The first step to getting sections, of course, is to define their locations. Orca3D provides an interface to quickly define a list of station, buttock, waterline, diagonal, cant, and incline locations. This list is maintained and stored with your model, and sections will be computed through the surface(s) that you have selected, at these locations.
Toolbar
Menu Orca3D > Hull Design > Sections Command OrcaSections
1. Start the command with the toolbar icon, menu selection, or keyboard command. 2. Select the surface(s) to be included (or you may preselect the surfaces prior to starting
the command)
3. The Add Sections dialog will appear:
Sections 161
© 2012 by DRS Defense Solutions, LLC, all rights reserved Diagonals, Inclines, or Cants)
5. Define the Section locations by List (plane constant), and/or Spacing or Number. Checking "Update Bounding Box" will automatically fill in the minimum and maximum dimensions of the selected surface(s) in the direction perpendicular to the Section type in the Start and End fields. Note that if the Start value is less than the End value, the
Spacing must be greater than 0, and if the Start is greater than the End, the Spacing must be less than 0. See Defining Locations below for more detail.
6. Select the Layer location for the Sections.
7. Click Add to add your Sections to the Sections list. The list of Section locations will be shown in the Section tree.
8. Click Preview to see planes in the model representing the Section locations. 9. Repeat for other Section types.
10.You may turn off visibility for one or more Sections, using the check boxes in the tree. 11.You may right click on any Section in the tree to remove it, preview it, or change its color. 12.Right-click on a node (for example, "Stations" to operate on all of the sections of that
type.
13.Click on OK. The Sections will be computed on the selected surface(s). If this surface is edited using the Orca control points, they will be updated in real-time.
14.The calculation and visibility of all of the Sections may be temporarily turned off, using the OrcaShowSection command, or the icon ( ). Individual Sections or groups of Sections may be turned off with the checkbox in the Sections tree. When turned off, the Sections will not be computed or displayed, and will not be included in analyses (such as the sectional area curve in Hydrostatics).
You may also define your section locations by importing the section list from another Rhino model. Click on the Import button, and navigate to the desired model. If the units of the imported section list are different from the current model, they are converted into the current model units. For example, if the station spacing in the imported model was one foot, and the current model is in meters, the station spacing would be 0.3048 meters. You must select the Layer Location for imported sections; that information is not imported from the other model.
Defining Locations
When you specify Section locations, you are specifying a plane constant. For example, if X is the longitudinal coordinate, Y is transverse, and Z is vertical, then:
Stations are defined by an X value Buttocks are defined by a Y value Waterlines are defined by a Z value
Diagonals are defined by the height (Z value) at which they cross the centerplane, and the angle from horizontal (in the Y-Z plane) (you can think of them as waterlines that have been heeled)
Inclines are defined by the height (Z value) at which they cross the vertical axis at the origin, and the angle from horizontal (in the X-Z plane) (you can think of them as
waterlines that have been rotated in profile view)
Cants are defined by the longitudinal location (X value) at which they cross the longitudinal axis, and the angle from transverse (in the X-Y plane) (you can think of them as stations that have been rotated in plan view)
Orca3D gives you multiple ways to enter these values in the Sections dialog:
List Locations: Enter one or more values, separated by commas. Group Definition:
Spacing: Enter the section spacing, together with Start and End values. Sections will begin at the Start value, and continue at the Spacing value until the End value is reached. For diagonals, inclines, and cants, the angle must be specified as well.
Number: Enter the number of sections, together with the Start and End values. The distance between Start and End will be divided into the Number of sections to determine the spacing. For diagonals, inclines, and cants, the angle must be specified as well. Spacing and Number: Enter the Spacing and Number, together with the Start value. The Number of sections will be inserted with the specified Spacing, beginning at the Start location. For diagonals, inclines, and cants, the angle must be specified as well.
Update Bounding Box: When this box is checked, the Start and End values will be filled in automatically with the minimum and maximum values of the selected surface(s) in the appropriate dimensions (e.g., longitudinal min and max for stations and cants, transverse min and max for buttocks, vertical min and max for waterlines, diagonals, and inclines). As you select the different Section Types, these values will update.