The Offset Line tool creates a parallel line from your drawn polyline or boundary. To access the Offset Line tool, you left click to select a drawn polyline or boundary and navigate to the Tools tab, or you can right click on the line or boundary to bring up the mini toolbar and select Offset Line from there. This article will show you methods and examples of how and when to use the Offset Line tool. 


Offset Line tool in the Tools tab ribbon.


Overview


Offset Line - Z Offset Method

The Offset Line tool offers up to three methods and a drawing guide to create a parallel copy of a drawn polyline or boundary (depending on the plan):

  1. On Terrain
  2. ΔZ
  3. Slope
Ridge/Mountain Offset Methods
Peak Offset Methods
Offset Line editing methods available through the Ridge plan.Offset Line editing methods available through the Peak plan.


1. On Terrain: Create an Offset Line Directly on the 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-clickat the location where you want the offset line to be created. 
    1. The vertices of the new line are placed directly 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. 

Create an Offset line from the back of the curb to the edge of the pavement on the terrain.


2. ΔZ: 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 polyline, and a negative value creates a line below the original polyline.
    2. Setting the value at 0 m creates an offset line at the same elevation of the original polyline. 
  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. 

Create an offset line from the design line of a coastal rock wall to create the top edge of the rock wall using the ΔZ mode.


3. Slope: User Specified Angle

You can create an offset line that is angled at a positive or negative degree or percentage from the original design line. Combine the angle of the offset line with the distance guide to create an exact slope and distance from the line.

  1. Right click on the drawn polyline or boundary you want to offset and choose Offset Z from the mini toolbar. 
  2. Change the method to Slope and type in the slope angle. 
    1. Activate the Distance drawing guide and set the distance you want to place your line from the original line. 
  3. Left click to create a copy of the original line.

Create an offset line from the central design line of a haul road with a lowered slope and with the help of a drawing guide.


Examples of Using the Offset Line Tool Per Plan

Ridge Plan

With the Ridge plan, you can survey what you have as a single moment in time and use the Offset Line tool to model aspects of the elevation terrain to match the real world for a more accurate survey:


Model a Curb and Gutter

Read the full Curb and Gutter article.

A curb from photogrammetry that appears blended with a smooth slope.

The Slope lens view of the same curb that has a smooth slope.

The curb corrected using the Offset Line tool to create a surface and modify the terrain.


Peak Plan

With the Peak plan, use the Offset Line tool to help you design the future, using offset lines from a design line to create a surface and grade:


Design a Coastal Rock Wall

Read the full Coastal Rock Wall article.

Road-side beach corroding away from ocean waves and needs a protective coastal rock wall.

Graded Coastal Rock Wall design with cut and fill.

Complete coastal rock wall built after monitoring it over time using the Timeline and doing a final drone flight.


Design a Water Retention Pond

Read the full Water Retention Pond article.

Water runoff pattern shows optimal location to build a water retention pond.

Retention pond surface design created with the help of the Offset Line tool.

Completed retention pond design showing the graded pond and an estimated water volume.


Design a Haul Road

Read the full Haul Road article.

Haul Road design line along the hill of a quarry. We use the Offset Line tool to create a road from the design line.

Surface created from the haul road design line with offsets.

Completed Haul Road design with grading, cut and fill shown, and the Elevation Lens enabled.


Tips and Tricks

  • While the Offset Line tool is enabled, you can switch between any drawn polyline or boundary in the project by selecting them with a left click and creating a new offset line from whichever line you currently have selected.
    Quickly place multiple offset lines without deselecting the tool. In this case, drawing a berm of a haul road.
  • Only one polyline or boundary can be selected at a time, which means you can only create one offset line at a time.
  • You can change the settings of the Slope angles in the Z Offset Method to be expressed as either degrees or percentage by going to File>Project Settings and changing the Slope Unit in the dropdown options.