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Preparing AutoCAD drawings for conversion
into Arc/Info themes
( This success story describes the process used by AutoCAD mappers during
the conversion of AutoCAD maps to Arc/Info themes. It was submitted by one
of our marketing partners in Vancouver BC Canada. )
Our clients use MapTools to prepare AutoCAD drawings for conversion to Arc/Info
themes in ArcCAD, which we market along with many other GIS/CAD products.
MapTools allows the client to clean-up, reduce and give intelligence to
a drawing in a couple of hours instead of weeks or months if they were to
use standard AutoCAD techniques.
The process usually starts with PET, or parametric editing, to extract and
separate text and send them to different layers having meaning to ArcCAD data
capture. For example, a single 3 digit number may be mixed in with other text
but may also represent a unique value to a polygon that will become a GIS
poly. Simply use the statement - search for ??? - to collect these 3 digit
text labels and send them to a separate layer and, if needed, move the text
to position it into the polygon, all in one PET statement. Later this text
can be captured with ArcCAD to give the polygon theme intelligence and save
months of tedious data entry time down the road. PET is also used to organize
linework into appropriate layers while at the same time changing into continuous
2D polylines for easy ArcCAD conversion, all automatically.
Cleaning polygons prior to conversion is extremely important, since if there
are no dangle nodes in ArcCAD to begin with, then processing and post editing
is much quicker. Also, tolerances can be much tighter. MapTools makes both
cleaning and subsequent editing much faster and certainly more precise. Many
drawing that purport to be clean are not, we have often seen as many as 1300
unclosed polys even after cleaning in ArcCAD, a large task to manually fix.
MapTools is used to redo such drawings automatically.
Another very important feature of MapTools is its ability to reduce file
size on drawings having contours or rivers, that have been digitized or created
by automatic means, such as converted aerial photos, or raster-to-vector conversion.
In Forestry or Geology such maps are common, and often choke computer processing
by their size. We have reports of 30 minute long regens in AutoCAD on drawings
of this nature. Curvefit fixes that problem - period.I can't recommend MapTools
strongly enough for anybody working with AutoCAD maps. But the program is
at its most powerful when the user sits down and learns it thouroughly, and
is creative with inventing tricks with PET, CLEAN and CURVEFIT.
Mel A. Fisher, P.Eng.President
Geokinetic Systems Inc.
Vancouver, BC Canada
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