The Display of Lines

The second page of the code prefix property sheet is called Line, and an example of this is shown below.  The fields in the page allow you to define how any lines joining the points of a feature using the current code prefix are to be displayed.

The Enabled check button allows you to specify whether a line will be displayed or not.  If it is ticked, a line will be displayed using the parameters in the dialog.  If not, the items on the property page will be disabled. 

Layer, Style and Pen (Attributes)

The Attributes group allows you to define the line's graphical attributes using the Layer, Style and Pen fields.  A preview window shows an example of the line.  The Lines settings box consists of a series of check buttons which further refine the line parameters.  Most of these are used in specific circumstances and will be described later.  There are two that are more general in nature.

Two checkboxes have recently been added:

When ticked, Ignore in Break by Distance will allow you to use the Line -> Break by Distance option without affecting any of the lines using the indicated prefix.

The second tickbox, Ignore in Sections, will ignore this line feature when calculating a section profile through features without using any DTM triangles. If sectioning through the DTM triangles and the feature is used in them, a code will not be applied to the section profile at that point.

Line Checkboxes (Settings)

There are dimensions and comma codes that allow n4ce to display parallel and offset lines using the surveyed line feature and to construct additional points along the line feature.  In normal circumstances, these lines are still displayed but there are no points at the line apexes. If Commit Constructions is checked, n4ce will create new features to represent the parallel lines or add additional points for corners and line formations.  Any offset lines will be moved from their surveyed location to the offset position as displayed on the screen. 

Width Scalable (such as a hedge). The line that is displayed will be scaled such that the width of the complex line pattern is controlled by the dimension. Note that this functionality is kept for complex line styles.

Offset Half Width allows you to offset the displayed line by half the width. This can be used when the face of a feature has been surveyed and you want to move the line to the extent of the feature's width. The function is used in tandem with the Width Scalable option, an example of the use of this option would be when a hedge has been surveyed and the face of the hedge is what has been surveyed.

Variable POW allows you to change the width of a surveyed feature (i.e hedge) so that it represents the true thickness of the element. An example of this can be seen below:

P=-4.5 is the width value inserted into the points shown. You can see the difference in width throughout the hedge as a result of the parallel values inputted on each point.

Close Ends on P&W will join the end of a line feature to create a closure; for instance, the hedge feature below is closed off at the end:

Force in DTM allows you to ensure that the line segments of the line feature form part of the DTM triangles.  This is necessary where there are sharp changes of slope, such as at the tops of embankments.

Commit Constructions will create new points from the original points where the dimensions, P (Parallel), O (Offset) and W (Width) have been used. These dimensions do not create features from the original points without creating points, this is where you would select Commit Constructions. See explanation below to understand the difference before and after when creating a new model with the option selected.

Before Commit Constructions	After Commit Constructions

When creating a new model with the data, you can choose from numerous options under the Commit box. In the above example, you can see the paralleled lines have had relevant points added to them as we selected Parallel Strings to ensure that the Commit Construction option would work.

3-Pt Line to Rectangle is an option that, when selected, will automatically create a 4-Point rectangle from a 3-Point line. This is useful when creating a DTM, all four corners of a rectangle are considered in the surface and not just three points in the original data. 

3-pt Line to Rectangle Inactive	3-pt Line to Rectangle Active

Auto Close automatically creates a line from the last point back to the first point. This can be used where the feature represents a building footprint or a pedestrian refuge in the middle of a carriageway.

Alternate Segments is an option used to create lines with alternative segments. If the option is not selected, a continuous line feature will be created in the model space and in turn, will not be a true representation of its construction.

Alternate Segments not selected

Alternate Segments selected

Iso Tree Canopy allows you to create a Tree Canopy using a variable line positioned using a dimension. The construction of the tree will rely on using industry standard measurements such as North, South, West and East values.

Always Curve Line enables the line to always be curved and will ignore any instances of C, D and T. Parallel lines will also be curved even if they are not the same code.