Selection Previewing in ADT/AutoCAD 2006

AutoCAD 2006 and, by extension, ADT 2006, include a new feature that has drawing objects highlight as the cursor rolls over them. This gives a preview of the object that would be selected if you clicked at any given moment. Some of you may like it, some may hate it. Here is how to turn it on, turn it off and fine tune its use, to suit your tastes.

There are three system variables that control this new behavior. The SELECTIONPREVIEW system variable is the sledgehammer: use it to turn off the highlighting altogether [0], on when no command is active [1], on when a command is active [2] or always on [3]. If you leave it on for at least part of the time, the PREVIEWEFFECT system variable controls what is displayed: 0 = dashed lines, 1 = thickened lines and 2 = dashed and thickened lines. The PREVIEWFILTER system variable allows you to exclude certain items, if you leave it turned on. See the list of bitcodes below for items that can be excluded.

From the Help:
--------------------------------------------------------------------------

SELECTIONPREVIEW System Variable
Type: Bitcode
Saved in: Registry
Initial value: 3
Controls the display of selection previewing. Objects are highlighted when the pickbox cursor rolls over them. This selection previewing indicates that the object would be selected if you clicked. The setting is stored as a bitcode using the sum of the following values:
0 Off
1 On when no commands are active
2 On when a command prompts for object selection

--------------------------------------------------------------------------

PREVIEWEFFECT System Variable
Type: Integer
Saved in: Registry
Initial value: 2
Specifies the visual effect used for previewing selection of objects.
0 Dashed lines (the default display for selected objects)
1 Thickened lines
2 Dashed and thickened lines

--------------------------------------------------------------------------

PREVIEWFILTER System Variable
Type: Bitcode
Saved in: Registry
Initial value: 1
Excludes specified object types from selection previewing. The setting is stored as a bitcode using the sum of the following values:
0 Excludes nothing
1 Excludes objects on locked layers
2 Excludes objects in xrefs
4 Excludes tables
8 Excludes multiline text objects
16 Excludes hatch objects
32 Excludes objects in groups