Editing with Guide Curves

A fitted curve can be shaped or faired using other curves as guides. The mechanism is quite simple - guide curves are used to arrange the positions of groups of data points from the curve being edited. Any active curve within the design can be used as a guide for any other. The use of a guide curve is a one-time operation - it does not establish any lasting link between the curves in question.

The curve to be used as the guide is selected (using the Left Mouse button in a graphics view), and the Data Point Snapping dialog launched (CURVE \ USE AS GUIDE).

Figure 3:68. Using a guide curve: the selected data points will be moved horizontally so that in this view they will appear to lie on the guide curve on the right

A number of data points from another curve may then be selected graphically, and moved onto the guide curve by selecting APPLY from the dialog. The dialog presents a number of options regarding the way that the points are moved.

The user specifies how the points move in the two dimensions of the current view using the 3 Radio buttons in the Method group:

• Horizontally with respect to the current view (Horizontal button)

• Vertically with respect to the current view (Vertical button)

• To the nearest point on the guide curve (Nearest button)

The user also specifies if and how the points move in the third dimension (that means, the direction normal to the current view):

If Use current view plane is unchecked, the points are moved in three dimensions so that they will actually lie on the guide curve.

Otherwise, the points are moved parallel to the current view, so that they appear to lie on the guide curve in that view.