By Dennis Collin
Recently I posted on Revit’s somewhat limited ability to work with Navisworks coordination models and how it is not possible to accurately trace or measure from the attached reference. However, AutoCAD can also reference several different file formats including Navisworks NWD and NWC formats. These references can be traced and accurately measured as required.
To link in a coordination file, click on the Insert tab and choose attach reference, selecting NWD/NWC format. Once selected, placement options like manual, automatic, rotation and scale can be enabled as required.
The coordination model should appear in the view. It should be noted that the model will only display in 3D visual style modes. If the visual style is set to 2D drafting visual style, then a message displays along with a bounding box instead of the actual model.
Once linked, users can snap to and measure the file, place dimensions and other annotations as desired. The object snaps don’t work quite as well as native geometry, but nevertheless the functionality is accurate enough for coordination purposes. In certain instances, I have found the addition of construction lines can help to obtain an elusive reference point!
Like Point Cloud Attachments, coordination models cannot be bound into a drawing. However, they can be reloaded, detached and re-pathed if required. Should the model need to be published to a recipient, I would advise users to use AutoCAD’s Etransmit function.
Once traced, the coordination model could be detached and the model outline trace could be accurately positioned in Revit if required.