SmartTrace is an enhanced sketch routine. AutoCAD's Sketch command is acceptable for some tracing, but if a large contour map is sketched, it creates a huge file that loads and regenerates slowly. The problem is that the sketch command creates points at user specified increments, this small increment may be appropriate for sharp corners, however, in relatively straight stretches this is very inefficient.
SmartTrace solves this problem. The routine works by reducing the number of vertices created on polyline tracing by using a deflection angle and minimum and maximum distance. In sharp turns, it will create points at the minimum distance specified, and in relatively straight stretches it creates points at the maximum distance specified. If the angle of the polyline turns more than the specified deflection angle, SmartTrace also creates a point.
Deflection Angle <4.0>: press Enter A
range of 3 to 5 degrees is best.
Minimum Distance <5.0>: press Enter
Usually 5% of map scale, or 1/20 inch.
Maximum Distance <50.0>: press Enter Usually
50% of map scale, or 1/2 inch.
Start point: pick beginning point on polyline
Begin Tracing ... Press Pick Button to End. Carefully move
along polyline. press the pick button to complete the
polyline
Pulldown Menu Location: Draw
Keyboard Command: TABLET3
Prerequisite: None