Breaklines

Background

A discontinuity line defines a fault line in the topography of the surface. In fact, a discontinuity line is a geometric definition of a line during the triangulation stage to create contour lines, ensuring that points on one side of the line and points on the other side do not connect to form a triangle.

Operation

To add breaklines to the planned surface, right-click on the relevant surface in the WORKSPACE, and select: Set breaklines. Here you have two options to choose from:

1. From lines list - from a custom line list or a DIS file.

2. Set layers - by defining existing 3D Polylines in the DWG on certain layers as breaklines.

Defining a Discontinuity Line (From lines list)

A window for breaklines will open on the right. The window is divided into two parts (for further details, see the Lines Connections chapter), with the lower part containing the list of breaklines and allowing actions on the list such as deleting a whole line, saving as a DIS file, and more.

The upper part displays the details of the highlighted line (the one highlighted in the Lines List), the coordinates that make it up, and allows actions on the line itself such as adding or removing points.

Selecting Points Using Locate

You can define the line by selecting coordinates displayed on the drawing. Click on Locate from the options list at the top, go to the drawing area, and connect the desired coordinates to the discontinuity line. (To create a closed area where no contour lines are calculated at all, type "S" in the ACAD command line after marking the line).

This definition of the discontinuity line will force the software to perform interpolation as desired. (To redo the interpolation, run the contour lines again).

Manually Entering Point Names

You can enter the coordinates that make up the line into the coordinate table. Enter the coordinate number in the first row and press Enter, then the second coordinate number in the second row, and so on. You can also enter a range of coordinates, e.g., 1-35.

Defining Breaklines by Selecting Polyline

In addition to the two presented options, you can also define breaklines by selecting 3D Polylines from ACAD (note that the breaklines must be 3D Polylines and that 2D Polylines cannot be used to define breaklines). To do this, select the desired line from the drawing area and press Enter. To enter another line, define a new line and repeat the Select action, etc.

After defining the lines, update the surface construction by clicking Update surface. The new contour lines will be calculated, taking the breaklines into account.

For further information on line connection definitions, see here.

Using Set Layers Filtering

CivilCAD allows the definition of breaklines by filtering lines defined in a DWG file. You can filter lines of any type (Line, LwPolyline, 2DPolyline, 3DPolyline). It is recommended that these lines in the drawing have elevation, but it is possible to filter lines without elevation and define the elevation later. Let's explain with an example how the filtering operation can be done.

Click on Set layers. A filter control will open. This control can also be accessed by clicking the “funnel” button in the Lines window.

The top part of this control displays a window with a list of layers in the project’s DWG file. In this window, mark the desired layers from which all the lines will be filtered. The lower part of the window (Entities) shows the types of objects the software will filter.

Now, choose the desired layers and types of lines, and click Apply. This will cause the software to scan the lines from the marked layers and add them to the list of breaklines.

To simplify the work, you do not need to remember the names of the desired layers to mark them. Click Select and then select the desired line and press Enter. The layer and line type will be automatically marked in the appropriate windows.

After clicking Apply, the software will prompt if you also want to add the points of the filtered lines to the coordinate list. (Click No to not add them).

If there are already lines in the list, the software will ask if you want to delete the existing list or add the new lines to it.

Click Refresh to refresh the lines in the drawing.

If the software alerts that some points do not have elevation, it may be that lines with certain points without elevation were filtered, and the lines need to be corrected.

Line Corrections

Manual Correction from the List

You can manually locate and correct the points by searching for the coordinates where the elevation is 0 in the coordinate window. To do this, enter 0 in the search window, mark Accurate Height, and click OK. The software will locate and mark the coordinates with elevation 0. Enter the desired elevation for each of these points.

Deleting Specific Lines

You can delete specific lines from the line list or by a specific elevation (see Lines Connections).

Editing Lines from the Drawing

After defining breaklines, various editing actions can be performed on the lines, such as moving them. To do this, go to the drawing, move and change the defined breaklines, and then right-click on the relevant surface name in the Surfaces branch. Click on Set breaklines and then Update layers.

Setting Line Elevation According to Topography

By marking the lines lacking elevations in the line list and clicking Get topo data to get the elevation according to the existing state or Get design data to get the elevation according to the planned state (see Lines Connections).

After correcting the elevations of the desired lines, click Refresh to update the lines according to the changes made in the coordinate list.