A Note on Terminology

Civil data generally has been subjected to a frustrating amount of confusion in terminology between different software packages. As such, the methods available in CivilTools are defined as follows:

Breakline - a 3d LineString. Vertices and elevation points are used as triangulation points, and line segments are forced triangle edges in the Constrained Delaunay Triangulation process.

Grading Template - a group of features with varying properties (such as a fixed width and/or slope, targeting an existing topographic surface, etc), used to grade in a linear fashion on one or both sides of a breakline.

Grading Region - a collection of one or more templates applied to one or more breaklines.

Breaklines can be created with or without associated Templates; however, Templates must have a Breakline to use as a base, and further, any Templates must be contained within a Region, where required parameters are defined.

Breaklines

Breaklines can be created in various ways, including:

• by copying an existing LineString object and applying elevations to its vertices from various sources
• by extracting them from an existing Region
• by offsetting an existing Breakline (horizontal and vertical distances must both be specified)

In addition to directly manipulating the Breakline in any of the ways a regular LineString can be manipulated, Breaklines can be modified in the following ways:

• adding elevation points - points that serve as vertices only in the vertical dimension (i.e., they cannot change the horizontal properties of a line segment)
• setting elevation values from a specified source
• setting elevation values directly
• setting elevation values by specifying a slope along a given segment
• raising or lowering the entire Breakline by a specified amount

Breaklines can also be edited in a vertical profile view.

Templates