Product: MapInfo Professional
Version: 7.5 b24
Platform: Not Platform Related
Category: Autotrace
Summary:
What is the Autotrace feature?
Question:
What is the Autotrace feature?
Answer:
It is very difficult to digitize a polygon network, such as the United States. Where polygons share a common border, the border must be digitized twice. If digitizing everything as polylines, it is very tedious to combine them into polygons. (First, make two copies of each shared polyline. Then, for each desired polygon, select the appropriate polylines, combine them to make one polyline, and convert that polyline into a polygon.)
The autotrace feature will allow a user to easily trace the nodes of another object when using the Polyline or Polygon tools. Think of this feature as an extension of Snap mode -- it will be available only when Snap mode is turned on, and can be used with either the mouse or the digitizer.
It will work like this: When drawing a polygon/polyline, turn on Snap mode and click on a node of the polyline or polygon desired to be autotraced. Then, move the mouse (or digitizer) to another node of the same object, hold down the Shift key, and click. MapInfo will automatically trace all the segments between the two nodes and add them to the polygon/polyline being drawn. If autotracing a polygon, use the Ctrl key instead of the Shift key -- the Shift key autotraces the shorter path between the two nodes, and the Ctrl key autotraces the longer path (just like when selecting multiple nodes in Reshape mode).
As soon as the Shift/Ctrl key is pressed, MapInfo will highlight the path to be autotraced. This provides visual feedback of the action that's about to be performed. If the Shift/Ctrl key is let go of before clicking the button, the path is unhighlighted.
Only one object can be autotraced at a time. The second node that is Shift-clicked must belong to the same object as the first node. If it belongs to a different object, then MapInfo will simply draw a straight line between the two nodes.
Last Modified: 04/13/2005 03:04:01 PM
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