From the Help Desk – Breaklines vs. Edits – Add Line

Questions:

1. What is the difference between using a breakline as opposed to using the “Add line” option in the edits for the surface definition? I need to setup break lines for top of curb and flow line on a topo and was wondering which option is better?

2. Also, how do you setup a curved breakline? I have top of curb returns at an intersection that are curved.

Answers:

1. The difference between breaklines and add lines is that breaklines will prevent the TIN lines from crossing them – as long as there is a breakline there, no TIN triangle will cross that breakline, thus making for more accurate contours. Lines just add elevation data to the surface and act more as points (the vertices of the lines are used as elevation points.)

2. To add curved breaklines, draw them in as feature lines. Feature lines allow curves where 3D polylines do not. These feature lines can then be added to a given surface as breaklines.