Intelligent Label Placement

A facility is provided to ‘tidy up’ crowded labelling, so as to minimize Label overlap and leader-line crossing. As well as changing label positions the facility may also change Label orientations, text justifications and alignments, and the definition of leader-line shapes and bend-points. The facility uses two versions of the SPREAD command, which may be used to position Labels locally or remotely.

With local positioning, Labels will be positioned around their significant design elements in such a way as to minimize Label overlap and leader-line crossing. Labels will not be moved from their initial positions unless it is necessary. If they are moved then, as far as possible, leader lines will be straight and at ± 45° to the VIEW axis.

An example of 'local spreading' is shown in Figures 13:14 and 13:15 below.

Figure 13:14. Poorly positioned Labels

Figure 13:15. Result of SPREAD command on Labels shown in Figure 4-16

In the above example, the command

SPREAD LOCAL SELECT INSIDE @ @

was used to define a window within which the labels to be repositioned lie. By default, the Labels will be offset by 25mm (in the X and Y directions) from the Label attachment point. The SPREAD LOCAL command can be used with the Marine general selection syntax (see the Design Reference Manual, Part 2). Other variations of the SPREAD LOCAL command are:

With remote positioning, labels will be positioned around the VIEW border. It is possible to define a margin outside the VIEW frame that will define the positioning of the Labels. It is also possible to define a side of the VIEW frame alongside of which repositioned Labels will not be placed, and the minimum permissible gap between any two Labels can also be specified.

Labels will be repositioned at the (allowed) VIEW side nearest to their attachment points. Labels along the top and bottom sides will be rotated through 90° (readable from the right-hand side) unless otherwise specified. To avoid overlapping, some leader lines will be doglegged at 45°.

Examples of the SPREAD REMOTE command are:

Note: All options must be specified on the same command line; the previous SPREAD parameter settings will not be remembered.