Autotek autocad raster design 2010 用户手册

In most respects, REM objects are similar to other AutoCAD objects. However,
some behavior and characteristics of REM objects are specific to their function
in Raster Design.

When you create a REM object, it is associated with an image. Any AutoCAD
command that changes the geometry or location of a REM object causes the
REM object to dissociate from the image. Such commands include MOVE,
SCALE, ROTATE, and ERASE. REM Smooth also causes a dissociation. For more
information, see 

 (page 194).

If the geometry or location of your source image changes, the associated REM
objects adjust accordingly. For example, if you move an image to a new
location, all the REM objects associated with the image move with it and are
not deleted. If an image is erased or unloaded, all the REM objects associated
with it are also erased.

If you define a rectangular region as a REM object and then move it, the
original raster data in the source image is deleted.

If your REM primitive or enhanced bitonal region is defined over an
intersection, the intersection is preserved even after you MOVE the primitive
object.

NOTE REM region and primitive objects that are dissociated from an image cannot
be refined.

In order to save your changes to your REM objects, you must either merge the
objects into an image, or create a new raster image from the objects. For more
information, see 

 (page 198) and 

 (page 199).

REM objects cannot be plotted.

There are only two conditions under which REM cannot automatically
determine what image to acquire data from:

■

Overlapping images: One image overlaps the other, and the geometry for
the REM object is within or touching both images.

166 | Chapter 7   Raster Entity Manipulation