The Calculate Long option is the simplest way of taking sections. In its most basic form, you will be asked to indicate a start and a finish location for the section cut line with the graphic cursor. However, this cut line is not restricted to a single segment line between two locations.
When selected, the property sheet asking you to define the section will be displayed.
The Definition page allows you to define the position of the section cut line. The two data groups to the right of the page are empty when calculating long sections.
The plan position of the cut line is defined in the Cut Line group. The Chainage field allows you to define the start chainage of the section. When sections are calculated, only the offset along the cut line is stored. When plotting the section, you may wish to specify a chainage value which will be added to the offsets.
The radio buttons allow you to define the method by which you will specify the cut line position.
Project Select List - Option to project the list of points onto long, feature and point sections for section symbols.
Sketch - The location of each point in the cut line is defined by a series of mouse indicated locations. Use the left mouse button for each location until they have all been indicated. The right mouse button can then be used to take and preview the section.
Points - The location of each point in the cut line is defined by an existing point in the current model. Use the left mouse button to indicate each point in turn and use the right mouse button to take and preview the section.
Feature - The location of each point in cut line is defined by those points in an existing feature. Indicate the feature and section will be calculated and previewed. You should note that the feature itself does not necessarily appear in the section profile. The feature is simply used to indicate the position of the cut line and if it is not included in the model or not forced into the model, it will not appear. If you wish to have a section profile taken from a feature with other DTMs, use the Feature Section option described below.
CAD Line - The location of each point in the cut line is defined by a CAD polyline. Indicate the polyline and the section will be calculated and previewed. The search will take place in the CAD models in the current backcloth or the CAD model associated with the current DTM.
Co-ordinates - The location of each point in the cut line is defined as series of points in a co-ordinate block. You will be asked to select the co-ordinate block and the section will be calculated and previewed.