CST2013: Create a Spline

Modeling: CurvesCurvesSpline

In this dialog box you may specify the control points of a spline either numerically or by using expressions. The construction will always be performed in the currently active coordinate system.

Each spline will be assigned to a previously defined curve. Thus the corresponding menu or toolbar items will only be active if at least one curve has been defined before (Navigation Tree: Curves :New Curve).

Within its curve each item is identified by a unique name. The curve item can be addressed by this name for subsequent editing operations.

As soon as the curve item is defined it will appear in the main plot window and on the navigation tree.

The picture below shows an open and a closed spline defined in global coordinates:

Name

Specify the unique name for the spline.

Curve

Select the curve to which this spline item will be assigned from the list of previously defined curves or enter a new name.

Points frame

In this frame you can edit, insert or delete control points of the spline. If the spline is open (the first and the last control points are different), the curve actually passes through the first and last control points. The curve tangents at these points are then given by the first and last edges of the control point polygon. If the spline is closed, the curve does not pass through any control point at all.

X, Y or U, V: In these fields you enter new control point coordinates or edit the coordinates of a previously selected control point. Each of these entries must be either a simple numerical value or a valid expression.

Relative to previous: Check here if you want to define the control point coordinates relatively to the previously entered control point.

Insert: Inserts a new control point into the list above the currently selected control point. You can then specify the coordinates of the new control point in the X, Y or U,V fields.

Delete: Deletes the currently selected control point from the list.

Import/Export: Press this button to get Load From... and Save As... options.

Load From...: Opens a file selector dialog to specify a two column ASCII file containing point coordinates X,Y or U,V. The separator of the columns can be space, tab, comma or semicolon.

Save As...: Opens a file save dialog to save point coordiantes to a two column ASCII file.

Clear: Deletes all control points from the list.

OK

Press this button to finally create the spline.

Cancel

Closes this dialog box without performing any further action.

Help

Shows this help text.