The Redline Tools panel on the Review tab enables you to mark up viewpoints and clash results with redline annotations.
The Thickness and Color controls enable you to modify the redline settings. These changes do not affect already drawn redlines. Also, thickness only applies to lines; it does not affect redline text, which has a default size and weight and cannot be modified.
All redlines can only be added to a saved viewpoint or to a clash result which has a saved viewpoint. If you don’t have any saved viewpoints, adding a tag will automatically create and save a viewpoint for you.
You can also convert measurements to redlines. For more information, see Measuring.
The Clash Detective feature is available for Autodesk Navisworks Manage users only.