help

Edit Knots

Used to insert or remove knots. A knot is a point on the control polygon of a B-spline curve.

You can access this tool from the following:

  • Ribbon: Modeling > Curves > Modify Curves
  • Toolbox: Modify B-spline Curves

Insert Knots icon

Lets you add a knot point to a B-spline curve.
Remove Knots icon

Lets you remove an existing knot point from a B-spline curve.
Method The available methods for inserting or removing knots are:
  • By Point — (When Insert Knots icon is selected) Lets you insert a knot on a B-spline curve by picking a location on the curve.
  • By Parameter — (When Insert Knots icon is selected) Lets you insert a knot at a location that is defined by the B-spline parameter value.
  • Single — (When Remove Knots icon is selected) Lets you pick a knot location to remove from the curve. You can pick one at a time.
  • By Tolerance — (When Remove Knots icon is selected) Lets you specify a tolerance. The tool will remove as many knots as possible, such that the deviation between the new and the original B-spline curves will not be greater than the input tolerance.
Knot Value Used with the By Parameter method to specify the location on the curve where a new knot will be inserted.
Tolerance Used to specify a value for the By Tolerance method.
Control Points If on, control points are turned on for the selected B-spline curve.
Note: You can turn off control points with the Edit Control Points tool.