Civil 3D Tip - Undo Mark, Undo Back

by David Lewis

Introduction

Certain commands contain sub commands that become available when users enter the command directly into the command line, however these sub commands are often overlooked and are not used to their full potential. A common tool everyone is familiar with is UNDO, but many users don’t realise there is more to undo than just stepping back to the last command.  

Typing UNDO into the command line allows users to control multiple settings, including ‘Auto’, ‘Control’, ‘Begin’, ‘End’, ‘Mark’ and ‘Back’. This blog will focus on the use of Mark and Back.

Autodesk definition of Undo Mark and Undo Back

“Mark places a mark in the undo information. Back undoes all the work done back to this mark. If you undo one operation at a time, you are informed when you reach the mark.

You can place as many marks as necessary. Back moves back one mark at a time, removing the mark. When you use the Number option to undo multiple actions, UNDO stops if it encounters a mark.”

Example

1. Create an initial design, type UNDO into the command line and choose ‘Mark’ from the list of settings available on the command line. This will mark this version of the design (Fig 1). 

2. Having marked the initial design, continue to add to the design. In the below example new additions have been identified in Green (Fig 2).

3. After realising the new design has not turned out how you had initially intended, you are able to return to the marked Undo by typing UNDO into the command line and selecting ‘Back.’ This will return the drawing to its Marked undo (Fig 3).

Note: Users can place multiple Mark Undo at relevant points during the process. This enables users to return to various iterations whilst the drawing session is open. This command can also be used in conjunction with the SAVE command to produce various design options.