You would like to add or modify waypoints of a visual offset. If either the position of the tag or the robot position changed since you taught it, you'll need to redefine the position of the tag before making any modification or adding waypoints to the visual offset node.
Knowledge
1. Go in the installation tab-->URCaps-->Camera-->Tags then select the corresponding tag and click the following icon
2. If the position changed enough so you need to move the robot, you should then select define new snapshot position
3. Define the new position of the tag for both far and close relative position then save it.
4. You can now modify/add waypoints relative to the current position of the tag.