The following sequence of images shows an overview of how a simple yacht hull surface can be quickly generated. In the help, this example is illustrated in more detail including all the user interface actions involved.

YachtLINES can also be used to generate a similar surface using hull parameters directly rather than manipulating the control points directly. The surface can then be converted to a BSpline surface to work on any local details or imperfections.

The surface produced in this example can be downloaded here: bsurface.geo

A simple rectangular surface is generated from the Create BSpline Surface Dialog, the size, mesh of control points and mathematical order can be specified from the beginning. BSpline surfaces can also be created by dragging a rectangle producing a simple linear BSpline surface defined by the four control points and refined by using the modelling tools.

The surface generated with the parameters show above will be planar as shown above.

The surface can now be edited by selecting it and pressing the F2 button. Initally, all the control points will be shown. Changing the view to an Y/Z projection will show the control points in a sectional view. The points can now be edited to create the section shape of the simple yacht hull we're creating.

Note that in this section view all the control points of the surface are visible but as each control point row has the same Y/Z coordinate it only appears as if one is visible. Because all the control points appear at the same (2D) location in the view, all the control points on row beneath the mouse cursor are translated at the same time.

Changing the view to a 3D projection, the number of visible control points can be changed to show only a selected column or row of the surface.

To create the stem of the hull, all the control points are moved to the centre line. This can be done by editing the control points numerically in the coordinate grid shown attibutes panel, below.

Then the transom of the hull can be worked upon.

At this point the surface will begin to take up the a yacht 'like' shape.

Local features, such at the forefoot curve can be added.

At this point, the parameter lines are not as useful a guide to the shape of the surface. Conventional hull surface contours can be shown to give a better indication of shape. The surface can now be further refined by editing point locations or by adding further control point rows or columns.

The surface can be rendered and the specular 'white' reflection spot used to indicate how shape changes when it is rotated within the view.

..the isophote (zebra lines) from the surface can also be displayed.