Fairing the Design

Normally when importing the boundary curves, section , the user would also fair the curves. This is done using the Edit dialog, to access this click the curves fairing icon on the toolbar.

The Lines approach to fairing is based very much on the traditional methods used in lofting and design offices. The batons are replaced by the B-Spline and weights are applied by specifying conditions (KNOTS) at selected points.

The ultimate fairness of the ship design is a subjective decision and the same judgement must be made when using Lines. The principal means for measuring the fairness of a curve in Lines is showing the inverse of the radius curvature at points on the B-spline as already described.

If necessary the user can now proceed to fair the curve, this is done using the Edit dialog, to access this click the Edit icon, .

Various techniques are available for fairing the curve, these include:

• Removing and replacing points

• Offsetting points

• Moving points

• Inserting points

• Setting knuckle, tangent or ordinary points

• Offsetting the vertices of the B-spline

• Inserting and removing knots

• Automatic fairing

All of the options relating to the adjustment of points or vertices can be done either using the cursor or by specifying U and or V values as required.

It is not the intention of this chapter to give a detailed example of all the above options. An explanation of the Various buttons, is given in Screen Based Reference Guide.

When the fairness of the curve is acceptable to the user, the current curve should be stored in the section directory by accepting, using the accept icon from the View toolbar.