SMS:Breaklines

A breakline is a feature or polyline representing a ridge, thalweg, or other shape to preserve in a surface made up of triangular elements or scatter set. In other words, a breakline is a series of edges to which the mesh or scatter triangles should conform to, i.e., not intersect.

Breaklines (a) Original triangulation and breakline. (b) Triangulation after the breakline has been processed by inserting new mesh nodes along the breakline.

Mesh Module Breaklines

Breaklines are processed using the Force Breaklines command from the Nodestrings menu. How breaklines are processed is controlled by the breakline options in the Nodestring Options dialog.

Scatter Module Breaklines

Breaklines are processed using the Force Breaklines command from the Breaklines menu. Scatter breaklines are always processed by swapping triangle edges to ensure that the edges of the triangles will conform to the breakline.

Importing Scatter Breaklines

Scatter breaklines can be imported along with scatter data using the File Import Wizard. In order to import breaklines, the tabular file must be prepared in one of two supported formats. They are illustrated below. In either case, an additional column of data defines the breakline information. In the Import Wizard, this column should be mapped as "Breakline". This brings up the Scatter Breakline Options dialog

Note: Scatter breaklines must be imported at the same time as their corresponding scatter vertices.

Example Files

Example of a tab delimited file using breakline names:

xcoord        ycoord       zcoord   name
215962.9      85203.098    1.483    Breakline1
215957.638    85193.069    1.483    Breakline1
215963.278    85184.35     1.483    Breakline1
215979.111    85179.328    1.483    Breakline1
216056.51     85209.371    1.483    Breakline1
215992.462    85201.477    7.034    Breakline2
216127.386    85264.681    7.034    Breakline2
216267.187    85327.936    7.034    Breakline2
216371.217    85381.431    7.034    Breakline2
219261.939    90247.944    8.763    
219461.211    90220.556    9.167    
219678.994    90179.064    9.468    

Example of a tab delimited file using the following breakline tags:

• Start: 1
• Continue: 2
• End: 4
• Not in breakline: 5

xcoord        ycoord       zcoord   breakline_tag
215962.9      85203.098    1.483    1
215957.638    85193.069    1.483    2
215963.278    85184.35     1.483    2
215979.111    85179.328    1.483    2
216056.51     85209.371    1.483    4
215992.462    85201.477    7.034    1
216127.386    85264.681    7.034    2
216267.187    85327.936    7.034    2
216371.217    85381.431    7.034    4
219261.939    90247.944    8.763    5
219461.211    90220.556    9.167    5
219678.994    90179.064    9.468    5

Related Topics

• Editing 2D Meshes
• Generate Contour Breaklines