Hull group intersection lines

Hull group intersection lines are hull lines at the intersections of the shapes of hull groups. The system searches for intersections between two hull groups, and creates an identical hull line for both of the two intersecting hull groups along the intersection.

Hull group intersection lines are similar to hull boundary lines, which are hull lines on the outer edges of hull groups. Just as boundary lines, group intersection lines can be used as relations when creating shell plates by defining the relations manually with the Shell Plates by Relations function. The system cannot use groups intersection lines when defining the shell plate relations automatically in the Enclosed Shell Plate function. Because intersecting hull groups have identical group intersection lines at their intersection point, by relating a shell plate to a group intersection line you can make the shell plate contour follow the shape of the intersecting hull group.

Limitations

Group intersection lines are read-only, and cannot be created, modified or deleted in the Shell application.
Group intersection lines are not topological.
Defining and assigning hull line ranges and subsets does not apply to group intersection lines.

Extracting group intersection lines

Hull group intersection lines are extracted from hull groups and saved in the hull database in the following situations:

When a new project is created.
When the currently used hull shape database is updated. This can be done in System Management > Projects > Update Hull Database.
When a new hull shape database is activated. This can be done in System Management > Projects > Activate Database.

Extracting and saving group intersection lines is optional. The system will show a dialog where you can select whether to update the hull database with hull boundary lines and/or hull group intersection lines or not.

If you do not need these hull lines or do not want to update them, clear one or both of the check boxes. Click OK.

Notes on the extraction of group intersection lines

Group intersection lines are not created if the shape does not have intersecting hull groups.
When a hull database is activated, group intersection lines are only extracted if the shape is different from the previous shape. If the shape is the same, groups intersection lines are not or extracted.
When the hull database is updated, group intersection lines are extracted, but those lines which have not changed will not be replaced with new ones. This way shell plate's relations to those lines will remain as is.

Viewing group intersection lines

Hull group intersection lines can be viewed in shell views like other types of hull lines, but they are not visible by default. To make group intersections lines visible, select the Groups intersections option in the Show Hull Lines function. It is not possible to set the range of group intersection lines to be shown. When this option is selected, all the group intersection lines that belong to hull groups that are set to be visible in the view are shown. You can choose to show the lines either as solid or dashed.

In addition to the Shell application, hull group intersection lines can also be shown in the 2D & 3D Contek and 3D-Show applications as well as in Hull Viewer.

Line numbering

Group intersection line numbers are expressed as <intersecting_groupnumber>.<line_number>, where the first part is the hull group with which the current group is intersecting, and the second part is the line number. The first part can be up to 4 digits, and the second part is 3 digits. In the case of intersecting hull groups 1 and 2, 2.001 is line number 1 in group 1, and 1.001 is line number 1 in group 2. Line number 100 in group 2 would be 1.1.

See Examples below.

Presentation

Hull group intersection lines use the same pen colour and dash pattern as knuckles.

Visibility of the group intersection lines in different hull groups

Which hull groups are visible in the shell view can be set in Drawing Properties. Select the desired groups from Hull groups. Only those group intersection lines that belong to the selected hull groups are visible in the view.

For example, in Example 2: One hull group intersecting two hull groups below, if only hull group 1 is selected to be visible in the view, only lines 1 and 4 are shown. If groups 0 and 1 are selected, lines 1,2 and 4 are shown.

Group intersection lines in the COS environment

Hull groups intersection lines are part of the Hull shape object, and not part of any subset of hull line ranges. All operations on the Hull shape object in the Check Out/In dialog apply to both the hull shape itself and also to the group intersection lines.

If you want to share the group intersection line data with other sites, you must save the Hull shape object to COS.

Examples

The following examples illustrate the results of the extraction of hull group intersection lines in different situations.

Example 1: Two intersecting hull groups

Two hull groups intersect. A group intersection hull line is added to both groups at the intersection, resulting in two lines.

Hull line for group 0 (group 1 is the intersecting group) gets line number 1,001.
Hull line for group 1 (group 0 is the intersecting group) gets line number 0,001.

Example 2: One hull group intersecting two hull groups

Three hull groups, one group intersects with the two other groups, resulting in four group intersection lines.

Hull line for group 1 (group 0 is the first intersecting group) gets line number 0,001.
Hull line for group 0 ( group 1 is the intersecting group) gets line number 1,001.
Hull line for group 2 ( group 1 is the intersecting group) gets line number 1,002.
Hull line for group 1 ( group 2 is the second intersecting group) gets line number 2,002.

Example 3: Three hull groups intersecting with one other

Three hull groups intersecting with one other, resulting in three pairs of two group intersection lines.

AD – Hull line for group 0 (group 1 is the intersecting group) gets line number 1,000.
AD – Hull line for group 1 (group 0 is the intersecting group) gets line number 0,000.
BC – Hull line for group 0 (group 2 is the intersecting group) gets line number 2,001.
BC – Hull line for group 2 (group 0 is the intersecting group) gets line number 0,001.
BC – Hull line for group 1 (group 2 is the intersecting group) gets line number 2,002.
BC – Hull line for group 2 (group 1 is the intersecting group) gets line number 1,002.