Working with Markups > Measurements > ECAD Measurements > To Create a Minimum Gap Measurement
  
To Create a Minimum Gap Measurement
You can select two points in the graphics area, and then click Markup > Minimum Gap to create the measurement or perform the following steps:
1. Click Markup > Minimum Gap. The Measure Minimum Gap dialog box opens.
2. Select a location for the start point of the measurement. It appears in the Reference panel.
3. Press CTRL, and then select a location for the end point of the measurement. It appears in the Reference panel, and the measurement appears under Results.
4. To measure the closest geometries regardless of their current visibility clear the Measure between objects on visible sublayers only check box. The results are updated.
5. Click . The measurement is saved to the annotation set.