Adding Triangles to and Removing Triangles from Groups

The Triangles Add and Triangles Remove options allow you to add triangles to DTM groups and remove triangles from DTM groups.  Remember that if a group has been locked, you will not be able to reassign its group nor will you be able to remove it from its groups.  When selected, each will display a similar pop-up menu.  The menu for adding triangles to groups is shown to the right.

The Sketch options allow you to add or remove triangles using the mouse cursor.  There are five options.

Indicate         

A single triangle can be added or removed using this option and you will be asked to indicate the triangle.  Please ensure that the indicated position is inside the required triangle and not on an edge otherwise the wrong triangle may be selected.

Apex               

Multiple triangles can be added or removed using this option and you will be asked to indicate the DTM apex.  All triangles that use that DTM apex will be added or removed.

Line                

This option allows you to add or remove triangles that intersect a sketched line and you will be asked to indicate the start and finish points of the line.  Note that those triangles indicated by the start and finish points will also be added or removed.

Rectangle     

This option allows you to add or remove triangles inside a rectangle and you will be asked to indicate two corners of the rectangle.  Only those triangles wholly inside the rectangle will be considered.

Polygon         

This option allows you to add or remove triangles inside a polygon and you will be asked to indicate the apexes of the polygon.  You do not need to close the polygon as this will be done automatically for you and only those triangles wholly inside the polygon will be considered.

Feature

The Feature options allow you to add or remove triangles based upon the geometry of line features.  There are four options and, depending on the option, you will be asked to indicate one or two-line features.

Boundary      

This option allows you to add or remove features inside a polygonal boundary represented by a line feature.  All triangles inside the boundary are considered and if the feature is not a closed polygon feature, it will be considered as such.

All                    

This option allows you to add or remove all the triangles that use any of the apexes of a line feature.  After the feature is indicated, all the triangles on both sides will be considered.

One Side       

This option allows you to add or remove all the triangles that have been created on one side of a line feature and also use one of the apexes of the indicated line feature.  For this option, you will also be asked to indicate the side of the feature on which you wish to look for triangles.

Between       

This option allows you to add or remove triangles that appear between two line features.  After indicating the two features, only those triangles that use the apexes of the two features will be considered.  The triangles must use at least one apex from each of the features and cannot use an apex that is not part of either feature.

The Other Slope option allows you to add or remove triangles based upon slope.  When selected, the dialog box to the right will be displayed.  The Range group allows you to define how the entered slope values will be used as follows.  The slope values, which are displayed in the Slopes group, should be entered in the format 1 in x rather than as a percentage.

Less than Min      

With this radio button set, triangles with slopes less than that shown in the Minimum field will be considered.  Triangles with the same slope as the minimum value will be ignored.

Between                    

When this radio button set, triangles with slopes that lie between the values shown in the Minimum and Maximum fields will be considered.  Triangles with the same slope as either the maximum or minimum value will be added or removed.

Greater than Max    

With this radio button set, triangles with slopes greater than that shown in the Maximum field will be considered.  Triangles with the same slope as the maximum value will be ignored.

The Other Prefix option allows you to add or remove triangles based upon line feature prefixes.  An example of this is where you wish to add or remove those triangles that form part of foundation slabs.  When selected, the dialog box to the right will be displayed.  The Prefix field is a drop list of all the prefixes that you have defined in the current project.  You can either drop the list and select the required prefix or type the prefix into the field.  Only line feature prefixes will be considered and only closed line features will be used to add or remove triangles.  All triangles inside the polygon formed by the line feature will be considered.

Other

The Other Unassigned option is only displayed when you are adding triangles to DTM groups.  If this option is selected, all triangles that have not been assigned to a group will be added to the current group.

The Other All option is only displayed when you are removing triangles from DTM groups.  If this option is selected, all triangles that have been assigned to a group will be unassigned unless the group has been locked.