Working with Markers

You can choose to display all markers or no markers, or you may choose to only show those markers whose station number is the same as the current station.

In the design views, markers may be selected in a similar manner to the control points: by simply clicking on them with the left mouse button or by dragging a box around them. Holding down the Shift or Control key while making the selection allows you to add more markers to the current selection or remove previously selected markers from the selection.

Selected markers are highlighted in the highlighting colour.

Note:

You may have to lock the surfaces to hide the control points, as selection of control points takes precedence over selection of markers; i.e. if the drag box contains control points, these will be selected rather than the markers.

In the Markers table, you may only make a continuous selection. However, data may be sorted by right clicking in the column header and choosing from the pop-up menu to sort ascending or descending based on the contents of that column. The markers may be unsorted by right clicking in any of the column headers and selecting Unsort Rows from the pop-up menu:

Adding Markers

To add a marker to a drawing window

Ø Select Add Marker from the Marker menu or use the Ctrl+M shortcut key.

A pencil cursor will be displayed.

Ø Click the mouse at the position of the new marker.

Use the position indicators to place the marker at the required position. The added marker will be associated with the current station as displayed in the control box.

Markers may also be placed graphically in the Plan or Profile views. For these 2D views, the third dimension takes the value of the last entered marker. For example, if you wanted to enter makers on the 2m waterline, first switch to the Plan view. Add a marker in the Plan view; double click the marker so that you can specify its height as 2m, then any subsequently added markers (in the Plan view) will have their height at 2m. Markers on Buttock lines may be entered in a similar fashion in the Profile view.

Alternatively, a marker can be added directly into the Markers window. To do this

Ø Select the Markers window

Ø If there is no Markers file yet, select File | New

Ø Highlight a row by clicking in the far left hand column.

Ø Select Add Marker from the Edit menu.

Ø Enter the number of markers you wish to add and hit Return.

Rows will be added after the row selected, with cells initialised to zero.

Note:

You must have a design open before you can add markers.

Pasting Markers from Excel

If you have for example an excel spreadsheet with for example 1284 rows with offset points:

Ø Make sure the columns in Excel are sorted the same as the marker window i.e. Long pos. Offset, height.

Ø Copy all rows in Excel

Ø Edit | Add Marker and specify the number of markers you wish to add (1284)

Ø Click in row number 1 cell in the Long Pos. column in the Markers window

Ø Paste

Ø Check that all markers have been imported.

Deleting Markers

To delete a marker from a view window

Ø Select the marker(s) to be deleted

Ø Select Delete Marker from the Marker menu or use the Delete key on your keyboard

Ø Click yes to confirm you want to delete the selected markers.

The marker will be deleted.

To delete a marker from the Markers window

Ø Select the Markers window

Ø Select the row(s) of the marker(s) that you wish to delete

Ø Select Delete Marker from the Marker Menu or use the Delete key on your keyboard

Ø Click yes to confirm you want to delete the selected markers.

Rows will be deleted from the Markers window.

Modifying Markers

The co-ordinates in the Markers window may be edited to move a marker in space. To edit a marker

Ø Click on a cell in the Markers window.

Ø Enter the changed Station Number, Longitudinal Position, Offset, or Height.

Alternatively, to edit a marker directly from a view window

Ø Double click on a marker in one of the drawing windows.

A small dialog box will appear containing data about the marker. You may select and edit any of the marker's co-ordinates. When you click OK the marker will be updated to the new position.

You may also set the data for a number of markers together:

Ø Select the markers in one of the drawing windows.

Ø Select Properties from the Markers menu.

If you have selected several markers, those fields that contain exactly the same data for all the selected markers will be displayed with the common data. If the data differs, the field will be left blank. Editing the data in any field will update all the selected markers. This can be useful for making sure that all the markers on one station have identical longitudinal positions, or for specifying which section they should be linked to.

Sorting Markers

When to sort markers

The order in which markers are sorted along a section line is important when:

§ the marker data is used in Prefit standalone to automatically generate a surface

§ when you want to use the Display | Connect Marker Stations as a reference during manual surface fitting tasks

§ When Generating a TriMesh Surface

The order of the markers is irrelevant when you are using the Fitting a Surface to Markers command in which case you can skip this section.

Sorting Markers - Concept

Markers that have been assigned to the same Station Index (see Linking Markers to a Section) can be sorted for each station using the Sort Marker Stations command from the Markers menu. This uses a nearest neighbour sort, which works in most instances, but can be confounded if the section shape is complex and/or the spacing between markers varies significantly. To view the connectivity (and ordering) of the markers turn on the Display | Connect Marker Stations option: Ctrl+J, . This is best done in the Body Plan view, with the Display | Show Markers for Current Station option selected ().

Sorting Markers - Procedures

A single marker can be moved along the ordering by using Ctrl+Cursor keys; left and down keys move the point one positions towards the start of the ordering whilst up and right keys move the point one position towards the end of the ordering; the Home key makes it the first point and the End key makes the it the last point:

Before and after:
Moving the selected point one position towards the start of the curve corrects the marker ordering.

To re-order a range of markers, select them in the new desired order (from the keel outwards towards the deck edge (or deck centre line) and select Markers | Re-order Selected Markers (Ctrl+Shift+R). If the new order is the reverse of what is required, simply repeat the command without changing the selection, and the order will be reversed.


Markers incorrectly ordered	Start selecting Markers in correct order

Start with marker that should be closest to keel in the group	Markers selected in correct order. Use Re-Order Selected Markers command to re-order

Points are now ordered in the selection order, if this is the inverse of what is required, simply repeat the Use Re-Order Selected Markers command without changing the selection.

When a marker is added, it will be inserted to so as to minimise the increase in section length. This normally ensures that it is inserted in the correct location.

Keyboard tools for Sorting Markers

Before and after:
Moving the selected point one position towards the start of the curve corrects the marker ordering

Linking Markers to a Surface

Unless you have used the Generating Markers for Developable Surfaces to create your marker data, you will have to link the markers to the surface manually. To do this,

§ Select the marker in any view window

§ Select Marker | Marker Properties (or use the Properties Pane)

§ And use the drop down selection list to select the surface you wish to link the marker to:

After a marker has been linked to a surface, its colour changes to the surface colour.

Location

The location of the marker on the surface can either be:

§ Internal (in the middle of the surface)

§ Edge (either Top, Bottom, Fwd or Aft egde)

§ Corner point (either Top/Aft, Bottom/Aft, TopFwd or Top Aft)

For most surface fitting cases it is not necessary to set the Location for each marker and just linking it to the surface will suffice. Once markers have been associated with a particular surface edge, you can fit the surface edge to its markers by simply selecting a control point in the edge and selecting Markers | Fit edge to markers (see below). This is very useful as it allows you to easily change an edge’s properties (number of control points or stiffness) and refit the edge to obtain the best possible fit to the markers without having to always reselect the markers. It also makes it very easy to add or remove markers to those used for the edge fitting.

Linking Markers to a Section

In order to be able to compare the marker data with the surface sections, Maxsurf allows you to link markers to a section using the “station index”. The station index is the number to the left of the Grid Spacing dialog:

St 5 has station index number 7.

Linking the markers to each section is best done in Profile or Plan view using a selection window:

A group of markers that have been linked to one section is called a “Marker Station”. Once a marker has been linked to a section, you can display each section and the associated markers (Marker Station) in the body plan view:

Displaying the markers for each section makes manual fitting of
a surface to a set of markers a lot easier.

Automatically linking the Markers

Manually linking the markers to each section can be a tedious process. A very powerful tool to automatically link the markers to each section is the Generating a Grid from Markers command.

Also see

Display | Markers on page 212

Body Plan Window on page 31

Saving Markers

When the Markers window is frontmost, you save the Marker data as a txt file:

Ø File | Save Markers

Reading Markers Files

It is possible to read a text file of markers into Maxsurf. This text file may be created from the Save Markers or Save Offsets commands in Maxsurf or created in a spreadsheet, word processor or other application.

To open a marker file:

Ø Switch to the Marker window

Ø Select File | Open and specify the text file you would like to open

The format for the Markers file is tab delimited text. Each coordinate is separated by a Tab character, and each line ends with a Carriage Return character. An example would be:

1	2.33	-0.2	1.2
1	2.33	0.1	2.4
2	4.66	-0.7	1.0
3	7	0.3	1.4

Column 1 is the station number with which the marker is associated. This controls when the marker is displayed and when it is hidden when the Show Markers for Current Station command is active. Column 2 is the longitudinal position from the zero point, Column 3 the offset from the centreline and column 4 the height above the zero point.

Alternatively you may create markers by Importing DXF Markers. The DXF file is imported by choosing File | Import | DXF markers.

Also see: Adding Markers.