There are several commands that are useful for fairing a design. These operate on groups of control points: either controls within a particular row or column; a patch of control points in a surface or across bonded surfaces, or arbitrary control points.
The smoothing and straightening commands are particularly useful for manipulating the edges or features of a surface, e.g. creating a straight bow profile, producing a smooth, fair chine line, etc.
Smoothing may also be useful when applied to a patch of control points for maintaining a fair net and hence a fair design.
The align functions are useful when you wish to place control points in the same vector or plane. The control points may be from the same or different surfaces. These functions are also useful for fairing across the edges of bonded surfaces. If the Align to Plane or Align to Vector functions are called while holding the shift key down a constraints dialog box will appear. In this dialog you may specify movement constraints in certain planes.
The size function may be used to enlarge or reduce a portion of a design, by re-scaling a group of control points. In a similar way, certain areas of a design can be rotated by rotating the control points in that area. To re-size or rotate complete surfaces, please refer to the Size and Rotate commands in the Surfaces menu, these are described in the Surfaces section.
In this section:
§ Moving a Group of Control Points
§ Resizing a Group of Control Points
§ Rotating a Group of Control Points
Also of interest may be:
§ Smoothing and Straightening - Rows or Columns
§ Smoothing or Straightening a Patch
§ Discontinuities and Feature Lines
This command may be used to move an area of a surface.
§ Select the control points you wish to move.
§ Choose Move Controls from the Controls menu.
§ In the dialog type in the desired movements.
§ Click OK.
It is also possible to change the properties of a group or selection of control points using the Controls Properties.
§ Select a group of control points
§ Select Control Properties from the Controls menu.
The same dialog will appear, but only those values that are common between all the selected control points will be filled in. You can change any of the values and all the selected control points will have their respective values updated.
This function is useful for aligning columns of control points; see below:
§ Select the control points you wish to align:
§ Select Control Properties from the Controls menu:
Any data fields, which are common for all the selected control points will be filled in; any data fields which differ for the selected control points will be left blank. In this case the surface name and column number are the same for all the selected control points.
§ Type in the longitudinal position you wish to set for all the control points and click OK.
The selected control points are now all set to the same longitudinal position of –5.26m.
The Size Controls command may be used to enlarge or reduce an area of a surface.
§ Select the control points you wish to resize.
§ Choose Size Controls from the Controls menu.
§ In the dialog type in the desired length, width and depth dimensions; proportional scaling may be achieved by ticking the Proportional Scaling boxes next to the dimensions.
Note that the values that appear when the dialog is first displayed are the dimensions of the bounding box containing the desired control points. To scale the control points, type in the dimensions of the new bounding box you wish the control points to occupy.
§ Choose the origin for the re-scaling in the Size About fields.
This will control the direction in which the control points are moved. The Size About point will remain unchanged when the control points are resized.
§ Click OK.
To rotate a group of control points:
§ Select the control points you wish to rotate.
§ Choose Rotate Controls from the Controls menu.
§ Type in the rotations about each of the axes.
§ Type in the rotation centre.
§ Click OK.
