Graphics Issues after Linking or Importing CAD

Causes and solutions

In many instances, graphics issues that occur after linking or importing a CAD file are related to the maximum distance limit of 20 miles or 32 kilometers.

You can avoid most of these problems by applying the following strategies:

• When you start a project, move the project base point and the survey point to the desired locations, clip them, and pin them in place. Avoid moving them unnecessarily.
• If the survey point is located more than 20 miles or 32 kilometers from the internal origin, turn off its visibility in views to avoid issues.
• Ensure you create Revit objects near the internal origin (the default position of the project base point).
• Before importing a CAD file into Revit, use the CAD software to export only the data you want to bring into Revit. See About Imported Geometry.

  For example, if you want to use site data in a Revit model, in AutoCAD use the WBLOCK command and select the survey information to export to the drawing file. This strategy prevents unnecessary data from causing issues in the Revit model.

• Before linking a CAD file into Revit, eliminate any data that is not required for the Revit model. In particular, remove any elements that are not relevant to the desired geometry.
• Before linking or importing a CAD file, confirm that the total span of its geometry is less than 20 miles or 32 kilometers (including the Z direction).

Read the following list of symptoms and additional solutions, where available.

Can't snap to elements

When placing elements or sketching a line, you try to use snaps to align with existing geometry. However, the snaps don't work as expected.

Use the strategies described above to resolve the issue.

When zooming in and out, elements shift position

When you zoom in and out of section views and elevation views, elements seem to jump around, shifting positions unexpectedly.

Use the strategies described above to resolve the issue. In addition, try one of these solutions:

• Hide linked models in affected views.
• When linking a file, select the option Current view only. The linked file displays only in the current view of the Revit model.

Elements display as wireframe

In section views and elevation views, elements display using the Wireframe view style instead of the Hidden Line or Shaded view style, as specified for the view.

Use the strategies described above to resolve the issue.

Some elements from a linked model do not print

After you link a file to the Revit model, some elements that display in a view do not print as expected.

Use the strategies described above to resolve the issue. In addition, try one of these solutions:

• Before printing, on the Print Setup dialog, clear the check box for Hide crop boundaries.
• Define the project base point for the Revit model, and share coordinates between the Revit model and the linked file.
• See Troubleshooting: Printing Views and Sheets for more solutions.

Geometry in the file has extents greater than 20 miles (33km)

If this message displays when you try to link or import a CAD file, see this topic.

Incoming geometry is too large or too small

When you import or link the geometry, it displays in the Revit model much larger or smaller than intended. This scaling issue may result when units were not defined correctly in the CAD software.

In the CAD software, define units appropriately. When importing or linking the file into Revit, on the Import/Link CAD Formats dialog, select the appropriate value for Import units.