InsertControlPoint

Toolbar Menu

Point Edit

Edit

Control Points >

Insert Control Point

The InsertControlPoint command adds control points in a curve or a row of control points on a surface.

Steps

  1. Select a curve or surface.
  2. Pick a location for the control point or control point row.
    Inserting control points affects the shape of the curve or surface. The InsertKnot command does not change the curve or surface shape.
  3. Press Enter to complete the command.
Command-line options

Direction
(Surfaces only)

Specify the u, v, or both directions.

Toggle
(Surfaces only)

Toggles the direction between u and v.

Extend

Extends the surface by half the distance from the end of the surface to the next control points.

Midpoint

Places the control point mid-way between two control points.

RemoveControlPoint

Toolbar Menu

Point Edit

Edit

Control Points >

Remove Control Point

The RemoveControlPoint command removes control points from a curve or a row of control points from a surface.

Steps

  1. Select a curve or surface.
  2. Move the cursor until control points highlight and click.
  3. Press Enter to complete the command.

Notes

  • Removing control points affects the shape of the curve or surface.
  • You can also select an existing control points and press Delete.

InsertEditPoint

Toolbar Menu

Organic

Edit

Control Points >

Insert Edit Point

The InsertEditPoint command adds edit points to a curve.

Steps

  1. Select a curve.
    The edit points are displayed on the selected curve.
  2. Pick a location on the curve.

 

InsertKink

Toolbar Menu

Point Edit

Edit

Control Points >

Insert Kink

The InsertKink command adds kinks to a curve or surface.

Steps

  1. Select the curve or surface.
  2. Pick locations where you want to insert a kink.
  3. Press Enter to end the command.
    A curve is split into multiple joined curves.

 

InsertKnot

Toolbar Menu

Point Edit
Organic

Edit

Control Points >

Insert Knot

The InsertKnot command adds knots in curves or surfaces.

Steps

  1. Select the object.
  2. Pick a location for the knot.

Note

  • Inserting a knot in a surface also displays an isoparametric curves at the knot location if isoparametric curves are being displayed.
  • The status bar distance pane displays the parameter value when inserting a knot to a curve. You can also type a parameter value to add a new knot.
Command-line options

Automatic

Adds a knot/knot line halfway between existing knots to maintain as uniform a structure as possible.

Increases the knot density of a curve or surface to add more control points while maintaining an even knot distribution for better point pulling behavior.

Midpoints

Places markers half-way between the existing knots/knot lines that can act as guides for inserting knots midway between existing knots.

Symmetrical

Adds knots on both sides of the center of the curve or surface.

Undo

Reverses the last action.

Direction
(Surfaces only)

Specify the u, v, or both directions.

Toggle
(Surfaces only)

Toggles the direction between u and v.

SubCrv

Type subcrv to select part of a curve as input.

RemoveKnot

Toolbar Menu

Organic
Point Edit

Edit

Control Points >

Remove Knot

The RemoveKnot command deletes a knot from a curve or surface.

Steps

  1. Select a curve or surface.
  2. Click the knot to remove and press Enter.

The RemoveKnot command can be used to remove the connecting joint between two joined curves. The resulting curve will not Explode into separate parts.

Command-line options

Direction
(Surfaces only)

Specify the u, v, or both directions.

Toggle
(Surfaces only)

Toggles the direction between u and v.

Undo

Reverses the last action.

SubCrv

Type subcrv to select part of a curve as input.

RemoveMultiKnot

Toolbar Menu

Curve Tools
Surface Tools

Not on menus.

The RemoveMultiKnot command removes multiple but not fully-multiple knots from curves and surfaces.

  • Multiple knots means more than one knot at a location. Fully-multiple knots means as many as possible at a location, which is equal to the degree.
  • There may be a kink at that point that is desired. Surfaces created with the Sweep2, BlendSrf, and OffsetSrf commands can be built with multiple knots.
  • The Simple Sweep option in the Sweep2 dialog box makes surfaces that do not have multiple knots, but this option is only available in restricted cases where all the curves are perfectly matched and correctly placed. The usual behavior of the Sweep2 command allows accurate sweeps to be made from diverse input.
  • The RemoveMultiKnot command removes these stacked knots. Removing the multiple knots can cause some loss in the surface precision, but in practice, this is usually not a problem.
  • The advantage to removing these knots is that the surface point count is reduced.

Command-line options

RemoveFullyMultipleKnots (Yes/No)

Select Yes to also remove kinks from the curve.

MaxKinkAngle

"Kink angle" is the tangent direction difference between two adjacent segments.

Any kinks with an angle smaller than MaxKinkAngle will be removed.

In this example, the kink will be removed when MaxKinkAngle is set larger than 10 degrees.

  • Removing a fully multiple knot (kink) from a degree-1 curve or surface merges the spans next to it into a linear span.

See also

Edit objects using control points.

Edit surfaces