The Offset Line tool creates a parallel line to your project item. It only works on the selected item and appears in the TOOLS for Polyline tab. 


Offset Line works on:

  • Polyline items
  • Boundary items



The Offset Line tool can create parallel lines either on terrain or with a user specified Z offset. 


Overview


Quick Usage Guide

On Terrain

  1. Select the line or boundary you want to offset.
  2. Go to the TOOLS tab and enable Offset Line in the Create group.
  3. In the dialog box, select the On Terrain Z Offset Method.
  4. Left-click on the location where you want the offset line to appear. 
    1. The vertices of the new line are placed on the terrain.

  5. Each additional left-click creates an offset line to the original line. 
  6. Right-click to exit the Offset Line tool. 


User Specified Z Offset

  1. Select the line or boundary you want to offset.
  2. Go to the TOOLS tab and enable Offset Line in the Create group.
  3. In the dialog box, select the ΔZ Offset Method and set the Z offset value. 
    1. A positive value creates a line above the original item, and a negative value creates a line under the original item.
  4. Left-click on the location you want the offset line to appear. 
    1. The vertices of the new line are increased or decreased (as per the set Z offset value) from the original line's elevation.

  5. Each additional left-click draws a parallel line with the same Z offset setting.
  6. Right-click to exit the Offset Line tool. 


Example of When to Use the Offset Line Tool

  • Use the offset tool for road survey. 
    • In general, curbs and gutters are not accurately model in the photogrammetry results, which can lead to a bad water flow analysis. 
    • Draw a curb line and offset it to create an accurate surface model of the curb and the gutter. 
    • Use that surface to Modify Terrain and precisely shape the gutter.


Tips and Tricks

  • When the Offset tool is enabled and a survey item is selected, you can click on another project item to switch the base object to offset. 
  • It is not possible to do multiple offset lines at the same time. 
    • Only one base object can be selected at a time.