Autotek autocad raster design 2010 用户手册

 (page 309) tab is specific to Raster Design. Three other tabs

(Object Snap, Polar Tracking, Snap and Grid) are AutoCAD standards and link
to the AutoCAD Help system.

The Options button opens the AutoCAD Options dialog box where the Drafting
tab lets you set the AutoSnap Marker Size and Aperture Size. All controls in
this dialog box are explained in the AutoCAD Help system.

Use this tab to turn Raster Snap on or off and to control its behavior.

You can use the raster snap modes to help you trace a bitonal raster entity
with the vectorization tools, to help you select raster objects for rubbing and
cropping, and to help you select raster objects for Raster Entity Manipulation.

Snap modes determine where your cursor will snap to as you move it around
the image. If you choose more than one snap mode, then the crosshairs snap
to the closest snap points. When the crosshairs snap to a point you want to
select, pick the point.

Center

Snaps to the center of a raster line. The entire width of the line must be in
the aperture (snap window).

End

Snaps to the end of a raster line.

NOTE When a line ends where it intersects another line, this is considered an
intersection, not an end point.

Corner

Snaps to the intersection of two lines.

Intersection

Snaps to the intersection of three or more raster lines. The entire intersection
must be in the snap window.

Edge

Snaps to the edge of a raster line. Any part of the raster line can be in the
snap window.

Raster Snap Tab (Drafting Settings Dialog Box) | 309