Creating an IntelliHull Surface

The following example illustrates the process of creating an IntelliHull surface from scratch. It may take some time for all the images to load up but the example itself may take around 15-20 minutes in the software. The commands and operations used to generated IntelliHull surface are shown in more detail in the help including use of the parametric hull form transformations.

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

Changing the view to Y/Z (sections) draw an IntelliCurve. A good layout is around 16 points, one on the centreline, 5 on the flat of bottom, 4 around the bilge radius, 5 on the flat of side and 1 for the deck.

Constraints can now be applied. A straight constraint between the 1st and 7th point to create the flat of bottom of a midship section.

A straight constraint between the 10th and last point to create the flat of side

A blend constraint between the 7th and 10th points to represent the bilge radius.

Using the attibutes panel, the main control points of the section can now be edited to define the dimensions of the midship section more accurately. Note that the constrained points are still visible but cannot be edited.

The editied midship section will now look like this.

A plane constraint can be added to the section, allowing all points to be located on a plane X=50 in one operation.

The midship section curve can now be copied aft to create a curve to control the aft extent of the parallel middle body.

As this curve has a transverse shape that is the same as the midship curve, it can be made to reference the midship section curve. Then if the midship curve is changed, the curves representing the ends of the parallel middle body will update accordingly.

The curve to represent the forward ends of the parallel middle body is created by copying the midship section curve forward and applying the offset constraint to reference the midship section curve accordingly.

The curves representing the ends of the parallel middle body can now be edited. The y and z coordinates of the control points are locked by the offset constraint and the points can only be moved in the x direction, indicated on screen.

Creating the shape of the forward flat of side.

The aft extent of the parallel middle is edited...

...and requires some additional shape to represent the aft flat of bottom.

The porcupine plot of curvature can be used to identify any unfairness in the shape of the curves. As the surface is defined with a relatively small amount of information it can sometimes be quite sensitive.

The definition for the parallel middle body is now ready.

The bow curve is created by copying the midship section forward and using the plane constraint to rotate the curve on to the centreline.

The shape of the bow curve can be updated but to create a basic inclined straight stem with a radius at the forefoot it is not necessary to change the definition of the constraints.

A curve is required to control the tangency of the surface as it enters the bow. This can be created by taking a copy of the bow curve and, much like the curves representing the ends of the parallel middle body, this curve can be made an offset of the bow curve.

As the offset constraint is effective in the Y direction, the control points can only be moved in that direction.

The shape of the bow tangent curve is often not straight forward and it is often better to create an initial shape and update it once the surface is visible

The transom can be created by copying the midship section aft.

Its shape can then be adjusted, but much like the bow curve, it may be possible to reuse some of the constraints.

Here the transom only goes the full breath of the ship at deck level.

Now that all the definition curves are available, the IntelliHull surface can be generated. Unlike the first version of IntelliHull, the software no longer tried to guess what the role of each curve in the definition and this is now assigned by the user. Note: The background grid has been removed for clarity at this stage.

The forward parallel middle body extent curve is assigned to be a panel break.

Similarly, for the aft parallel middle body extent curve.

The bow tangent curve is defined to have a tangent role.

At this point the parameter lines can often provide a mislead indication of surface shape. Displaying the contours provides better hull shape feedback.

In the example, the bow tangent is a little to large near the deck.

It can be reduced in size and shape to match the other definition of the surface. It shape can often depend on the characteristics of the flat of side and bow definition curves.

The shape looks better bow.

Now a bulb can be added, but the initial shape does look so good.

The underlying surface can be displayed illustrated the bulb shape changes before they are applied to the main hull surface.

The tip of the bulb is raised up and applied to the surface.

The shape of the bulb is improved.

At this stage further fairing can be undertake. As well as updating the bow tangent there are some problems around the transom as there are some odd lines near the cursor.

An update to the transom or aft parallel middle body extent curves can improve the hull lines in this area.

A lines plan of the hull can be generated once surface quality is satisfactor.