Autodesk 00126-050008-1620A - Autocad 2006 Essentials User Manual page 161

The following dialog box appears:
The raster snap is only influenced by three parameters of the Options tab: Max
Width, Max Break and Approximation Accuracy.
Max Width
Max Break
Approximation
Accuracy
You can measure the Max Width and Max Break values directly from a raster
image.
To measure Max Width on an image
1. Click the button next to the Max Width box.
2. Specify two points in the raster image, so that the line connecting these points
crosses the widest part of the raster line.
This parameter defines the maximum width of raster objects
that the raster snap deals with.
This option defines the length of the largest break that is
ignored in a raster line. If raster line breaks are less than the
specified value, then it is recognized as an entire raster
object. This may be important when the snap is made to the
midpoint, endpoint, or object intersection.
The Approximation Accuracy parameter defines the
accepted deviation of raster symbol entities from their vector
prototypes. If the original raster entities are distorted, for
instance, raster circles are elliptical, then you can improve
the snap accuracy by moving the Approximation Accuracy
slider to the left (Rough). If the original raster image is of high
quality, then move the slider to the right (Fine).
11 Hybrid Editing Tools
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