You can underlay and snap to 2D geometry stored in DWF, DWFx, DGN, and PDF files.
Underlays are similar to attached raster images in that they provide visual content but also support object snapping and clipping. Unlike external references, underlays cannot be bound to the drawing.
You can underlay the following file types:
- DWF - A DWF (Design Web Format) file is a highly compressed file format that is created from a DWG file.
- DWFx - DWFx, the future of DWF, is based on the XML Paper Specification (XPS) format from Microsoft.
- PDF - Adobe System's document exchange format.
- DGN - Bentley System's Microstation format. DGN Support is limited to V7/V8 DGN files and 2D objects. The 2D objects are imported or attached with full (X, Y, Z) coordinate information, as was present in the original file. If the file contains 3D solids, surfaces, or other 3D objects, a warning is displayed. This content is not supported in this file.
Use the Ribbon Contextual Tab to Work with Underlays
If you select an underlay when the ribbon is active, the DWF Underlay Ribbon Contextual tab, the PDF Underlay Ribbon Contextual tab, or the DGN Underlay Ribbon Contextual tab displays depending on the type of underlay selected. The contextual tab contains options for adjusting, clipping and displaying underlays. The ribbon contextual tab is dismissed automatically after the underlay is deselected.
About Attaching Files as Underlays
You can attach a DWF, DWFx, DGN, or PDF file as an underlay to a drawing file. You can reference and place underlay files in drawing files the same way as you do raster image files; they are not actually part of the drawing file. Like raster files, ...
About Unloading Underlay Files
To improve performance, you can unload underlays from a drawing file. When you do not need an underlay in the current drawing session, you can improve performance by temporarily unloading it. Unloaded underlays are not displayed or plotted. ...
About Detaching Underlay Files
Underlays that are no longer needed can be detached from a drawing file. When you detach an underlay, all instances of the underlay are removed from the drawing, and the linking path to the file is removed. To hide the display of an underlay ...
About Modifying the Position, Scale, or Rotation of an Underlay
You specify an underlay's position, scale, or rotation when you attach an underlay file. You can also modify these settings later during the drafting process. By default, the insertion point of a file is 0, 0, 0, its scale factor is 1, and its ...
DWG Compare Limitations
Drawing comparison does not support all object types in AutoCAD and AutoCAD specialized toolsets. Limitations for AutoCAD Object Types The DWG Compare feature does not support all object types in AutoCAD. The exceptions include OLE objects, cameras, ...