Updating curves

The user controls when to update (modify) the waterlines and sections (to produce waterline endings and frame feet, respectively) using the end surface.

Modification of curves is done by selecting End Surfaces > Update Curves . The exact manner in which this is done is specified by the Update Curves page of the End Surfaces dialog (End Surfaces \ Options... ). These are as follows:

• Use Macro - Check this to use a macro that will be executed when End Surfaces \ Update Curves is performed. This allows you to specify your own behavior (for example, updating longitudinal control curves) by creating a macro file that is executed. The Browse... button lets you locate this file. The dropdown box lists the 8 most recently-used macros.

If Use Macro is not checked, the user is presented with a variety of options for updating waterlines and sections using the end surface and other curves. These options involve a fixed sequence of events:

1. The set of waterlines (All, Active, Inactive, None) chosen in the Modify Waterlines group are updated.

   • If Use Transition Curve is checked, the region of waterline between the transition curve and the end surface is allowed to take on whatever shape is necessary to achieve a fair blend.

   • Otherwise, the waterline is fixed all the way up to the tangent curve. For this to work correctly, the waterline must already meet the end surface at the tangent curve, and be tangential to it.

   • If Lock Tangent Curve is checked, the shape of the tangent curve (that means, the points where the waterline ending arcs begin) is not allowed to change.

   • Otherwise, the shape of the tangent curve is allowed to change, as described in the previous section.

2. The set of sections (All, Active, Inactive, None) chosen in the Auto Regenerate Sections group is regenerated, by interpolating the specified set of waterlines (generally those that were updated in Step 1).

3. The set of waterlines (All, Active, Inactive, None) chosen in the Auto Regenerate Waterlines group is regenerated, by interpolating the specified set of sections (generally those that were updated in Step 2).