Revit Link Coordinate Mapping TN

This feature can be used to shift the location of a model between Revit and RSS coordinate systems. Please note, however, that Revit has fixed Origin point which is the same as in RSS (that is 0, 0, 0). One of the possible benefits of using coordinate mapping is the ability to roundtrip a model that uses negative elevations.
There is a new Offset tab page in the Settings dialog.

The RSS point is always set to (0, 0, 0) and this cannot be changed. The Revit point, however, can be changed; it uses feet units when in Imperial mode, and cm when in Metric mode.

The Reset button sets Revit point to be (0, 0, 0).

During the import a dialog box will open to warn the user if the Origin is not (0, 0, 0):

If the model you are importing already has a non-default Origin set that Origin will be used (not the one defined in the Offset page).

Once a global offset has been defined for an RSS model it is saved in the RSS model and treated as a read-only value. (Bentley Support engineer Eric Helmueller has written an Excel spreadsheet that will let you reset the read-only coordinate. DA Model Move and Merge)

http://communities.bentley.com/products/structural/structural_analysis___design/m/structural_analysis_and_design_gallery/default.aspx

During the export the same approach is used: if the offset is not zero, then it will be written to the model and all subsequent updates will use that offset.

Note that previously the link tried to link the bottom most level with the base level in RSS. It doesn’t do that now; instead the user should manually shift the model by using the global offset if they wish to roundtrip such models.