AutoCAD 2008 User's
Guide > Share Data Between
Drawings and Applications > Work with Data in
Other Formats > Import, Attach, or
Open Other File Formats > Attach DWF Files as
Underlays >
Work with Attached DWF Underlay Files
After a DWF underlay is attached to a drawing, you can modify its position, scale, or rotation, and you can use DWF object snaps to locate objects relative to the objects in the DWF underlay.
While you can specify the insertion point, scale factor, and rotation angle at the time you attach a DWF file, you may find the need to alter those settings as your drawing progresses. By default, the insertion point of a DWF file is 0,0,0, its scale factor is 1, and its rotation angle is 0.
Because an attached DWF underlay acts like an attached raster image, general modify commands behave the same allowing you to move, scale, rotate, mirror, array, and so on. You can also affect alterations after you select a DWF underlay by choosing commands from the right-click menu or from the Properties palette.
Use Object Snaps with DWF Underlays
DWF object snaps are similar to regular object snaps except that they can be turned on and off separately from regular object snaps, and that they apply only to the objects in an attached DWF file.
Use DWF object snaps if you need to draw or edit objects relative to the objects displayed by one or more attached DWF underlays. Object snapping to DWF underlay geometry is the same as object snapping to DWG geometry. Object snapping for DWF underlays is turned on and off with the DWFOSNAP system variable.
DWF object snapping can also be turned on and off from a shortcut menu. Select a DWF underlay file, then right-click. Click DWF Object Snap on the shortcut menu.
While DWF underlay behavior generally follows the pattern set by raster images, one exception is the way that grips work. In this case, the behavior more closely follows that for blocks.
DWF underlays normally display only a base grip. The base grip can be used for repositioning the underlay in the drawing. If you’ve set up a clipping boundary, additional grips appear for each corner of the boundary. See Change DWF Underlay Display Properties and Clipping.
The grip for the base point looks like the standard block base point. The base point cannot be reset from within the host DWG and is established when the DWF is published from the coordinate origin of the source DWG file. If an existing (legacy) DWF file does not have a base point defined, the lower-left corner is used as the base point (0,0,0).
